Postharvest biology and technology of tropical and subtropical fruits: Volume 4: Mangosteen to white sapote

Postharvest biology and technology of tropical and subtropical fruits © Woodhead Publishing Limited, 2011 1 2 3 4 5 6 ...

Author: Elhadi M Yahia

77 downloads 1901 Views 17MB Size Report

This content was uploaded by our users and we assume good faith they have the permission to share this book. If you own the copyright to this book and it is wrongfully on our website, we offer a simple DMCA procedure to remove your content from our site. Start by pressing the button below!
Report copyright / DMCA form

DOWNLOAD PDF

Postharvest biology and technology of tropical and subtropical fruits

© Woodhead Publishing Limited, 2011

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Related titles: Postharvest biology and technology of tropical and subtropical fruits Volume 1 (ISBN 978-1-84569-733-4) While products such as bananas, pineapples and kiwi fruit have long been available to consumers in temperate zones, novel fruits such as litchi and longan are now also entering the market. Tropical and subtropical fruits are vulnerable to postharvest losses and may also be transported long distances for sale. Therefore technologies for quality maintenance postharvest and a thorough understanding of the underpinning biological mechanisms are essential. This authoritative four-volume collection considers the postharvest biology and technology of tropical and subtropical fruit. Volume 1 focuses on key issues of fruit physiology, quality, safety and handling relevant to all those in the tropical and subtropical fruits supply chain. Postharvest biology and technology of tropical and subtropical fruits Volume 2 (ISBN 978-1-84569-734-1) Chapters in Volume 2 of this important collection review factors affecting the quality of different tropical and subtropical fruits, concentrating on postharvest biology and technology. Important issues relevant to each specific product are discussed, such as postharvest physiology, preharvest factors affecting postharvest quality, quality maintenance postharvest, pests and diseases and value-added processed products, among other topics. Postharvest biology and technology of tropical and subtropical fruits Volume 3 (ISBN 978-1-84569-735-8) Chapters in Volume 3 of this important collection review factors affecting the quality of different tropical and subtropical fruits, concentrating on postharvest biology and technology. Important issues relevant to each specific product are discussed, such as postharvest physiology, preharvest factors affecting postharvest quality, quality maintenance postharvest, pests and diseases and value-added processed products, among other topics. Details of these books and a complete list of Woodhead’s titles can be obtained by: • visiting our web site at www.woodheadpublishing.com • contacting Customer Services (e-mail: [email protected]; fax: +44 (0) 1223 832819; tel.: +44 (0) 1223 499140 ext. 130; address: Woodhead Publishing Limited, 80 High Street, Sawston, Cambridge CB22 3HJ, UK


Woodhead Publishing Series in Food Science, Technology and Nutrition: Number 209

Postharvest biology and technology of tropical and subtropical fruits Volume 4: Mangosteen to white sapote

Edited by Elhadi M. Yahia


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Published by Woodhead Publishing Limited, 80 High Street, Sawston, Cambridge CB22 3HJ, UK www.woodheadpublishing.com Woodhead Publishing, 1518 Walnut Street, Suite 1100, Philadelphia, PA 19102-3406, USA Woodhead Publishing India Private Limited, G-2, Vardaan House, 7/28 Ansari Road, Daryaganj, New Delhi – 110002, India www.woodheadpublishingindia.com First published 2011, Woodhead Publishing Limited © Woodhead Publishing Limited, 2011. Chapter 15 was prepared by US government employees; this chapter is therefore in the public domain and cannot be copyrighted. The authors have asserted their moral rights. This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. Reasonable efforts have been made to publish reliable data and information, but the authors and the publisher cannot assume responsibility for the validity of all materials. Neither the authors nor the publisher, nor anyone else associated with this publication, shall be liable for any loss, damage or liability directly or indirectly caused or alleged to be caused by this book. Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming and recording, or by any information storage or retrieval system, without permission in writing from Woodhead Publishing Limited. The consent of Woodhead Publishing Limited does not extend to copying for general distribution, for promotion, for creating new works, or for resale. Specific permission must be obtained in writing from Woodhead Publishing Limited for such copying. Trademark notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation, without intent to infringe. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library. Library of Congress Control Number: 2011929803 ISBN 978-0-85709-090-4 (print) ISBN 978-0-85709-261-8 (online) ISSN 2042-8049 Woodhead Publishing in Food Science, Technology and Nutrition (print) ISSN 2042-8057 Woodhead Publishing in Food Science, Technology and Nutrition (online) The publisher’s policy is to use permanent paper from mills that operate a sustainable forestry policy, and which has been manufactured from pulp which is processed using acid-free and elemental chlorine-free practices. Furthermore, the publisher ensures that the text paper and cover board used have met acceptable environmental accreditation standards. Cover image: Fruit stand in Malaysia (Photo: Elhadi M. Yahia). Typeset by RefineCatch Limited, Bungay, Suffolk Printed by TJI Digital Limited, Padstow, Cornwall, UK


Contents

Contributor contact details .......................................................................... Woodhead Publishing Series in Food Science, Technology and Nutrition ..... Foreword ......................................................................................................

xv xxiii xxxi

1 Mangosteen (Garcinia mangostana L.)............................................... S. Ketsa, Kasetsart University, Thailand and R. E. Paull, University of Hawaii at Manoa, USA 1.1 Introduction................................................................................. 1.2 Fruit development and postharvest physiology .......................... 1.3 Maturity and quality components ............................................... 1.4 Preharvest factors affecting fruit quality .................................... 1.5 Postharvest handling factors affecting quality ............................ 1.6 Physiological disorders ............................................................... 1.7 Pathological disorders ................................................................. 1.8 Harvesting practices.................................................................... 1.9 Postharvest operations ................................................................ 1.10 Processing ................................................................................... 1.11 Conclusions................................................................................. 1.12 Acknowledgements..................................................................... 1.13 References...................................................................................

1

2 Melon (Cucumis melo L.)..................................................................... M. E. Saltveit, University of California, Davis, USA 2.1 Introduction................................................................................. 2.2 Fruit development and postharvest physiology .......................... 2.3 Maturity and quality components and indices ............................ 2.4 Preharvest factors affecting fruit quality .................................... 2.5 Postharvest handling factors affecting fruit quality ....................


1 4 10 11 12 14 21 22 22 23 25 25 25 31 31 33 35 36 36

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

vi 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Contents 2.6 2.7 2.8 2.9 2.10 2.11 2.12

Physiological disorders ............................................................... Pathological disorders ................................................................. Insect pests and their control ...................................................... Postharvest handling practices .................................................... Processing ................................................................................... Conclusions................................................................................. References...................................................................................

38 39 39 39 42 42 43

3 Nance (Byrsonima crassifolia (L.) Kunth).......................................... O. Duarte, National Agrarian University, La Molina, Peru 3.1 Introduction................................................................................. 3.2 Fruit development and postharvest physiology .......................... 3.3 Maturity and quality components and indices ............................ 3.4 Preharvest factors affecting quality ............................................ 3.5 Postharvest handling factors affecting quality ............................ 3.6 Physiological disorders ............................................................... 3.7 Pathological disorders ................................................................. 3.8 Insect pests and their control ...................................................... 3.9 Postharvest handling practices .................................................... 3.10 Processing ................................................................................... 3.11 Conclusion .................................................................................. 3.12 References...................................................................................

44 44 46 47 47 48 48 48 48 48 49 49 50

4 Noni (Morinda citrifolia L.) ................................................................. A. Carrillo-López, Autonomous University of Sinaloa, Mexico and E. M. Yahia, Autonomous University of Queretaro, Mexico 4.1 Introduction................................................................................. 4.2 Fruit growth, development and maturation ................................ 4.3 Preharvest conditions and postharvest handling factors affecting quality .......................................................................... 4.4 Pathological disorders ................................................................. 4.5 Insect pests and their control ...................................................... 4.6 Postharvest handling practices .................................................... 4.7 Processing ................................................................................... 4.8 Conclusions................................................................................. 4.9 References...................................................................................

51

5 Olive (Olea europaea L.) ...................................................................... C. H. Crisosto and L. Ferguson, University of California, USA and G. Nanos, University of Thessaly, Greece 5.1 Introduction................................................................................. 5.2 Fruit development and postharvest physiology .......................... 5.3 Maturity and quality components and indices ............................ 5.4 Postharvest handling factors affecting quality ............................ 5.5 Physiological disorders ...............................................................

63


51 55 56 57 57 57 59 59 60

63 65 67 70 71

Contents 5.6 5.7 5.8 5.9 5.10 5.11 5.12 5.13 5.14

vii

Pathological disorders ................................................................. Insect pests and their control ...................................................... Harvest operations ...................................................................... Packinghouse handling practices ................................................ Grades and standards for processed olives ................................. Recommended storage and shipping conditions......................... Processing ................................................................................... Conclusions................................................................................. References...................................................................................

71 72 72 75 80 83 84 84 84

6 Papaya (Carica papaya L.)................................................................... S. P. Singh, Curtin University of Technology, Australia and D. V. Sudhakar Rao, Indian Institute of Horticultural Research, India 6.1 Introduction................................................................................. 6.2 Fruit development and postharvest physiology .......................... 6.3 Maturity indices .......................................................................... 6.4 Preharvest factors affecting fruit quality .................................... 6.5 Postharvest factors affecting fruit quality ................................... 6.6 Physiological disorders ............................................................... 6.7 Postharvest pathological disorders ............................................. 6.8 Postharvest insect pests and phytosanitary treatments ............... 6.9 Postharvest handling practices .................................................... 6.10 Processing ................................................................................... 6.11 Conclusions................................................................................. 6.12 References...................................................................................

86

7 Passion fruit (Passiflora edulis Sim.) .................................................. W. C. Schotsmans, Institute of Agricultural Research and Technology, Spain and G. Fischer, National University of Colombia, Colombia 7.1 Introduction................................................................................. 7.2 Preharvest factors affecting fruit quality .................................... 7.3 Postharvest physiology and quality ............................................ 7.4 Postharvest handling factors affecting quality ............................ 7.5 Crop losses .................................................................................. 7.6 Processing ................................................................................... 7.7 Conclusions................................................................................. 7.8 References................................................................................... 8 Pecan (Carya illinoiensis (Wangenh.) K. Koch.)................................ A. A. Gardea and M. A. Martínez-Téllez, Research Center for Food and Development, Mexico and E. M. Yahia, Autonomous University of Queretaro, Mexico 8.1 Introduction.................................................................................


86 90 96 96 98 103 104 107 111 114 116 118 125

125 130 132 133 135 137 138 138 143

143

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

viii 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Contents 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 8.10 8.11 8.12 8.13

Nutritional value of pecan nuts ................................................... Harvesting, handling and storage ............................................... Current quality grading system ................................................... In-shell and shelled pecan ........................................................... Description of main quality attributes ........................................ Storage ........................................................................................ Postharvest physiology factors affecting nut quality .................. Potential improvements in handling ........................................... Processing ................................................................................... Conclusions................................................................................. Acknowledgements..................................................................... References...................................................................................

145 147 152 154 155 156 158 160 161 161 162 162

9 Persimmon (Diospyros kaki L.) ........................................................... A. B. Woolf, The New Zealand Institute for Plant & Food Research Limited, New Zealand and R. Ben-Arie, Israel Fruit Growers’ Association, Israel 9.1 Introduction................................................................................. 9.2 Fruit development and postharvest physiology .......................... 9.3 Maturity, quality at harvest and phytonutrients .......................... 9.4 Preharvest factors affecting postharvest fruit quality ................. 9.5 Postharvest handling factors affecting fruit quality .................... 9.6 Physiological disorders ............................................................... 9.7 Pathological disorders ................................................................. 9.8 Insect pests and their control ...................................................... 9.9 Postharvest handling practices .................................................... 9.10 Processing ................................................................................... 9.11 Conclusions................................................................................. 9.12 References...................................................................................

166

10 Pineapple (Ananas comosus L. Merr.) ................................................ A. Hassan and Z. Othman, Malaysian Agricultural Research and Development Institute (MARDI), Malaysia and J. Siriphanich, Kasetsart University, Kamphang Saen, Thailand 10.1 Introduction................................................................................. 10.2 Fruit development and postharvest physiology .......................... 10.3 Physical and biochemical changes during maturation and ripening ................................................................................ 10.4 Preharvest factors affecting fruit quality .................................... 10.5 Postharvest factors affecting quality ........................................... 10.6 Physiological disorders ............................................................... 10.7 Pathological disorders ................................................................. 10.8 Insect pests and their control ...................................................... 10.9 Postharvest handling practices ....................................................

194


166 168 170 172 175 180 181 183 184 186 187 187

194 196 197 201 203 204 206 206 208

Contents 10.10 10.11 10.12 10.13

ix

Processing ................................................................................... Conclusions................................................................................. Acknowledgements..................................................................... References...................................................................................

211 212 212 212

11 Pistachio (Pistacia vera L.) .................................................................. M. Kashaninejad, Gorgan University of Agricultural Sciences and Natural Resources, Iran and L. G. Tabil, University of Saskatchewan, Canada 11.1 Introduction................................................................................. 11.2 Physiological disorders ............................................................... 11.3 Postharvest pathology and mycotoxin contamination ................ 11.4 Postharvest handling practices .................................................... 11.5 Processing of fresh pistachio nuts............................................... 11.6 Processing of dried pistachio nuts .............................................. 11.7 References...................................................................................

218

12 Pitahaya (pitaya) (Hylocereus spp.) .................................................... F. Le Bellec and F. Vaillant, Centre for Agricultural Research and Development (CIRAD), France 12.1 Introduction................................................................................. 12.2 Uses and market .......................................................................... 12.3 Botany, origin and morphology .................................................. 12.4 Cropping system ......................................................................... 12.5 Cultivation techniques ................................................................ 12.6 Pests and diseases ....................................................................... 12.7 Quality components and indices ................................................. 12.8 Postharvest handling factors affecting quality ............................ 12.9 Processing ................................................................................... 12.10 Conclusions................................................................................. 12.11 References...................................................................................

247

13 Pitanga (Eugenia uniflora L.) .............................................................. M. Vizzotto and L. Cabral, Brazilian Agricultural Research Corporation (EMBRAPA), Brazil and A. Santos Lopes, Federal University of Pará, Brazil 13.1 Introduction................................................................................. 13.2 Postharvest physiology ............................................................... 13.3 Maturity and quality components and composition.................... 13.4 Postharvest handling factors affecting quality ............................ 13.5 Postharvest handling practices .................................................... 13.6 Processing ................................................................................... 13.7 Conclusions................................................................................. 13.8 References...................................................................................


218 228 231 232 234 242 244

247 248 248 254 255 259 260 262 263 266 267 272

272 274 276 278 279 280 284 284

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

x 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Contents

14 Pomegranate (Punica granatum L.).................................................... M. Erkan, Akdeniz University, Turkey and A. A. Kader, University of California, Davis, USA 14.1 Introduction................................................................................. 14.2 Fruit development and postharvest physiology .......................... 14.3 Maturity and quality components and indices ............................ 14.4 Preharvest factors affecting fruit quality .................................... 14.5 Postharvest handling factors affecting quality ............................ 14.6 Physiological disorders ............................................................... 14.7 Pathological disorders ................................................................. 14.8 Postharvest handling practices .................................................... 14.9 Processing ................................................................................... 14.10 Conclusions................................................................................. 14.11 References...................................................................................

287

15 Rambutan (Nephelium lappaceum L.) ................................................ M. M. Wall, US Department of Agriculture, Agricultural Research Service (USDA-ARS), USA, D. Sivakumar, Tshwane University of Technology, South Africa and L. Korsten, University of Pretoria, South Africa 15.1 Introduction................................................................................. 15.2 Fruit development and postharvest physiology .......................... 15.3 Maturity and quality components and indices ............................ 15.4 Preharvest factors affecting fruit quality .................................... 15.5 Postharvest handling factors affecting quality ............................ 15.6 Physiological disorders ............................................................... 15.7 Pathological disorders ................................................................. 15.8 Insect pests and their control ...................................................... 15.9 Postharvest handling practices .................................................... 15.10 Processing ................................................................................... 15.11 Conclusions................................................................................. 15.12 References...................................................................................

312

16 Salak (Salacca zalacca (Gaertner) Voss) ............................................ S. Supapvanich, Kasetsart University, Thailand, R. Megia, Bogor Agricultural University, Indonesia and P. Ding, University of Putra Malaysia, Malaysia 16.1 Introduction................................................................................. 16.2 Fruit development and postharvest physiology .......................... 16.3 Changes in quality components during maturation .................... 16.4 Preharvest factors affecting fruit quality .................................... 16.5 Postharvest factors and physiological disorders affecting fruit quality ................................................................................. 16.6 Postharvest pathology and entomology ...................................... 16.7 Postharvest handling practices ....................................................

334


287 292 294 295 296 299 301 302 305 306 307

312 313 316 317 317 319 320 324 325 328 328 329

334 341 341 343 343 344 345

Contents

xi

16.8 Processing ................................................................................... 16.9 Conclusions................................................................................. 16.10 References...................................................................................

347 348 348

17 Sapodilla (Manilkara achras (Mill) Fosb., syn Achras sapota, L.) ... E. M. Yahia and F. Guttierrez-Orozco, Autonomous University of Queretaro, Mexico 17.1 Introduction................................................................................. 17.2 Fruit development and postharvest physiology .......................... 17.3 Maturity and quality components and indices ............................ 17.4 Preharvest factors affecting fruit quality .................................... 17.5 Postharvest handling factors affecting quality ............................ 17.6 Physiological disorders ............................................................... 17.7 Pathological disorders ................................................................. 17.8 Insect pests and their control ...................................................... 17.9 Postharvest handling practices .................................................... 17.10 Processing ................................................................................... 17.11 Conclusions................................................................................. 17.12 References...................................................................................

351

18 Soursop (Annona muricata L.) ............................................................ M. A. Coêlho de Lima and R. E. Alves, Brazilian Agricultural Research Corporation (EMBRAPA), Brazil 18.1 Introduction................................................................................. 18.2 Fruit growth and ripening ........................................................... 18.3 Maturity and quality components and indices ............................ 18.4 Preharvest factors affecting fruit quality .................................... 18.5 Postharvest handling factors affecting quality ............................ 18.6 Physiological disorders ............................................................... 18.7 Pathological disorders ................................................................. 18.8 Postharvest handling practices .................................................... 18.9 Conclusions................................................................................. 18.10 References................................................................................... 19 Star apple (Chrysophyllum cainito L.) ................................................ E. M. Yahia and F. Guttierrez-Orozco, Autonomous University of Queretaro, Mexico 19.1 Introduction................................................................................. 19.2 Fruit development and postharvest physiology .......................... 19.3 Maturity and quality components and indices ............................ 19.4 Preharvest factors affecting fruit quality .................................... 19.5 Postharvest handling factors affecting quality ............................ 19.6 Physiological disorders ............................................................... 19.7 Pathological disorders ................................................................. 19.8 Insect pests and their control ......................................................


351 353 354 356 356 357 357 358 358 359 360 360 363 363 367 370 379 380 382 383 383 386 386 392 392 395 395 396 396 396 396 396

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

xii 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Contents 19.9 19.10 19.11 19.12

Postharvest handling practices .................................................... Processing ................................................................................... Conclusions................................................................................. References...................................................................................

20 Sugar apple (Annona squamosa L.) and atemoya (A. cherimola Mill. × A. squamosa L.) ................................................ C. Wongs-Aree, King Mongkut’s University of Technology Thonburi (KMUTT), Thailand and S. Noichinda, King Mongkut’s University of Technology North Bangkok (KMUTNB), Thailand 20.1 Introduction................................................................................. 20.2 Fruit development and postharvest physiology .......................... 20.3 Maturity ...................................................................................... 20.4 Preharvest factors affecting fruit quality .................................... 20.5 Postharvest handling factors affecting quality ............................ 20.6 Physiological disorders ............................................................... 20.7 Diseases, insect pests and their control....................................... 20.8 Postharvest handling practices .................................................... 20.9 Processing ................................................................................... 20.10 Conclusions................................................................................. 20.11 Acknowledgements..................................................................... 20.12 References...................................................................................

397 397 397 398 399

399 405 408 410 411 412 414 415 421 422 422 423

21 Tamarillo (Solanum betaceum (Cav.)) ................................................ W. C. Schotsmans, Institute of Agricultural Research and Technology, Spain, A. East, Massey University, New Zealand and A. Woolf, The New Zealand Institute for Plant & Food Research Limited, New Zealand 21.1 Introduction................................................................................. 21.2 Preharvest factors affecting fruit quality .................................... 21.3 Postharvest physiology and quality ............................................ 21.4 Postharvest handling factors affecting quality ............................ 21.5 Crop losses .................................................................................. 21.6 Processing ................................................................................... 21.7 Conclusions................................................................................. 21.8 References...................................................................................

427

22 Tamarind (Tamarindus indica L.) ....................................................... E. M. Yahia, Autonomous University of Queretaro, Mexico and N. K.-E. Salih, Agricultural Research Corporation, Sudan 22.1 Introduction................................................................................. 22.2 Fruit growth and ripening ........................................................... 22.3 Maturity and quality components and indices ............................ 22.4 Preharvest factors affecting fruit quality .................................... 22.5 Diseases and pests and their control ...........................................

442


427 431 432 434 435 437 438 438

442 448 448 449 450

Contents 22.6 22.7 22.8 22.9 22.10

Postharvest handling factors affecting quality ............................ Postharvest handling practices .................................................... Processing ................................................................................... Conclusions................................................................................. References...................................................................................

23 Wax apple (Syzygium samarangense (Blume) Merr. and L.M. Perry) and related species .......................................................... Z.-H Shü, Meiho University, Taiwan, C.-C. Hsieh and H.-L. Lin, National Chung-hsing University, Taiwan 23.1 Introduction................................................................................. 23.2 Fruit development and postharvest physiology .......................... 23.3 Maturity, quality components and indices .................................. 23.4 Physiological disorders ............................................................... 23.5 Pathological disorders ................................................................. 23.6 Insect pests and their control ...................................................... 23.7 Postharvest handling practices .................................................... 23.8 Conclusions................................................................................. 23.9 References...................................................................................

xiii 451 452 453 455 455 458 458 464 464 464 467 467 469 470 470

24 White sapote (Casimiroa edulis Llave & Lex) ................................... E. M. Yahia and F. Guttierrez-Orozco, Autonomous University of Queretaro, Mexico 24.1 Introduction................................................................................. 24.2 Fruit development and postharvest physiology .......................... 24.3 Maturation and quality components and indices ........................ 24.4 Preharvest factors affecting fruit quality .................................... 24.5 Postharvest handling factors affecting quality ............................ 24.6 Physiological disorders ............................................................... 24.7 Pathological disorders ................................................................. 24.8 Insect pests and their control ...................................................... 24.9 Postharvest handling practices .................................................... 24.10 Processing ................................................................................... 24.11 Conclusions................................................................................. 24.12 References...................................................................................

474 477 477 478 478 478 479 479 479 480 480 480

Index.............................................................................................................

483


474

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Contributor contact details Chapter 3

(* = main contact) Chapter 1 S. Ketsa* Department of Horticulture Faculty of Agriculture Kasetsart University Bangkok, 10900 Thailand

O. Duarte Universidad Nacional Agraria – La Molina Monte Real 207, Dept. 7 Chacarilla, Surco Lima 33 Peru Email: [email protected]

Email: [email protected] R. E. Paull Department of Tropical Plant and Soil Sciences University of Hawaii at Manoa Honolulu, HI 96822 USA Email: [email protected] Chapter 2 M. E. Saltveit Mann Laboratory Department of Plant Sciences University of California Davis, CS 95616 USA

Chapter 4 A. Carrillo López* Maestría en Ciencia y Tecnología de Alimentos Facultad de Ciencias QuímicoBiológicas Universidad Autónoma de Sinaloa Blvd de las Américas s/n Culiacán Sinaloa, C. P. 80000 México Email: [email protected] [email protected]

Email: [email protected]


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

xvi 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Contributor contact details

E. M. Yahia Facultad de Ciencias Naturales Universidad Autónoma de Querétaro Avenida de las Ciencias S/N Juriquilla, 76230 Querétaro, Qro México

D. V. Sudhakar Rao Division of Postharvest Technology Indian Institute of Horticultural Research Hessaraghatta Lake Bangalore, 560 089 India



Chapter 5

Chapter 7

C. H. Crisosto* and L. Ferguson Department of Plant Sciences University of California, Davis One Shields Avenue Davis, CA 95616 USA

W. C. Schotsmans* Department of Postharvest Science Institut de Recerca i Tecnologia Agroalimentàries Avenida de Alcalde Rovira Roure 191 25198 Lleida Spain

Email: [email protected] [email protected]


G. Nanos School of Agricultural Sciences University of Thessaly Fitoko Str 38446 Volos Greece

G. Fischer Facultad de Agronomía Universidad Nacional de Colombia A. A. 14490, Av. Carr. 30 No. 45–03 Bogotá Colombia



Chapter 6

Chapter 8

S. P. Singh* Department of Environment and Agriculture Curtin University of Technology GPO Box U1987 Perth 6845 Australia

A. A. Gardea* Unidad Guaymas Centro de Investigación en Alimentación y Desarrollo, A.C. Carretera a Varadero Nacional km 6.6. Guaymas, Sonora, 85480 Mexico

Email: sukhvinder.pal.singh@gmail. com



Contributor contact details M. A. Martínez-Téllez Centro de Investigación en Alimentación y Desarrollo, A.C. Carretera a la Victoria, km 0.6 Hermosillo, Sonora, 83000 México Email: [email protected] E. M. Yahia Facultad de Ciencias Naturales Universidad Autónoma de Querétaro Avenida las Ciencias S/N Juriquilla, 76230 Querétaro, Qro México Email: [email protected]

Chapter 10 A. Hassan* and Z. Othman Malaysian Agricultural Research and Development Institute (MARDI) GPO Box 12301 50774 Kuala Lumpur Malaysia Email: [email protected] J. Siriphanich Department of Horticulture Faculty of Agriculture Kamphaeng Saen Kasetsart University Nakhon Pathom, 73140 Thailand Email: [email protected]

Chapter 9

Chapter 11

A. B. Woolf* The New Zealand Institute for Plant and Food Research Mt Albert Private Bag 92169 Auckland Mail Centre 1142, Auckland New Zealand Email: [email protected] R. Ben-Arie Fruit Storage Research Laboratory Israel Fruit Growers’ Association Kiryat Shemona 10200, Israel Email: [email protected]

xvii

M. Kashaninejad* Department of Food Science and Technology Gorgan University of Agricultural Sciences and Natural Resources Beheshti Avenue Gorgan 49137-15739 Iran Email: [email protected] [email protected] L. G. Tabil Department of Chemical and Biological Engineering University of Saskatchewan 57 Campus Drive Saskatoon SK S7N 5A9 Canada Email: [email protected]


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

xviii 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Chapter 12 F. Le Bellec* CIRAD, UPR 103 HORTSYS TA B-103/PS4, Boulevard de la Lironde 34398 Montpellier Cedex 5 France Email: [email protected] F. Vaillant CIRAD, UMR 95 QUALISUD TA B-95/16, 73 rue Jean François Breton 34398 Montpellier Cedex 5 France Email: [email protected] Chapter 13

L. Cabral Brazilian Agricultural Research Corporation (EMBRAPA) Embrapa Food Technology Av. das Américas, 29501 Guaratiba, Rio de Janeiro CEP 23020-470 Brazil Email: [email protected] Chapter 14 M. Erkan* Department of Horticulture Faculty of Agriculture Akdeniz University 07059 Antalya Turkey Email: [email protected]

M. Vizzotto* Brazilian Agricultural Research Corporation (EMBRAPA) Embrapa Temperate Agricultural Rodovia BR 392, km 78 Pelotas RS – Brazil – CEP 96010-971 Email: marcia.vizzotto@cpact. embrapa.br

A. A. Kader Department of Plant Sciences University of California, Davis CA 95616 USA Email: [email protected] Chapter 15

A. S. Lopes Federal University of Pará (UFPA) College of Food Engineering Rua Augusto Corrêa 01, Guamá Belem, PA CEP 66075-110 Brazil

M. M. Wall* US Department of Agriculture Agricultural Research Service P.O. Box 4459 Hilo Hawaii 96720 USA




Contributor contact details D. Sivakumar Department of Crop Sciences Tshwane University of Technology Pretoria 0001 South Africa Email: [email protected] L. Korsten Department of Microbiology and Plant Pathology University of Pretoria Pretoria 0002 South Africa Email: [email protected] Chapter 16 S. Supapvanich* Faculty of Natural Resources and Agro-Industry Chalermprakiat Sakonnakhon Province Campus Kasetsart University 59 Chiangkhrua, Muang Sakonnakhon Province 47000 Thailand Email: [email protected] R. Megia Department of Biology-FMIPA Bogor Agricultural University Darmaga Campus Bogor 16680 Indonesia Email: [email protected]

xix

P. Ding Department of Crop Science Faculty of Agriculture Universiti Putra Malaysia 43400 UPM Serdang, Selangor Malaysia Email: [email protected] Chapters 17, 19 and 24 E. M. Yahia* and F. Guttierrez-Orozco Facultad de Ciencias Naturales Universidad Autónoma de Querétaro Avenida las Ciencias S/N Juriquilla, 76230 Querétaro, Qro México Email: [email protected]; [email protected] Chapter 18 M. A. Coêlho de Lima* Brazilian Agricultural Research Corporation (EMBRAPA) Embrapa Tropical Semi-Arid BR 428 Km 152 P. O. Box 23 56302-970, Petrolina Pernambuco State Brazil Email: [email protected] R. E. Alves Brazilian Agricultural Research Corporation (EMBRAPA) Embrapa Tropical Agroindustry Dra Sara Mesquite Street, 2270 60511-110, Fortaleza Ceará State Brazil Email: [email protected]


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

xx 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Chapter 20 C. Wongs-Aree* Postharvest Technology Program School of Bioresources and Technology King Mongkut’s University of Technology Thonburi (KMUTT) Bangkok 10140 Thailand

A. B. Woolf The New Zealand Institute for Plant and Food Research Limited Mt Albert Research Centre Private Bag 92169 Mt Albert New Zealand Email: allan.woolf@plantandfood. co.nz

Email: [email protected] S. Noichinda Faculty of Applied Science King Mongkut’s University of Technology North Bangkok (KMUTNB) Bangkok 10800 Thailand

Chapter 22 E. M. Yahia* Facultad de Ciencias Naturales Universidad Autónoma de Querétaro Avenida las Ciencias S/N Juriquilla, 76230 Querétaro, Qro México

Email: [email protected] Email: [email protected] Chapter 21 W. C. Schotsmans* Department of Postharvest Science Institut de Recerca I Tecnologia Agroalimentàries Avenida de Alcalde Rovira Roure 191 25198 Lleida Spain Email: [email protected]

N. K.-E. Salih Forestry Research Center Agricultural Research Corporation P. O. Box 7089 Khartoum Sudan Email: [email protected] Chapter 23

A. East Centre for Postharvest and Refrigeration Research Massey University Private Bag 11222 Palmerston North 4442 New Zealand

Z.-H. Shü* Research Institute of Health and Biotechnology and Department of Science and Technology Meiho University Neipu, Pingtung 912 Taiwan




Contributor contact details C.-C. Hsieh Department of Horticulture National Chun-hsing University Taichung 400 Taiwan

H.-L. Lin Department of Horticulture National Chung-Hsing University Taichung 400 Taiwan




xxi 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Woodhead Publishing Series in Food Science, Technology and Nutrition

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Chilled foods: a comprehensive guide Edited by C. Dennis and M. Stringer Yoghurt: science and technology A. Y. Tamime and R. K. Robinson Food processing technology: principles and practice P. J. Fellows Bender’s dictionary of nutrition and food technology Sixth edition D. A. Bender Determination of veterinary residues in food Edited by N. T. Crosby Food contaminants: sources and surveillance Edited by C. Creaser and R. Purchase Nitrates and nitrites in food and water Edited by M. J. Hill Pesticide chemistry and bioscience: the food-environment challenge Edited by G. T. Brooks and T. Roberts Pesticides: developments, impacts and controls Edited by G. A. Best and A. D. Ruthven Dietary fibre: chemical and biological aspects Edited by D. A. T. Southgate, K. W. Waldron, I. T. Johnson and G. R. Fenwick Vitamins and minerals in health and nutrition M. Tolonen Technology of biscuits, crackers and cookies Second edition D. Manley Instrumentation and sensors for the food industry Edited by E. Kress-Rogers Food and cancer prevention: chemical and biological aspects Edited by K. W. Waldron, I. T. Johnson and G. R. Fenwick Food colloids: proteins, lipids and polysaccharides Edited by E. Dickinson and B. Bergenstahl Food emulsions and foams Edited by E. Dickinson Maillard reactions in chemistry, food and health Edited by T. P. Labuza, V. Monnier, J. Baynes and J. O’Brien The Maillard reaction in foods and medicine Edited by J. O’Brien, H. E. Nursten, M. J. Crabbe and J. M. Ames Encapsulation and controlled release Edited by D. R. Karsa and R. A. Stephenson Flavours and fragrances Edited by A. D. Swift Feta and related cheeses Edited by A. Y. Tamime and R. K. Robinson


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

xxiv 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


22 Biochemistry of milk products Edited by A. T. Andrews and J. R. Varley 23 Physical properties of foods and food processing systems M. J. Lewis 24 Food irradiation: a reference guide V. M. Wilkinson and G. Gould 25 Kent’s technology of cereals: an introduction for students of food science and agriculture Fourth edition N. L. Kent and A. D. Evers 26 Biosensors for food analysis Edited by A. O. Scott 27 Separation processes in the food and biotechnology industries: principles and applications Edited by A.S. Grandison and M. J. Lewis 28 Handbook of indices of food quality and authenticity R.S. Singhal, P. K. Kulkarni and D. V. Rege 29 Principles and practices for the safe processing of foods D. A. Shapton and N. F. Shapton 30 Biscuit, cookie and cracker manufacturing manuals Volume 1: ingredients D. Manley 31 Biscuit, cookie and cracker manufacturing manuals Volume 2: biscuit doughs D. Manley 32 Biscuit, cookie and cracker manufacturing manuals Volume 3: biscuit dough piece forming D. Manley 33 Biscuit, cookie and cracker manufacturing manuals Volume 4: baking and cooling of biscuits D. Manley 34 Biscuit, cookie and cracker manufacturing manuals Volume 5: secondary processing in biscuit manufacturing D. Manley 35 Biscuit, cookie and cracker manufacturing manuals Volume 6: biscuit packaging and storage D. Manley 36 Practical dehydration Second edition M. Greensmith 37 Lawrie’s meat science Sixth edition R. A. Lawrie 38 Yoghurt: science and technology Second edition A. Y Tamime and R. K. Robinson 39 New ingredients in food processing: biochemistry and agriculture G. Linden and D. Lorient 40 Benders’ dictionary of nutrition and food technology Seventh edition D A Bender and A. E. Bender 41 Technology of biscuits, crackers and cookies Third edition D. Manley 42 Food processing technology: principles and practice Second edition P. J. Fellows 43 Managing frozen foods Edited by C. J. Kennedy 44 Handbook of hydrocolloids Edited by G. O. Phillips and P. A. Williams 45 Food labelling Edited by J. R. Blanchfield 46 Cereal biotechnology Edited by P. C. Morris and J. H. Bryce 47 Food intolerance and the food industry Edited by T. Dean 48 The stability and shelf-life of food Edited by D. Kilcast and P. Subramaniam 49 Functional foods: concept to product Edited by G. R. Gibson and C. M. Williams 50 Chilled foods: a comprehensive guide Second edition Edited by M. Stringer and C. Dennis 51 HACCP in the meat industry Edited by M. Brown 52 Biscuit, cracker and cookie recipes for the food industry D. Manley 53 Cereals processing technology Edited by G. Owens 54 Baking problems solved S. P. Cauvain and L. S. Young 55 Thermal technologies in food processing Edited by P. Richardson 56 Frying: improving quality Edited by J. B. Rossell 57 Food chemical safety Volume 1: contaminants Edited by D. Watson


Woodhead Publishing Series in Food Science, Technology and Nutrition 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95

xxv

Making the most of HACCP: learning from others’ experience Edited by T. Mayes and S. Mortimore Food process modelling Edited by L. M. M. Tijskens, M. L. A. T. M. Hertog and B. M. Nicolaï EU food law: a practical guide Edited by K. Goodburn Extrusion cooking: technologies and applications Edited by R. Guy Auditing in the food industry: from safety and quality to environmental and other audits Edited by M. Dillon and C. Griffith Handbook of herbs and spices Volume 1 Edited by K. V. Peter Food product development: maximising success M. Earle, R. Earle and A. Anderson Instrumentation and sensors for the food industry Second edition Edited by E. Kress-Rogers and C. J. B. Brimelow Food chemical safety Volume 2: additives Edited by D. Watson Fruit and vegetable biotechnology Edited by V. Valpuesta Foodborne pathogens: hazards, risk analysis and control Edited by C. de W. Blackburn and P. J. McClure Meat refrigeration S. J. James and C. James Lockhart and Wiseman’s crop husbandry Eighth edition H. J. S. Finch, A. M. Samuel and G. P. F. Lane Safety and quality issues in fish processing Edited by H. A. Bremner Minimal processing technologies in the food industries Edited by T. Ohlsson and N. Bengtsson Fruit and vegetable processing: improving quality Edited by W. Jongen The nutrition handbook for food processors Edited by C. J. K. Henry and C. Chapman Colour in food: improving quality Edited by D MacDougall Meat processing: improving quality Edited by J. P. Kerry, J. F. Kerry and D. A. Ledward Microbiological risk assessment in food processing Edited by M. Brown and M. Stringer Performance functional foods Edited by D. Watson Functional dairy products Volume 1 Edited by T. Mattila-Sandholm and M. Saarela Taints and off-flavours in foods Edited by B. Baigrie Yeasts in food Edited by T. Boekhout and V. Robert Phytochemical functional foods Edited by I. T. Johnson and G. Williamson Novel food packaging techniques Edited by R. Ahvenainen Detecting pathogens in food Edited by T. A. McMeekin Natural antimicrobials for the minimal processing of foods Edited by S. Roller Texture in food Volume 1: semi-solid foods Edited by B. M. McKenna Dairy processing: improving quality Edited by G Smit Hygiene in food processing: principles and practice Edited by H. L. M. Lelieveld, M. A. Mostert, B. White and J. Holah Rapid and on-line instrumentation for food quality assurance Edited by I. Tothill Sausage manufacture: principles and practice E. Essien Environmentally-friendly food processing Edited by B. Mattsson and U. Sonesson Bread making: improving quality Edited by S. P. Cauvain Food preservation techniques Edited by P. Zeuthen and L. Bøgh-Sørensen Food authenticity and traceability Edited by M. Lees Analytical methods for food additives R. Wood, L. Foster, A. Damant and P. Key


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

xxvi 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

96 97 98 99 100 101 102 103 104 105 106 107 108 109

110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133

Woodhead Publishing Series in Food Science, Technology and Nutrition Handbook of herbs and spices Volume 2 Edited by K. V. Peter Texture in food Volume 2: solid foods Edited by D. Kilcast Proteins in food processing Edited by R. Yada Detecting foreign bodies in food Edited by M. Edwards Understanding and measuring the shelf-life of food Edited by R. Steele Poultry meat processing and quality Edited by G. Mead Functional foods, ageing and degenerative disease Edited by C. Remacle and B. Reusens Mycotoxins in food: detection and control Edited by N. Magan and M. Olsen Improving the thermal processing of foods Edited by P. Richardson Pesticide, veterinary and other residues in food Edited by D. Watson Starch in food: structure, functions and applications Edited by A-C Eliasson Functional foods, cardiovascular disease and diabetes Edited by A. Arnoldi Brewing: science and practice D. E. Briggs, P. A. Brookes, R. Stevens and C. A. Boulton Using cereal science and technology for the benefit of consumers: proceedings of the 12th International ICC Cereal and Bread Congress, 24–26th May, 2004, Harrogate, UK Edited by S. P. Cauvain, L. S. Young and S. Salmon Improving the safety of fresh meat Edited by J. Sofos Understanding pathogen behaviour in food: virulence, stress response and resistance Edited by M. Griffiths The microwave processing of foods Edited by H. Schubert and M. Regier Food safety control in the poultry industry Edited by G. Mead Improving the safety of fresh fruit and vegetables Edited by W. Jongen Food, diet and obesity Edited by D. Mela Handbook of hygiene control in the food industry Edited by H. L. M. Lelieveld, M. A. Mostert and J. Holah Detecting allergens in food Edited by S. Koppelman and S. Hefle Improving the fat content of foods Edited by C. Williams and J. Buttriss Improving traceability in food processing and distribution Edited by I. Smith and A. Furness Flavour in food Edited by A. Voilley and P. Etievant The Chorleywood bread process S. P. Cauvain and L. S. Young Food spoilage microorganisms Edited by C. de W. Blackburn Emerging foodborne pathogens Edited by Y. Motarjemi and M. Adams Benders’ dictionary of nutrition and food technology Eighth edition D. A. Bender Optimising sweet taste in foods Edited by W. J. Spillane Brewing: new technologies Edited by C. Bamforth Handbook of herbs and spices Volume 3 Edited by K. V. Peter Lawrie’s meat science Seventh edition R. A. Lawrie in collaboration with D. A. Ledward Modifying lipids for use in food Edited by F. Gunstone Meat products handbook: practical science and technology G. Feiner Food consumption and disease risk: consumer-pathogen interactions Edited by M. Potter Acrylamide and other hazardous compounds in heat-treated foods Edited by K. Skog and J. Alexander Managing allergens in food Edited by C. Mills, H. Wichers and K. Hoffman-Sommergruber



xxvii

134 Microbiological analysis of red meat, poultry and eggs Edited by G. Mead 135 Maximising the value of marine by-products Edited by F. Shahidi 136 Chemical migration and food contact materials Edited by K. Barnes, R. Sinclair and D. Watson 137 Understanding consumers of food products Edited by L. Frewer and H. van Trijp 138 Reducing salt in foods: practical strategies Edited by D. Kilcast and F. Angus 139 Modelling microorganisms in food Edited by S. Brul, S. Van Gerwen and M. Zwietering 140 Tamime and Robinson’s Yoghurt: science and technology Third edition A. Y. Tamime and R. K. Robinson 141 Handbook of waste management and co-product recovery in food processing Volume 1 Edited by K. W. Waldron 142 Improving the flavour of cheese Edited by B. Weimer 143 Novel food ingredients for weight control Edited by C. J. K. Henry 144 Consumer-led food product development Edited by H. MacFie 145 Functional dairy products Volume 2 Edited by M. Saarela 146 Modifying flavour in food Edited by A. J. Taylor and J. Hort 147 Cheese problems solved Edited by P. L. H. McSweeney 148 Handbook of organic food safety and quality Edited by J. Cooper, C. Leifert and U. Niggli 149 Understanding and controlling the microstructure of complex foods Edited by D. J. McClements 150 Novel enzyme technology for food applications Edited by R. Rastall 151 Food preservation by pulsed electric fields: from research to application Edited by H. L. M. Lelieveld and S. W. H. de Haan 152 Technology of functional cereal products Edited by B. R. Hamaker 153 Case studies in food product development Edited by M. Earle and R. Earle 154 Delivery and controlled release of bioactives in foods and nutraceuticals Edited by N. Garti 155 Fruit and vegetable flavour: recent advances and future prospects Edited by B. Brückner and S. G. Wyllie 156 Food fortification and supplementation: technological, safety and regulatory aspects Edited by P. Berry Ottaway 157 Improving the health-promoting properties of fruit and vegetable products Edited by F. A. Tomás-Barberán and M. I. Gil 158 Improving seafood products for the consumer Edited by T. Børresen 159 In-pack processed foods: improving quality Edited by P. Richardson 160 Handbook of water and energy management in food processing Edited by J. Klemeš, R. Smith and J-K Kim 161 Environmentally compatible food packaging Edited by E. Chiellini 162 Improving farmed fish quality and safety Edited by Ø. Lie 163 Carbohydrate-active enzymes Edited by K-H Park 164 Chilled foods: a comprehensive guide Third edition Edited by M. Brown 165 Food for the ageing population Edited by M. M. Raats, C. P. G. M. de Groot and W. A Van Staveren 166 Improving the sensory and nutritional quality of fresh meat Edited by J. P. Kerry and D. A. Ledward 167 Shellfish safety and quality Edited by S. E. Shumway and G. E. Rodrick 168 Functional and speciality beverage technology Edited by P. Paquin


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

xxviii 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


169 Functional foods: principles and technology M. Guo 170 Endocrine-disrupting chemicals in food Edited by I. Shaw 171 Meals in science and practice: interdisciplinary research and business applications Edited by H. L. Meiselman 172 Food constituents and oral health: current status and future prospects Edited by M. Wilson 173 Handbook of hydrocolloids Second edition Edited by G. O. Phillips and P. A. Williams 174 Food processing technology: principles and practice Third edition P. J. Fellows 175 Science and technology of enrobed and filled chocolate, confectionery and bakery products Edited by G. Talbot 176 Foodborne pathogens: hazards, risk analysis and control Second edition Edited by C. de W. Blackburn and P. J. McClure 177 Designing functional foods: measuring and controlling food structure breakdown and absorption Edited by D. J. McClements and E. A. Decker 178 New technologies in aquaculture: improving production efficiency, quality and environmental management Edited by G. Burnell and G. Allan 179 More baking problems solved S. P. Cauvain and L. S. Young 180 Soft drink and fruit juice problems solved P. Ashurst and R. Hargitt 181 Biofilms in the food and beverage industries Edited by P. M. Fratamico, B. A. Annous and N. W. Gunther 182 Dairy-derived ingredients: food and neutraceutical uses Edited by M. Corredig 183 Handbook of waste management and co-product recovery in food processing Volume 2 Edited by K. W. Waldron 184 Innovations in food labelling Edited by J. Albert 185 Delivering performance in food supply chains Edited by C. Mena and G. Stevens 186 Chemical deterioration and physical instability of food and beverages Edited by L. H. Skibsted, J. Risbo and M. L. Andersen 187 Managing wine quality Volume 1: viticulture and wine quality Edited by A.G. Reynolds 188 Improving the safety and quality of milk Volume 1: milk production and processing Edited by M. Griffiths 189 Improving the safety and quality of milk Volume 2: improving quality in milk products Edited by M. Griffiths 190 Cereal grains: assessing and managing quality Edited by C. Wrigley and I. Batey 191 Sensory analysis for food and beverage quality control: a practical guide Edited by D. Kilcast 192 Managing wine quality Volume 2: oenology and wine quality Edited by A. G. Reynolds 193 Winemaking problems solved Edited by C. E. Butzke 194 Environmental assessment and management in the food industry Edited by U. Sonesson, J. Berlin and F. Ziegler 195 Consumer-driven innovation in food and personal care products Edited by S.R. Jaeger and H. MacFie 196 Tracing pathogens in the food chain Edited by S. Brul, P.M. Fratamico and T.A. McMeekin 197 Case studies in novel food processing technologies: innovations in processing, packaging, and predictive modelling Edited by C. J. Doona, K Kustin and F. E. Feeherry



xxix

198 Freeze-drying of pharmaceutical and food products T-C Hua, B-L Liu and H Zhang 199 Oxidation in foods and beverages and antioxidant applications Volume 1: understanding mechanisms of oxidation and antioxidant activity Edited by E. A. Decker, R. J. Elias and D. J. McClements 200 Oxidation in foods and beverages and antioxidant applications Volume 2: management in different industry sectors Edited by E. A. Decker, R. J. Elias and D. J. McClements 201 Protective cultures, antimicrobial metabolites and bacteriophages for food and beverage biopreservation Edited by C. Lacroix 202 Separation, extraction and concentration processes in the food, beverage and nutraceutical industries Edited by S. S. H. Rizvi 203 Determining mycotoxins and mycotoxigenic fungi in food and feed Edited by S. De Saeger 204 Developing children’s food products Edited by D. Kilcast and F. Angus 205 Functional foods: concept to product Second edition Edited by M. Saarela 206 Postharvest biology and technology of tropical and subtropical fruits Volume 1 Edited by E. M. Yahia 207 Postharvest biology and technology of tropical and subtropical fruits Volume 2 Edited by E. M. Yahia 208 Postharvest biology and technology of tropical and subtropical fruits Volume 3 Edited by E. M. Yahia 209 Postharvest biology and technology of tropical and subtropical fruits Volume 4 Edited by E. M. Yahia 210 Food and beverage stability and shelf life Edited by D. Kilcast and P. Subramaniam 211 Processed Meats: improving safety, nutrition and quality Edited by J. P. Kerry and J. F. Kerry 212 Food chain integrity: a holistic approach to food traceability, safety, quality and authenticity Edited by J. Hoorfar, K. Jordan, F. Butler and R. Prugger 213 Improving the safety and quality of eggs and egg products Volume 1 Edited by Y. Nys, M. Bain and F. Van Immerseel 214 Improving the safety and quality of eggs and egg products Volume 2 Edited by F. Van Immerseel, Y. Nys and M. Bain 215 Feed and fodder contamination: effects on livestock and food safety Edited by J. Fink-Gremmels 216 Hygienic design of food factories Edited by J. Holah and H. L. M. Lelieveld 217 Technology of biscuits, crackers and cookies Fourth edition Edited by D. Manley 218 Nanotechnology in the food, beverage and nutraceutical industries Edited by Q. Huang 219 Rice quality K. R. Bhattacharya 220 Meat, poultry and seafood packaging Edited by J. P. Kerry 221 Reducing saturated fats in foods Edited by G. Talbot 222 Handbook of food proteins Edited by G. O. Phillips and P. A. Williams 223 Lifetime nutritional influences on cognition, behaviour and psychiatric illness Edited by D. Benton


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Foreword

Most published postharvest research on fruit, covering decades of activity, has concentrated on temperate or model crops. There are good reasons for this, mainly associated with the well-established production and marketing industries, and long-established research teams in Europe, North America and Australasia. This great effort has given us much of our current understanding of fruit ripening, the characterisation of ethylene as a growth regulator, far reaching fundamental knowledge on core issues in plant science such as respiration, cell wall metabolism, aroma volatiles, and more latterly, on genetic and molecular control of fruit properties. This work has particularly provided the technology which has allowed a remarkable level of control of fruit quality after harvest, and provided the mainstay for substantial economic gains at the levels of both industry and national economies. However, estimates of world fruit production (2005–07) show that tropical crops including citrus make up to about 60% of world major fruit crop production (World Kiwifruit Review, 2010). In conjunction with this, the volume of global exports of tropical and subtropical fruit is about twice that of temperate fruit crops (data for 2007, for instance, show about 19 million tonnes for temperate and 38 million tonnes for tropical/subtropical produce; FAOSTATS database). Such crops comprise a major part of the economies of tropical and subtropical countries, and some such as bananas, plantains and breadfruit, are staple foods with critical dietary components. While the scale and importance of this in itself would warrant an extensive research base, one of the most compelling issues for postharvest researchers is the level of food waste. Various analyses of wastage along the value chain have been made, but the consensus seems to be that in developing countries, where most of the tropical and subtropical crops are grown, food losses can amount to up to 50% or more. A breakdown of this (Kader, 2005; World Economic Forum, 2009) suggests that most waste occurs between harvest and retail, with low percentages of food loss at the consumer end of the chain.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

xxxii 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Foreword

This provides an immediate target for postharvest research, and there is some urgency on this, given current concerns over food security in the next few decades (Nature, 2010). There will be collateral benefits. The most important may well be in increasing export potential of crops that traditionally have short storage lives and that are easily damaged during transport and handling. Even increasing access to near markets will provide economic gain, but there is greater potential in targeting more affluent markets and consumers who are seeking a wider range of fruit types and eating experiences, and are prepared to pay more for them. There are other advantages. Optimised postharvest procedures will result in greater maintenance of the nutritive and calorific value of fruit crops by minimising physiological deterioration and that from pests and diseases. And now that sustainability has become a serious market issue, there are environmental impacts from reducing food loss. For instance, there have been estimates that water losses associated with food wastage could reach a level where up to half the original water supply from irrigation is lost (World Economic Forum, 2009). So how will postharvest research on tropical and subtropical fruit crops help? We have to know our commodities, and the contents of this book directly addresses this. Understanding the fruit crop, fruit development, when to harvest, the specific ripening process, and postharvest response, is critical to optimising postharvest storage and handling. We tend, however, to try to impose traditional postharvest practices on all crops, often when this is not appropriate. Low temperature storage is an obvious case, and tropical crops particularly are chillingly sensitive: there is a constant struggle to prolong storage life through temperature control with a recalcitrant commodity. Many improvements in quality control through the supply chain can be made for a lot of crops with very simple application of basic postharvest handling and storage practices. These target pest and diseases, disinfestation issues, and ways of reducing the rate of fruit ripening while increasing tolerance to storage and transport conditions. However, we can be more innovative. In most cases, there has been relatively little done in breeding and selection of tropical and subtropical fruit crops with postharvest quality attributes as targets. There is a lot of scope here, particularly in the new genomics era, where faster and smarter breeding can be undertaken, and more value extracted from existing genetic material. There is quite a lot of research currently underway on tackling tropical fruit problems through fresh cut technology, and the use of edible coatings and biofilms, to prolong storage and shelf life. While this may have a minor impact on local use and in decreasing food wastage in less urban environments and markets, there may be larger benefits for urban and export markets. There is also an approach that might require extra thought and greater interrogation of the properties of the particular crops. Instead of imposing highly technical storage conditions, understanding how the fruit responds to ambient conditions and then seeing if there are innovative ways of handling the crop under those conditions might be more economical and practical under less sophisticated systems. The history of postharvest suggests that local innovation has often been


Foreword

xxxiii

very effective and perhaps we have been persuaded to look at modern technology at the expense of more original thinking. We need robust knowledge of our crops, and then very targeted postharvest approaches to reducing waste and ensuring high market quality. This is not a choice, but is an imperative for local economies, and for future food security. Ian Ferguson The New Zealand Institute for Plant & Food Research

References FAOSTATS database. Kader A A (2005) Increasing food availability by reducing postharvest losses of fresh produce. Acta Hortic, 682, 2169–2175. (2010) The growing problem. Nature, 466, 456–561. World Economic Forum (2009) Driving sustainable consumption. Value chain waste: Overview briefing. World Kiwifruit Review (World Kiwifruit Review).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

1 Mangosteen (Garcinia mangostana L.) S. Ketsa, Kasetsart University, Thailand and R. E. Paull, University of Hawaii at Manoa, USA

Abstract: Mangosteen (Garcinia mangostana L.) is one of the most admired tropical fruit and known widely as the Queen of Fruits for its beautiful purple blue pericarp and delicious flavor. The edible aril is white, soft and juicy with sweet pleasant taste. Mangosteen is a climacteric fruit that undergoes rapid postharvest changes resulting in a short shelf life at ambient temperature. Physiological disorders induced by preharvest and postharvest factors have a major impact on the appearance and eating quality. In addition to fresh consumption, the aril is processed into other products. The fruit pericarp also contains many chemical compounds that have possible medicinal value. Key words: mangosteen, postharvest change, physiological disorder, postharvest handling quality.

1.1

Introduction

1.1.1 Origin, botany, morphology and structure The mangosteen (Garcinia mangostana L.) originated in Southeast Asia and is a member of the family Clusiaceae. In earlier works, the genus had been placed in the Guttiferae. The genus name Garcinia was given by Linnaeus in honor of French naturalist Laurent Garcin for his work as a botanist in the eighteenth century. Laurent Garcin with others had made one of the most detailed descriptions of the fruit. Although the word ‘mango’ occurs in the word ‘mangosteen’ there is no botanical relationship at the genus or family levels. The name mangosteen is thought to have been derived from Malay or Javanese. According to Verheij (1991: 443): The mangosteen as a fresh fruit is in great demand in its native range and is savored by all who find its subtle flavors a refreshing balance of sweet and sour. It should be pointed out that Asians consider many foods to be either ‘cooling’ such as the mangosteen or ‘heating’ such as the durian depending on whether they possess


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

2 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Postharvest biology and technology of tropical and subtropical fruits elements that reflect yin and yang. This duality is commonly used to help describe balance in many aspects of life in general and food in particular throughout Asia.

Morton (1987: 505) describes the mangosteen as follows: The mangosteen is a very slow-growing, erect tree with a pyramidal crown. The tree can attain 6 to 25 m (20 to 82 ft) and has dark-brown or nearly black, flaking bark, the inner bark containing much yellow, gummy, bitter latex. This evergreen has opposite, short-stalked leaves that are ovate-oblong or elliptic, leathery and thick, dark-green, slightly glossy above and yellowish-green and dull beneath. New leaves have a rosy hue. The mature leaves are 9 to 25 cm long (3 1/2 to 10 in) and 4.5 to 10 cm wide (1 3/4 to 4 in) with conspicuous, pale midribs. Female flowers are 4 to 5 cm wide (1 1/2 to 2 in). The flowers are borne singly or in pairs at the tips of young branchlets; their fleshy petals may be yellowish-green, edged with red or mostly red, and the petals are quickly shed.

No male flowers or trees have been described, though it is said to be dioecious. Mangosteen is only known as a female cultivated plant. Based on morphological characters, mangosteen may be a sterile allopolyploid hybrid (2n = 88 − 90) between two Garcinia spp. Morton (1987: 505) further describes that: the smooth round fruit, 3.4 to 7.5 cm in diameter (1 1/3 to 3 in), is capped by a prominent calyx at the stem end that has 4 to 8 triangular, flat remnants of the stigma in a rosette at the apex. When the fruit is mature and ripe, it is dark-purple to reddishpurple. The rind (pericarp) is 6 to 10 mm thick (1/4 to 3/8 in) and spongy and in cross-section is red outside and purplish-white on the inside. The pericarp has a bitter yellow latex, and a purple, staining juice. Inside the pericarp are 4 to 8 triangular segments of snow-white, juicy, soft edible flesh (aril) that clings to the seeds. The fruit may be seedless or have 1 to 5 fully developed seeds. The seeds are ovoid-oblong, somewhat flattened, 2.5 cm (1 in) long and 1.6 cm wide (5/8 in).

The edible aril is white, juicy, sweet and slightly-acid, with a pleasant flavor (Fu et al., 2007; Ji et al., 2007). It is similar in shape and size to a tangerine. The circle of wedge-shaped arils contains 4 to 8 segments, the larger of which contain the apomictic seeds that are unpalatable unless roasted. Fruit are harvested at various stages of ripeness, referred to as Stage 1 to Stage 6. During ripening, Hue angle and pericarp firmness decline significantly, while soluble solids contents (SSC) increases and titratable acidity (TA) decreases resulting in an increase of SSC : TA ratio, and better tasting fruit. Fruit harvested at Stage 1 and allowed to ripen to Stage 6 show no significant differences in sensory quality and fruit appearance to fruit harvested at Stage 6. In the absence of fertilization, asexual ovary nucellus tissue development occurs that ensures fruit and aril growth. The asexual embryos develop from the nucellus tissue and these apomixic ‘seed’ are used in propagation. The ‘seed’ is a clone of the mother plant with little variation (Richards, 1990; Ramage et al., 2004), but the absence of true seed associated with sexual fertilization limits varietal development and selection. DNA and RNA marker analysis from material sourced globally has shown variation among the different mangosteen populations.


Mangosteen (Garcinia mangostana L.)

3

The majority of the samples had essentially the same genetic make-up (genotype) but significant differences were found in same samples (Yapwattanaphun and Subhadrabandhu, 2004). This difference could be due to chance mutation or selection within the limited variation that is known to occur. 1.1.2 Worldwide importance Mangosteen fruit is now grown worldwide and is being exported and marketed in more developed countries. Often it is advertised and marketed as a novel functional food and is sometimes called a ‘super fruit’. It is presumed to have a combination of

• • • •

appealing characteristics, such as taste, fragrance and visual qualities, nutrient richness, antioxidant strength, and potential impact for lowering risk of human diseases (Gross and Crown, 2007).

1.1.3 Nutritional value and health benefits The aril, though having a pleasant taste and flavor, has a low nutrient content (Table 1.1). Recent research on antioxidant determination showed that plant foods with rich colors had high scores of oxygen radical absorbance capacity (ORAC) whereas those that were white (without pigments) had low ORAC (Wu et al., 2004). Following this simple and subjective index, the white mangosteen aril Table 1.1 Nutritional values of mangosteen fruit (per 100 g edible portion). Content

per 100 g edible portion

Water Energy Protein Fat Carbohydrate Dietary fiber Ash Calcium Phosphorus Iron Copper Zinc B1 (Tiamine) B2 (Riboflavin) Niacin Vitamin C

80.9 g 76.0 cal 0.5 g 0.2 g 18.4 g 1.7 g 0.2 g 9.0 mg 14.0 mg 0.5 mg 0.11 mg 0.1 mg 0.09 mg 0.06 mg 0.1 mg 2.0 mg

Source: Anon. (2004). Fruits in Thailand. Department of Agricultural Extension, Ministry of Agriculture and Cooperatives, Bangkok, Thailand.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

4 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


should have a low ORAC, though no ORAC results have been reported for the aril to date. Some mangosteen juice products contain whole fruit purée or polyphenols extracted from the inedible pericarp (rind) as a formulation strategy to add phytochemical value. The resulting juice has a purple color and astringency derived from pericarp pigments. Xanthone extracts taken from the pericarp (Jung et al., 2006) and added to a juice could be beneficial (Anon, 2007). Apha-mangostin, a xanthone, can stimulate apoptosis in leukemia cells in vitro (Matsumoto et al., 2004). The preliminary nature of this research means that no definite conclusions can be drawn about possible health benefits for humans eating mangosteen.

1.2

Fruit development and postharvest physiology

1.2.1 Fruit growth, development and maturation At fruit set, fruit shape is almost spherical, with fruit length and width being almost equal and remaining so throughout the fruit growth (Fig. 1.1). Width and length increase slowly during the first two weeks after flowering then increase rapidly up to week 5 and more slowly thereafter. Fresh weight showed a similar pattern of growth, slow during the first two weeks and rapidly increasing. Aril fresh weight increased steadily from week 2 until the end of week 12 when it was 29% of the whole fruit (Wanichkul and Kosiyachinda, 1979a). Surprisingly, pericarp thickness

Fig. 1.1 Changes in length (●), width ({), fresh weight (∆), pericarp thickness (▲) and soluble solids (■) content in aril () of mangosteen fruit during growth and development (Wanichkul and Kosiyachinda, 1979a).



5

changed only slightly between weeks 2 and 12. The data also suggested that growth was mainly expansion rather than cell division after week 2. Mangosteen fruit take about 12 weeks from fruit set to maturity that can vary about one week (Wanichkul and Kosiyachinda, 1979b). This small variation in maturation time is not commercially significant as growers can harvest fruit at a range of maturities. Fruit can be harvested as early as Stage 1 when fruit are light greenish-yellow with 5–10% scattered pink spots that ripen to acceptable eating quality at room temperature. The earlier Stage 0, when the fruit are yellowish-white or yellowish-white with light-green, are also considered mature though the aril eating quality is inferior to fruit harvested at Stage 1 and later (Palapol et al., 2009a). 1.2.2 Respiration, ethylene production and ripening Ripening fruit exhibits a respiratory climacteric pattern (Noichinda, 1992; Piriyavinit, 2008). The respiratory rate of fruit harvested at Stage 0 and ripened at 25 °C is about 10 ml/kg-h rising to about 30 ml/kg-h at the climacteric peak on day 4 and then falls to about 18 ml/kg-ml on day 7 (Fig. 1.2). Stage 0 fruit treated with exogenous ethylene treatment have an earlier climacteric respiratory rise. The higher the concentration of ethylene applied, the sooner the climacteric respiration occurs. The respiratory peak of Stage 0 fruit occurs on day 4 and when treated with 1, 10 and 100 uL/L ethylene on days 2.6, 2 and 1.5 with respiration rate at 26, 30, 31 and 32.5 ml/kg-h, respectively. Mechanical impact also increases the respiration rate of the fruit, the greater the impact the greater respiratory rate increases (Noichinda, 1992).

Fig. 1.2

Respiration (∆), ethylene production () and internal concentrations of ethylene (●) in mangosteen fruit harvested at Stage 0 (Noichinda, 1992).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

6 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Ethylene production during ripening is delayed compared to the rise in respiration (Fig. 1.2). The rise in ethylene begins to increase after day 4 with the peak occurring after the respiratory peak on day 6.5, and then declines. The initial rate of ethylene production on day 1 for Stage 0 fruit is about 2 ul/kg-h and at the maximum about 14 ul/kg-h. The internal ethylene concentration at Stage 0 on day 1 is about 0.75 ppm, increasing to 2.5 ppm on day 2.5 and rapidly increases to a maximum of about 19 ppm by day 6 (Noichinda, 1992). The increase in ethylene production by whole fruit and the aril parallels a similar increase in 1-aminocyclopropane-1-carboxylic acid oxidase (ACO) activity by the fruit aril. The aril ACO activity largely explains the ethylene production data, while possible additional 1-aminocyclopropane-1-carboxylic acid synthase (ACS) activity occurs in the pericarp. Fruit stored at 15 °C showed an ethylene production peak on day 1, which is a few days earlier than the maximum found in fruit stored at 25 °C. The rapid appearance of the ethylene peak in fruit stored at 15 °C is likely associated with chilling injury. As the storage duration at 15 °C increases, the changes in ethylene production, 1-aminocyclopropane-1-carboxylic acid (ACC) levels, and the activities of ACS and ACO occur later than in fruit held at 25 °C. The pericarp of fruit stored at 15 °C and treated with 1-MCP have reduced activity of both ACS and ACO (Piriyavinit, 2008). Pericarp color change is coincident with the changes in respiration and ethylene production (Noichinda, 1992). The climacteric rise starts on day 2 as the fruit turns from to a light-greenish yellow with 51–100% scattered pink spots (Stage 2) (see Plate I in the colour section between pages 238 and 239). Pericarp color develops rapidly from Stage 2 to Stage 3 (reddish-pink), 4 (red to reddish-purple), 5 (dark purple) and 6 (purple black) within five or six days, depending on temperature. Fruit firmness also sharply decreases when fruit turns reddish-pink on day 3. The TSS: TA ratio and eating quality of fruit ripened to Stage 3 are not significantly different from fruit ripened to Stages 5 and 6. Consumers prefer to eat fruit ripened to Stage 5 or 6 as the fruit pericarp of Stage 4 fruit is still firm and is difficult to remove by hand (Palapol et al., 2009a). 1.2.3 Color development The pericarp color development occurs both on and off the tree. Tongdee and Suwanagul (1989) developed a skin color index scale for mangosteen maturity that is divided into 6 Stages (see Plate I in the colour section). Stage 0 fruit are yellowish white or yellowish white with light green, changing to light greenishyellow with 5–50% scattered pink spots at Stage 1. When the fruit are light greenish-yellow with 51–100% scattered pink spots is Stage 2, to when the spots are not as distinct as in Stage 2 or reddish-pink is Stage 3. Later stages are when red to reddish-purple (Stage 4), dark purple (Stage 5) and purple-black (Stage 6). Fruit harvested at Stage 0 develop skin color the same as fruit ripened on tree at Stage 6. Fruit when harvested at Stage 1, 2, 3, 4 and 5 reach Stage 6 in 6, 5, 4, 3, 2 and 1 days at 25 °C, respectively (Palapol et al., 2009a). Ratanamarno (1998) reported that mangosteen fruit at Stage 1 when stored at low temperatures (15 °C)



7

changed to Stage 6 later than fruit stored at 35 °C and fruit stored at room temperature (30 °C). After transferring fruit stored at 15 °C to 25 °C, the red coloration (Hue value) and anthocyanin content increased rapidly and the increase correlated closely with an increase in ethylene production (Palapol et al., 2009a). Color development in mangosteen pericarp is closely correlated with the increase total anthocyanins (Fig. 1.3). The rapid increase in anthocyanin suggests that the precursors are readily available for conversion to cyanidins. No other pigments appear to contribute to skin color.

Fig. 1.3 (a) Cross section of mangosteen pericarp showing outer pericarp (OP) and inner pericarp (IP). The bar denotes 2 mm. (b) Hue values (▲) of skin color and total anthocyanin contents of inner (■) and outer () mangosteen pericarp during color development from light greenish yellow with 5% scattered pink spots to purple black (Stages 1–6) (Palapol et al., 2009a).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

8 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


The increase in total anthocyanin contents of the inner pericarp tissue follows the same trend as the outer pericarp though with a lower Hue value and total anthocyanin content. Hue value is a good objective measure of fruit maturity (Palapol et al., 2009a). The anthocyanins in the outer pericarp have been separated and identified by HPLC/MS. The five compounds reported are cyanidin-sophoroside, cyanidinglucoside, cyanidin-glucoside-pentoside, cyanidin-glucoside-X, cyanidin-X2 and cyanidin-X, where X denotes an unidentified residue of m/z 190. The 190 mass does not correspond to any common sugar residue. Cyanidin-3-sophoroside and cyanidin-3-glucoside are the major compounds and the only ones that increased with fruit color development (Fig. 1.4). The anthocyanin biosynthesis pathway has several key steps. The mangosteen anthocyanin biosynthesis genes GmPAL to G23mUFGT have been completely characterized (Palapol et al., 2009b). GmPAL to G23mUFGT all belong to multigene families and show sequence similarity to anthocyanin related genes in many other plants including several fruit. The transcript levels of the three mangosteen MYBs, GmMYB1, GmMYB7 and GmMYB10, increased markedly with onset of red coloration both on-tree and after harvest (Fig. 1.5). GmMYB10 is the most

Fig. 1.4 Anthocyanin profiles in outer pericarp of mangosteen fruit harvested at Stage 1 to 6 (light greenish yellow with 5% scattered pink spots to purple black) during color development. Peak identity was as follows: (1) cyaniding-sophoroside, (2) cyanidingglucosider-pentoside, (3) cyanidin-glucoside and cyanin-glucoside-X (overlapping peak), (4) cyaniding-X2, and (5) cyaniding-X. X denotes a residue of m/z 190 which has not been identified (Palapol et al., 2009a).



9

Fig. 1.5 Transient activation of the mangosteen and Arabidopsis DFR promoter by GmMYBs, AtPAPl, and AtbHLH2 transcription factors. All TFs were co-infiltrated with DFR-Luc promoter in transient tobacco transformation assays. The dual luciferase (LUC) to 35S Renilla (REN), where an increase in activity equates to an increase in LUC relative to REN (Hellens et al., 2005). Error bars are the means ± SE for four replicate reactions (Palapol et al., 2009a).

up-regulated of the GmMYB transcription factors (299-fold on the tree and 501-fold postharvest fruit at Stage 5 – (dark purple)) and declines at Stage 6 (black purple) (Fig. 1.5). This expression pattern is similar to that of MdMYB10 in apple (Espley et al., 2007) and VvMYBPA1 in grape berry skins (Bogs et al., 2007). The expression patterns suggest that GmMYB10 is a potential candidate to regulate anthocyanin biosynthesis in mangosteen fruit. The expression pattern of all anthocyanin biosynthesis genes correlated with that of GmMYB10, in expression changes and with onset of color development, and declines in synthesis at the final stages. Mangosteen fruit color changes correlate well with ethylene production. Treatment with the ethylene receptor inhibitor 1-MCP delays the increase in Hue value (red), ethylene production and anthocyanin accumulation. In both 1-MCP and ethylene plus1-MCP treatments, 1-MCP down-regulates the expression of GmMYB genes, especially GmMYB10, and the anthocyanin biosynthetic genes. This correlative data gives strong support to the conclusion that ethylene and the expression of the GmMYB10 transcription factors closely control anthocyanin biosynthesis in mangosteen (Palapol et al., 2009b). Direct data is needed to show that ethylene directly regulates GmMYB10 and all anthocyanin biosynthesis genes at the transcription level. Though 1-MCP delays ethylene production, exogenous ethylene does not induce ethylene and anthocyanin production (Piriyavinit, 2008; Palapol et al., 2009b).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

10 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Ethylene application also does not increase the expression anthocyanin biosynthetic and MYB transcription genes (Palapol et al., 2009b). Mangosteen fruit stored at 15 °C developed fruit color more slowly than the fruit stored at 25 °C (Palapol, 2009a). Storage of fruit at 15 °C, besides having delayed color development and ethylene production, inhibits the transcript levels of all anthocyanin biosynthetic genes that increased in abundance when transferred to 25 °C (Palapol et al., 2009b). Maybe the failure to see an ethylene response is because ethylene sensitivity is changing (increasing) during ripening. 1.2.4 Softening Pericarp firmness declines sharply from Stage 1 at 779.3 to 46.5 N at Stage 6 (Palapol et al., 2009a). The softening of the pericarp and also the aril parallels fruit ripening. As ripening starts, the fruit pericarp changes from uniform green to the development of red spots while the aril remains firm and connected to the pericarp. As the fruit ripens further to the pericarp having dark purple at an overripe stage, the aril becomes soft and juicy, and easily separates from the pericarp. Aril firmness declines slowly at room temperature between day 0 and day 4, and then shows a sharp change from day 4 to day 10 as the fruit develop full pericarp purple color. At 13 °C, aril firmness changes little over the 10 days of ripening. The water soluble pectin content in aril increased more rapidly at room temperature than when held at 13 °C. Aril insoluble pectin content declines during ripening with a sharp change between day 4 and day 8, while both pectin methylesterase and polygalacturonase activities increase more rapidly when held at room temperature than at 13 °C. This data suggest that changes in cell wall solubilization may be responsible for aril softening during ripening (Noichinda et al., 2007). The difference in firmness of mangosteen aril held at different temperatures reflects a correlation between water soluble pectin and activities of pectin methylesterase and polygalacturonase. However, high pectin methylesterase activity is detected at harvest (day 0) while polygalacturonase activity increases after harvest when held at both temperatures (Noichinda et al., 2007). This result suggests that pectin methylesterase (PME) may not have access to pectin during early fruit ripening and polygaloturonase (PG) does not increase until later when cell wall changes allow esterase activity and provision for de-esterified substrate for PG.

1.3

Maturity and quality components

Fruit color is the major criterion used to judge maturity and for grading of mangosteen fruit. The fruit are usually harvested at different stages according to color, from light greenish-yellow with scattered pink spots to dark purple. After harvest, the purple color continues to develop very quickly. For high fruit quality, the minimum harvest color stage is that of a fruit with distinct irregular, pink-red spots over the whole pericarp surface. If fruit are harvested with a light greenishyellow with scattered pink spots, the fruit do not ripen to full flavor (Tongdee and Suwanagul, 1989; Paull and Ketsa, 2004).



11

Table 1.2 Time, quality and sensory evaluation of mangosteen fruit harvested at Stage 1 (A) and allowed to ripen at 25 °C, or harvested at the six different maturity stages and measurements made when the fruit reached Stage 6 (B). Fruit Time Firmness (N) a*/b* ratio stage (d) A B A B

% SSC A

B

A

B

A

B

B

1 2 3 4 5 6

15.2c 15.3bc 16.3ab 16.6a 17.1a 17.2a

17.2 17.3 17.5 17.9 17.5 17.4

0.77bc 0.78b 0.84a 0.80ab 0.79b 0.73c

0.81 0.81 0.80 0.78 0.75 0.74

19.8bc 19.6bc 19.3c 20.8bc 21.7ab 23.7a

21.2b 21.3b 21.9ab 23.0ab 23.5a 23.7a

4.2 3.7 3.8 4.0 3.7 4.1

0 1 2 3 5 9

6.66a 5.30b 4.91c 4.59d 4.20e 3.84f

44.8 0.03b 43.6 0.44b 46.0 1.16b 42.9 2.28b 45.0 3.71b 47.9 16.69a

11.06b 12.09ab 12.10ab 10.04b 9.63b 13.95a

% TA

SSC/TA

Sensory

Source: Palapol et al. (2009a). Notes: The firmness values in column A are log (In) transformed data, with original data from Stage 1 to 6, being 779.3, 201.3, 136.0, 98.4, 66.5 and 46.5 N, respectively. Means within any column followed by the same letter are not significantly different (P > 0.05).

Postharvest fruit quality is generally dependent on the stage of maturity at harvest. Fruit harvested at Stages 1 to 6 and allowed to ripen to Stage 6 showed no significant differences in fruit quality or sensory characteristics (Table 1.2). This suggests that ripening had already initiated before harvest of Stage 1 fruit but not Stage 0. This ripening habit provides considerable harvest flexibility allowing the Thai grower to harvest fruit for export at Stage 1 (light greenish yellow with 5% scattered pink spots) that develop full flavor and have a slightly longer shelf-life over fruit harvested at later stages. The Malaysian harvest guideline for mangosteen export is similar to Thailand, being reddish-yellow with patches of red (Osman and Milan, 2006).

1.4

Preharvest factors affecting fruit quality

Like other fruit crops, fruit quality depends on many preharvest factors. However, only a few preharvest factors are considered to have significant impact on fruit quality after harvest. 1.4.1 Location Orchard on soils with poor drainage or a low slope favors the occurrence of translucent aril and ‘gamboges’ (Laywisadkul, 1994; Chutimunthakun, 2001). ‘Gamboges’ is a physiological disorder that leads to the occurrence of yellow latex exudate on the pericarp surface and occasionally the aril. Therefore, growers seek land for growing mangosteen trees that has good drainage and also higher slope. Over watering of trees can also result in translucent aril and ‘gamboge’. 1.4.2 Fertilizer Application of complete chemical fertilizers plus calcium and zinc, during fruit growth plays an important role in ensuring high yield and quality of mangosteen


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

12 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


fruit. Good fertilization practice can also reduce the occurrence of translucent aril and gamboge. Fertilizer is applied at least three times during vegetative growth, again pre-flowering and lastly during fruit development (Sdoodee et al., 2006). 1.4.3 Pests Thrips are considered to be the most important insect pests. They feed on young fruit with the scars becoming obvious at fruit maturation concomitant with the change from green to reddish and purple (see Plate II(A) in the colour section). Typical symptoms include silvering of fruit skin, pale yellow/brown discoloration, elongated and patchy scars or hardened scars, and ‘alligator skin’ like scars that may cover the entire fruit surface (see Plate II(A) in the colour section). Heavily scarred skin can sometimes prevent normal fruit growth (Affandi and Emilda, 2009). Fruit from outside the canopy are more likely to have thrips damage than those inside the canopy (Sdoodee et al., 2006). According to Affandi and Emilda (2009), several thrips control methods used for other fruit can be adopted for mangosteen. For example, botanical pesticides such as ‘Sabadilla’ derived from the seeds of Schoenocaulon officinale, as well as biopesticides such as abamectin and spinosad can be used (Hoddle et al., 2002; Wee et al., 1999; Faber et al., 2000; Astridge and Fay, 2006). Other cultural control techniques used to reduce thrips population are composted organic yard waste, composted mulch applied under plant canopy, and augmentation of predatory thrips Franklinothrips orizabensis, F. vespiformis and Leptothrips mc-cornnelli (Hoddle et al., 2002; Wee et al., 1999). The University of California Statewide Integrated Pest Management Program (2006) suggested integrated pest management (IPM) for controlling thrips. Such a plan would include the optimal use of natural enemies, removing all weeds under the canopy to eradicate alternative hosts, regular pruning of infected trees, use of a fluorescent yellow sticky trap, and application of reflective mulch to disturb host plant orientation of the thrips. Use of fluorescent yellow sticky traps is limited for monitoring the population of thrips due to the cost of adhesive glues such as the one called tangle foot (Chu et al., 2006). Chemical insecticide should be used as a last alternative. If necessary, monochrotophos, methiocarb or carbosulfan can be applied in mangosteen orchards to control thrips. After harvest, thrip-damaged fruit can be coated with carnauba or shellac waxes that results in a better appearance. The appearance of damaged fruit after coating resembles that of normal fruit (Phongsopa et al., 1994). This practice is used by Thai exporters.

1.5

Postharvest handling factors affecting quality

1.5.1 Temperature management The rapid ripening of mangosteen fruit at ambient temperatures is accompanied by shriveling of the calyx. The pericarp color changes and calyx shriveling result



13

in the loss of marketability within a few days. Temperature management is essential to prolong shelf life. Storage of fruit at low temperature is commonly used to maintain quality and extend shelf life, because low temperature reduces the rate of respiration, ethylene production and other metabolic processes (Wills et al., 1998). Mangosteen can be stored at 12–13 °C and have a shelf life of about three weeks with acceptable eating quality (Choehom et al., 2003). Storage at 4 or 8 °C can lead to significant pericarp hardening, although the aril may still be acceptable after 44 days (Augustin and Azudin, 1986). When stored at 4 to 8 °C, surface coatings can reduce weight loss, prevent calyx wilting and assist in maintaining appearance. Dipping the calyx and the stem end of the fruit in various concentrations of hormones (e.g., BA, GA3 and NAA) before storage at 12 °C also delays shriveling and extends the storage period (Choehom et al., 2003). 1.5.2 Physical damage The surface of the mangosteen pericarp consists of a continuous epidermis layer covered by cuticular wax with lenticels. The epidermis covers a thick layer of parenchyma tissue and inner strip of sclereids (Phongsopa et al., 1994). The spongy pericarp serves as an excellent packing material to protect the soft aril during transportation. However, mechanical injury due to compression or impact injury, common in handling, results in some pericarp hardening (Tongdee and Sawanagul, 1989; Ketsa and Koolpluksee, 1992). Mechanical injury induced firmness increase occurs within three hours of the injury to both reddish and dark purple fruit. The firmness increase in injured dark purple fruit occurs more rapidly than that to reddish brown fruit. Regardless of fruit maturity, holding fruit in a nitrogen atmosphere after injury significantly inhibits the firmness increase compared to fruit held in air (Bunsiri et al., 2003). The firmness that develops is directly related to the height from which the fruit are dropped, the higher the drop height, the greater the firmness that occurs in the damaged pericarp (Tongdee and Sawanagul, 1989; Bunsiri et al., 2003). Thrips caused the greatest percentage of fruit surface scarring (46.7%) preharvest, while pericarp hardening is a harvest and postharvest handling problem which at the consumers’ home can affect 33% of the fruit. Pushpariksha (2008) summarized the impact on postharvest quality of mechanical injury as pericarp cracking, surface scarring, pericarp hardening, aril translucency, gamboge and decay. 1.5.3 Water loss The thrip-damaged epidermis at anthesis leads to the formation of a periderm layer as the fruit develops. These thrip-damaged fruits have a higher weight loss rate of 2.23% per day after harvest, compared to 1.63% per day for undamaged fruit (Phongsopa et al., 1994). Weight loss also induces pericarp hardening similar to the pericarp hardening associated with chilling injury (Dangcham et al., 2008), whereas impact induces pericarp hardening only in the damaged area (Bunsiri et al., 2003). Calyx and stem end shrivel are related to weight loss and results in


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

14 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


poor postharvest appearance (Choehom et al., 2003). When stored at 13 °C (89–90% RH), weight loss of up to 6.8% can occur in 18 days, while coated fruit lose about 4% (Noichinda, 1992). Wax application reduces weight loss during storage at both ambient and low temperatures (Noichinda, 1992; Phongsopa et al., 1994; Choehom et al., 2003). Plant growth regulators such as BA, GA3 and NAA applied in combination or alone prior to storage, delays calyx and stem end shriveling (Choehom et al., 2003). 1.5.4 Atmosphere and coatings The recommended controlled atmosphere storage conditions are 13 °C, with 10–15% carbon dioxide and 2% oxygen (Pakkasarn, 1997). Aryucharoen (2004) confirmed the 13 °C storage temperature but recommended 3–5% carbon dioxide and 2% oxygen. For maximum storage life Wichitrananon (2001) found that fruit stored at 13 °C are still acceptable after 42 days when stored in 0% carbon dioxide and 0% oxygen. Fruit wrapped with polyethylene and polyvinyl chloride films and stored at 13 °C had almost twice the storage life of fruit stored without wraps (Pranamornkij, 1997). Ratanatraiphop (2003) reported that fruit coated with Stra-fresh #7055, glucomanan, chitosan and methylecellulose reduced weight loss, softening and pericarp color change, respiration rate and ethylene production during storage at 15 °C and had a storage life of 28 to 32 days, while the control fruit had storage life of 24 days. Similarly, Chanloy (2006) reported that fruit coated with 1% methylcellulose and 1000 mg/l GA, placed into polyethylene bags with 3% carbon dioxide or without polyethylene bags and stored at 13 °C had storage life of 32 and 28 days, respectively, compared to 24 days for the control.

1.6

Physiological disorders

1.6.1 Chilling injury The symptoms of CI in mangosteen fruit included darkening and hardening of the pericarp (Kader, 2007). These symptoms occur when fruit are moved to higher temperatures following storage at less than 10 °C for longer than 15 days or more than five days at 5 °C. Decay susceptibility also increases at chilling temperatures. The aril may still have acceptable quality after 44 days at 4 to 8 °C (Augustin and Azudin, 1986). Pericarp hardening is the most common symptom of CI in mangostee fruit (Uthairatanakij and Ketsa, 1996; Ponrod, 2002; Choehom et al., 2003). Fruit stored at 6 °C had greater pericarp firmness than those stored at 12 °C and the more mature (reddish purple) fruit had greater firmness than less mature (reddish brown) fruit. The unacceptable CI symptom of pericarp hardening of mangosteen fruit is found within 5, 10 and 20 days after storage at 3, 6 and 12 °C, respectively (Choehom et al., 2003). The pericarp hardening is more pronounced after storage at 6 °C for nine days and then transferred to room temperature (29.5 °C) for three days.



15

The lower the storage temperature the sooner pericarp hardening develops (Uthairatanakij, 1995; Uthairatanakij and Ketsa, 1996; Kosiyachinda, 1986; Dangcham et al., 2008). Pericarp hardening is associated with an increase in lignin content (Uthairatanakij and Ketsa, 1996; Dangcham et al., 2007). A negative correlation exists between total free phenolics and lignin contents, and pericarp firmness and is similar to that found in mangosteen fruit after impact (Ketsa and Atantee, 1998; Bunsiri et al., 2003). Lignin accumulation is also found in cherimoya fruit after prolonged storage at chilling temperature (Maldonado et al., 2002). Cai et al. (2006) reported that the firmness of loquat fruit increases during postharvest ripening and is positively correlated with lignin accumulation in the flesh tissue. Lignification is a process that also occurs in secondary wall formation and under special conditions such as wounding, pathogen attack or fungal elicitor treatment (Vance et al., 1980; Ride, 1983). The degree of mangosteen pericarp hardening due to CI is related to the activity of enzymes involved in phenolic metabolism. The decrease in phenolic occurs concomitantly with the increased firmness and lignin contents in mangosteen pericarp stored at low temperature and suggests that phenolics may be incorporated into lignin. The resulting incorporation leads to an increase in pericarp lignin contents and hardening. The turnover of phenolics in mangosteen fruit subject to chilling temperature may be more rapid than their synthesis resulting in decline in phenolics (Dangcham et al., 2008). Total free phenolics declined and lignin contents increased more rapidly in the more mature reddish purple fruit than in reddish brown fruit and was greater in fruit stored at lower temperatures (Dangcham et al., 2007). Total free phenolics declines throughout storage whereas phenylalanine ammonia lyase (PAL) activity slightly increases only at the end of storage. This result suggests that phenolics are being incorporated into lignin at the start of storage and that CI induced an increase in PAL. The increase in pericarp firmness following storage at 6 °C is about 16-fold, while the lignin contents increase about 1.75-fold. This difference in increase suggests that the increase in lignin contents alone may not fully explain the rapid increase in pericarp firmness after low temperature storage. Lignins are found in both the free and bound state in plant cell walls (Morrison, 1974) and participate in cross-linking cell wall polysaccharides (Kondo et al., 1990; Lam et al., 1994; Ralph et al., 1995). Ester linkage occurs between glycosyluronic groups and the lignin hydroxyl groups, and ether linkage between polysaccharides and lignins (Iiyama et al., 1994; Lawoko, 2005). In addition, linkages are formed between lignin and proteins (Keller et al., 1988; Whetten et al., 1998). In plant tissues, lignin synthesis is correlated with activities of many enzymes such as PAL, cinnamyl alcohol dehydrogenase (CAD) and peroxidase (POD) (Lewis and Yamamoto, 1990). The increased firmness of loquat fruit (Cai et al., 2006) and bamboo shoot (Luo et al., 2007) is a consequence of lignification, and associated with an increase of PAL, CAD and POD activities. PAL is an important enzyme required for synthesis of phenolic compounds that catalyses the conversion of L-phenylalanine to trans-cinnamic acid, a precursor of various phenylpropanoids,


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

16 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


such as lignins, coumarins and flavonoids (Hahlbrock and Scheel, 1989; Lewis and Yamamoto, 1990; Schuster and Retey, 1995). Chilling temperatures can generally stimulate the biosynthesis of phenolic compounds by enhancing PAL activity (Aquino-Bolaños et al., 2000). PAL activity has been reported to be involved with CI development in many plants such as ‘Fortune’ mandarin, pineapple and ‘Navelate’ oranges (Martínez-Téllez and Lafuente, 1993; SanchezBallesta et al., 2000; Zhou et al., 2003; Sala et al., 2005). PAL activity of fresh-cut asparagus also increased in the first 10 days, before decreasing during the latter period of storage concomitant with lignin content (An et al., 2007). These results are similar to the findings in mangosteen fruit stored at 6 °C. PAL mRNA accumulates at start of storage at 6 °C and then decreases. The increase in mangosteen PAL gene expression at low temperature occurs prior to the increased PAL activity, lignin accumulation and pericarp hardening (Dangcham et al., 2008). The accumulation of PAL mRNA initially without an increase in PAL activity and phenolic levels, might be the result of low temperature stress, while the accumulation when fruit are transferred to room temperature was concomitant with the pericarp hardening (Dangcham et al., 2008). Similarly an increase in LgPOD activity occurs in mangosteen fruit stored at 6 °C then transferred to room temperature. This increase in LgPOD is concomitant with an increase in POD activity, lignin content and pericarp hardening (Dangcham et al., 2008). Low O2 treatment applied during and after low temperature storage of mangosteen fruit does not reduce pericarp hardening. Pericarp firmness and lignin contents still increased under low O2 during storage at 6 °C and at room temperature after transfer from 6 °C. This contrasted previous reports that mangosteen pericarp damaged after impact and fruit stored at low temperature under N2 is not as firm, and had lower lignin contents and more total phenolics than damaged pericarp held in the air (Uthairatanakij, 1995; Ketsa and Atantee, 1998; Bunsiri et al., 2003). Low temperature may exert a greater inhibitory effect on many enzymes involved in lignin synthesis, while a low O2 level only affects the last lignifications step of monolignol polymerization (Imberty et al., 1985). We confirmed this by applying low O2 treatment to stored mangosteen fruit after transfer to room temperature, and this had a greater effect on pericarp hardening than low O2 treatment applied only during low temperature storage. This suggests that low temperature may delay biochemical reactions involved in PAL and POD activities and the metabolic turnover of phenolic would be slower. Upon transfer to room temperature, all biochemical reactions involved in lignin synthesis become more rapid and have a greater O2 requirement. POD activity in mangosteen pericarp is low when stored at 6 °C under low O2 level, but its activity increased after transfer to room temperature. Low O2 levels occur in fruit that have received a wax coating (Peng and Jiang, 2003; Dong et al., 2004) or in modified atmosphere packaging (Shen et al., 2006) and they also have reduced POD activity. POD activity in fruit pericarp after transfer from 6 °C to room temperature under low O2 level is low, while in normal air a small increase occurs. However, low O2 is also found to have no effect on POD activity at the



17

end of storage. This confirms the previous idea that low temperature has a greater impact on biochemical changes than low O2 level. Moreover, POD activity in mangosteen fruit stored at 6 °C under low O2 and transferred to room temperature is high while lignin content is low. In contrast, POD activity in mangosteen fruit stored at 6 °C under normal air is low while lignin content is higher after transfer to room temperature. This indicated that O2 is required for the oxidation in the final step of polymerization for lignin synthesis in mangosteen pericarp (Bunsiri et al., 2003a). CAD activity in fruit pericarp does not change during low temperature storage or after transfer to room temperature while pericarp firmness increased. This suggested that CAD may not be a rate-limiting step in lignin synthesis in mangosteen fruit pericarp during low temperature storage. CAD activity in damaged pericarp of mangosteen fruit after impact increases 15 min after impact, concomitant with an increase in lignin synthesis, and CAD activity increases much more than PAL and POD activities (Bunsiri, 2003). The increase in lignin contents in loquat fruit (Cai et al., 2006), copper stress treated Panax ginseng root (Ali et al., 2006) and bamboo shoot (Luo et al., 2007) is associated with CAD activity. Furthermore, CAD activity in transgenic plants (CAD antisense) such as tobacco (Halpin et al., 1994) and poplars (Baucher et al., 1996) is reduced, but the amount of lignin does not change. Thus, CAD might not be related to lignin synthesis and pericarp hardening of mangosteen fruit stored at low temperatures. 1.6.2 Pericarp hardening after impact The firmness increase in mangosteen pericarp following impact is well recognized (Tongdee and Suwanagul, 1989; Ketsa and Atantee, 1998; Uthairatakij and Ketsa, 1996). The increase in damaged pericarp firmness is more rapid in more mature fruit, fruit subjected to a greater drop height, and when oxygen is present than in less mature fruit, lower drop height and low oxygen level. The increased firmness of damaged pericarp occurred concomitantly with an increase of lignin content (Fig. 1.6). Lignin content in damaged pericarp is less under nitrogen atmosphere than under oxygen, as the final step of lignin biosynthesis requires oxygen for the polymerization of monomeric lignin precursors catalyzed by peroxidase. The increase of lignin in damaged pericarp after impact is supported histochemical microscopy and consistent with the increase in thioglycolic lignin (Bunsiri et al., 2003b). Following impact, the firmness of damaged pericarp increased rapidly, concomitantly with an increase in lignin content. The increase in lignin content in damaged pericarp is substantial when compared to the increases in firmness of damaged pericarp, as the basal lignin content in undamaged pericarp is initially high. The increase in firmness of damaged pericarp three hours after impact is 215 to 385%, while the increase in lignin content of damaged pericarp is 150 to 288%, dependent upon fruit maturity and drop height. Lignin-carbohydrate complex (LCC) increase in damaged pericarp of mangosteen fruit and the increase in lignin and carbohydrate contents is greater than that of protein content. The increase in


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

18 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Fig. 1.6 Firmness (a) and lignin content (b) of undamaged (■) and damaged () pericarp of dark purple mangosteen fruit after physical impact at a drop height of 100 cm. Fruit were held at room temperature (29 °C) before impact (t = 0) or 15, 30, 60, 120 and 180 min after impact. Data are means ± SD of six replicate fruit (Bunsiri, 2003).

lignin, carbohydrate and protein contents in LCC of damaged pericarp requires oxygen (Whetten and Sederoff, 1995; Bunsiri et al., 2003b). A transient, significant increase is found in the activity of PAL, CAD and POD. The activity of PAL increases about four-fold, that of CAD about eight-fold; and POD activity increases about six-fold within 15 min after mechanical impact. The significant increase in activities is found to occur between 10 and 15 minutes after impact, and a considerable decrease in activities is observed between 15 and 20 minutes after impact (Bunsiri, 2003). The data indicates that mechanical impact induces a concomitant increase in the activities of several enzymes involved at the early (PAL) and late stages (CAD and POD) of lignin synthesis. The rapid increase in the activities of PAL, CAD and POD in the pericarp slightly precedes (15 min) a detectable increase in pericarp lignin levels (Fig. 1.7). The increase in the activity of these and other enzymes might therefore be the cause of the increased lignin levels (Boudet, 2000). The present results are similar



19

Fig. 1.7 Phenylalanine ammonia lyase (a), cinnamylalcohol dehydrogenase (b) and peroxidase (c) activities of undamaged () and damaged (■) pericarp of dark purple mangosteen fruit after physical impact at a drop height of 100 cm. Fruit held at room temperature (29 °C) before impact (t = 0) or 15, 30, 60, 120, 180 min after impact. Data are expressed as units per mg pericarp protein, whereby one unit is defined as the activity to produce 1 μM cinnamic acid within 1 h. Data are means ± SD of six replicate fruit (Bunsiri, 2003).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

20 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


to those found in bamboo shoots, where an increase in firmness after harvest was positively correlated with an increase of the contents of lignin and cellulose. The lignin accumulation in the bamboo shoot is positively correlated with an increase in the activities of PAL, CAD and POD (Luo et al., 2007). The rapidity of the increase in enzyme activity (four- to eight-fold increase) in as little as 15 minutes after the mechanical impact indicates that de novo synthesis of the proteins is unlikely. A detectable increase in protein synthesis by an outside stimulus, if involving the activation of genes, usually requires at least one hour (Alberts et al., 2008). The present data suggest that the mechanical impact leads to activation of existing proteins. If so, it is at present unclear how the impact would exert such a post-translational effect. 1.6.3 Translucent aril Translucent aril is a major physiological disorder that develops in the field before harvest. Symptoms are internal and include flesh changes from white to translucent (see Plate II(B) in the colour section) and textural changes from soft to firm and crisp (Pankasemsuk et al., 1996). Heavy and continuous rains during fruit growth and ripening favor translucency development in certain locations where the drainage is poor. The greater the rainfall that occurs at harvest times, the higher the incidence of fruit with translucent arils. The incidence of translucent aril is assumed to be caused by excess water uptake during fruit growth and development. The excess water may penetrate fruit rind, subsequently causing translucent aril (Sdoodee and Limpun-Udom, 2002). Orchards with greater slopes and better drainage have a lower incidence of fruit with translucent aril. Orchards with shallow water tables (1 to 50 cm) also have higher incidence of translucent aril than orchards with deeper water tables (101 to 200 cm) (Chanaweerawan, 2001). Similarly, when mangosteen are irrigated (75 mm per day) for five days during the harvesting, more fruit have translucent aril than trees with normal irrigation (15 to 20 mm per day) (Laywisadkul, 1994). The crucial period when excess rainfall or irrigation can lead to greater incidence of fruit with translucent aril is from about nine weeks after blooming (Chutimunthakun, 2001). The aril that is translucent is firmer than normal, and the translucent aril tissue has twice the amount of damaged protoplasts than normal aril. This is assumed to be due to excessive water uptake causing higher turgor pressure resulting in disruption of plasma membrane and cell death. Subsequently water and solutes leak out from protoplasts to the intercellular space leading to translucent aril (Luckanatinvong, 1996; Dangcham, 2000). Translucent aril has lower alcohol insoluble solids, soluble pectin and CDTA soluble pectin and higher Na2CO3 soluble pectin than normal aril (Dangcham, 2000). The translucent aril also contains higher ratio of K : Ca, K : Mg, and K : Ca+Mg than normal aril (Pludbuntong, 2007). Accumulation of calcium in light-exposed fruit is higher than shaded fruit and the incidence of translucent aril is lower in fruit on the top of the canopy that are light-exposed (Chiarawipa, 2002). The pericarp of non-



21

translucent fruit contains higher N, Ca, K, and B contents than fruit with translucent aril (Pechkeo, 2007). Since calcium plays an important role in maintaining cell wall integrity (Helper, 2005), low content of Ca may lead to weaken cell walls of aril that cannot resist the influx of water. Foliar application of calcium chloride and boric acid to mangosteen trees increases the ratio of normal aril to translucent aril fruit (Pechkeo, 2007). Top cutting, soil mulching and foliar application of calcium can also alleviate the incidence of translucent aril (Chiarawipa, 2002), while soil application of complete fertilizers to mangosteen trees prior to full bloom and foliar application of complete fertilizers plus zinc during fruit set can reduce translucency in aril (Jirapat, 2002). 1.6.4 Gamboge Gamboge or gummosis is also a physiological disorder characterized by yellow exudation of gum onto the fruit surface (see Plate II(C) in the colour section). Sometimes yellow gum is also exuded from the inner pericarp into aril surface or between the carpels inside the fruit (see Plate II(C) in the colour section). The aril with the yellow gum tastes bitter, so consumers avoid buying mangosteen fruit with yellow gum on the fruit surface. It is believed that the environmental conditions that cause both translucent aril and gamboge are the same. Heavy and continuous rains during fruit growth and ripening favor gamboge in certain locations where the drainage is poor. However, the evidence that water relations are involved in gamboge is not strong as for aril translucency. An imbalance or deficiency of essential elements in soil and mangosteen tree may also contribute to gamboge (Pechkeo, 2007). Fruit harvested early in the season have a higher incidence of gamboge than fruit harvested late irrespective of the amount of rainfall. Extra irrigation does result in more fruit with gamboge (Laywisadkul, 1994). Even though environmental conditions and nutrient deficiency are believed to be involved in the incidence of gamboges, it is not known how this occurs. Latex in mangosteen fruit is produced by latex cells or laticifer inside the pericarp and exported via laticiferous vessels. Under conditions of the excessive water uptake breakage of laticiferous vessels may occur, which in turn allows yellow gum to leak out from pericarp and this yellow gum moves inward to aril or outwards to the fruit surface. Soil drainage, soil mulching, top pruning and foliar application of calcium, boron and zinc can alleviate gamboge (Chiarawipa, 2002; Jirapat, 2002; Pechkeo, 2007).

1.7

Pathological disorders

Unlike other tropical fruit, pre and postharvest diseases of mangosteen fruit are not a serious problem. This may be due to the pericarps physical and chemical properties. The fruit pericarp is thick and hard, and contain chemicals whose activity can act as antibiotic compounds. Occasionally postharvest diseases are reported for mangosteen fruit such as black aril rot caused by Lasiodiplodia theobromae (Pat.) triffon and Manbl (Botryodiplodia theobromae), white aril rot


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

22 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


caused by Phomopsis sp. (Sacc.) Bnbak and soft aril rot caused by Pestalotia sp. Seaver. Most of these diseases infect the fruit in orchards and it is recommended to periodically spray with an approved fungicide before harvest (Visanthanon, 1999).

1.8

Harvesting practices

Mature fruit at any stage from Stage 1 to Stage 6 can be harvested depending on the market and purpose. Common practice for growers in Thailand is to pick up fruit at Stage 1 (light greenish yellow with 5–50% scattered pink spots) for export markets, Stage 2 (light greenish yellow with 51–100% scattered pink spots) or Stage 3 (reddish pink) for the local and regional markets. The sensory quality of fruit harvested at Stages 1 to 5 and ripened to Stage 6 is similar to fruit harvested at Stage 6 from the tree (Palapol et al., 2009a). Since mangosteen fruit are prone to pericarp hardening after impact, growers harvest carefully to minimize physical damage using baskets made of linen cloth or nylon net connected to bamboo poles to reach mangosteen fruit high in the tree. Fruit are carefully placed into plastic baskets and then taken to a packinghouse or directly to the markets.

1.9

Postharvest operations

1.9.1 Packinghouse practices Fruit in containers are moved from the orchard to a packinghouse or packing station. The containers must be able to protect the fruit against bruising and abrasion, so fruit should not be packed in containers over 30 cm deep otherwise fruit at the bottom will be subject to compression injury resulting in pericarp hardening. Fruit are culled to separate good fruit without skin damage from fruit with skin and calyx blemish, and sorted so that undersize fruit can be sold in local markets. Fruit are graded based on color according to market requirement for export or local use. After grading, yellow gum on the fruit surface is scrapped off with a knife and pressurized air supply is used to blow insects and dirt from underneath the calyx. Fruit for export are graded by weight and the normal range is 70 to 100 g per fruit, while undersized fruit with and without skin blemish are sold at the local markets. Fruit for export are packed individually into partition sections of single-layered corrugated 5 kg cartons or four fruit are packed into individual foam or plastic trays wrapped with PVC film and packed into a master carton. The latter is better at preserving calyx and stem freshness but increases packing costs. 1.9.2 Control of ripening Mangosteen is a climacteric fruit with a respiratory peak that occurs sooner when fruit are treated with ethylene (Noichinda, 1992). Inhibition of ethylene biosynthesis or ethylene action, therefore, may be effective in slowing down a number of ripening



23

processes. A six-hour treatment with 1-MCP delays pericarp color development and aril softening during storage at 25 °C or 15 °C, leading to a longer shelf life (Piriyavinit, 2008). In fruit stored at 25 °C and treated with 1-MCP, the typical pericarp color changes are delayed until about day 6, and the decrease of aril firmness is delayed until day 4. At 15 °C, the pericarp color changes are inhibited until day 15, and the aril firmness only until day 4. Thai exporters have adopted a six-hour 1-MCP fumigation to delay pericarp color change and this provides greater flexibility in handling. Care is needed to avoid high rates of 1-MCP fumigation that can lead to pericarp hardening and fruit that will not be ripened normally. The use of gaseous ethylene and calcium carbide does not stimulate early ripening of mangosteen fruit compared to the control fruit. This suggests that the ripening process has already been induced before Stage 1 (Piriyavinit, 2008) or that the fruit’s sensitivity to ethylene increases during ripening. 1.9.3 Storage recommendation Fruit can be stored at room temperature (28 to 29 °C) for a few days, and their calyx and stem ends will start to become shriveled. The fruit pericarp will also be hardened due to weight loss as the storage time at room temperature is increased. Mangosteen fruit is a tropical fruit which is prone to chilling injury if stored below 10–12 °C (Choehom et al., 2003; Dangcham et al., 2008). This optimum storage temperature of 10–12 °C (85–95% RH) gives a storage life of approximately three weeks with an acceptable aril quality (Choehom, 2003; Noichinda, 1992). Mangosteen fruit can be stored below the optimum temperature for only a few days and must be consumed right after removal from low temperature storage otherwise the fruit pericarp will become hardened due to chilling injury (Dangcham et al., 2008).

1.10

Processing

1.10.1 Fresh-cut Unripe mangosteen fruit are used in the fresh-cut trade and not the ripe stage as used for other fruit. The fresh-cut mangosteen product is crispy with a sweet taste. This product is popular in southern Thailand, one of the main mangosteen growing areas. Mangosteen fruit at Stage 0 (yellowish white or yellowish white with light green) or Stage 1 (light greenish yellow with 5 to 50% scattered pink spots) are chosen and their pericarp is carefully removed from the aril in order to prevent latex from the pericarp contaminating the aril and resulting in aril darkening and a bitter taste. Aril without the pericarp is soaked in lime water solution (calcium hydroxide solution) containing 1% alum + 1% NaCl, or 0.50% citric acid + 0.25% calcium chloride (Kitpipit, 2005) for 30 minutes to prevent browning and softening. Subsequently the aril is washed with clean water, and all arils with blemishes are removed. The whiteness of fresh-cut aril can only be maintained for about five hours and then it changes steadily to an unappealing darker color. Fresh-cut mangosteen is prepared daily to meet demand.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

24 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


1.10.2 Paste Ripe or over-ripe mangosteen fruit are used to make a mangosteen paste. Fruit are cleaned and the pericarp removed. Aril with or without seeds is heated and stirred with medium or low heat. Thirty kilograms of mangosteen fruit make about 1 kilogram of paste, which can be processed into leather or candy. The paste with seeds has a nutty taste. 1.10.3 Juice Mangosteen fruit has a high content of antioxidants which are thought to be beneficial for health and this presumed health benefit has meant that mangosteen juice has become increasingly popular. Aril is boiled (2:3, v/v) and filtered to remove the seeds. Sugar and salt are added to the juice to improve flavor and boiled once more. Since the juice is white, it is not regarded as attractive as the fresh intact mangosteen fruit. Therefore, colorant extracted from mangosteen pericarp is added to the juice to improve juice color to be slightly pink. If too much mangosteen colorant is added, the juice tastes astringent due to tannins in the pericarp. The juice is marketed in metal cans, plastic or glass bottles. 1.10.4 Drying The pericarp of ripe or overripe mangosteen fruit is removed. The aril with seeds whose water content is approximately 70% is dried at less than 80 °C for two hours and at 70 °C for eight hours. Aril and seeds become a homogenous mixture after drying and the water content is reduced to approximately 13%. Dried aril tastes sweet and sour and with seeds will also have a nutty taste because of seed kernel. Ten kilograms of mangosteen fruit yields about 1 kilogram of dried product. Since pericarp of mangosteen fruit is rich in chemicals whose properties can be used as medicine, the pericarp can be dried similarly to the aril and kept for future use. Dried pericarp can be also made into powder and kept for medical use. 1.10.5 Freezing Mangosteen fruit at Stages 4 or 5 can be frozen. Fruit without blemish and defects are cut into halves at the equatorial planet and opened to check if the fruit aril is translucent or has no gamboge. Blemish free fruit are then wrapped individually with plastic tape surrounding the cut area and frozen at −40 °C for 120 minutes. If the fruit had not been cut in halves, it takes ~140 minutes to freeze. The frozen fruit must be stored at −20 °C. Sophanodora and Sripongpunkul (1990) reported that arils dipped in the solution containing 0.25% calcium chloride and 0.50% citric acid for one minute before freezing at −30 °C for 220 minutes retained their natural color and were accepted by consumers. 1.10.6 Freeze-dried and other products After the pericarp is removed, the aril can be freeze-dried in a three step process. First, the aril is frozen at −40 to −20 °C for 2 to 6 hours, then held under vacuum



25

(10 mtorr) at −20 to 10 °C for 5 to 10 hours. Thirdly, aril is frozen at −10 to 0 °C for 2 to 6 hours. Freeze-dried mangosteen is sealed in aluminum foil-lined plastic bags to prevent moisture absorption and light exposure. The freeze dried product has a shelf life at room temperature of at least six months. Mangosteen fruit can be processed into other products such as wine, vinegar, ice cream, yoghurt and cosmetics.

1.11

Conclusions

Mangosteen fruit is named the Queen of Tropical Fruit due to its attractive appearance and taste. Nowadays mangosteen fruit are consumed worldwide, either fresh or processed, because they have amazing compounds whose properties have a great potential benefit to human health. However, fresh mangosteen fruit are perishable and sensitive to chilling injury and a barrier to marketing. Preharvest fruit disorders for which solutions are not available can lead to significant harvest and postharvest loss.

1.12 Acknowledgements The research cited in this chapter was made possible, in part through financial support from the Thailand Research Fund (TRF) and the Commission on Higher Education, Ministry of Education and Kasetsart University Research and Development Institute (KURDI).

1.13

References

Affandi and Emilda D (2009), ‘Mangosteen thrips: collection, identification and control’, J Fruit Ornamental Plant Res, 17, 219–233. Available from http://www.insad.pl/files/ journal.pdf/journal2009.2/full21%202009(2). [Accessed June 14, 2010] Alberts B, Johnson A, Lewis J, Raff M, Roberts K and Walter P (2008), Molecular Biology of the Cell, 5th edn, New York, Garland. Ali M B, Singh N, Shohael A M, Hahn E J and Paek K Y (2006), ‘Phenolics metabolism and lignin synthesis in root suspension cultures of Panax ginseng in response to copper stress’, Plant Sci, 171, 147–154. An J, Zhang M and Lu Q (2007), ‘Changes in some quality indexes in fresh-cut green asparagus pretreated with aqueous ozone and subsequent modified atmosphere packaging’, J Food Eng, 78, 340–344. Anon. (2004), Fruits in Thailand, Department of Agricultural Extension, Ministry of Agriculture and Cooperatives, Bangkok, Thailand Anon. (2007), ORAC antioxidant value list: comparison chart. Available from: http://www. wolfberryjuice.com/antioxidants-orac-list.htm. [Accessed September 5, 2007] Aquino-Bolaños E N, Cantwell M I, Peiser G and Mercado-Silva E (2000), ‘Changes in the quality of fresh-cut jicama in relation to storage temperatures and controlled atmosphere’, J Food Sci, 65, 1238–1243. Aryucharoen S (2004), Effects of maturity stage, oxygen, and carbon dioxide concentrations on the quality of mangosteen fruit stored at low temperature. M.S. Thesis, Bangkok, King Mongkut University of Thonburi Technology.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

26 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Astridge D and Fay H (2006), Red-banded thrips in rare fruit. Available from: http://www2. dpi.qld.gov.au/horticulture/5064.html. [Accessed January 6, 2006] Augustin M A and Azudin M N (1986), ‘Storage of mangosteen (Garcinia mangostana L.)’, ASEAN Food J, 2, 78–80. Baucher M, Chabbert B, Pilate G, van Doorsselaere J, Tollier M T, et al. (1996), ‘Red xylem and higher lignin extractability by down-regulating a cinnamyl alcohol dehydrogenase in poplar’, Plant Physiol, 112, 1479–1490. Bogs J, Jaffe F W, Takos A M, Walker A R and Robinson S P (2007), ‘The grapevine transcription factor VvMYBPA1 regulates proanthocyanidin synthesis during fruit development’, Plant Physiol, 143, 1347–1361. Boudet A M (2000), ‘Lignins and lignification’, Plant Physiol Biochem, 38, 81–96. Bunsiri A (2003), Characterization of lignin and enzymes involved in the increased firmness of mangosteen fruits pericarp after impact. Ph.D. Thesis, Bangkok, Kasetsart University. Bunsiri A, Ketsa S and Paull R E (2003a), ‘Phenolic metabolism and lignin synthesis in damaged pericarp of mangosteen fruit after impact’, Postharvest Biol Technol, 29, 61–71. Bunsiri A., Paull R E and Ketsa S (2003b), ‘Lignin accumulation in relation to increased damaged pericarp of mangosteen fruit after impact’, Thai J Agric Sci, 37, 373–381. Cai C, Xu C J, Li X, Ferguson I B and Chen K S (2006), ‘Accumulation of lignin in relation to change in activities of lignification enzymes in loquat fruit flesh after harvest’, Postharvest Biol Technol, 40, 163–169. Chanloy N (2006), Effects of carbon dioxide packaging methylecellulose coating and gibberellic acid on storage life of mangosteen (Garcinia mangostana L.). M.S. Thesis, Bangkok, King Mongkut University of Thonburi Technology. Chanaweerawan S (2001), Influence of the slope of planting areas and water table levels on yield and quality of mangosteen fruit. M.S. Thesis, Songkhla, Prince of Songkla University. Chiarawipa R (2002), Mitigation of an occurrence of translucent flesh and gamboges of mangosteen fruits. M.S. Thesis, Songkhla, Prince of Songkla University. Choehom R, Ketsa S and van Doorn W G (2003), ‘Chilling injury in mangosteen fruit’, J Hort Sci Biotechnol, 78, 559–562. Chu C C, Ciompelik M, Chang M A, Richards N and Henneberry M (2006), ‘Developing and evaluating traps formonitoring Scirtothrips dorsalis (Thysanoptera: Thripidae)’, Fla Ent, 89(1), 47–55. Chutimunthakun T (2001), Prevention of the incidence of translucent flesh disorder and internal gumming fruits in mangosteen (Garcinia mangostana Linn.) and screening techniques. M.Sc. Thesis, Songkhla, Prince of Songkla University. Dangcham S (2000), Mechanism of flesh translucent disorder development of mangosteen fruit (Gacinia mangostana L.). M.S. Thesis, Bangkok, Kasetsart University. Dangcham S, Bowen J, Ferguson I B and Ketsa S (2008), ‘Effect of temperature and low oxygen on pericarp hardening of mangosteen fruit stored at low temperature’, Postharvest Biol Technol, 50, 37–44. Dangcham S and Ketsa S (2007), ‘Relationship between maturity stages and low temperature involved in the pericarp hardening of mangosteen fruit after storage’, Thai J Agric Sci, 40, 143–150. Dong H, Cheng L, Tan J, Zheng K and Jiang Y (2004), ‘Effects of chitosan coating on quality and shelf life of peeled litchi fruit’, J Food Eng, 64, 355–358. Espley R V, Hellens R P, Putterill J, Stevenson D E, Kutty-Amma S and Allan A C (2007), ‘Red colouration in apple fruit is due to the activity of the MYB transcription factor, MdMYB10’, Plant J, 49, 414–427. Faber B A, Wee L Y and Phillips P A (2000), ‘Effect of Abactin treatment for avocado thrips on population of Persea and avocado bud mite and their associated damage to leaves and fruit’, Calif Avo Soc Yearbook, 84, 95–109.



27

Fu C, Loo A E, Chia F P and Huang D. (2007), ‘Oligomeric proanthocyanidins from mangosteen pericarps’, J Agric Food Chem, 55, 7689–7694. Gross P M and Crown I (2007), Is mangosteen a superfruit? Nutrient and antioxidant properties, Natural Products Information Center, Available from: http://www.npicenter.com/anm/ templates/newsATemp.aspx?articleid=17613&zoneid=43. [Accessed September 20, 2010] Hahlbrock K and Scheel D (1989), ‘Physiology and molecular biology of phenylpropanoid metabolism’, Annu Rev Plant Physiol Plant Mol Biol, 40, 347–369. Halpin C, Knight M E, Foxon G A, Campbell M M, Boudet A M, et al. (1994), ‘Manipulation of lignin quality by down regulation of cinnamyl alcohol dehydrogenase’, Plant J, 6, 339–350. Hellens R, Allan A, Triel E N, Bolitho K, Grafton K, et al. (2005), ‘Transient expression vectors for functional genomics, quantification of promoter activity and RNA silencing in plants’, Plant Methods, 1: 1–14. Helper P K (2005), ‘Calcium: A central regulator of plant growth and development’, Plant Cell, 17, 2142–2155. Hoddle M S, Morse J G, Philliph P A, Faber B and Jetter, K M (2002), ‘Avocado thrips: New challenge for growers’, Calif Agric, 56(3), 103–107. Iiyama K, Lan T B T and Stone B A (1994), ‘Covalent cross-links in the cell wall’, Plant Physiol, 104, 315–320. Imberty A, Goldberg R and Catesson A M (1985), ‘Isolation and characterization of Populus isoperoxidases involved in the last step of lignin formation’, Planta, 164, 221–226. Ji X, Avula B and Khan I A (2007), ‘Quantitative and qualitative determination of six xanthones in Garcinia mangostana L. by LC–PDA and LC–ESI-MS’, J Pharm Biomed Anal 43, 1270–1276. Jirapat J (2002), Improving cultural practices to enhance yield and quality of mangosteen. M. S. Thesis, Songkhla, Prince of Songkla University. Jung H A, Su B N, Keller W J, Mehta R G and Kinghorn A D (2006), ‘Antioxidant xanthones from the pericarp of Garcinia mangostana (Mangosteen)’, J Agric Food Chem, 54, 2077–2082. Kader A A (2007), Mangosteen. Available from: http://postharvest.ucdavis.edu/produce/ producefacts/Fruit/mangosteen.shtml. [Accessed May 12, 2007] Keller B, Saner N, and Lam C J (1988), ‘Glycine-rich proteins in bean: gene structure and association of the proteins in bean: gene structure and association of the protein with the vascular system’, EMBO J, 7, 3625–3634. Ketsa S and Atantee S (1998), ‘Phenolics, lignin, peroxidase activity and increased firmness of damaged pericarp of mangosteen fruit after impact’, Postharvest Biol Technol, 14, 117–124. Ketsa S and Koolpluksee M (1992), ‘Some physical and biochemical characteristics of damaged pericarp of mangosteen fruit after impact’, Postharvest Biol Technol, 2, 209–215. Kitpipit H (2005), Production improvement and extending the shelf life of fresh-cut unripe mangosteen (mangkhut-cut). M. S. Thesis, Songkhla, Prince of Songkla University. Kondo T, Hiroi T, Mizuno K and Kato T (1990), ‘Characterization of lignin-carbohydrate complexes of Italian ryegrass and alfalfa’, Can J Plant Sci, 70, 193–201. Kosiyachinda S (1986), ‘Harvesting studies in mangosteen, rambutan, durian. Section II’, House Agricultural Magazine, 10(8), 37–41 (in Thai). Lam T B T, Iiyama K, and Stone B A (1994), ‘An approach to the estimation of ferulic acid bridges in unfractioned cell walls of wheat internodes’, Phytochem, 37, 327–333. Lawoko M (2005), Lignin polysaccharide networks in softwood and chemical pulps: characterization, structure and reactivity. Doctoral Dissertation, Stockholm, KTH Fiber-och polymerteknologi. Laywisadkul S (1994), Factors influencing the development of translucent disorder in mangosteens. M.S. Thesis, Bangkok, Kasetsart University.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

28 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Lewis N G and Yamamoto E (1990), ‘Lignin: occurrence, biogenesis and biodegradation’, Annu Rev Plant Physiol Plant Mol Biol, 41, 455–496. Luckanatinvong V (1996), The study on chemical compostion, cell viability and influence of water on flesh translucent disorder in mangosteen (Garcinia mangostana L.). M.S. Thesis, Bangkok, Kasetsart University. Luo Z, Xu X, Cai Z and Yan B (2007), ‘Effects of ethylene and 1-methylcyclopropene (1-MCP) on lignification of postharvest bamboo shoot’, Food Chem, 105, 521–527. Maldonado R, Molina-Garcia A D, Sanchez-Ballesta M T, Escribano M I and Merrodio, C (2002), ‘High CO2 atmosphere modulating the phenolic response associated with cell adhesion and hardening of Annona cherimola fruit stored at chilling temperature’, J Agric Food Chem, 50, 7564–7569. Martínez-Téllez M A and Lafuente M T (1993), ‘Chilling-induced changes in phenylalanine ammonia-lyase, peroxidase, and polyphenol oxidase activities in citrus flavedo tissue’, Acta Hortic, 343, 257–263. Matsumoto K, Akao Y, Yi H, Ohguchi K, Ito T, et al. (2004), ‘Preferential target is mitochondria in alpha-mangostin-induced apoptosis in human leukemia HL60 cells’, Bioorganic Med Chem, 12, 5799–5806. Morrison I M (1974), ‘Structural investigations on the lignin-carbohydrate complexes of Lolium perenne’, Biochem J, 139, 197–204. Morton J (1987), ‘Mangosteen’, in Morton J F, Fruits of Warm Climates, Miami, FL, 301– 304. Available from http://www.hort.purdue.edu/newcrop/morton/mangosteen.html. [Accessed June 14, 2010]. Noichinda S (1992), Effect of modified atmosphere condition on quality and storage life of mangosteen (Garcinia mangostana L.) fruit. M.S. Thesis, Bangkok, Kasetsart University. Noichinda S, Bodhipadma K, Singhkhornart S and Ketsa S (2007), ‘Change in pectic substances and cell wall hydrolase enzymes of mangosteen (Garcinia mangostana) fruit’, New Zealand J Crop Hort Sci, 35, 220–233. Osman M B and Milan A R (2006), Mangosteen: Garcinia mangostana L. Southampton Centre for Underutilised Crops, Southampton, University of Southampton. Pakkasarn S (1997), Effect of controlled atmosphere condition on prolonging storage life of mangosteens. M.S. Thesis, Bangkok, King Mongkut University of Thonburi Technology. Palapol Y (2009), Characterization of MYB transcription factors and anthocyanin biosynthesis genes of mangosteen fruit during red colouration. Ph.D. Thesis, Bangkok, Kasetsart University. Palapol Y, Ketsa S, Stevenson D, Cooney J M, Allan A C and Ferguson I B (2009a), ‘Colour development and quality of mangosteen (Garcinia mangostana L.) fruit during ripening and after harvest’, Postharvest Biol Technol, 51, 349–353. Palapol Y, Ketsa S, Wang K L, Allan A C and Ferguson I B (2009b), ‘A MYB transcription factor regulates anthocyanin biosynthesis in mangosteen (Garcinia mangostana L.) fruit during ripening’, Planta, 229, 1323–1334. Paull R E and Ketsa S (2004), ‘Mangosteen’, in Gross K C, Wang C Y and M. Saltveit, The Commercial Storage of Fruits, Vegetables, and Florist and Nursery Stocks. United States Department of Agriculture (USDA), Agriculture Handbook No. 66 (third edition). Available from: http://www.ba.ars.usda.gov/hb66/contents.html. [Accessed April 20, 2005] Pechkeo S (2007), Changes of plant nutrients concentration in mangosteen (Garcinia mangostana L.) during phonological development and effects of calcium on the development of translucent flesh disorder and gamboge of mangosteen fruits. M.S.Thesis, Songkhla, Prince of Songkla University. Peng L T and Jiang Y M (2003), ‘Effects of chitosan coating on shelf life and quality of fresh-cut Chinese water chestnut’; Lebensm.-Wiss U-Technol, 36, 359–364. Pankasemsuk T, Garner Jr J O, Matta F B and Silva J L (1996), ‘Translucent flesh disorder of mangosteen fruit (Garcinia mangostana L.)’, HortSci, 31, 112–113.



29

Phongsopa S, Singhavorakij C and Siriphanich J (1994), ‘Structure, quality and surface coating in mangosteens with normal and damaged peel’, Kasetsart J (Nat Sci), 28, 161–166. Piriyavinit P (2008), Control of ripening in mangosteen (Garcinia mangostana L.) fruit after harvest. M.S. Thesis, Bangkok, Kasetsart University. Pludbuntong W (2007), Effects of calcium and boron applications on yield and quality of mangosteen (Garcinia mangostana L.). M.S. Thesis, Bangkok, King Mongkut’s Institute of Technology Ladkrabang. Ponrod W (2002), Abscisic acid and polyamines content during growth of mangosteen and the effect of spermine application on chilling injury during low temperature storage. M.S. Thesis, Bangkok, King Mongkut University of Thonburi Technology. Pranamornkij T (1997), Effect of modified atmosphere packaging on prolonging storage life of mangosteen fruits (Garcinia mangostana L.). M.S. Thesis, Bangkok, King Mongkut University of Thonburi Technology. Pushpariksha P (2008), Postharvest damage and physical properties of mangosteen as related to quality grading. Ph.D. Thesis, Bangkok, Kasetsart University. Ralph J, Grabber J H and Hatfield R D (1995), ‘Lignin-ferulate cross-links in grasses: active incorporation of ferulate polysaccharide esters into ryegrass lignins’, Carbohydrate Res, 275, 167–178. Ramage C M, Sando L, Peace C P, Carroll B J and Drew R A (2004), ‘Genetic diversity revealed in the apomictic fruit species Garcinia mangostana L. (mangosteen)’, Euphytica, 136, 1–10. Ratanamarno S (1998) Effects of light and temperature on pigment contents and phenylalanine ammonia-lyase (PAL) activity in mangosteen pericarp. Ph.D. Thesis, Chiangmai, Chiangmai University. Ratanatraiphop T (2003), Development of coating for prolonging storage life of mangosteen. M.S. Thesis, Bangkok, Kasetsart University. Richards A J (1990), ‘Studies in Garcinia, dioecious tropical forest trees: the origin of the mangosteen (G. mangostana L.)’, Bot J Linn Soc, 103, 301–308. Ride J P (1983), ‘Cell walls and other structural barriers in defence’, in Callow J A (ed), Biochemical Plant Pathology, New York, Wiley, 215–236. Sala J M, Sanchez-Ballesta M T, Alférez F, Mulas M, Zacarias L, Lafuente M T (2005), ‘A comparative study of the postharvest performance of an ABA-deficient mutant of oranges II. Antioxidant enzymatic system and phenylalanine ammonia-lyase in non-chilling and chilling peel disorders of citrus fruit’, Postharvest Biol Technol, 37, 232–240. Sanchez-Ballesta M T, Lafuente M T, Zacarias L and Granell A (2000), ‘Phenylalanine ammonia-lyase in the response of citrus fruits to cold temperature’, Physiol Plant, 108, 382–389. Schuster B and Retey J (1995), ‘The mechanism of action of phenylalanine ammonia-lyase: the role of prosthetic dehydroalanine’, Proc Natl Acad Sci USA, 92, 8433–8437. Sdoodee S and Limpun-Udom S (2002), ‘Effect of excess water on the incidence of translucent flesh disorder in mangosteen (Garcinia mangostana L.)’, Acta Hortic, 575, 813–820. Sdoodee S, Sae-Lim M and Chanawan S (2006), Development for the methods of enhancing fruit quality of mangosteen in southern Thailand. Final Report, Songkhla, Prince of Songkla University. Shen Q, Kong F and Wang Q (2006), ‘Effect of modified atmosphere packaging on the browning and lignification of bamboo shoots’, J Food Eng, 77, 348–354. Sophanodora P and Sripongpunkul C (1990), ‘Prevention of browning in frozen mangosteen’, Songklanakarin J Sci Technol, 12, 289–294. Tongdee S C and Suwanagul A (1989), ‘Postharvest mechanical damage in mangosteen’, ASEAN Food J, 4(4), 151–155.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

30 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Uthairatanakij A (1995), A study on some physical and biochemical characteristics of hardened pericarp of mangosteen fruits after low temperature storage. M.S. Thesis, Bangkok, Kasetsart University. Uthairatanakij A and Ketsa S (1996), ‘Physico-chemical changes in pericarp of mangosteen fruits after low temperature storage’, in Vijaysegaran S, Pauziah M, Mohamed M S and Tarmizi S A (eds), Proceedings of the International Conference on Tropical Fruits. Volume I. Malaysian Agricultural Research and Development Institute (MARDI), Serdang, Selangor, 411–422. Vance C P, Kirk T K and Sherwood R T (1980), ‘Lignification as a mechanism of disease resistance’, Annu Rev Phytopathol, 18, 259–288. Verheij E W M (1991), ‘Garcinia mangostana L.’, in Verheijm E W H and Coronel R E, Plant Resources of South-East Asia. No.2. Edible Fruits and Nuts, Wageningen, Pudoc, 177–181. Visanthanon N (1999), Diseases of Tropical Fruit Crops and their Control, Bangkok, J. Film Progress Co., Ltd. Wanichkul K and Kosiyachinda S (1979a), ‘Fruit development of mangosteen (Garcinia mangostana Linn.)’, Kasetsart J (Nat Sci), 13, 63–72. Wanichkul K and Kosiyachinda S (1979b), ‘Harvesting index and postharvest changes of mangosteen (Garcinia mangostana Linn.)’, Kasetsart J (Nat Sci), 13, 45–62. Wee L Y, Philliph P A, Hoddle M S and Morse J G (1999), ‘Further progress on avocado thrips biology and management’, Calif Avo Soc Yearbook, 83, 105–125. Whetten R W, MacKay J J and Sederoff R R (1998), ‘Recent advances in understanding lignin biosynthesis’, Ann Rev Plant Physiol Plant Mol Biol, 49, 585–609. Whetten R W and Sederoff R R (1995), ‘Lignin biosynthesis’, Plant Cell, 7, 1001–1013. Wichitrananon W (2001), Influence of maturation and proportions of carbon dioxide, oxygen and nitrogen on ripening development ethylene performing quality and storage life of mangosteen (Garcinia mangostana Linn.). M.S. Thesis, Bangkok, King Mongkut University of Thonburi Technology. Wills R B H, McGlasson W B, Graham D and Joyce D (1998). Postharvest: An Introduction to the Physiology and Handling of Fruit, Vegetables and Ornamentals. 4th edition., Adelaide., Hyde Park Press. Wu X, Beecher G R, Holden J M, Haytowitz D B, Gebhardt S E and Prior R L (2004), ‘Lipophilic and hydrophilic antioxidant capacities of common foods in the United States’, J Agric Food Chem, 16(52), 4026–4037. Yapwattanaphun C and Subhadrabandhu S (2004), ‘Phylogenetic relationship of mangosteen (Garcinia mangostana L.) and several wild relatives (Garcinia spp.) revealed by ITS sequence data’, J Amer Soc Hort Sci, 129, 368–373. Zhou Y, Dahler J M, Underhill S J R and Wills R B H (2003), ‘Enzymes associated with blackheart development in pineapple fruit’, Food Chem, 80, 565–572.


Plate I

(Chapter 1) Color development of mangosteen fruit at different stages of growth and development (Palapol, 2009).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

(a)

(b)

(c)

(d)

Plate II (Chapter 1) Fruit damaged by thrips (a), translucent aril (b), gamboge with yellow gum outside on fruit surface (c) and with yellow gum inside on the aril (d) (courtesy of Yossapol Palapol).

Plate III (Chapter 2) Honeydew melons showing a packaging pattern in a cardboard container and symptom of chilling injury (darkening of the skin) (courtesy of Marita Cantwell).


2 Melon (Cucumis melo L.) M. E. Saltveit, University of California, Davis, USA

Abstract: Melons contribute to the nutritive and aesthetic quality of our diet. When harvested mature, most melons exhibit a climacteric in respiration and ethylene production coincident with ripening (i.e., softening, aroma development). Ethylene antagonists, such as CO2 and 1-methylcyclopropene (1-MCP), can slow ripening. Sugar content usually declines after harvest because of the lack of storage carbohydrates to be hydrolysed into simple sugars. The chilling sensitivity of most melon cultivars precludes their storage below 5 ° to 10 °C, but this sensitivity varies greatly with cultivar and stage of maturity. Fresh-cut melons are increasingly important and present unique postharvest challenges to maintain quality. Key words: melon, postharvest, climacteric, chilling injury, fresh-cut.

2.1

Introduction

2.1.1 Botany, morphology and structure Melons are cucurbits; cultivated species of the Cucurbitacese. This family contains about 750 species in 96 genera that are found mainly in the tropics. Most plants are tendril-bearing vines that produce fleshy fruits derived from an inferior ovary; a pepo. The four major cucurbit crops are cucumber, melon, squash (pumpkin), and watermelon (Table 2.1). This chapter will focus on the postharvest biology and technology of melons (Cucumis melo L.). The specie Cucumis melo is further divided into several botanical varieties or types. The three most important types are cantalupensis, inodorus, and reticulates (Table 2.2) Melons are monoecious or andromonoecious annuals with long trailing vines and round stems. Staminate flowers are borne in axillary clusters on the main stem, while perfect flowers are borne at the first node of lateral branches. The flowers are predominately yellow. The fruit is a multi-carpled berry that is epigynous. Fruits vary in size, shape, rind characteristics, and flesh color depending on variety. Seeds are cream-colored, oval, and on average 10 mm long.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

32 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Postharvest biology and technology of tropical and subtropical fruits Table 2.1 The four major cucurbit crops Common name

Scientific name

Melon Cucumber Watermelon

Cucumis melo L Cucumis sativus L. Citrullus lanatus (Thunb.) Matsum. & Nakai. Cucurbita maxima Duch. Ex Lam. Cucurbita moschata Duch. Ex Poir. Cucurbita pepo L.

Squash, pumpkin Squash, pumpkin Squash, pumpkin Table 2.2

Major groups of melons (Cucumis melo L.)

Scientific name

Characteristics

Cantalupensis

Skin that is rough and warty, not netted. European cantaloupe and Algerian melon.

Inodorus

Canary melon, Casaba, Kolkhoznitsa melon, Hami melon, honeydew, Navajo Yellow, Piel de Sapo/Santa Claus, sugar melon, tigger (tiger) melon, and Japanese melons.

Reticulatus

True muskmelons, with netted skin. Examples include Bailan melon, North American cantaloupe, Galia, Ogen, Persian, Sharlyn melons. Modern crossbred varieties, e.g. Crenshaw (Casaba X Persian), Crane (Japanese X N.A. cantaloupe)

2.1.2 Worldwide importance China produces about 50% of the world’s crop by weight. Turkey and Iran are the next largest melon-producing countries, with the U.S. and Spain rounding out the top five producers. Europe, Central America, and Africa are also important world production centers. In Japan, melons are usually grown in greenhouses. The yield of US Western Shipping melons has remained stable for the last 20 years. In 2008, the total value of US cantaloupe production was $371 million and honeydew production was valued at $68 million. Cantaloupe production was the highest on record since 2003, while honeydew production was the lowest on record since 1992. Combined, all melons made up the third highest ranked vegetable crop in the US behind lettuce and onions. 2.1.3 Culinary uses, nutritional value and health benefits Melons are usually consumed as desserts, snacks, breakfast or picnic foods. Recently, processed melon products (e.g., pre-cut product displays, in-store salad bars) have been developed to appeal to the single serving market and to smaller households. Seedless varieties have also helped spur consumption. Improved harvesting and handling techniques, as well as the development of sweeter hybrid varieties have improved quality and consumer acceptance. However, even under the best conditions, total carotenoids and vitamin C declined after harvest.


Melon (Cucumis melo L.)

33

A serving of cantaloupe is about 180 grams (1 cup; 250 ml) and contains 60 calories. There is little fat and only 1 g of protein per serving. The carbohydrates are comprised of 14 g of sugar and 2 g of dietary fiber. The yellow and orange fleshed melons contain beta-carotene (provitamin A), and all melons are good sources of vitamin C. A serving of cantaloupe supplies 120% and 110% of the daily requirements of vitamin A and C, respectively. This food is also a good source of niacin, vitamin B6, folate, and potassium.

2.2


2.2.1 Fruit growth, development and maturation After pollination, the kinetics of growth is a simple sigmoid curve with the initial phase of cell division accompanied by small changes in fruit size. Expansion of cells gives rise to a linear increase in size over time. Fruit growth is uniform along all dimensions to produce spherical fruit or predominately along the longitudinal axis to produce oblong fruit. Unlike fruit in which cellular expansion occurs primarily at the floral end, the roughly uniform expansion of melon fruit produces a uniform distribution of minerals throughout the tissue. The dilution of poorly translocated minerals (e.g., calcium) in tissues that expand to a greater extent than others can produce a dilution of essential minerals and make the tissues susceptible to physiological disorders such as blossom end rot in tomatoes and bitter pit in apples. This unequal distribution does not occur in melons, so if any physiological disorders occur (e.g., surface pitting from chilling injury), they are uniformly distributed about the surface. Maturation of the fruit is marked by a reduction and finally a cessation of increases in both size and fresh weight, while the rate of increase in dry weight due to translocation of sugars continues to decline as fruit near full ripeness. An abscission layer forms in the subtending stem in the cantaloupe and muskmelon types, while such a physical abscission zone fails to develop in the inodorus group. However, physiological abscission may occur in all melons even before the start of the development of a physical abscission layer as the result of diminished function of the vascular system (i.e., phloem and xylem) as fruit attain full size and start to ripen. The ease of separation of the fruit at the abscission zone provides an excellent indicator of harvestable maturity. The lack of an abscission zone in honeydew may explain why their maturity at harvest can be so variable. It is difficult to ascertain the level of maturity by a purely visual examination of the exposed honeydew fruit in the field. A gentle tug can easily separate a mature cantaloupe fruit from the vine, while honeydew fruit must be cut from the vine to prevent tearing of the fruit near the point of detachment from the stem. 2.2.2 Respiration, ethylene production and ripening Most melons are climacteric and exhibit elevated rates of respiration and ethylene production coincident with ripening (Fig. 2.1). During normal ripening, melons


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

34 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Fig. 2.1 Climacteric rise in respiration and ethylene production in cantaloupe melons left on the vine (attached) or harvested (detached). The arrows indicate when the fruit were harvested or when they naturally abscised (Shellie and Saltveit, 1993).

can produce copious amounts of ethylene which stimulates their further ripening and can affect ethylene sensitive crops stored with them. The stimulation of ethylene production by ethylene is termed auto-catalytic ethylene production. Holding partially ripe cantaloupes and other melons at 15 ° to 20 °C will allow them to produce their own ethylene and develop good eating quality without additional ethylene treatment. In fact, ethylene exposure may promote rapid ripening with the loss of shelf life. Honeydews (and other ‘winter’ melons) are sometimes harvested before they develop the ability to produce enough ethylene to ripen normally. Exposing these fruit to 100 to 150 ppm ethylene in air for around 24 hours stimulates ripening with its associated changes in aroma and softening. However, most melons are now harvested mature enough to not require a postharvest ethylene treatment. The sugar content of harvested melons does not increase upon ripening because at harvest, mature melons do not have extensive reserves of starch which can be hydrolyzed into sugars. Improper handling (e.g., elevated temperatures, injuries) can stimulate respiration with the loss of sugars and taste quality.



35

Softening associated with ripening has been extensively studied and mutant lines have been created through traditional plant breeding or generic engineering with diminish rates of softening (Pech et al., 2008). The disruption of ethylene production or sensing has been a major focus of such research. However, the discovery that some components of ripening (e.g., aroma development) are not tightly coupled to ethylene production indicated that ripening could be modified by altering other metabolic pathways.

2.3

Maturity and quality components and indices

Melons are harvested by maturity, not by size; although size is an important component of their marketability. The soluble solids (e.g., sugar) content is the primary factor governing maturity. 2.3.1 Commercial maturity of cantaloupe Maturity is optimal at the firm-ripe stage or ‘3/4 to full-slip’ when a clear abscission (i.e., slip, separation) from the vine occurs with light pressure. Cantaloupes can ripen after harvest (i.e., soften and develop characteristic aroma and flavor) but do not increase in sugar content. For maximum quality, cantaloupes should be harvested at the ‘full-slip’ stage for local markets since the sugar content, flavor and texture improve very rapidly as the fruit approaches this stage of development, but a less mature stage is optimal for shipment to distant markets to avoid excessive losses from over-ripeness and decay. High quality melons should be nearly spherical and uniform in appearance. An abscission zone should have formed producing a full slip with no adhering peduncle (i.e., stem-attachment). Fruit can be harvested at one-half or quarter slip if their soluble solids content is sufficiently high. The surface should lack scars, sunburn or other defects. The fruit should be firm with no evidence of bruising or excessive scuffing. The fruit should be heavy for its size and have a firm internal cavity without loose seeds or accumulated liquid. U.S. grades are Fancy, No. 1, Commercial and No. 2. Distinction among grades is based predominantly on external appearances and measured soluble solids. Federal Grade Standards specify a minimum of 11% soluble solids for U.S. Fancy (‘Very good internal quality’) and 9% soluble solids for U.S. 1 (‘Good internal quality’). A refractometer is usually used to measure the °Brix, which is accepted as the current standard measurement for soluble solids. Sizing is based on count per 18.2 kg (40 lb.) container. There are typically 9, 12, 15 and occasionally 18 or 23 melons per carton. A cardboard divider is folded at different locations to produce compartments for the different sized fruit (see Plate III in the colour section between pages 238 and 239). 2.3.2 Commercial maturity of honeydew There are three commercial maturities for honeydew melons.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

36 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


1 Mature, unripe. Ground color white with greenish accents, no characteristic aroma, peel fuzzy/hairy and not waxy. California Grade Standards establish a minimum legal harvest index of 10% soluble solids (10 ° Brix). 2 Mature, ripening. Ground color white with slightly discernible green tint, slightly waxy peel, blossom-end firm and unyielding, no or slight aroma. Preferred commercial maturity class. 3 Ripe. Ground color creamy white with yellow accents, clearly waxy peel, characteristic aroma noticeable, blossom-end yields slightly to press. The fruit should be well-shaped, nearly spherical and uniform in appearance. There should be an absence of scars or surface defects, with no evidence of bruising. The fruit should appear heavy for size, and the surface should be waxy and not fuzzy. The US grades are similar to those for cantaloupe, but more emphasis is given to surface appearance. Sizing is based on count per 13.6 kg (30 lb) container, most typically four or five, and occasionally six melons per carton. The maturity and ripeness of ‘Winter’ melons (e.g., Crenshaw, Persian, Casaba, Juan Canary, and Santa Claus) can be difficult to determine because they do not form an abscission zone and ‘slip’ from the vine when ripe. These melons may require ethylene to enhance ripening, which can be administered in transit from production areas, or at distribution centers.

2.4


Good cultural practices should be followed with adequate and consistent watering to avoid rapid expansion of the fruit which could cause cracking. Fertilization should allow uniform growth and provide sufficient trace minerals (e.g., calcium) to lessen the development of physiological disorders. However, calcium fertilization may have limited benefit because most soils have adequate calcium and calcium has limited mobility in the plant. Like other field crops, melon yield increased with increasing nitrogen fertilization, but quality was not affected by nitrogen level. Exposure to chilling or excessively high temperatures before harvest may increase the fruits susceptibility to postharvest chilling injury. Intense solar radiation on exposed fruit (either in the field or during transit to a packing facility in uncovered field containers) may raise the skin and underlying flesh temperature sufficiently to cause damage (e.g., sunburn, sunscald) with symptoms of skin discoloration and poor or abnormal ripening. Incomplete pollination can produce misshaped fruit; e.g., a pear-shaped fruit.

2.5

Postharvest handling factors affecting fruit quality

2.5.1 Temperature management Melons are often harvested in the summer at elevated temperatures. The fruit should be rapidly cooled soon after harvest to maintain optimal quality. Precooling



37

to 10 °C is typical, but cooling to 4 °C is more desirable. Forced-air is the most common method used to cool field packed fruit. The use of hydrocooling is diminishing as packing shifts from the packing shed to the field. Immersion of hot fruit in cold water during hydrocooling may permit intrusion of water through the stem scar and the absorption of contaminants that have accumulated in the cooling water. 2.5.2 Physical damage Surface abrasion and scuffing, especially in the non-netted inodorus varieties, increases skin discoloration and water loss, which is a major cause of the loss of firmness. The open seed cavity in many mature melons makes them susceptible to a postharvest defect in which the tissues associated with the seeds become separated from the pericarp wall because of violent physical motion (e.g., rolling, dumping, shaking). The early harvest of US Western Shipping melons and their relatively closed cavity minimizes this type of damage during transportation to distant markets (see Plate IV in the colour section). 2.5.3 Water loss The spherical nature of melon fruit minimizes the surface to volume ratio, and their well developed rind and skin combine to limit water loss. However, apart from biochemical changes in cell wall plasticity which produces tissue softening, water loss can cause a loss of firmness. This is especially true in fresh-cut melon products where the removal of natural barriers to diffusion leaves the exposed tissue susceptible to vapor-pressure deficit driven water loss. Waxing, plastic wraps, packaging and maintaining high relative humidity surrounding the commodity have been be used to lessen water loss. 2.5.4 Atmosphere Melons, especially cantaloupes, derive a slight benefit from storage at 2 ° to 7 °C in 3 to 5% oxygen and 10 to 20% carbon dioxide. This fungistatic level of carbon dioxide suppresses decay on the stem and rind, and acts as an ethylene antagonistic to slow ripening with its associated softening and color changes. Controlled and modified atmospheres may also reduce chilling sensitivity. However, 20% carbon dioxide will cause a carbonated flavor in the fruit flesh which can be lost upon transfer to air. Oxygen levels below 1% and carbon dioxide levels above 20% may impair ripening and produce off-flavors and odors. Beneficial atmospheres can be generated by enclosing the fruit in plastic films. Plastic wraps can also reduce water loss and its associated loss of firmness. Melons shipped substantial distances (e.g., cantaloupes shipped from South America to Europe) often use a bag-in-box design where cooled fruit are placed within a plastic bag in a box. The bag is folded over before the box is closed. The


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

38 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


bag retards gas diffusion so the humidity around the fruit increases, which lowers water loss, and fruit respiration elevates the carbon dioxide level to around 10% which retards microbial growth. Since this beneficial carbon dioxide level is a balance between carbon dioxide diffusion out of the bag and carbon dioxide production by the fruit, it is very important to maintain the temperature (and thereby the rate of respiration) for which the package design was optimized. Melons must be cooled before packaging and the maintenance of the proper temperature is crucial if they are to be kept in plastic during retail marketing. The high rate of respiration during the climacteric of ripening melons can produce sufficient heat to raise their temperature. Package design should allow sufficient air movement around the fruit to remove this vital heat and maintain the desired storage temperature.

2.6


2.6.1 Chilling injury Melons are chilling sensitive and are adversely affected by storage at low, non-freezing temperatures. The level of sensitivity varies with maturity, cultivar and previous growing and handling conditions. Cantaloupes are slightly chilling sensitive and can exhibit surface browning and increased decay after extended storage below 2 °C. Honeydew and other melons are more sensitive. In these melons, chilling produces water-soaked areas in the flesh, browning of the surface, increased decay and a failure to ripen normally (see Plate III in the colour section). Since chilling affects ripening, riper fruit (e.g., maturity #3 honeydew) are less susceptible to chilling injury. Honeydew that are mature but unripe should be stored at 10 °C, while ripe fruit can be stored at 5 ° to 7 °C without suffering chilling injury. Experimental treatments involving exposures to low or high temperatures for short intervals, dips in various aqueous solutions, and modified atmospheres have been developed which lessen the development of chilling injury symptoms. However, commercial handling of melons is best served by adhering to proper temperature management to avoid chilling in the first place. 2.6.2 Other physiological disorders Most physiological disorders (e.g., water soaked and flesh browning) are associated with exposure to extreme conditions; elevated temperatures, and ethylene or carbon dioxide concentrations, and low temperatures or oxygen concentrations. Premature softening and water-soaking of fruit flesh have been associated with low calcium levels. Postharvest dips in aqueous calcium solutions increase calcium levels in whole and segmented fruit. However, this method cannot be used with field-packed fruit. Melons develop few disorders after harvest if held under proper storage conditions.



2.7

39


Postharvest losses are predominately caused by physical injury due to bruising and chilling injury and not by diseases. However, melons are susceptible to a number of bacterial and fungal diseases; they include powdery mildew, downy mildew, Alternaria leaf spot, Anthracnose, and Fusarium wilt. Melons are also susceptible to watermelon mosaic, cucumber mosaic, cantaloupe latent virus; diseases which are transmitted by aphids. Squash mosaic virus is seed borne and beetle transmitted. Curly top virus is transmitted by beet leaf hoppers. Melon diseases can be controlled through crop rotation, using resistant cultivars and approved fungicides. Disease vectors can be controlled with insecticides. Postharvest fungicide dips are essential to control postharvest diseases during storage, or long distance transport. A recommended fungicide application is a mixture of 500 ppm benomyl (Benlate) and guazatine (Panoctine). Hot water dips may be used to supplement or augment such fungicidal treatments.

2.8

Insect pests and their control

The pests which affect melons include melon aphid, green peach aphid, cucumber beetle, leafhopper, leaf miner, red spider mites, and melon worm. Soil pests include nematodes, wire worms, and corn seed maggot. Some insects are disease vectors, with bacterial wilt being transmitted by the cucumber beetle.

2.9

Postharvest handling practices

2.9.1 Harvest operations Melons are harvested mature and undergo significant changes in aroma production and firmness, and lesser changes in sugar content after harvest. Mature cantaloupes are harvested at the full slip stage when the fruit easily separates from the stem. Reduced susceptibility to mechanically injury and additional marketing-life can be achieved by harvesting the fruit at a mature, but less ripe stage of development. Less mature fruit do not so easily detach from the stem and these half-slip and quarter-slip fruits can be identified by the portion of stem remaining attached to the harvested fruit. Honeydew types of melons do not form this abscission zone between the fruit and stem. These fruit should be cut, not pulled from the vine to prevent mechanical damage to the stem-end of the fruit. Harvesting is almost entirely done by hand because it is difficult to distinguish the proper stage of melon maturity mechanically and to permit multiple harvests. Harvest aids are commonly employed in field packing operations and to pick up the boxed melons. However, the large machines necessary for field packing can severely damage the vines and only permit one harvest.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

40 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


2.9.2 Packinghouse practices Melons are warm-season fruit that are often harvested when day time temperatures are quite hot. Harvesting in the early morning or at night can reduce the heat load. Melons can be harvested into lined, low-volume bins for transport to packing facilities (Fig. 2.2). Bulk melons are usually dry dumped before being sorted and cooled. However, field packing is preferred to minimize handling and subsequent mechanical injury. Field heat is removed at the packing facility by hydro-cooling before grading, sizing and packing of bulk melons, or by forced-air cooling for packaged melons. Sizing and sorting the fruit to produce uniform packs and the application of post-harvest treatments (e.g., applying wax, fungicides) is more easily accomplished in a packing facility. Diligent supervision is needed to maintain consistent quality in field packing operations.

Fig. 2.2 Postharvest harvesting and handling of melon fruit that are packed in the field or in a packing shed.

2.9.3 Control of ripening and senescence Temperature management remains the primary means of controlling the rate of ripening. The rate of respiration, and thereby the rate of most associated metabolic processes increases two- to three-fold for every 10 °C rise in fruit temperature. Rapid ripening increases moisture loss and reduces quality and storage life. To maximize quality retention, harvested fruit should be cooled to their lowest tolerated temperature. Most fruit and vegetables should be stored at the



41

lowest non-freezing temperature; usually 0 °C. However, since melons are chilling sensitive they must be stored at a higher temperature which naturally results in a shorter shelf life than non-chilling sensitive fruit. Since ripening is so tightly coupled with ethylene production, genetically modified lines of melons have been produced with greatly diminished rates of ethylene production. These lines have slower rates of ripening and extended shelflife. The natural variability in the amplitude and rapidity of the climacteric has also been used to develop lines with altered rates of ripening by traditional breeding methods. Interestingly, fruit left to ripen on the plant continue to exhibit a climacteric in ethylene production, but the rise in respiration (i.e., carbon dioxide production), which usually accompanies the rise in ethylene production in harvested fruit, is greatly diminished until the fruit is detached or naturally abscises (Shelly and Saltveit, 1993; Hadfield et al., 1995: Bower et al., 2002). It appears that detachment of the fruit during harvest interrupts the flow of something into the fruit which lessens the climacteric rise in respiration. Since the respiratory climacteric consumes sugars which are critical to the taste quality of the fruit, maintaining the effect of this inhibitory factor in harvested fruit could extend their shelf life and taste quality. Ethylene antagonistic such as carbon dioxide and 1-MCP can block ethylene perception and the positive feedback of ethylene on ethylene production and slow the rate of natural or imposed ethylene-induced ripening. However, although these treatments can slow ripening, their use does not diminish the need for prompt cooling and proper temperature management for optimal retention of quality. 2.9.4 Recommended storage and shipping conditions Storage life of cantaloupes is typically 12–15 days within the optimal range of 2.2 °–5.0 °C and 85–90% R.H. Holding the temperature at 2.2 °C can extend the storage life to 21 days, but sensory quality will be reduced as this reduces the production of characteristic flavors and aromas. Honeydews are slightly more chilling sensitive than cantaloupes and should be stored at 7 °C and 85–90% R.H for a storage life of 12–15 days. Short term storage during transit can range from 2.5–5 °C, but these exposures should be minimized since holding melons at these temperatures for seven days may induce chilling injury; especially in the more susceptible cultivars. The damage may not be apparent until the fruit are transfer to typical retail display temperatures where the symptoms of chilling injury will quickly develop. Temperature fluctuations resulting in condensation of water on the fruit’s surface should be avoided as the free water on the surface promotes mold growth. The optimum temperature and handling conditions for honeydew melons are essentially the same as for Crenshaw and Persian melons. Their storage period, however, is shorter and generally does not exceed 14 days. Casaba, Juan Canary,


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

42 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


and Santa Claus melons retain best quality at the high end of the storage temperature range, 10 °C for up to 21 days.

2.10

Processing

2.10.1 Fresh-cut processing The main impediment to marketing fresh-cut melons is the loss of firmness and development of water-soaked areas. Retention of firmness and texture can be maximized with post-processing dips in aqueous calcium solutions. Various calcium salts have been studied (e.g., calcium chloride, calcium lactate), but each imparts a flavor which consumers may find objectionable. Rapid marketing and proper temperature and humidity management is absolutely crucial to maintain the quality of fresh-cut melons. Fresh-cut melon portions should be washed in a chilled chlorinated water bath immediately after cutting. A further wash in a chilled citric acid and tribasic calcium phosphate solution after sorting and grading would help to maintain quality. Although not the only route of contamination, edible portions of the melon flesh may be contaminated in the cutting or rind removal process. Treatments which would be too severe to apply to the whole fruit destined for prolonged storage and transit (e.g., gaseous ozone and hot water), can be used prior to processing since their main target is to decontaminate the peel which is removed during processing.

2.11

Conclusions

As packing moves away from using a packing shed to predominately field packing, postharvest treatments of whole fruit will be limited to those that can be applied to boxed fruit. Aqueous applications of waxes and fungicides, and quarantine treatments will need to be modified to accommodate the types of containers used in field packaging. The genetic engineering of various metabolic pathways; especially those involved in ethylene production and perception, will continue to be active areas of research and commercial implementation. Instruments are currently being developed that could nondestructively and rapidly measure fruit soluble solids. Once perfected, these instruments could be incorporated into mechanical harvesters, used by pickers to distinguish ripe and unripe fruit more effectively in the field, or used on a pack house grading line to segregate the fruit into maturity and quality classes that would have more uniform postharvest characteristics. Future genetic modifications and technological innovations may augment postharvest melon handling, but they will not eliminate the need for the basic tenants of postharvest biology and technology; maintain proper fruit temperature, relative humidity, and sanitation, and handle the fruit gently and rapidly.



2.12

43

References

Beaulieu JC, and Gorny JR (2004) ‘Fresh-cut fruits’, in The Commercial Storage of Fruits, Vegetables, and Florist and Nursery Stocks, Agriculture Handbook Number 66, eds. Gross KC, Wang CY, and Saltveit ME, http://www.ba.ars.usda.gov/hb66/ contents.html Bower J, Holford P, Latché A, and Pech JC (2002) Culture conditions and detachment of the fruit influence the effect of ethylene on the climacteric respiration of melon, Postharvest Biol Tech, 26, 135–146. Hadfield KA, Jocelyn K, Rose C, and Bennett AB (1995) The respiratory climacteric is present in Charentais (Cucumis melo cv. Reticulatus F1 Alpha) melons ripened on or off the plant, J Expt Bot, 46(293), 1923–1925. Lester G and Shellie KC (2004) ‘Honey dew melon’, in The Commercial Storage of Fruits, Vegetables, and Florist and Nursery Stocks, Agriculture Handbook Number 66, eds. Gross KC, Wang CY, and Saltveit ME, http://www.ba.ars.usda.gov/hb66/contents.html Miccolis V and Saltveit ME (1991), Morphological and physiological changes during fruit growth and maturation of seven melon (Cucumis melo L.) cultivars, J Amer Soc Hort Sci, 116(6), 1025–1029. Miccolis V and Saltveit ME (1995), Influence of storage period and temperature on the postharvest characteristic of six winter-type muskmelon (Cucumis melo L.) cultivars, Postharvest Biol Tech, 5, 211–219. Pech JC, Bouzayena B, and Latchéa A (2008) Climacteric fruit ripening: Ethylenedependent and independent regulation of ripening pathways in melon fruit, Plant Science, 175(1–2), 114–120. Saltveit ME (2003), A summary of CA requirements and recommendations for vegetables, Acta Hortic, 600, 723–727. Saltveit ME (2003), ‘Fresh-cut vegetables’, in Postharvest Physiology and Pathology of Vegetables, eds. J.A. Bartz and JK Brecht, Marcel Dekker, Inc. pp. 691–712. ISBN: 0-8247-0687-0. Saltveit ME (2005), Wound-induced physiological changes in fresh-cut produce, Proc. APEC Symposium, August 1–3, Bangkok, Thailand. Shellie KC and Saltveit ME (1993), The lack of a respiratory rise in muskmelon fruit ripening on the plant challenges the definition of climacteric behavior, J Expt Bot, 44, 1403–1406. Shellie KC and Lester G (2004) ‘Netted melons’, in The Commercial Storage of Fruits, Vegetables, and Florist and Nursery Stocks, Agriculture Handbook Number 66, eds. Gross KC, Wang CY, and Saltveit ME, http://www.ba.ars.usda.gov/hb66/contents.html Suslow TV, Cantwell M, and Mitchell J (2009) Melon Produce Facts. http://postharvest. ucdavis.edu/Produce/ProduceFacts/Fruit/honeydew.shtml


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

(a)

(b)

(c)

(d)

Plate II (Chapter 1) Fruit damaged by thrips (a), translucent aril (b), gamboge with yellow gum outside on fruit surface (c) and with yellow gum inside on the aril (d) (courtesy of Yossapol Palapol).

Plate III (Chapter 2) Honeydew melons showing a packaging pattern in a cardboard container and symptom of chilling injury (darkening of the skin) (courtesy of Marita Cantwell).


Plate IV (Chapter 2) Cantaloupe melons with a closed (left) and open (right) seed cavity (courtesy Marita Cantwell). Note the thickness of the rind and the structural stability of the seeds and associated tissues.

Plate V

(Chapter 3) Nance inflorescences. Notice the change in color of the petals from yellow to orange as they get older.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

3 Nance (Byrsonima crassifolia (L.) Kunth) O. Duarte, National Agrarian University, La Molina, Peru

Abstract: Nance is a popular minor fruit in Central America commonly found in markets although there are practically no commercial plantations. The fruit is gathered from seedling trees that are sown either by birds or by man as backyard trees. The fruit can be sweet or acid and is used fresh in juices, boiled in syrup, candied or after having gone through an alcoholic fermentation process. Many people dislike it because of the soapy smell produced by its high fat content. The tree bark has high tannin content and is used to cure diarrhea and other ailments. Key words: nance, Byrsonima crassifolia, postharvest, tannin, fat content, alcoholic fermentation.

3.1

Introduction

3.1.1 Origin, botany, morphology and structure Nance, nancite (Central America), peralejo (Cuba), nanche, nanchi, chi, nanchite (Mexico), indano (Perú), changugu, craboo, maricao, peralejo, perdejo, peralejo de sabana (Caribbean), muricí (Brazil), golden spoon or golden cherry (USA), are some of the names of the fruit of Byrsonima crassifolia. This species is native to the dry tropical forests of southern Mexico, the Antilles, Central America and the Amazon basin in South America. It belongs to the Malpighiaceae family and several related species exist, such as Byrsonima coriacea, B. verbascifolia and others (Standley and Steyermark, 1946; Williams, 1981; Barbeau, 1990). It is an evergreen tree that can reach 10 m but normally will grow to 3–4 m in height. The trunk is not very straight and its wood can be used to make small wooden objects. The leaves are simple, entire, opposite, shiny on their upper side and have a short petiole. They can reach 6 to 16 cm length and 3 to 8 cm width. According to Morton (1987) the showy flowers are hermaphroditic with a diameter of about 1.5 cm. The five sepals are green and the five petals turn from yellow to an orange or reddish color as they get older. The flowers come in terminal


Nance (Byrsonima crassifolia (L.) Kunth)

45

inflorescences and change color gradually according to the age of the flowers so that the different colors can be seen in the inflorescence (see Plate V in the colour section between pages 238 and 239). The flowers are dependant on pollination by insects like Trigona folviventris Guerin., Apis mellifera and Polyubia occidentalis Oliver (Duarte and Vernon, 2002). The ovary is trilocular with one ovule per locule and with three stigmas. The fruit is a globular drupe measuring from 1 to 2 cm in diameter (see Plate VI in the colour section). The external peel is soft and normally turns from green to yellow, and sometimes orange, red when ripe. However the peel of some types remains green when ripe. The pulp is about 0.5 cm thick and white to yellowish-white or cream in color. The fruit can be sweet, acid or sometimes bitter. Fruit weight can vary from 2 to 5 g. The fruit has a single round stone in the center that consists of three embryos with their covers fused together. Therefore sometimes three plants can germinate from a single ‘seed’, but normally only one of the embryos germinates (Donadio et al., 2002). 3.1.2 Worldwide importance and economic value Nance is mainly consumed in its areas of production where most of the crop is sold by roadside vendors. The rest reaches the markets of certain cities in Mexico and Central America. In many of these countries, restaurants, juice vendors and housewives buy the fruit mainly to make juices or desserts. Some fruit is exported from Central America to Canada and the United States as frozen fruit or pulp, to avoid quarantine barriers. Also fruit in syrup or alcohol is exported in small amounts for Central American and Caribbean immigrants living in the United States or Canada. 3.1.3 Culinary uses, nutritional value and health benefits The fruit is normally eaten fresh but can also be processed into juices, pulps (which can be used in fruit yoghurts), jams (which have a buttery taste), alcoholic products or candied products or preserved in syrup (fruit composition is shown in Table 3.1). The fruit has a relatively high fat content and in some places lipids are extracted from it. According to Donadio et al. (2002) the peel can contain 25% fat and the seed around 11%, the pulp acidity is about 2.45% with a Brix of 4.49 °, the pH is around 3 and it has a low content of vitamins that according to Morton (1987) is about 0.010 to 0.014 mg thiamine, 0.015 to 0.039 mg riboflavin, 0.266 to 0.327 niacin and 90 to 129 mg ascorbic acid per 100 g of fresh pulp. Bayuelo-Jimenez (2008) says the distinct fruit aroma that some people dislike is mainly due to ethylbutanoate (sweet and fruity), ethylhexanoate (fruity), butyric acid (rancid cheese), hexanoic acid (pungent cheese) and phenylethyl alcohol (floral scent). The leaves and the trunk bark are rich in tannins, as well as the unripe fruits. The tannins are used for tanning and a decoction of this bark is used to cure diarrhea, to lower fever and as an anti inflammatory.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

46 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Table 3.1 Chemical composition of 100 grams of the edible portion of fresh nance (Byrsonima crassifolia) fruit in the green-mature and mature stages and weight composition of the fruit Chemical composition

Green-mature

Mature

Moisture Total dry matter: – Ashes – Organic matter

83.99 g 16.01 g 0.70 g 15.30 g

83.04 g 16.96 g 0.74 g 15.22 g

Organic matter breakdown: – Crude protein – Ether extract (Fats) – Crude fiber – Nitrogen free extract of which reducing sugars constitute

0.92 g 1.59 g 2.26 g 10.54 g 7.45 g

0.89 g 2.23 g 2.33 g 10.77 g 8.86 g

Weight composition: Seed Pulp and peel

10.22% 89.78%

14.42% 85.58%

Source: Duarte and Vernon, 2002.

3.2


3.2.1 Fruit growth, development and maturation According to Duarte and Vernon (2002) this species needs cross pollination for adequate fruit set. These authors found that when using a mosquito net to cover the inflorescences almost no fruit set occurred (0.5–1.0%) whereas the percentage of fruit set in uncovered fruits was 40–46%. The fruit will take from five to six months from anthesis to ripening (Fig. 3.1). The fruit are initially green in color turning lighter as they mature and finally becoming yellow, although some types can be almost red, dark orange or green. The mature fruit will normally drop to the ground from where it is picked at harvest time. The day the fruit drops from the tree it cannot be eaten because it has

Fig. 3.1 Nance (Byrsonima crassifolia) fruit growth curve for weight (continuous line) and diameter (dotted line) at El Zamorano, Honduras (Duarte and Vernon, 2002).



47

an astringent taste due to high concentration of tannins. This unpleasant taste will normally disappear next day and by that time the fruit will have a softer texture (this can be checked by pressing it between the fingers). The fruit can also be harvested several days before it drops naturally, as is described in the following section.

3.2.2 Respiration, ethylene production and ripening There is not much written information on this aspect. According to Velásquez de Klimo (2006), the fruit shows a climacteric rise in ethylene production during the third day of storage at 20 °C, while there is no defined pattern in carbon dioxide production. Yet, at the same time this author indicates that other workers claim that nance is not a climacteric fruit. However, there is no doubt that the fruit can be harvested as soon as it starts changing color to paler green or yellow or to the color of the variety. This fruit will ripen normally and can be eaten as soon as the calyx abscises from it and the fruit shows certain softness when pressed between the fingers. Further studies need to be done to define the behavior of this fruit that from the above information seems more likely to be climacteric.

3.3


As already mentioned, the fruit is normally considered mature when it drops naturally. No maturity indices has been developed other than color or fruit drop, which is the more commonly used index. There are no commercial orchards and therefore no standard varieties of nance exist. There is a broad classification of fruit by flavor as acid or sweet, sometimes by the ripe fruit color. The main quality criteria are size and degree of damage, either mechanical, from insects or from diseases. The spotlessly clean fruit are separated sometimes from the fruit that are damaged, contain larvae or show bruises. Insects can also attack the fruit and sometimes larvae are found inside. Aside from this there are no strict quality control measures, since nance is most frequently sold for making juices or pulp or desserts or alcoholic beverages, than for consumption as a raw fruit. Obviously the consumer prefers a spotless fruit but many times there is not much to choose from in the market.

3.4

Preharvest factors affecting quality

Damage by some fungal diseases and attack from insects that lay eggs that evolve into larvae can occur. Sometimes leaf cutting ants (Atta sp.) can be a problem, cutting and taking pieces of the fruit which normally will render the fruit useless.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

48 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

3.5



Mixing fruit of different sizes and maturity stages causes problems, as the softer fruits get squeezed by the less soft fruits and ooze their juices. There is a tendency to pack the fruits incompetently using inadequate packing material and containers that have excessive volumes. In many instances fruit arrives squashed at the market or supermarket due to excessive size of the packing container or its roughness.

3.6


No information is available on physiological disorders of nance.

3.7


Nance plant and fruit are both very tolerant and there are very few diseases that affect them. Sooty molds, though, that live on the honey dew (secretion) that certain sucking insects leave on the plant, can be problematic.

3.8


According to Bayuelo-Jimenez (2008) there are some insects that attack nance trees, among them Macrospis festina which eats the fruits, and Oncideres dejean and Orthezia insignis which cut the branches.

3.9


Ideally the fruit should be picked from the tree just before it will drop. This is not practical and therefore it is recommended to harvest the fruits that are turning lighter green or to put a netting or canvas under the canopy so the fruit do not touch the ground when they drop. Fruits picked up from the ground are likely to have become moist and been attacked by insects like ants and others that will damage them. The fruits should be classified by size into at least three categories – small, medium and large. They should also be classified by softness and maturity stage as well as by appearance, separating fruit without blemishes from the others as well as those of different sizes or colors. Fruits of similar size and maturity stages should be packed together. Packing containers should be small, with a capacity of no more than five or six kilograms and with smooth and padded walls and bottoms. Storage temperatures should be around 9 to 13 °C as at these temperatures the fruit quality remains acceptable for 10 to 12 days. It is recommended that the fruit



49

should not be left for more than 24 hours at room temperature. Keeping fruits under water is also mentioned as a storage technique (Morton, 1987).

3.10

Processing

The most common method of processing usually involves placing the fruit with some water in a blender at low speed to separate the pulp from the stones. This pulp can then be used to make juices. Another practice is boiling the fruit with sugar to make a jam. The seeds are strained afterwards. Sometimes the fruit is candied by boiling with a larger quantity of sugar so rather than producing syrup a sweet paste is left that surrounds the seed. Fruit with excellent appearance are processed in a light syrup and sold in supermarkets in glass jars. Various alcoholic products can be made with nance fruit. Ripe and blemish free fruits can be put in a jar after washing, some sugar added and the spaces filled with water. The jars are then left in the sun until alcoholic fermentation has taken place. The resulting product is a good tasting liquor that can be stored for years. Alternatively the fruit can be put in a jar and the spaces filled with boiled water before it is left for the internal sugars to ferment. This method takes longer. Another method is to fill the jar with fruit and sugar cane alcohol (aguardiente) instead of water. The jar is left for several months so that the alcohol penetrates the pulp and at the same time takes on the flavors and aromas of the ripe fruit. When freezing the fruit it is best to use the Individually Quick Freeze (IQF) system to avoid the formation of ice crystals in the fruit. If ice crystals form they damage the fruit′s internal structure, so it will look bad once it has thawed. The fruit should be kept at −18 °C for best results after prolonged storage.

3.11

Conclusion

Nance is probably among the five or six most popular fruits in countries like Guatemala, El Salvador, Honduras and Nicaragua and is fairly popular in Mexico, Panama and parts of Brazil. However, there is very little literature available on this crop. It is normally not cultivated in technically conducted plantings and its propagation is sexual resulting in high variability. An export market for the crop already exists, as the fruit is exported to the United States and Canada where it is an ethnic product for a particular population sector. This reinforces the need for more research on this crop in order to raise its level of production, quality and commercial importance. In all probability if selected plant materials are propagated asexually (which can be done very successfully), the plants properly cultivated, and the fruit handled and stored according to the latest technical information, nance could become an interesting species to grow in some areas, especially for the export market.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

50 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

3.12


References

Barbeau G (1990), Frutas tropicales en Nicaragua, Dirección General de Técnicas Agropecuarias. Managua, Nicaragua, Editorial Ciencias Sociales. Bayuelo-Jimenez J (2008), The nance (Byrsonima crassifolia). In: Janick J and Paul R (eds). The Encyclopedia of Fruit and Nuts. Wallingford, UK, CAB International, pp 459–461. Donadio L C, Moro F V and Servidone A A (2002), Frutas Brasileiras. Jaboticabal, Sao Paulo, Brasil, Editora Novos Talentos, p 288. Duarte O and Vernon R (2002), Biología floral y reproductiva del nance (Byrsonima sp). Proc. Interamerican Soc. Trop. Hort. 46: 40–41. Morton J (1987), Fruits for Warm Climates. Greensboro, N.C., USA. Media Incorporated. Standley P C and Steyermark J A (1946), Flora de Guatemala. Fieldiana: Botany 24(5): 478–479. Velásquez de Klimo I (2006), Manejo pos cosecha del nance (Byrsonima crassifolia (L) HBK). Ministerio de Agricultura y Ganadería. San Salvador, El Salvador. IICA Frutales, Programa Nacional de Frutales. Williams L O (1981), The Useful Plants of Central America. Ceiba 24(1–2): 202–203.


Plate IV (Chapter 2) Cantaloupe melons with a closed (left) and open (right) seed cavity (courtesy Marita Cantwell). Note the thickness of the rind and the structural stability of the seeds and associated tissues.

Plate V

(Chapter 3) Nance inflorescences. Notice the change in color of the petals from yellow to orange as they get older.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Plate VI

(Chapter 3) Nance ripening fruits: some are starting to turn yellow.

Plate VII

(Chapter 4) Unpicked Noni fruit.


4 Noni (Morinda citrifolia L.) A. Carrillo-López, Autonomous University of Sinaloa, Mexico and E. M. Yahia, Autonomous University of Queretaro, Mexico

Abstract: Noni (Morinda citrifolia L.) is the small tropical evergreen tree native to South-East Asia whose whole fruit, juice, seed, leaf, bark and root are used as sources of traditional medicines by Australian aboriginal, Pacific Island and South-East Asian communities. These plant parts have shown antioxidant, antimicrobial, anti-cancer and anti-inflammatory properties. Noni cultivation has spread extensively to regions such as Mexico, Central and South America, and in recent years its economic value has grown significantly worldwide due to assertions of its health benefits. The largest markets for noni products are North America, Europe, Japan, Mexico, Asia and Australia. It is sold mainly as juice, but the fruit is also often marketed in its fresh, unprocessed form in both formal and informal markets. Optimization of agricultural techniques, postharvest practices and processing technologies for noni are required. Postharvest handling information on the fruit is quite scarce. Key words: Morinda citrifolia, noni, postharvest, processing, postharvest handling, anticancer, anti-inflammation.

4.1

Introduction

4.1.1 Origin, botany, morphology and structure The noni (Morinda citrifolia), a small evergreen tree, is native to South East Asia (Indonesia to Australia) and is a member of the Rubiaceae family. Its fruit is known worldwide by many vernacular names including Indian mulberry, hog apple, mengkudu, pain killer, gogu atoni, great morinda, jo ban, mona and kesengel, but the most widely-used commercial name is noni (Wagner et al., 1999). The plant flowers and fruits all year round, producing a small, white, perfect flower (one that has both male and female organs). The fruit develops into an oval shape, reaching 4–10 cm in length and 3–4 cm in diameter (see Plate VII in the colour section between pages 238 and 239). When ripe the fruit has a rancid cheese odor, and therefore is also known as cheese fruit. It contains many seeds,


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

52 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


which are similar in size and shape to apple seeds, but have a harder seed coat. Whereas, there have been many assertions of the health benefits of noni, no governments have yet approved any claims of its health benefits. However, the European Commission (2010) has recently authorized the placing on the market of puree and concentrate of Morinda citrifolia as a novel food ingredient. Previously, the European Commission did the same for leaves of Morinda citrifolia in 2008 (European Commission, 2008) and pasteurized noni juice in 2003 (European Commission, 2003). 4.1.2 Worldwide importance Morinda citrifolia cultivation has spread extensively to regions beyond its origin area: Mexico, Central and South America (Panama, Venezuela, Surinam). It is a source of traditional medicine in coastal Aboriginal communities in Cape York, the Pacific Islands and South East Asia, and in recent years has experienced significant economic growth worldwide due to assertions of its various health benefits. The largest markets for noni are North America, Europe, Japan, Mexico, Asia and Australia, with the worldwide market for these products estimated at US$400 million (McPherson et al., 2007). Some countries (e.g. Costa Rica and Cambodia), have increased cultivation of noni accordingly. Plate VIII in the colour section shows noni fruit in a popular market in Mexico. 4.1.3 Chemical composition Some of the physicochemical characteristics of noni fruit are as follows: water: 90%; pH: 3.72; dry matter: 9.87; total soluble solids: 8 °Brix; protein content: 2.5%; lipid content: 0.15%; glucose content: 11.97 g L−1; fructose: 8.27 g L−1; potassium: 3900 mg L−1; sodium: 214 mg L−1; magnesium: 14 mg L−1; calcium: 28 mg L−1; vitamin C: 155 mg 100 g−1 (Chunhieng 2003). The main components of the dry matter appear to be soluble solids, dietary fiber and proteins, and the main amino acids are aspartic acid, glutamic acid and isoleucine (Chunhieng et al., 2005). Minerals (mainly potassium, sulphur, calcium and phosphorus) account for 8.4% of the dry matter. Vitamins that have been reported in the noni fruit include ascorbic acid (24–158 mg 100 g−1 dry matter) (Morton, 1992; Shovic and Whistler, 2001), and provitamin A (Dixon et al., 1999). Altogether, more than 150 phytochemical compounds have been identified in the fruit and other parts of the noni plant. The major phytochemicals are phenolic compounds, organic acids and alkaloids (Wang and Su, 2001). Commonly reported phenolic compounds include antraquinones (damnacanthal, morindone and morindin), aucubin, asperuloside, and scopoletin (Wang and Su, 2001). Caproic and caprilic acids are the main organic acids (Dittmar, 1993). The principal alkaloid, at least according to Heinicke (1985) is xeronine, however this author reported no chemical characterization for the ‘alkaloid’ xeronine, nor has this subsequently been found and characterized in noni or other plant tissue by anyone else (McClatchey, 2002).


Noni (Morinda citrifolia L.)

53

Phenolic compounds have been found to be the major group of functional phytochemicals in noni juice. Damnacanthal (in root), scopoletin (plant), morindone (in root), alizarin (in root), aucubin (in plant), nordamnacanthal, rubiadin (in root), rubiadin-1-methyl ether (in root bark) and other anthraquinone glycosides have been identified (Morton, 1992; Dittmar, 1993; Dixon et al., 1999; Wang and Su, 2001). According to Farine et al. (1996), fifty-one compounds were abundant enough to be identified by gas chromatography-mass spectroscopy. The ripe fruit is characterized by a large amount of carboxylic acids, especially octanoic and hexanoic acids, but also alcohols (3-methyl-3-buten-1-ol), esters (methyl octanoate, methyl decanoate), ketones (2-heptanone), and lactones ((E)-6-dodeceno-Y-lactone) can be found (Farine et al., 1996). More recently, Pino et al. (2010) reported that ninety-six compounds were identified in noni fruit, out of which octanoic acid (about 70% of total extract) and hexanoic acid (about 8% of total extract) were found to be the major constituents. During fruit maturation and ripening, the concentrations of octanoic acid, decanoic acid and 2E-nonenal decreased, while concentration of some esters (methyl hexanoate, methyl octanoate, ethyl octanoate and methyl 4E-decenoate) increased (Pino et al., 2010). Two unsaturated esters, 3-methyl-3-buten-1-yl hexanoate and 3-methyl-3-buten-1-yl octanoate, were reported for the first time in noni fruit. Concentrations of these two constituents also significantly decreased during maturation and ripening (Pino et al., 2010). 4.1.4 Culinary uses, nutritional value and health benefits Despite its strong smell and bitter taste, the fruit is eaten either raw or cooked. South East Asians and Australian Aborigines consume the fruit raw with salt or cook it with curry. The seeds are also edible when roasted. The main use of Morinda citrifolia today, though, is in the form of a liquid tonic extracted from the fruit. An industry has developed around this fruit juice which is marketed as ‘Noni’ or ‘Noni juice’. The whole fruit of Morinda citrifolia, its juice, seeds, leaves, bark and root are recognized to possess medicinal properties and the Polynesians have been using the noni plant for food and medicinal purposes for more than 2000 years. The fruit is claimed to prevent and cure several diseases (Chan-Blanco et al., 2006; Hirazumi et al., 1994). Traditional uses of noni include the treatment of diarrhea, intestinal parasites, indigestion and stomach ulcers, diabetes, high blood pressure, headache, kidney and bladder tumors, fevers, inflamed and sore gums, sore throat with cough, toothache, arthritis, sprains and broken bones, cough, tuberculosis, asthma and respiratory afflictions, menstrual cramps, regulation of menstruation and prostate complaints, skin problems such as abscesses, boils, blemishes, wounds and infections (Macpherson et al., 2007). In particular, parts of the plant and its fruit are considered remedies for imbalances of the digestive, intestinal, respiratory and immune systems. The likely mode of action is stimulation of the immune system to fight bacterial, viral, parasitic and fungal infections and to prevent the formation and proliferation of tumors (Dixon et al., 1999).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

54 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


In recent years different parts of the noni plant have been the subject of medical research aimed at investigating noni’s effects on health. Some of these studies are discussed below. Anti-microbial effects Atkinson (1956) reported that noni inhibits the growth of certain bacteria, such as Staphylococcus aureus, Pseudomonas aeruginosa, Proteus morgaii, Bacillus subtilis, Escherichia coli, Helicobacter pylori, Salmonella and Shigella. It is claimed that the antimicrobial effect may be due to the presence of phenolic compounds such as acubin, L-asperuloside, alizarin, scopoletin and other anthraquinones. Duncan et al. (1998) also reported that the antioxidant scopoletin has an anti-microbial effect. Another study by Locher et al. (1995) showed that an acetonitrile extract of the dried fruit inhibited the growth of Pseudomonas aeruginosa, Bacillus subtilis, Escherichia coli and Streptococcus pyrogen. Saludes et al. (2002) found that ethanol and hexane extracts of noni have an anti-tubercular effect since they inhibit 89–95% the growth of Mycobacterium tuberculosis. The major components identified in the hexane extract were E-phytol, cycloartenol, stigmasterol, β-sitosterol, campesta-5,7,22-trien-3-b-ol, and the ketosteroids, stigmasta-4-en-3-one and stigmasta-4-22-dien-3-one. Other studies reported a significant antimicrobial effect on different strains of Salmonella, Shigella and E. coli (Bushnell et al., 1950; Dittmar, 1993). The antimicrobial effect in these studies was highly dependent on the stage of ripeness and processing. A greater effect was seen in ripe fruit that had not been dried. Anti-cancer properties Noni juice is a rich source of antioxidants (Wang et al., 2009) which are important in neutralizing ‘free radicals’ or particles that cause DNA damage that can lead to cancer. When mice were inoculated with Lewis lung carcinoma, those ingesting a daily dose of 15 mg of noni juice had an increase of 119% in life span (Hirazumi et al., 1994) and nine out of 22 mice with terminal cancer survived for more than 50 days. In addition, the ingestion of noni extract, combined with conventional chemotherapy in the treatment of mice with cancer, proved to increase their life spans (Hirazumi et al., 1994). Commercial noni juice has been shown to be able to prevent the formation of chemical carcinogen-DNA adducts (Wang and Su, 2001). Rats with artificially-induced cancer in specific organs were fed for one week with 10% noni juice in their drinking water. They showed reduced DNA-adduct formation, depending on sex and organ (Wang and Su, 2001). In addition, the antioxidant damnacanthal, an anthraquinone found in the plant’s root, has been characterized and has shown some important functional properties, mainly anti-carcinogenic attributes (Solomon, 1999). Anti-inflammatory and other effects Noni juice selectively inhibited COX enzyme activity in vitro and had a strong anti-inflammatory effect comparable to that of CELEBREX® and without side effects (Su et al., 2001). Kamiya et al. (2004) have demonstrated the effects of



55

noni fruit on preventing arteriosclerosis, a disease related to the oxidation of low density lipoproteins (LDL). Methanol and ethyl acetate extracts from noni inhibited copper induced LDL oxidation by 88 and 96%, respectively, using the thiobarbituric acid reactive substance method. This beneficial effect could be due to the presence of lignans and phenylpropanoid dimers (Kamiya et al., 2004). Two clinical studies also reported relief of arthritis and diabetes due to noni consumption (Elkins, 1998; Solomon, 1999). Lastly, noni juice has a low glycemic index which helps balance blood sugar levels (Macpherson et al., 2007). The antioxidant scopoletin, a coumarin was also found to have analgesic properties as well as a significant ability to control serotonin levels in the body (Levland and Larson, 1979). Safety issue The suggested link between noni juice ingestion and liver toxicity has been refuted on the basis that it is not consistent with histopathology and clinical chemistry results of subchronic oral toxicity tests in animals as well as observed laboratory values of clinical safety studies (West et al., 2006). Furthermore, the opinion of the European Food Safety Authority (EFSA, 2006) through the scientific panel on dietetic products, nutrition and allergies, was that it is unlikely that consumption of noni juice, at the observed levels of intake, induces adverse human liver effects. There is no convincing evidence for a causal relationship between the acute hepatitis observed in the case studies reported by Stadlbauer et al. (2005), Millonig et al. (2005) or Yuce et al. (2006) and the consumption of noni juice. Conversely, liver protective effects of noni juice have been demonstrated by Jensen et al. (2006).

4.2

Fruit growth, development and maturation

In Hawaii, noni fruit are harvested year round, although there are seasonal trends in the amount of flowering and fruit production that may be affected or modified by the weather and by fertilizers and irrigation. Fruit production may diminish somewhat during the winter months in Hawaii (Nelson, 2003). It is possible to find fruits at different stages of maturity on the same plant at the same time (Chan-Blanco, 2006). In Hawaii, the flowers of Morinda citrifolia develop into mature fruits over a span of at least several weeks. However, there are no published scientific data on the precise time required for fruit growth and development from fruit set to maturation and ripening. The fruit is light green when unripe, becoming whitish yellow when ripe (hard white stage). When harvested at ‘hard white’ stage, in few days the fruit turns soft and translucent yellow (Janick and Paull, 2008). A personal experience with this fruit was as follows: the noni fruit was harvested from a small orchard in Culiacán México at the ‘hard white’ ripeness stage and became very soft, with translucent yellow skin and acquired a putrid smell in two days at about 30 °C. Fruit may be picked and used at any stage of development. Fruit with the appropriate level of maturity should be selected depending on its end use.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

56 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Postharvest biology and technology of tropical and subtropical fruits Table 4.1 Skin color and firmness during noni fruit maturation and ripening Maturity stage

Color

Firmness

1 2 3 4 5

Dark green Green-yellow Pale yellow Pale yellow Translucent-grayish

Very hard Very hard Very hard Fairly hard Soft

Source: Chan-Blanco et al. (2006).

Table 4.2

Noni fruit physical characteristics

Fruit weight, g Length of fruit, cm Girth of fruit, cm Specific gravity, g mL−1 Recovery of juice (%) Pulp percentage Seed percentage

147.9 9.8 5.26 1.13 38.95–46.72 44.76–46.72 3.24–4.31

Adapted from Rethinam and Sivaraman, 2007.

The evolution of the color and firmness of fruits maturing and ripening on the tree is shown in Table 4.1. Some physical fruit characteristics of importance to noni fruit processors are shown in Table 4.2.

4.3

Preharvest conditions and postharvest handling factors affecting quality

Scientific publications about the effects of preharvest conditions and postharvest handling of noni fruit quality are scarce. At the preharvest stage, a high incidence of pathological infection such as sooty mold can reduce photosynthesis in the plant, resulting in poor plant growth and reduced fruit size and quality. Pathological disorders are treated in more detail in the following section. Singh et al. (2007) indicated that the shelf life of the fruit postharvest was up to 5–7 days in open conditions at room temperature of 25–30 °C and relative humidity of 70–75%. Mature fruit tend to change color from greenish yellow to creamy yellow from the third day onwards, whereas ripe fruit of yellowish green color, turn to white on the fifth day. Regarding weight, 12–15 g of loss in weight was found in mature fruits and about 16–18 g of loss in weight of ripe fruit. Optimum storage conditions and the effects of changing temperatures on fruit quality remain to be investigated.



4.4

57


A very severe pathological problem called ‘black flag’ has been reported from the Hawaiian area (Nelson, 2004), which is caused by phytophtora species. Infection results in extensive blight of leaves, stem and fruit and green fruit of all ages are susceptible to infection. Fruit may be infected through the flowers, epidermis, or pedicel. More often, though, fruit infection occurs through the peduncle, which joins the fruit with the stem, and progresses from the base of the fruit to the fruit apex. The entire fruit and the adjacent stems turn dark brown or black. Rotten fruit may become desiccated (‘mummified’) when dry weather follows a black flag epidemic. The disease may be controlled with foliar applications of phosphorus acid fertilizers (Nelson, 2004). Nelson and Abad (2010) reported a new species of phytophtora causing black flag. They described how this taxon’s morphology does not match any of the valid 95 Phytophthora species described to date and proposed a name for this new species: Phytophtora morindae. Another pathological problem in noni is sooty mold, a black, superficial growth of a nonparasitic fungus that utilizes the sugary exudates produced by softbodied insects such as scales and aphids. Sooty mold can easily be wiped off leaves by hand or can be controlled by a soapy water spray (Nelson, 2001). A big threat to noni cultivation in the Pacific is root-knot disease caused by nematodes (Meloidogyne spp.). Attack by nematodes severely stunts plant growth and allows the root infection by opportunistic pathogens such as the fungus Sclerotium rolfsii (Janick and Paul, 2008). Root-knot is best controlled by avoiding infection in the seedlings in the nursery, using disease-free plantlets and avoiding the introduction of nematode-infected plants to a new field. Moderate irrigation is recommended.

4.5


According to Nelson (2001), pests known to attack noni in Hawaii include aphids (Aphis gossypii), ants, scales (the green scale), mites (eriophyid mites), whiteflies (fringe guava whitefly), and slugs. Noni monocultures favor pest outbreaks; thus, the severity and frequency of pest attacks can be minimized by intercropping with other species of non-host plants. Pest outbreaks can also be prevented by the elimination of weeds that favor pests development and mites can be reduced by pruning affected leaves. According to Janick and Paul (2008) the most severe damage in Hawaii is associated with whiteflies, whereas in Micronesia the most problematic species is the leaf miner. In general, insect damage may be more severe in locations that are dry or have low rainfall.

4.6


4.6.1 Harvest operations Noni fruit are harvested by hand by picking individual fruit from the branches. After harvesting, the fruit ripens within a week at ambient temperature, and


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

58 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


therefore because of its short storage life the fruit cannot currently be transported to distant places even within the same country. According to Singh et al. (2007), harvesting fruit with the pedicel helps to maintain quality postharvest and improve market acceptability. In this study, the highest level of spoilage was observed in fruit harvested without the pedicel. 4.6.2 Packinghouse practices Fruit are placed in baskets, bags or bins for transport to the processing facility. Noni fruit do not bruise or damage easily, so usually no special padded containers or other precautions are used to prevent significant fruit damage (Nelson, 2003). However, for commercialization purposes some fruits are wrapped together in small trays (Fig. 4.1). 4.6.3 Recommended storage and shipping conditions If harvested at the ‘hard white’ ripeness stage or earlier, exposure of noni fruit to direct sunlight or to warm temperatures immediately after harvest is not a significant concern. Noni fruit are usually not refrigerated after harvest (Nelson, 2003). However, because of the increased interest in noni products, it will become important to investigate the optimal handling practices so sale of the fresh fruit outside its area of cultivation becomes possible.

Fig. 4.1

Packaged noni fruit.



4.7

59

Processing

Most noni is consumed as juice (Dixon et al., 1999). Fruit for juice production are picked at their ‘hard white’ stage a few days before they turn whitish yellow, become soft and fall from the tree. The ‘hard white’ fruit should be washed before the flesh softens, then the fruit are held at ambient or room temperature for one to several days to ripen and soften before they are processed. The juice seeps out naturally from the pulp into juice-collection containers, but it can be extracted by squeezing the fruit with a press (Janick and Paull, 2008). If ripe fruit are allowed to sit for an extended period, they begin attracting unwanted fruit flies, rats and other insects or pests, so this should not be allowed to happen. According to Nelson (2003), in Hawaii, noni fruit juice and juice products are processed and prepared by a variety of methods. ‘Traditional’ juice is drip-extracted and then fermented/aged for at least two months. The ‘non-traditional’ method of juice extraction involves pressing or squeezing the juice from ripe fruits. Noni juice may be diluted, or bottled in its pure state. Some noni juices are pasteurized, but not all (Nelson, 2003). Noni juice concentrate can be produced by flash evaporation and the pulp of the fruit is also chopped, dehydrated and powdered for use in reconstituted noni juice products in the dietary supplement industry (Nelson, 2003). For powders or fresh-cut products, fruit can be processed before it fully ripens, as unripe fruit is easier to handle with some types of chopping and drying equipment.

4.8

Conclusions

The noni (Morinda citrifolia) plant, and especially its fruit, has been used for centuries in folk medicine. The most important compounds identified in noni fruit are phenolics (such as damnacanthal and scopoletin), organic acids (caproic and caprylic acid), vitamins (ascorbic acid and provitamin A), amino acids (such as aspartic acid), and minerals. In vitro research and some animal experiments have shown that noni has antimicrobial, anti-cancer, antioxidant, anti-inflammatory, analgesic and cardiovascular activity. Consumption of noni juice is currently high, not only in the producing countries, but also in the USA, Japan and Europe, and this market interest suggests a promising future. However, to determine the real potential of this fruit, more studies are needed to identify its nutritional and functional compounds and the technological processes required to preserve them. Furthermore, studies on the postharvest handling of the fresh fruit are also still needed, due to the necessity of transporting the fruit far from the local production areas for processing or sale. Postharvest physiology (respiration rate, ethylene production rate and ethylene sensitivity), optimal ripening and storage temperatures, and other factors that affect fruit quality after harvest should be investigated.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

60 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

4.9


References

Atkinson N (1956), Antibacterial substances from flowering plants. 3. Antibacterial activity of dried Australian plants by rapid direct plate test. Australian Journal of Experimental Biology 34:17–26. Bushnell OA, Fukuda M and Makinodian T (1950), The antibacterial properties of some plants found in Hawaii. Pacific Science 4:167–183. Chan-Blanco Y, Vaillant F, Perez AM, Reynes M, Brillouet J-M and Brat P (2006), The noni fruit (Morinda citrifolia L.): A review of agricultural research, nutritional and therapeutic properties. Journal of Food Composition and Analysis 19(6–7):645–654. Chunhieng MT (2003), Développement de nouveaux aliments santé tropicale application á la noix du Brésil Bertholettia excelsa et au fruit de Cambodge Morinda citrifolia. PhD thesis, INPL, France. Chunhieng T, Hay L and Montet D (2005), Detailed study of the juice composition of noni (Morinda citrifolia) fruits from Cambodia. Fruits (Paris) 60(1):13–24. Dittmar A (1993), Morinda citrifolia L. – Use in Indigenous Samoan medicine. Journal of Herbs, Spices and Medicinal Plants 1(3):77–92. Dixon AR, McMillen H and Etkin NL (1999), Ferment this: The transformation of Noni, a traditional Polynesian medicine (Morinda citrifolia, Rubiaceae). Economic Botany 53(1):51–68. Duncan SH, Flint HJ and Stewart CS (1998), Inhibitory activity of gut bacteria against Escherichia coli O157 mediated by dietary plant metabolites. FEMS Microbiology Letters 164: 258–283. EFSA (2006). European Food Safety Authority. Opinion on a request from the Commission related to the safety of noni juice (Juice of the fruit of morinda citrifolia). EFSA Journal 376:1–12. Available from: http://www.efsa.europa.eu/en/scdocs/scdoc/376.htm [Accessed 29 July 2010]. Elkins R (1998), Hawaiian Noni (Morinda citrifolia) Prize Herb of Hawaii and the South Pacific. Woodland Publishing, Utah. European Commission (2003), Commision decision of 5 June 2003 authorising the placing in the market of noni juice (juice of the fruit of Morinda citrifolia) as a novel food ingredient under regulation (EC) No 258/97 of the European Parliament and of the council. In Official Journal of the European Union, 2003, 001. European Commission (2008), Commision decision of 15 December 2008 authorising the placing in the market of leaves of Morinda citrifolia as a novel food ingredient under regulation (EC) No 258/97 of the European Parliament and of the council. In Official Journal of the European Union, 2008. European Commission (2010), Commision decision of 21 April 2010 authorising the placing in the market of puree and concentrate of the fruits of Morinda citrifolia as a novel food ingredient under regulation (EC) No 258/97 of the European Parliament and of the council. In Official Journal of the European Union, 2010. L102/49. Available from: http://ec.europa.eu/food/food/biotechnology/novelfood/index_en.htm [Accessed 29 July 2010]. Farine, JP, Legal L, Moreteau, B, Le Quere, JL (1996), Volatile components of ripe fruits of Morinda citrifolia and their effects on Drosophila. Phytochemistry 41: 433–438. Heinicke RM (1985), The pharmacologically active ingredient of Noni. Pacific Tropical Botanical Garden Bulletin 15:10–14. Hirazumi A, Furusawa E, Chou SC and Hokama Y (1994), Anticancer activity of Morinda citrifolia (noni) on intraperitoneally implanted Lewis lung carcinoma in syngenic mice. Proceedings of the Western Pharmacological Society 37:145–146. Janick J and Paull RE (2008), The Encyclopedia of Fruit & Nuts. CAB International, London UK. pp. 954. ISBN 9780851996387. Jensen CJ, Westendorf J, Wang MY and Wadsworth, DP (2006). Noni juice protect the liver. European Journal of Gastroenterology & Hepatology 18:575–577.



61

Kamiya K, Tanaka Y, Endang H, Umar M and Satake T (2004), Chemical constituents of Morinda citrifolia fruits inhibit copper-induced low-density lipoprotein oxidation. Journal of Agricultural and Food Chemistry 52:5843–5848. Levland O and Larson HO (1979), Some chemical constituents of Morinda citrifolia. Planta Medica 36(2):186–187. Locher CP, Burch MT, Mower HF, Berestecky J, Davis H, et al. (1995), Anti-microbial activity and anti-complement activity of extracts obtained from selected Hawaiian medicinal plants. Journal of Ethnopharmacology 49:23–32. McClatchey W (2002), From Polynesian healers to health food stores: changing perspectives of Morinda citrifolia (Rubiaceae). Integrative Cancer Therapies 1(2): 110–120. Macpherson H, Daniells J, Wedding B and Davis C (2007), The potential for a new value adding industry for noni tropical fruit producers. Australian Government Rural Industries Research and Development Corporation. Publication No 07/132. p 46. Millonig G, Stadlman S and Vogel W (2005). Herbal hepatoxicity: acute hepatitis caused by a Noni preparation (Morinda citrifolia). European Journal of Gastroenterol & Hepatology 17:445–447. Morton JF (1992), The ocean-going noni or Indian mulberry (Morinda citrifolia, Rubiaceae) and some of its ‘colorful’ relatives. Economic Botany 46(3):241–256. Nelson SC (2001), Noni cultivation in Hawaii. Fruit and Nuts 4:1–4. Nelson SC (2003), Noni cultivation and production in Hawaii. In: Proceedings of the 2002 Hawaii Noni Conference. University of Hawaii at Nanoa, College of Tropical Agriculture and Human Resources, Hawaii. Nelson SC (2004), Black flag of noni (Morinda citrifolia) caused by a Phytophtora species. Honolulu (HI), University of Hawaii. p. 4 (Plant Disease; PD-19). Nelson SC and Abad ZG (2010), Phytophthora morindae, a new species causing black flag disease on noni (Morinda citrifolia L) in Hawaii. Mycologia 102(1):122–134. Pino JA, Márquez E, Quijano CE and Castro D (2010), Volatile compounds in noni (Morinda citrifolia L.) at two ripening stages. Ciencia e Tecnologia de Alimentos 30(1):183–187. Rethinam P and Sivaraman K (2007), Noni (Morinda citrifolia L.) the miracle fruit – a holistic review. International Journal of Noni Research 2(1–2):4–37. Saludes JP, Garson MJ, Franzblau SG and Aguinaldo AM (2002), Antitubercular constituents from the hexane fraction of Morinda citrifolia L. (Rubiaceae). Phytotherapic Research 16:683–685. Shovic AC and Whistler WA (2001), Food sources of provitamin A and vitamin C in the American Pacific. Tropical Science 41:199–202. Singh DR, Srivastava RC, Subhash Chand and Abhay Kumar (2007), Morinda citrifolia L. – An evergreen plant for diversification in commercial horticulture. International Journal of Noni Research 2(1–2): 45–61. Solomon N (1999), The Noni Phenomenon. Discover the powerful tropical healer that fights cancer, lowers high blood pressure and relieves chronic pain. Direct Source Publishing; ISBN: 1887938877. Stadlbauer V, Fickert P, Lackner C, Schmerlaib J, Krisper P, et al. (2005). Hepatotoxicity of Noni juice: Report of two cases. World Journal of Gastroenterology 11: 4758–4760. Su C, Wang MY, Nowicki D, Jensen J and Anderson G (2001), Selective COX-2 inhibition of Morinda citrifolia (Noni) in vitro. In: Proceedings of the Eicosanoids and other bioactive lipids in cancer, inflammation and related disease. The 7th Annual Conference, 14–17 October 2001, Loews Vanderbilt Plaza, Nashville, Tennessee, USA. Wagner WL, Herbst DH and Sohmer, SH (1999), Manual of Flowering Plants of Hawai’i (Revised Edition); University of Hawai’i Press. Wang MY, Lutfiyya MN, Weidenbacher-Hoper V, Anderson G, Su CX and West B J (2009), Antioxidant activity of noni juice in heavy smokers. Chemistry Central Journal 3(13):1–5.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

62 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Wang MY and Su C (2001), Cancer preventive effect of Morinda citrifolia (Noni). Annals of the NY Academy of Science 952:161–168. West BJ, Jensen CJ, Westendorf J and White LD (2006), A safety review of noni fruit juice. Journal of Food Science 71:R100–R106. Yuce B, Gulberg V, Diebold J and Gerbes AL (2006). Hepatitis induced by noni juice from Morinda citrifolia: a rare cause of hepatotoxicity or the tip of the iceberg? Digestion 73:167–170.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Plate VI

(Chapter 3) Nance ripening fruits: some are starting to turn yellow.

Plate VII

(Chapter 4) Unpicked Noni fruit.


Plate VIII

(Chapter 4) Picked Noni fruit on a market stall.

Plate IX (Chapter 9) Bruising and cutting damage produced during mechanical olive harvest in ‘Manzanillo’ table olives destined for California black ripe olive processing.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

5 Olive (Olea europaea L.) C. H. Crisosto and L. Ferguson, University of California, USA and G. Nanos, University of Thessaly, Greece

Abstract: Olives (Olea europaea L.) are extensively cultivated around the world today in proper climates apart from the Mediterranean region. Olives must be properly harvested, handled, processed and stored for successful high quality table olives or oil production. Most of the world table olives are processed as Spanish-style green olives and California-style black-ripe olives, but Greek-style naturally ripe olives, stuffed olives and many other types and forms of olive fruit foodstuffs are marketed around the world. Most olives are used for olive oil extraction, which is produced and consumed, not only in the Mediterranean basin, but also all over the world. Key words: Olea europaea, curing, pickled, canning, olive packed styles, chilling injury.

5.1

Introduction

5.1.1 Origin, botany, morphology and structure A member of the Oleaceae family (Olea europaea L.), is a small tree native to the eastern part of the Mediterranean region. The ancient Egyptians, Greeks, Romans and other Mediterranean nations cultivated olives for their oil and fruit. The olive is a drupe, botanically similar to other stone fruits. It consists of the carpel with the wall of the ovary developing into both fleshy and dry portions; the skin (exocarp), which is free of hairs, and contains stomata; and the pit (endocarp) enclosing the seed. The fleshy mesocarp, from which edible oil is also extracted with physical methods, is the edible portion of the olive after processing. When processed, the exocarp is also eaten. Fruit shape, size and pit size and surface morphology vary greatly among cultivars. 5.1.2 Worldwide importance and economic value Olives are one of the most extensively cultivated and fast expanding fruit crops in the world. The area under olive cultivation tripled from 2 600 000 to 8 500 000


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

64 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Postharvest biology and technology of tropical and subtropical fruits Table 5.1

Eleven largest olive producing countries

Rank

Country/region

Production (in tons)

Cultivated area (in hectares)

— 1 2 3 4 5 6 7 8 9 10 11

World Spain Italy Greece Turkey Syria Tunisia Morocco Egypt Algeria Portugal Lebanon

17 317 089 6 160 100 3 149 830 2 300 000 1 800 000 998 988 500 000 470 000 318 339 300 000 280 000 275 000

8 597 064 2 400 000 1 140 685 765 000 594 000 498 981 1 500 000 550 000 49 888 178 000 430 000 250 000

Source: http://www.internationaloliveoil.org

hectares between 1960 and 2004. The ten largest producing countries, according to the Food and Agriculture Organization, are all located in the Mediterranean region and produce 95% of the world’s olives (Table 5.1). Thus, olives are one of the few crops with such major economic importance for the region. In the Mediterranean region including southern Europe, northern Africa and the Middle East, olives and olive oil have been common ingredients of everyday foods for many centuries. Much lower consumption of olive products is found around the world, but due to the positive effects on human health, olive products are highly appreciated today in the markets worldwide. Commercial olive production is today a multimillion dollar business in California, Australia and other southern hemisphere countries. Olive oil is the major commercial product from olives including all kinds of specialty olive oils (from certain cultivars or blends, locations and growing methods), followed by table olives and their products. Only a few raw olives are marketed, usually locally for home curing. 5.1.3 Culinary uses, nutritional value and health benefits Table olives are prepared from sound, clean, and sufficiently mature fruit classified by stage of ripeness and the processing method used. Fresh harvested olive has a bitter component (oleuropein), a low sugar content (2.6–6%) compared with other drupes (12% or more) and a high oil content (12–35%) depending on the time of year, production method, location and cultivar. These characteristics make it a fruit that (almost always) cannot be consumed directly from the tree and it has to undergo a series of processes that differ considerably from region to region, and depending on variety. The bitterness is generally removed by treatment (curing) with one of the following: dilute base of sodium or potassium hydroxide (lye), salt and water (brine), dry salt or repeatedly rinsing the fruit in water at room temperature prior to canning or packing in brine solution.


Olive (Olea europaea L.)

65

Spanish-style green olive is a major processing method around the Mediterranean region and highly consumed. Most olives grown in California and an appreciable amount of fruit around the world are processed into California-style black-ripe for canning. These fruit are mainly used for salads, pizza, and even finger food. Olives can be sold in various sizes, whole, pitted, chopped, sliced, stuffed or as paste. After curing to remove bitterness, the olives are conserved or packed into brine and often some edible acid in small quantities. Lactic or acetic acid in the form of vinegar may be added to acidify the solution and prohibit further fermentation during storage. Various other methods of olive processing are used around the world. Olive oil is extracted with physical methods from olives after washing, crushing, shaking and centrifuging. The olive oil is stored, packed and marketed around the world for use as raw oil or for cooking. One serving of olives has only 2.5 grams of fat, which is only 3% of the total suggested fat intake per day. Olives contain 12–35% olive oil with the table olive cultivars usually containing less oil than the small-fruited cultivars for oil production. The fatty acid content of olive oils varies by cultivar, maturity, cultivation practices and growing area. Generally, based on the Committee of Codex Alimentarius, they are as follows: stearic acid (18:0), 0.5 to 5%; oleic (18:1), 56 to 83%; linoleic (18:2), 3.5 to 20%; linolenic (18:3), 0.1 to 1.5%; palmitic (16:0), 7.5 to 20%; palmitoleic (16:1), 0.3 to 3.5%; arachidic (20:0), 55% also increased the percentage of edible flesh to more than 60%. Fruit with < 55% skin yellowing showed more wound-induced respiration and ethylene production due to slicing and deseeding and fully ripe fruit were easily bruised and difficult to handle. Therefore, selecting fruit with 55–80% yellow skin, which ensures > 50% edible flesh recovery, has been recommended for production of fresh-cut papaya (Paull and Chen, 1997). Tissue softening in fresh-cut papaya is primarily due to changes in cell wall composition induced by the activities of various hydrolytic enzymes and stressrelated proteins. Wounding of 60–70% yellow fruit used to make fresh-cut product enhanced the activities of various enzymes such as polygalacturonase, α-galactosidase, β-galactosidase, lipoxygenase, phospholipase D, and ACC synthase and ACC oxidase within 24 h, and levels remained significantly higher compared with those in intact fruit during 8 days storage at 5 °C (Karakurt and Huber, 2003). The total amount of pectin in fresh-cut papaya also declined, increased in solubility and exhibited depolymerization. In addition, this study confirmed that tissue softening was due to the physiological and biochemical alterations in the cell wall and membranes rather than to microbial activity. Gene expression analysis of the fresh-cut papaya has also revealed that wounding induces the expression of proteins involved in membrane degradation, free radical generation, and enzymes involved in stress responses (Karakurt and Huber, 2007). It has been suggested that tissue softening in fresh-cut papaya can be delayed by treatment of 70–80% ripe fruit with 1-MCP (2.5 μL L−1 for 12 h) before slicing


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

116 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


(Ergun et al., 2006). Softening in fresh-cut product from 1-MCP-treated fruit was significantly delayed during 6–10 days storage at 5 °C. The slices from 1-MCP treated fruit were acceptable to the sensory panel for six days while those from control fruit could only be stored for 2–3 days. The potential shelf life of fresh-cut ‘Maradol’ papaya has been suggested to be 2, 6 and 10 days at storage temperatures of 20, 10 and 5 °C, respectively. The degree of tissue softening and weight loss were also lower at 5 °C compared to 10 or 20 °C (Rivera-López et al., 2005). Storage of fresh-cut papaya at 5 °C also helped to prevent losses of soluble solids, ascorbic acid, β-carotene, and antioxidant capacity. This study also showed that slices were a better shape for fresh-cut products than cubes as the latter presented higher weight loss, lower SSC and lower overall quality. Another study on the comparison of cut shapes showed that papaya flesh cut into spheres (1.55 cm radius) showed lower weight loss, firmer texture, higher SSC and ascorbic acid and lower microbial count compared to the cubes (1.4 cm side) during 10 days storage at 4 °C (Argañosa et al., 2008). Furthermore, edible coatings have great potential to reduce problems of weight and textural losses in fresh-cut products, increasing their shelf life. The application of alginate- (2 % w/v) or gellan-based (0.5 % w/v) coating formulations containing 1% ascorbic acid on fresh-cut papaya reduced weight loss through improved water vapour resistance and delayed tissue softening during eight days storage at 4 °C (Tapia et al., 2008). González-Aguilar et al. (2009) reported that a medium molecular weight chitosan coating (0.02 g mL−1) maintained the quality of fresh-cut papaya in terms of higher colour values (L* and b*) and firmness. It showed antimicrobial activity and suppressed plate counts of mesophiles, moulds and yeasts during 14 days of storage at 5 °C. To summarize, the huge research interest in fresh-cut products has led to the development of techniques that involve minimum use of synthetic food additives which result in better retention of fruit quality. Both technological developments and consumer preferences indicate great scope for expansion of the fresh-cut papaya industry. 6.10.2 Other processed products Ripe papaya fruit can be processed into a number of other products such as pure juice, blended beverages, jam, jelly, dehydrated, fruit bars, candy, intermediate moisture and frozen products. Purée is the major intermediate product of papaya. It is further processed into products like juice, nectar, jam, jelly and leather. The slices and chunks of semi-ripe fruit can also be canned.

6.11

Conclusions

Papaya fruit is a rich source of vitamins, minerals and dietary antioxidants. The mature unripe and ripe fruit including seeds have been used in traditional medicine since ancient times. There is a great demand for papaya fruit in the fresh market and processing industry. A consistent supply of high quality fruit to the consumers


Papaya (Carica papaya L.)

117

and processors is a great challenge for papaya industry around the world. The tropical environmental conditions, where the papayas are grown, are congenial for the development of various diseases and insect-pests, and for promoting postharvest losses in fruit. The lack of cold chain, proper postharvest handling facilities, and limited market access due to phytosanitary requirements could be some of the reasons for the small share of major papaya producing countries in the world trade. Harvest maturity in papaya is a critical factor that determines fruit quality, shelf life, storage/shipping potential at low temperature, and susceptibility to mechanical injuries and diseases. Harvesting at colour break stage (10–12% yellow) is a commercial practice to ensure better postharvest life and long-distance shipping of fruit. The fruit harvested before optimum maturity fail to develop good eating quality. The delayed harvesting (>25% yellow) improves fruit quality, but limits shelf life and increases susceptibility to fruit-fly attack. The harvest maturity should therefore be determined by considering all these factors. Fruit harvested at colour break stage can be stored for 2–3 weeks at 7–13 °C temperature and 90–95% relative humidity. Fruit at advanced stages of ripeness are more tolerant to chilling conditions compared to less mature ones. The delicate nature of fruit skin predisposes it to mechanical injuries during harvest and postharvest handling operations, resulting in increased susceptibility of fruit to rots caused by wound pathogens. The marketability of fruit can be significantly increased by proper care to avoid the mechanical injuries and weight loss. MAP of papaya fruit with very low permeability films is beneficial to retard weight loss, fruit ripening and alleviate chilling injury during cold storage. The benefits associated with blocking of ethylene action by 1-MCP can be obtained only if the fruit are treated at >25% skin yellowing stage. The possibility of integration of 1-MCP into the current papaya handling protocol is limited because fruit treated at colour break stage fail to soften and produce ‘rubbery’ texture. However, the exposure of quarter- to half-ripe fruit to 1-MCP can delay the fruit softening and provide some benefits at the retail end. The phytosanitary treatments such as vapour heat, forced hot air and irradiation have been adopted commercially for fruit to be exported to countries such as the U.S.A. (mainland), Japan, Australia and New Zealand. The response of papaya fruit to these treatments varies greatly due to a number of factors including fruit maturity and growing conditions. The thermal treatments have been shown to cause some damage to fruit quality; while irradiation has been proven to be a safe technology without adverse effects on fruit quality. The postharvest diseases such as anthracnose, Rhizopus rot and stem-end rot are responsible for huge economic losses in fruit. The incidence and severity of these diseases can be reduced by integrated management practices such as orchard hygiene, preharvest and postharvest fungicide applications, packinghouse sanitation, heat treatments, and use of GRAS compounds alone or in combination with biocontrol agents. There is a great demand for fruit in the fresh-cut and processing industries. The fruit at 75% ripe stage are the most suitable for fresh-cut products, which can be safely handled at 5 °C for 5–10 days. The ‘tissue-softening’ is commonly a limiting


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

118 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


factor in the stability of the fresh-cut papaya. This problem can be minimized by treatment of fruit with 1-MCP before cutting. The fruit can also be processed into a number of products such as puree, juice, jam, jelly, fruit bars, etc. The demand for healthy and nutritious fruits and their products is increasing as the consumers are adopting a healthy lifestyle. These trends present a positive outlook for the papaya industry in the near future.

6.12

References

Akamine EK (1959), ‘Effects of carbon dioxide on quality and shelf-life of papaya’, Hawaii Agricultural Experiment Station Technical Progress Report No. 120. Akamine EK and Arisumi T (1953), ‘Control of postharvest storage decay of fruits of papaya (Carica papaya L.) with special reference to the effect of hot water’, Proceedings of the American Society for Horticultural Science, 61, 270–274. Akamine EK and Goo T (1971a), ‘Relationship between surface color development and total soluble solids in papaya’, HortScience, 6, 567–568. Akamine EK and Goo T (1971b), ‘Respiration of gamma irradiated fresh fruit’, Journal of Food Science, 36, 1074–1077. Akamine EK and Moy JH (1983), ‘Delay in postharvest ripening and senescence of fruits’, in Josephson E S and Peterson M S, Preservation of Food by Ionizing Radiation, Boca Raton, FL, USA, CRC Press III, 129–158. Ali ZM, Chin LH and Lazan H (2004), ‘A comparative study on wall degrading enzymes, pectin modifications and softening during ripening of selected tropical fruits’, Plant Science, 167, 317–327. Ali ZM, Ng S, Othman R, Goh L and Lazan H (1998), ‘Isolation, characterization and significance of papaya β-galactanases to cell wall modification and fruit softening during ripening’, Physiologia Plantarum, 104, 105–115. Alvarez AM (1980), ‘Improved marketability of fresh papaya by shipment in hypobaric containers’, HortScience, 15, 517–518. Alvarez AM and Nishijima WT (1987), ‘Postharvest diseases of papaya’, Plant Disease, 71, 681–686. Anonymous (2010), Papain production. http://practicalaction.org/docs/technical_ information_service/papain.pdf (Accessed on 02.08.2010). Argañosa ACS J, Raposo MFJ, Teixeira PCM and Morais AMMB (2008), ‘Effect of cuttype on quality of minimally processed papaya’, Journal of the Science of Food and Agriculture, 88, 2050–2060. Armstrong JW, Hansen JD, Hu BKS and Brown, SA (1989), ‘High–temperature, forced air quarantine treatment for papaya infested with Tephritid fruit flies (Diptera: Tephritidae)’, Journal of Economic Entomology, 82, 1667–1674. Armstrong JW and Mangan RL (2007), ‘Commercial quarantine heat treatments’, in Tang J, Mitcham E, Wang S and Lurie S, Heat Treatments for Postharvest Pest Control, Wallingford, UK, CAB International, 311–340. Azevedo IG, Oliveira JG, da Silva MG, Pereira T, Correa SF, et al. (2008), ‘P-type H+ATPases activity, membrane integrity, and apoplastic pH during papaya fruit ripening’, Postharvest Biology and Technology, 48, 242–247. Balock JW, Burditt AKJ, Seo ST and Akamine EK (1966), ‘Gamma radiation as a quarantine treatment for Hawaiian fruit flies’, Journal of Economic Entomology, 59, 202–204. Bautista-Baños S, Hernández-López M, Bosquez-Molina E and Wilson CL (2003), ‘Effects of chitosan and plant extracts on growth of Colletotrichum gloeosporioides, anthracnose levels and quality of papaya fruit’, Crop Protection, 22, 1087–1092.



119

Bosquez-Molina E, Ronquillo-de Jesús E, Bautista-Baños S, Verde-Calvo JR and MoralesLópez J (2010), ‘Inhibitory effect of essential oils against Colletotrichum gloeosporioides and Rhizopus stolonifer in stored papaya fruit and their possible application in coatings’, Postharvest Biology and Technology, 57, 132–137. Bron IU and Jacomino AP (2006), ‘Ripening and quality of “Golden” papaya fruit harvested at different maturity stages’, Brazilian Journal of Plant Physiology, 18, 389–396. Calegario FF, Puschmann R, Finger FL and Costa AFS (1997), ‘Relationship between peel color and fruit quality of papaya (Carica papaya L.) harvested at different maturity stages’, Proceedings of the Florida State Horticultural Society, 110, 228–231. Camargo RJ, Tadini CC and Sabato SF (2007), ‘Physical–chemical analyses of irradiated papayas (Carica papaya L.)’, Radiation Physics and Chemistry, 76, 1866–1868. Cappellini RA, Ceponis MJ and Lightner GW (1988), ‘Disorders in apricot and papaya shipments to the New York market, 1972–1985’, Plant Disease, 72, 366–368. Cenci SA, Soares AG, Mendes de Souza ML and Balbino JMS (1997), ‘Study of storage sunrise “Solo” papaya fruit under controlled atmosphere’, Seventh International Controlled Atmosphere Research Conference. Volume 3: Fruits other than apples and pears, Postharvest Horticulture Series – Department of Pomology, University of California, 17, 205–211. Chan HT Jr (1986), ‘Effects of heat treatments on the ethylene-forming enzyme system in papaya’, Journal of Food Science, 51, 581–583. Chan HT Jr (1988), ‘Alleviation of chilling injury in papayas’, HortScience, 23, 868–870. Chan HT Jr, Hibbard KL, Goo T and Akamine EK (1979), ‘Sugar composition of papayas during fruit development’, HortScience, 14, 140–141. Chan YK (2009), ‘Breeding papaya (Carica papaya L.)’ in Jain SM and Priyadarshan PM, Breeding Plantation Tree Crops: Tropical Species, New York, Springer, 121–159. Chan YK and Paull RE (2008), ‘Caricaceae’, in Janick J and Paull RE, The Encyclopaedia of Fruit & Nuts, Wallingford, UK, CAB International, 237–247. Chandrika UG, Jansz ER, Wickramasinghe SN and Warnasuriya ND (2003), ‘Carotenoids in yellow- and red-fleshed papaya (Carica papaya L)’, Journal of the Science of Food and Agriculture, 83, 1279–1282. Chau KF and Alvarez AM (1983), ‘Effects of low pressure storage on Colletotrichum gloeosprioides and postharvest infection of papaya’, HortScience, 18, 953–955. Chen NJ, Manenoi A and Paull RE (2007), ‘Papaya postharvest physiology and handling – problems and solutions’, Acta Horticulturae, 740, 285–294. Chen NJ and Paull RE (1986), ‘Development and prevention of chilling injury in papaya fruit’, Journal of the American Society for Horticultural Science, 111, 639–643. Chen NJ and Paull RE (2003), ‘Endoxylanase expressed during papaya fruit ripening: purification, cloning and characterization’, Functional Plant Biology, 30, 433–441. Couey HM and Hayes CF (1986), ‘Quarantine procedures for Hawaiian papaya using fruit selection and a two-stage hot-water immersion’, Journal of Economic Entomology, 79, 1307–1314. de Capdeville G, Teixeira Souza MJ, Pereira Santos JR, de Paula Miranda S, Rodrigues Caetano A and Gonçalves Torres FA (2007), ‘Selection and testing of epiphytic yeasts to control anthracnose in post-harvest of papaya fruit’, Scientia Horticulturae, 111, 179–185. Devitt LC, Fanning K, Dietzgen RG and Holton TA (2010), ‘Isolation and functional characterization of a lycopene beta-cyclase gene that controls fruit colour of papaya (Carica papaya L.)’, Journal of Experimental Botany, 61, 33–39. Di-Mascio P, Kaiser S and Sies H (1989), ‘Lycopene as the most efficient biological carotenoid singlet oxygen quencher’, Archives of Biochemistry and Biophysics, 274, 532–538. Eloisa M, Reyes Q and Paull RE (1994), ‘Skin freckles on solo papaya fruit’, Scientia Horticulturae, 58, 31–39. Ergun M and Huber DJ (2004), ‘Suppression of ethylene perception extends shelf-life and quality of “Sunrise Solo” papaya fruit at both pre-ripe and ripe stages of development’, European Journal of Horticultural Science, 69, 184–192.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

120 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Ergun M, Huber DJ, Jeong J and Bartz JA (2006), ‘Extended shelf life and quality of freshcut papaya derived from ripe fruit treated with the ethylene antagonist 1-methylcyclopropene’, Journal of the American Society for Horticultural Science, 131, 97–103. FAOSTAT (2010), http://faostat.fao.org/site/567/DesktopDefault.aspx? PageID=567#ancor (accessed on 20.01.2010). Fabi JP, Cordenunsi BR, De Mattos Barreto GP, Mercadante AZ, Lajolo FM and Do Nascimentoit JRO (2007), ‘Papaya fruit ripening: response to ethylene and 1-methylcyclopropene (1-MCP)’, Journal of Agricultural and Food Chemistry, 55, 6118–6123. Fabi JP, Cordenunsi BR, Seymour GB, Lajolo FM and Oliveira do Nascimento JR (2009), ‘Molecular cloning and characterization of a ripening-induced polygalacturonase related to papaya fruit softening’, Plant physiology and biochemistry, 47, 1075–1081. Firmin A (1997), ‘Physicochemical changes in papaya during storage’, Tropical Science, 37, 49–51. Flath RA and Forrey RR (1977), ‘Volatile components of papaya (Carica papaya L., Solo variety)’, Journal of Agricultural and Food Chemistry, 25, 103–109. Flath RA, Light DM, Jang EB, Mon TR and John JO (1990), ‘Headspace examination of volatile emission from ripening papaya (Carica papaya L., Solo variety)’, Journal of Agricultural and Food Chemistry, 38, 1060–1063. Follett PA (2009), ‘Generic radiation quarantine treatments: the next steps’, Journal of Economic Entomology, 102, 1399–1406. Follett PA and Neven LG (2006), ‘Current trends in quarantine entomology’, Annual Review of Entomology, 51, 359–385. Follett PA and Weinert E (2009), ‘Comparative radiation dose mapping of single fruit type and mixed-fruit boxes for export from Hawaii’, Journal of Food Processing and Preservation, 33, 231–244. Gamagaea SU, Sivakumara D and Wijesundera RLC (2004), ‘Evaluation of post-harvest application of sodium bicarbonate-incorporated wax formulation and Candida oleophila for the control of anthracnose of papaya’, Crop Protection, 23, 575–579. Gamagaea SU, Sivakumara D, Wilson Wijeratnama RS and Wijesundera RLC (2003), ‘Use of sodium bicarbonate and Candida oleophila to control anthracnose in papaya during storage’, Crop Protection, 22, 775–779. Ghanta PK (1994), ‘Physico–chemical changes in papaya cv. Ranchi during fruit development and maturity’, South Indian Horticulture, 42, 231–235. Giovannucci E (1999), ‘Tomatoes, tomato-based products, lycopene, and cancer: review of the epidemiologic literature’, Journal of the National Cancer Institute, 91, 317–331. González-Aguilar GA, Buta JG and Wang CY (2003), ‘Methyl jasmonate and modified atmosphere packaging (MAP) reduce decay and maintain postharvest quality of papaya “Sunrise” ’, Postharvest Biology and Technology, 28, 361–370. Hallman GJ (2000), ‘Factors affecting quarantine heat treatment efficacy’, Postharvest Biology and Technology, 21, 95–101. Hatton TT Jr and Reeder WF (1969), ‘Controlled atmosphere storage of papayas (1968)’, Proceedings of the American Society for Horticultural Science Tropical Region, 13, 251–256. Heidlas J, Lehr M, Idstein H and Schreier P (1984), ‘Free and bound terpene compounds in papaya (Carica papaya, L.) fruit pulp’, Journal of Agricultural and Food Chemistry, 32, 1020–1021. Hernandez Y, Lobo MG and González M (2009), ‘Factors affecting sample extraction in the liquid chromatographic determination of organic acids in papaya and pineapple’, Food Chemistry, 114, 734–741. Hodges DM and Toivonen PMA (2008), ‘Quality of fresh-cut fruits and vegetables as affected by exposure to abiotic stress’, Postharvest Biology and Technology, 48, 155–162.



121

Hofman PJ, Jobin-Décor M, Meiburg GF, Macnish AJ and Joyce DC (2001), ‘Ripening and quality responses of avocado, custard apple, mango and papaya fruit to 1-methylcyclopropene’, Australian Journal of Experimental Agriculture, 41, 567–572. Ido PJ (1976), ‘The effect of leaf pruning on yield and quality of “Solo” papayas in Hawaii’, Proceedings of the American Society for Horticultural Science Tropical Region, 101, 45–50. Isabelle M, Lee BL, Lim MT, Koh WP, Huang D and Ong CN (2010), ‘Antioxidant activity and profiles of common fruits in Singapore’, Food Chemistry, 123, 77–84. Jones WW and Kubota H (1940), ‘Some chemical and respirational changes in the papaya fruit during ripening and the effects of cold storage on these changes’, Plant Physiology, 15, 711–717. Karakurt Y and Huber DJ (2003), ‘Activities of several membrane and cell-wall hydrolases, ethylene biosynthetic enzymes, and cell wall polyuronide degradation during lowtemperature storage of intact and fresh-cut papaya (Carica papaya) fruit’, Postharvest Biology and Technology, 28, 219–229. Karakurt Y and Huber DJ (2007), ‘Characterization of wound-regulated cDNAs and their expression in fresh-cut and intact papaya fruit during low-temperature storage’, Postharvest Biology and Technology, 44, 179–183. Katague DB and Kirch ER (1965), ‘Chromatographic analysis of the volatile components of papaya fruit’, Journal of Pharmaceutical Sciences, 54, 891–894. Krishna KL, Paridhavi M and Patel JA (2008), ‘Review on nutritional, medicinal and pharmacological properties of papaya (Carica papaya Linn.)’, Natural Product Radiance, 7, 364–373. Lam, PF (1990), ‘Respiration rate, ethylene production and skin colour change of papaya at different temperatures’, Acta Horticulturae, 257–266. Lazan H, Ng S, Goh L and Ali ZM (2004), ‘Papaya β-galactosidase/galactanase isoforms in differential cell wall hydrolysis and fruit softening during ripening’, Plant Physiology and Biochemistry, 42, 847–853. Lazan H, Selamat MK and ALi ZM (1995), ‘β-Galactosidase, polygalacturonase and pectinesterase in differential softening and cell wall modification during papaya fruit ripening’, Physiologia Plantarum, 95, 106–112. MacLeod AJ and Pieris NM (1983), ‘Volatile components of papaya (Carica papaya L.) with particular reference to glucosinolate products’, Journal of Agricultural and Food Chemistry, 31, 1006–1008. Maharaj R and Sankat CK (1990), ‘Storability of papayas under refrigerated and controlled atmosphere’, Acta Horticulturae, 269, 375–385. Manenoi A, Bayogan ERV, Thumdee S and Paull RE (2007), ‘Utility of 1-methylcyclopropene as a papaya postharvest treatment’, Postharvest Biology and Technology, 44, 55–62. Manenoi A and Paull RE (2007), ‘Papaya fruit softening, endoxylanase gene expression, protein and activity’, Physiologia Plantarum, 131, 470–480. Martinez ORZ (1988), ‘Estudio preliminar sobre el rendimiento de la papaya, Carica papaya L. var. “Sunrise Solo”. Mediate raleo de frutas’, Proceedings of the InterAmerican Society for Tropical Horticulture, 32, 74–78. Morton JF (1987), Fruits of Warm Climates, Winterville, U.S.A., Creative Resources, Inc., 336–346. Moy JH (1993), ‘Efficacy of irradiation vs thermal methods as quarantine treatments for tropical fruits’, Radiation Physics and Chemistry, 42, 269–272. Moy JH and Wong L (2002), ‘The efficacy and progress in using radiation as a quarantine treatment of tropical fruits: a case study in Hawaii’, Radiation Physics and Chemistry, 63, 397–401. Nakasone HY (1986), ‘Papaya’, in Monselise PS, CRC Handbook of Fruit Set and Development, Boca Raton, FL, CRC Press, Inc., 277–301. Nazeeb M and Broughton WJ (1978), ‘Storage conditions and ripening of papaya “Bentong” and “Taiping” ’, Scientia Horticulturae, 9, 265–277.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

122 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Nishijima KA, Miura K, Armstrong JW, Brown SA and Hu BKS (1992), ‘Effect of forced, hot-air treatment of papaya fruit on fruit quality and incidence of postharvest diseases’, Plant Disease, 76, 723–727. Nishijima WT (1995), ‘Effect of hot-air and hot-water treatments of papaya fruits on fruit quality and incidence of diseases’, Acta Horticulturae, 370, 121–127. Nunes MCN, Emond JP and Brecht JK (2006), ‘Brief deviations from set point temperatures during normal airport handling operations negatively affect the quality of papaya (Carica papaya) fruit’, Postharvest Biology and Technology, 41, 328–340. O’Connor-Shaw RE, Roberts R, Ford AL and Nottingham SM (1994), ‘Shelf life of minimally processed honeydew, kiwifruit, papaya, pineapple and cantaloupe’, Journal of Food Science, 59, 1202–1206. Paull RE (1993), ‘Pineapple and Papaya’, in Seymour GB, Taylor JE and Tucker GA, Biochemistry of Fruit Ripening, London, UK, Chapman & Hall, 291–323. Paull RE (1995), ‘Preharvest factors and the heat sensitivity of field grown ripening papaya fruit’, Postharvest Biology and Technology, 6, 167–175. Paull RE (1996), ‘Ripening behavior of papaya (Carica papaya L.) exposed to gamma irradiation’, Postharvest Biology and Technology, 7, 359–370. Paull RE (1999), ‘Effect of temperature and relative humidity on fresh commodity quality’, Postharvest Biology and Technology, 15, 263–277. Paull RE and Chen NJ (1983), ‘Postharvest variation in cell wall-degrading enzymes of papaya (Carica papaya L.) during fruit ripening’, Plant Physiology, 72, 382–385. Paull RE and Chen NJ (1989), ‘Waxing and plastic wraps influence water loss from papaya fruit during storage and ripening’, Journal of the American Society for Horticultural Science, 114, 937–942. Paull RE and Chen NJ (1990), ‘Heatshock response in field-grown ripening papaya fruit’, Journal of the American Society for Horticultural Science, 115, 623–631. Paull RE and Chen NJ (2000), ‘Heat treatment and fruit ripening’, Postharvest Biology and Technology, 21, 21–37. Paull RE and Chen W (1997), ‘Fresh-cut of papaya (Carica papaya L.) and the physiology of halved fruit’, Postharvest Biology and Technology, 12, 93–99. Paull RE, Gross K and Qiu YX (1999), ‘Changes in papaya cell walls during fruit ripening’, Postharvest Biology and Technology, 16, 79–89. Paull RE, Irikura B, Wu P, Turano H, Chen NJ, et al. (2008), ‘Fruit development, ripening and quality related genes in the papaya genome’, Tropical Plant Biology, 1, 246–277. Paull RE and McDonald RE (1994), ‘Heat and cold treatments’, in Paull RE and Armstrong JW, Insect Pests and Fresh Horticultural Products: Treatments and Responses, Wallingford, UK, CAB International, 191–222. Paull RE, Nishijima WT, Reyes M and Cavaletto C (1997), ‘Postharvest handling and losses during marketing of papaya (Carica papaya L.)’, Postharvest Biology and Technology, 11, 165–179. Peleg M and Brito LG (1974), ‘External color as a maturity of papaya fruits’, Journal of Food Science, 39, 701–703. Pérez-Carrillo E and Yahia EM (2004), ‘Effect of postharvest hot air and fungicide treatments on the quality of “Maradol” papaya (Carica papaya L.)’, Journal of Food Quality, 27, 127–139. Pino JA, Almora K and Marbot R (2003), ‘Volatile components of papaya (Carica papaya L., Maradol variety) fruit’, Flavour and Fragrance Journal, 18, 492–496. Qiu YX, Nishina MS and Paull RE (1995), ‘Papaya fruit growth, calcium uptake, and fruit ripening’, Journal of the American Society for Horticultural Science, 120, 246–253. Quintana MEG and Paull RE (1993), ‘Mechanical injury during postharvest handling of “Solo” papaya fruit’, Journal of the American Society for Horticultural Science, 118, 618–622.



123

Raja ME (2010), ‘Boron nutrition on yield and postharvest life of papaya in semi arid tropics of South India’, Acta Horticulturae, 851, 513–518. Rivera-López J, Vázquez-Ortiz FA, Ayala-Zavala JF, Sotelo-Mundo RR and GonzálezAguilar GA (2005), ‘Cutting shape and storage temperature affect overall quality of fresh-cut papaya cv. “Maradol” ’, Journal of Food Science, 70, S482–S489. Rossetto MRM, Oliveira do Nascimento JR, Purgatto E, Fabi JP, Lajolo FM and Cordenunsi BR (2008), ‘Benzylglucosinolate, benzylisothiocyanate, and myrosinase activity in papaya fruit during development and ripening’, Journal of Agricultural and Food Chemistry, 56, 9592–9599. Selveraj Y, Pal DK, Subramanyam MD and Iyer CPA (1982a), ‘Changes in the chemical composition of four cultivars of papaya (Carica papaya L.) during growth and development’, Journal of Horticultural Science, 57, 135–143. Selveraj Y, Pal DK, Subramanyam MD and Iyer CPA (1982b), ‘Fruit set and developmental pattern of fruits of five papaya varieties’, Indian Journal of Horticulture, 39, 50–56. Seo ST, Farias GB and Harris EJ (1982), ‘Oriental fruit fly: ripening of fruit and its effect on index of infestation of Hawaiian papayas’, Journal of Economic Entomology, 75, 173–178. Seo ST, Hu BKS, Komura M, Lee CYL and Harris EJ (1974), ‘Dacus dorsalis: Vapor heat treatment in papaya’, Journal of Economic Entomology, 67, 240–242. Sharp JL (1993), ‘Heat and cold treatments for postharvest quarantine disinfestation of fruit flies (Diptera: Tephritidae) and other quarantine pests’, The Florida Entomologist, 76, 212–218. Shiga TM, Fabi JP, do Nascimento JRO, Petkowicz CLD, Vriesmann LC, et al. (2009), ‘Changes in cell wall composition associated to the softening of ripening papaya: evidence of extensive solubilization of large molecular mass galactouronides’, Journal of Agricultural and Food Chemistry, 57, 7064–7071. Singh SP (2010), ‘Prospective and retrospective approaches to postharvest quality management of fresh guava (Psidium guajava L.) fruit in supply chain’, Fresh Produce, 4, 36–48. Singh SP and Rao DVS (2005a), ‘Effect of modified atmosphere packaging (MAP) on the alleviation of chilling injury and dietary antioxidants levels in “Solo” papaya during low temperature storage’, European Journal of Horticultural Science, 70, 246–252. Singh SP and Rao DVS (2005b), ‘Quality assurance of papaya (Carica papaya L. cv. “Solo”) by shrink film wrapping during storage and ripening’, Journal of Food Science and Technology, 42, 523–525. Tapia MS, Rojas-Graü MA, Carmona A, Rodríguez FJ, Soliva-Fortuny R and Martin-Belloso O (2008), ‘Use of alginate- and gellan-based coatings for improving barrier, texture and nutritional properties of fresh-cut papaya’, Food Hydrocolloids, 22, 1493–1503. Thompson AK and Lee GR (1971), ‘Factors affecting the storage behaviour of papaya fruit’, Journal of Horticultural Science, 46, 511–516. USDA–APHIS (2006), ‘Treatments for fruits and vegetables. Rules and Regulations’, Federal Register, 71, 4451–4464. Wall MM (2006), ‘Ascorbic acid, vitamin A, and mineral composition of banana (Musa sp.) and papaya (Carica papaya) cultivars grown in Hawaii’, Journal of Food Composition and Analysis, 19, 434–445. Wang DN and Ko WH (1975), ‘Relationship between deformed fruit diseases of papaya and boron deficiency’, Phytopathology, 65, 445–447. Wills RBH and Widjanarko SB (1995), ‘Changes in physiology, composition and sensory characteristics of Australian papaya during ripening’, Australian Journal of Experimental Agriculture, 35, 1173–1176. Wills RBH and Widjanarko SB (1997), ‘Effects of storage at subambient temperatures on ripening of Australian papaya’, Australian Journal of Experimental Agriculture, 37, 127–129.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

124 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Yahia EM (1991), ‘Responses of papaya to insecticidal atmospheres (in Spanish)’, Proceedings of the Inter American Society for Tropical Horticulture, 35, 84–100. Yahia EM (1993), ‘Responses of some tropical fruits to insecticidal atmospheres’, Acta Horticulturae, 343, 371–376. Yahia EM (1998), ‘Modified and controlled atmospheres for tropical fruits’, Horticultural Reviews, 22, 123–183. Yahia EM, Rivera-Dominguez M and Hernandez O (1992), ‘Responses of papaya to shortterm insecticidal oxygen atmospheres’, Journal of the American Society for Horticultural Science, 117, 96–99. Yahia EM and Singh SP (2009), ‘Tropical fruits’, in Yahia EM, Modified and Controlled Atmospheres for the Storage, Transportation and Packaging of Horticultural Commodities Boca Raton, FL, CRC Press, 397–432. Zee FT, Nishina MS, Chan HTJ and Nishijima KA (1989), ‘Blossom end defects and fruit fly infestation in papayas following hot water quarantine treatment’, HortScience, 24, 323–325. Zhang LX and Paull RE (1990), ‘Ripening behaviour of papaya genotypes’, HortScience, 25, 454–455. Zhao M, Moy JH and Paull RE (1996), ‘Effect of gamma-irradiation on ripening papaya pectin’, Postharvest Biology and Technology, 8, 209–222. Zhou L, Christopher DA and Paull RE (2000), ‘Defoliation and fruit removal effects on papaya fruit production, sugar accumulation, and sucrose metabolism’, Journal of the American Society for Horticultural Science, 125, 644–652. Zhou L and Paull RE (2001), ‘Sucrose metabolism during papaya (Carica papaya) fruit growth and ripening’, Journal of the American Society for Horticultural Science, 126, 351–357.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Plate X

(Chapter 5) Trunk shaking harvester in high density hedgerow orchard.

(A)

(B)

Plate XI (Chapter 6) Effect of modified atmosphere packaging (MAP) on shelf life of ‘Red Lady’ papaya. Fruit were harvested at colour break stage, treated with fungicide (prochloraz; 100 ppm) and sealed in Cryovac® D-955 film. A. Storage for 12 days in MA plus 2 days in ambient air (2 weeks in total) at room temperature (RT; 26–32 °C, 32–45% RH) (D. V. Sudhakar Rao, unpublished). B. Storage for 21 days in MA plus 7 days in ambient air (4 weeks in total) at 18 °C, 72–80% RH (D. V. Sudhakar Rao, unpublished).


(a) (b)

(c) (d)

Plate XII (Chapter 6) Effect of exogenous application of ethylene on fruit ripening in ‘Red Lady’ papaya harvested at colour break stage. Ethylene (a & b) and control (c & d) fruit after 3 and 7 days at room temperature (RT; 26–32 °C, 46–65% RH) (D. V. Sudhakar Rao, unpublished).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

7 Passion fruit (Passiflora edulis Sim.) W. C. Schotsmans, Institute of Agricultural Research and Technology, Spain and G. Fischer, National University of Colombia, Colombia

Abstract: The species Passiflora edulis (sour passion fruit), is native from Brazil and is known in two forms, the purple and the yellow passion fruit. It is a climacteric fruit that quickly respires and produces a high amount of ethylene after harvest leading to a shorter shelf life for storage and transportation. The main quality issue is shrivelling due to water loss which affects consumer purchase decisions. Skin colour can be used as a maturity index for both the purple and the yellow form. For purple passion fruit storage at 4–5 °C is optimal whereas for yellow passion fruit a higher temperature of 10 °C is recommended. Both should be stored under high relative humidity to prevent water loss and shrivelling. Key words: Passiflora edulis, passion fruit, postharvest, processing, juice.

7.1

Introduction

7.1.1 Origin, botany, morphology and structure Sour passion fruit (Passiflora edulis Sim.) is a perennial vine of the Passifloraceae family (Rodriguez-Amaya, 2003). The Passifloraceae family consists of 18 genera one of which is the Passiflora genus with 530 species of which 50–60 are edible. The highest genetic diversity in Passifloraceae species is found in Colombia, where 167 species have been found, of which 165 were native, followed by Brazil (127 species) and Ecuador (90). This confirms the Andean area to be the birthplace of the genus (Ocampo Pérez et al., 2007). The species P. edulis (sour passion fruit) in particular however, is native from Brazil and is the species that dominates in the commercial orchards (Bernacci et al., 2008). Within this species, two distinct forms can be distinguished, the purple (often referred to as P. edulis f. edulis), and the yellow (mostly referred to as P. edulis f. flavicarpa Deg.). However, officially only P. edulis is accepted and P. edulis ‘Flavicarpa’ is considered a cultivar (Bernacci et al., 2008). Both have a similar round shape with


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

126 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


a leathery skin containing aromatic juicy pulp with small seeds. However, besides the difference in colour they also differ in certain other properties as will be discussed later on. The purple passion fruit is mainly cultivated in Africa and Australasia and the yellow passion fruit in South America. General names for both in Spanish are granadilla, parcha, maracuyá (mainly used for the yellow), gulupa (mainly used for the purple); in Portuguese, maracuja peroba, maracujazeiro; in French, grenadille, or couzou, adding the colour to distinguish between the yellow and purple form. The vine is woody and perennial with shallow roots and climbs with the aid of tendrils. The vines can be supported by trellises (commercial plantations) or by wires in small domestic farms (Rodriguez-Amaya, 2003) or garden walls in gardens. It can grow very fast (4.5–6 m per year) but has a relatively short life (3 to 6 years) (Morton, 1987; Rodriguez-Amaya, 2003). The leaves are evergreen, alternate and deeply three-lobed when mature. They are 7.5–20 cm long, glossy green on the upper surface, paler and dull beneath. Leaves, young stems and tendrils, especially those of the yellow form are tinged with red or purple. The plant generally begins to bear fruit in one to three years, but in Colombia purple passion fruit already starts to produce after 9–10 months. A single, bisexual flower forms at the nodes of the new growth at the same spot as the tendrils. The flower is 5–7.5 cm across and surrounded by three large, leaf like bracts and has five greenish-white sepals and five white petals (Morton, 1987; RodriguezAmaya, 2003). At the apex of the androgynophore, each flower has a central prominent style which branches out into three stigma and situated below five stamens with large anthers, making self-pollination difficult (Rodriguez-Amaya, 2003). From the basis of the androgynophore, many slender straight rays, white at the tip and purple at the base, form a corona or ‘crown’, which is probably the most recognizable feature of the flower. The fruit are nearly round or ovoid, 35 (purple) to 80 (yellow) grams on average, 4–7.5 cm in diameter with a smooth, leathery rind ranging in hue from dark-purple with faint, fine white specks, to light-yellow or pumpkin colour (Morton, 1987). The rind is 3 mm thick, wrinkles when the fruit is ripe (more in the purple than the yellow form) and adheres to a 6 mm thick white pith (Morton, 1987; Rodriguez-Amaya, 2003). Numerous (up to 250) small, hard, edible, black (purple fruit) or dark brown (yellow fruit) seeds are embedded in double-walled, membranous sacs filled with yellow-orange, pulpy juice in a cavity (Morton, 1987). The pulp has an intense fragrance and has an appealing, musky, guava-like, sub-acid to acid flavour (Morton, 1987; Rodriguez-Amaya, 2003). The purple passion fruit is subtropical and will grow and produce best at elevations of 650–2000 m. However, in Colombia, the commercial production of purple passion fruit can be found between 1400 and 2200 m above sea level (Fischer et al., 2009) and in Kenya cultivation is found up to 2500 m (Ulmer and MacDougal, 2004). The yellow passion fruit is tropical and prefers lower elevations (0–1000 m) but commercial production can be found in Colombia between 0 and 1300 m above sea level (Fischer et al., 2009). With respect to the


Passion fruit (Passiflora edulis Sim.)

127

production at higher altitudes, the temperature and radiance seem to have an important effect on the timing of production. However, in orchard without irrigation, water deficits also play a role (Menzel and Simpson, 1994). A temperature between 21 and 32 °C is best for development of the plant with the optimum being 26.5 °C (Rodriguez-Amaya, 2003). Depending on the region the annual rainfall should be between 600 mm (Northern Transvaal with high relative humidity (RH)) and 2500 mm (India) (Morton, 1987) and this needs to be well distributed with heavy rainfall during flowering problematic for pollination; and irrigation recommended during the dry periods (Rodriguez-Amaya, 2003). They need protection from wind and frost, although they have been known to recover from frost damage after drastic pruning (Morton, 1987). The plant is not very demanding when it comes to soil type but prefers light to heavy sandy loams (Morley-Bunker, 1999) with sufficient organic matter, few salts, and a pH in the range of 5.0 to 7.5 (Morton, 1987). Good drainage is necessary to avoid water logging and collar rot (Nakasone and Paull, 1998) but enough water needs to be available during flowering and fruiting. Since the vines are shallow-rooted they need protection which can be provided with organic mulch. 7.1.2 Worldwide importance and economic value Production of passion fruit occurs in South America, Africa, India, many countries of South-east Asia (particularly Indonesia), and the South Pacific, including Hawaii, Australia and New Zealand (Morley-Bunker, 1999). Previously, the countries covering more than 80–90% of the world production were Hawaii, Fiji, Australia, Kenya, South Africa, Papua-New Guinea and New Zealand; however, in the last two decades the production centre has shifted back to the original habitat of the plant, the Latin-American continent. The main producers for purple passion fruit are now Brazil, Ecuador and Peru, and for the yellow form, Brazil, Ecuador, Peru, Venezuela, Costa Rica, Kenya, Zimbabwe, Thailand, Malaysia and Indonesia (Isaacs, 2009). The biggest passion fruit producer in the world is Brazil where the purple form is preferred for fresh consumption and the yellow for juicing in large-scale juice extraction plants. In 2007, 664 286 ton were produced on 47 032 ha (IBRAF, 2007), mainly yellow passion fruit. Ecuador has also consolidated itself as the main juice exporter (18 000 ton in 2008) in a market strongly influenced by the seasonality of the production resulting in problems of over production and scarcity (Isaacs, 2009). Another considerable problem is the variability of the price for fresh passion fruit. In good years (2004 and 2007), prices reach above $2.5 per kg for yellow passion fruit or even $4.5 (2005), but in contrast in lesser years (2000) prices drop to $1.4 per kg. The main clients for passion fruit in Europe are Germany, Belgium, Luxemburg and the Netherlands (Isaacs, 2009). In Australia, the purple passion fruit was flourishing up to 1943 when Fusarium caused massive wilting resulting in the adaptation of yellow passion fruit as a rootstock for the production of purple passion fruit. In New Zealand, similar


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

128 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


problems arose but today, mostly in the Bay of Plenty region a profitable purple passion fruit industry exporting fruit and juice has developed. After recurring disease and pest problems on larger plantations, currently commercial culture of purple passion fruit can be found in Kenya on small and isolated plantings which can be better controlled. South Africa has successfully been producing purple passion fruit since the beginning of the century without serious problems. Purple passion fruit has been produced in India for many years, while the yellow form was only introduced a few decades ago. The latter was soon preferred for its more pronounced flavour and heavier and more regular crops (Morton, 1987). In Hawaii, a yellow passion fruit industry is firmly established and Fiji has a small juice-processing industry. 7.1.3 Cultivars and genetic variability Discussion has been ongoing as to whether the purple and yellow fruit were different forms, P. edulis forma edulis (purple) and P. edulis forma flavicarpa (yellow), but at taxonomic level, the use of the name P. edulis Sim. for either colour of sour passion fruit is indicated (Bernacci et al., 2008). There are a considerable amount of cultivars available but the specification of which cultivar is used is hardly ever given. A selection of available purple cultivars in Australasian and American markets include Australian Purple or Nelly Kelly, Black Beauty, Black Knight, Edgehill, Frederick, Kahuna, Paul Ecke, Purple Giant, Purple Possum, Red Rover. In the yellow range we find: Brazilian Golden, Golden Giant, Hawaiiana, McCain, Panama Gold, ‘Noel’s Special, Sweet Sunrise. The Brazilian cultivar BRS Ouro Vermelho produces both purple and yellow fruit. In Brazil a substantial amount of breeding work is being done to improve production and quality of the fruit. For the purple passion fruit attention has gone to Roxinho-Miúdo, Paulista and Maracujá-Maçã (Meletti et al., 2005). In the yellow range, IAC-273 and IAC-277 are gaining importance for fresh consumption with the main benefit in increased productivity with an average yield of 35–45 ton ha−1 whereas the average in Brazil so far is 10–15 ton ha−1. For the juice industry, IAC-275 was introduced, having a thin rind, a totally filled internal cavity, a higher soluble solids content (SSC), more vitamin C and a yield of more than 45 ton ha−1. This cultivar is now produced in six states of Brazil, as well as in Colombia and Venezuela (Pommer and Barbosa, 2009). 7.1.4 Culinary uses, nutritional value and health benefits The purple passion fruit is typically consumed fresh because it is sweeter, while the yellow passion fruit is used for processing due to its higher juice yield. Fresh passion fruit is eaten by cutting it in two and scooping out the pulp with a spoon. The pulp is also used in fruit salads, mousse, desserts, ice cream, and yoghurt or as a topping, with or without addition of sugar. After removing the seeds and homogenizing, it is also used to make jam and sauce which is then used in desserts as flavouring for cakes, and in icing. The juice is used pure or for preparation of



129

cocktails and is used in the processing industry to make juice blends. Cooking the juice with sugar makes thick passion fruit-flavoured syrup. The juicy pulp has high contents of potassium and vitamins A, B6, C and E (see Table 7.1) and carotenoids (Pruthi, 1963). In yellow passion fruit, 13 carotenoids have been identified (Mercadante et al., 1998), with ζ-carotene (1.26–12.86 μg g−1 FW) and β-carotene (2.39–13.35 μg g−1 FW) the main carotenoids available (Silva and Mercadante, 2002). Additionally, in yellow passion fruit juice substantial levels of polyphenols (435 mg l−1) have been reported (Mercadante et al., 1998). The main anthocyanin found is pelargonidin 3-diglucoside (1.4 mg 100 g−1 FW) (Pruthi et al., 1961). The predominant volatile compounds in passion fruit pulp belonged to the classes of esters (59.24%, mainly hexyl butanoate and hexyl hexanoate), aldehydes (15.27%, mainly benzaldehyde), ketones (11.70%, mainly 3-pentanone) and

Table 7.1 Nutritional characteristics of purple and yellow passion fruit. Ranges are presented. Purple

Parameter

Weight (g) Diameter (cm) Length (cm) pH Soluble solids content (%Brix) TA (%) Moisture (%) Proteins (%) Fat (%) Glucose (%) Fructose (%) Sucrose (%) Citric acid (%) Malic acid (%) Fibre (%) Ash (%) Sodium (mg 100 g−1 FW) Potassium (mg 100 g−1 FW) Calcium (mg 100 g−1 FW) Magnesium (mg 100 g−1 FW) Iron (mg 100 g−1 FW) Vitamin B6 (mg 100 g−1 FW) Vitamin C (mg 100 g−1 FW) Vitamin E (mg α-tocopherol equivalent 100 g−1 FW)

Yellow

Min

Max

Min

Max

34.49 4.35 4.68 2.97 11.9 0.5 71.83 2.2 0.07 1.93 1.95 2.67 2.58 0.22 11.84 0.47 7.08 100 6.06 16 0.6 0.236 20.9 0.05

55.86 5.57 5.37 4.64 17 5.7 72.57 3.1 0.7 2.27 2.25 3.13 3.42 0.38 13.76 1.887 30 764 53 29 1.6

85 6 7 2.8 11 2.2 55 0.7 0.2

165 8.5 11 3.15 21.4 4.5 79

30 1.12

0.5 3.8 0.4 20

40 0.8

Sources: Arjona et al. (1992), Romero-Rodriguez et al. (1994), Shiomi et al. (1996b), Silva and Mercadante (2002), Nascimento et al. (2003), Rodriguez-Amaya (2003), Leterme et al. (2006), Fonseca and Ospina (2007) and Vasco et al. (2008).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

130 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


alcohols (6.56%, mainly benzyl alcohol and 1-hexanol), the other characteristic aroma compounds for passion fruit were limonene, β-ionone and linalool (Narain et al., 2004). Additionally, the difference in flavour and aroma between the purple and yellow passion fruit can be attributed to presence or absence of certain compounds (Rodriguez-Amaya, 2003). Various parts of this plant are biologically active and extracts have been used to treat anxiety, insomnia, asthma, bronchitis, urinary tract infection (Zibadi and Watson, 2004), as a mild sedative, in the treatment of bronchial asthma, nervous gastrointestinal disorders and menopausal problems. These effects have been partially proven, leaf extract have shown antioxidant (Ferreres et al., 2007), anxiolytic (Petry et al., 2001; Coleta et al., 2006) and anti-inflammatory activity (Benincá et al., 2007; Montanher et al., 2007). Peel extract of purple passion fruit reduce blood pressure (Ichimura et al., 2006; Zibadi et al., 2007) and improves wheezing, coughing, and shortness of breath in asthma patients (Watson et al., 2008). The fruit extract accelerates healing of abdominal wall and gastric sutures (Gomes et al., 2006; Silva et al., 2006), colonic anastomosis (Bezerra et al., 2006) and bladder wounds (Gonçalves Filho et al., 2006) in the rat model. Additionally, passiflin, a protein extracted from the seeds has antifungal properties and inhibits growth of breast cancer cells (Lam and Ng, 2009) and inducing apoptosis and decreasing cell viability of MOLT-4 leukaemia lymphoma (De Neira, 2003).

7.2


7.2.1 Flowering and pollination In tropical regions flowering and production are almost uninterrupted, with two main production periods of three months. In subtropical regions, only one 6–7 months production period occurs. Long days (>10–12 h of daylight) are required to induce flowering (Rodriguez-Amaya, 2003), with day lengths of 11 h or less inhibiting flowering under natural conditions in Hawaii (Nakasone and Paull, 1998). Additionally, a reduction in irradiance below full sun will negatively affect yield and even short periods of low irradiance have residual effects during periods of full sun. Furthermore, flowering is prevented under high temperatures and low irradiance indicating an interaction between temperature and irradiance. This is an important consideration when growing passion fruit in wet tropical environments with extended cloud cover (Menzel and Simpson, 1994). Although they are hermaphrodites (containing male and female organs), passion fruit flowers are self-sterile (self-fertilization cannot happen), and yellow passion fruit flowers are even self-incompatible (self-pollination cannot occur). The different forms open at different times in the day, the flowers of the purple passion fruit from dawn until midday, the yellow open at midday and close in the evening. Three types of flowers can be found on yellow passion fruit and they are very sensitive to rain during the pollination period, with rain within 1.5 h after pollination preventing pollen germination and pollen tube growth (Morton, 1987; Rodriguez-Amaya, 2003).



131

Fruit set, numbers of seed, fruit weight, and juice yield depend on the amount of pollen deposited on the stigma (Akamine and Girolami, 1959); and without seed development, no juice will form (Knight and Winters, 1962). Passion fruit are usually pollinated by large bees (Xylocopa, Centris, Epicharis, Eulaema, Bombus, Ptiloglossa). Smaller bees like honeybees (Apis spp.) and stingless bees (Trigona sp.) are too small; they will visit the flowers but cannot transfer the pollen. Wooden logs are often placed in the orchards to ensure carpenter bee nesting. Hand pollination is also used to great extent and field workers can pollinate about 600 flowers per hour (Westerkamp and Gottsberger, 2000) with high success rates. Additionally, hand pollinated flowers are said to produce larger and juicier fruit (Rodriguez-Amaya, 2003). 7.2.2 Fruit growth, development and maturation Passion fruit have a single sigmoid growth curve with accelerated fruit growth during the first 20–21 days after anthesis (DAA) (Shiomi et al., 1996b; Hernández and Fischer, 2009). Pocasangre Enamorado et al. (1995) found that in yellow passion fruit, the maximum fruit size found at 21 DAA was due mainly to rind growth. For purple passion fruit, during this period there is also high respiration and ethylene production, followed by very low production up to 70 DAA (Shiomi et al., 1996b). The titratable acidity (TA) increases during the first 60 DAA for purple (Shiomi et al., 1996b) and 63–70 DAA for yellow (Pocasangre Enamorado et al., 1995; Vianna-Silva et al., 2005) and decreases thereafter. In general, SSC in the juice increases up to harvest; however, Pocasangre Enamorado et al. (1995) observed the highest accumulation of SSC 63 DAA. During this whole period the skin stays green up to 70 DAA after colour changes rapidly within the next 20–30 days (Shiomi et al., 1996b; Vianna-Silva et al., 2005). During the final stage of fruit maturation, vitamin C and carotene content will also increase. Purple (Arjona and Matta, 1991) and yellow (Vianna-Silva et al., 2005) passion fruit are mature around 70 DAA. 7.2.3 Maturity and harvest The skin colour of passion fruit can be used as a maturity index (Pruthi, 1963); seven maturity stages have been defined, related to the changes in colour of the skin from green to purple (see Plate XIII in the colour section between pages 238 and 239) for purple passion fruit (Pinzón et al., 2007) and from green to yellow (see Table 7.2) for yellow passion fruit (Vianna-Silva et al., 2008). Pinzón et al. (2007) recommend harvesting the purple passion fruit when the index reaches 3, which corresponds with 50% green and 50% purple (see Plate XIII in the colour section), approximately 70 days after flowering (Shiomi et al., 1996b). If harvested before this stage, fruit will not develop the full purple colour. Additionally, consumers prefer a purple colour at least 80–90% of the fruit surface and less than 75% is unacceptable for markets (Arjona and Matta, 1991).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

132 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Postharvest biology and technology of tropical and subtropical fruits Table 7.2

Maturity stages of yellow passion fruit

Maturity stage

Characterization

1 2 3 4 5 6 7

Peel totally green 4.7% of peel yellow 21.3% of peel yellow 28.5% of peel yellow 65.9% of peel yellow 82.4% of peel yellow 100% of peel yellow

Source: With permission from Vianna-Silva et al., 2008.

Fruit can be harvested when the skin is partially purple (approximately 70 days after flowering) as it will then continue to develop the full purple colour after harvest (Shiomi et al., 1996b). However, fruit will not develop the full purple colour if it is harvested at an immature stage (before 70 days after flowering). Additionally, consumers prefer a purple colour at least 80–90% of the fruit surface and less than 75% is unacceptable for markets (Arjona and Matta, 1991). The SSC/TA ratio is another parameter that can also be used as a maturity or ripening index. A higher SSC corresponds to more sweetness and a higher TA to more sourness (Harker et al., 2002). Shiomi et al. (1996a) and Pongjaruvat (2008) found that eating quality of purple passion fruit improved mainly due to a decrease in acidity. This is probably because in sensory tests, sourness has been shown to overshadow the sweetness sensation, and as sourness decreases with a decrease in TA during storage, sweetness is unmasked.

7.3

Postharvest physiology and quality

7.3.1 Respiration and ethylene production Passion fruit is a climacteric fruit with a high respiration rate of 400–1890 nmol kg−1s−1 for purple passion fruit at 20–25 °C (Shiomi et al., 1996b; Schotsmans et al., 2008). Ethylene production is also high and increases with ripening from 0.03 to 9.35 nmol kg−1s−1 (Shiomi et al., 1996b). The content of 1-aminocyclopropane-1carboxylic acid (ACC) and the activity of ACC synthase are low during the initial stage of ripening while the ACC oxidase activity is already high and they all increase during ripening, especially in juice sac and seed (Shiomi et al., 1996a; Mita et al., 1998). Expression of Pe-ACS1 and Pe-ACO1 are enhanced during ripening with increased expression of Pe-ACO1 starting first and expression much higher in arils than in seeds, resulting in a much higher level of ethylene being produced in arils than in seeds or peels during ripening (Mita et al., 1998). The level of expression of the ethylene receptors Pe-ETR1 and Pe-ERS1 did not significantly change over the course of ripening, but again much higher levels were found in arils than in seeds (Mita et al., 1998).



133

7.3.2 Ripening, quality components and indices The most noticeable change is in skin colour. For purple passion fruit (see Plate XIII in the colour section) the colour gradually changes from green to purple (Pinzón et al., 2007) and for yellow passion fruit (see Table 7.2) from green to yellow (Vianna-Silva et al., 2008), which makes this characteristic perfect for use as a maturity index as discussed before. In purple passion fruit, at the same time as the colour change, the weight of the pulp increases, reaching a maximum around maturity stage 4 (85–95% coloured, 15–20% green) (Pinzón et al., 2007) while the total weight decreases (Kishore et al., 2006; Pongjaruvat, 2008). This is also related to the development of shrivelling, which is maximal at full ripeness (Schotsmans et al., 2008) and negatively affects consumer and market perception. The seemingly contradictory effect of increase in pulp with decrease in total weight is due to water loss which happens mainly from the peel (Pongjaruvat, 2008) evidenced in the decrease in thickness of the skin (Kishore et al., 2006; Pinzón et al., 2007). Firmness decreases fastest in the initial stage of ripening, slowing down thereafter (Kishore et al., 2006; Pinzón et al., 2007). The pH remains stable between stages 0 and 4 at 3.0 and then increases to 3.5. The SSC increases up to stage 3 whereas the TA decreases, resulting in an increase in SSC/TA ratio (Kishore et al., 2006; Pinzón et al., 2007; Pongjaruvat, 2008). Additional changes include loss of vitamin C (42.6–34.0 mg 100 g−1) increase in reducing and total sugars and changes in the pulp colour from light yellow to pink with a perceptible increase in flavour with ripening (Kishore et al., 2006). In yellow passion fruit, as the colour changes, the pH remains stable between stages 0 and 6 at 2.6 and then increases to 3.7. SSC increases from 13.43 (totally green) to 16.3 (totally yellow), the TA increases from 5.21% to 5.37% at stage 2 and then decreases to 4.64 at stage 7. This again results in an increase in SSC/TA ratio during maturation from 2.4–2.6 at stage 0 to 3.5 at stage 7 (Vianna-Silva et al., 2008).

7.4


7.4.1 Handling and grading Fruit is harvested weekly or more frequently depending on the demand. Harvest is done by hand and preferably in the early hours of the day when the fruit is cooler and not subjected to sun and increase in temperature. Pressure is applied at the abscission zone near the calyx of the fruit or using scissors. Depending on market requirements, fruit are harvested with or without stem (Hernández and Fischer, 2009). For purple passion fruit, the colour changes can be used as a guide (Shiomi et al., 1996b). In other cases, fruit is gathered from the ground as it naturally drops when it ripens (Chavan and Kadam, 1995), however this is not advised as it increased the risk of bruising and infections. Passion fruit are harvested in small plastic baskets (of 2.5 kg) or cardboard boxes. Once harvested, diseased and damaged fruit (insect damage, physiological


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

134 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


or physical disorders) are removed. Fruit is further graded according to size and marketed in boxes containing three to four layers of fruit separated by newspaper to prevent deterioration (Hernández and Fischer, 2009). 7.4.2 Temperature and relative humidity The optimal reported storage conditions for passion fruit vary between 5 °C and 10 °C and 85–90% RH. Temperature markedly affects the changes during storage, with a lower temperature decreasing the weight loss of the fruits (Arjona et al., 1992; Shiomi et al., 1996b; Schotsmans et al., 2008), the respiration rate (Pongjaruvat, 2008; Schotsmans et al., 2008) and the loss of SSC (Arjona et al., 1992). For purple passion fruit storage at 4–5 °C is reported to increase the commercial life of the fruit by 50% compared with fruit stored at room temperature (Hernández and Fischer, 2009). However, for yellow passion fruit a higher temperature of 10 °C is recommended since at this temperature shrivelling and weight loss is minimal compared with lower (5 °C) and higher (15 °C) temperatures (Arjona et al., 1992). Water loss and thus weight loss and shrivelling can be decreased even more by ensuring a high RH using packaging (Pongjaruvat, 2008) or film wrap (Arjona et al., 1994a). The lower water loss will also ensure turgor pressure in the cells remains high and improve the stiffness or compression firmness of the fruit (Pongjaruvat, 2008). High RH appears to negatively affect pulp yield, however, this is due to the fact that less water is being lost from the skin thus keeping the fruit weight the same (Arjona et al., 1994a; Pongjaruvat, 2008). High RH also prevents shrivelling and toughening of the peel (Pruthi, 1963; Arjona et al., 1994b; Schotsmans et al., 2008). Although increasing RH has many beneficial effects, care has to be taken when using high RH since it can also result in increased fungal growth (Pongjaruvat, 2008). 7.4.3 Packaging The beneficial effect of packaging is already clear at higher temperatures. Wrapping purple passion fruit in ‘Vinipel’ film wrap (PVC), at ambient temperature (18 °C) preserves quality for up to 10 to 12 days. Lowering the temperature (6 °C) prolonged this beneficial effect to 24 days (16 days in cold room + 8 days shelf life) (Pachón et al., 2006). Likewise, packaging purple passion fruit in perforated HDPE of 0.03 mm thickness increased shelf life to 24 days at 5 °C while better preserving quality (SSC, TA) and nutritional value (vitamin C) of the fruit (Singh et al., 2007). Wrapping yellow passion fruit in plasticized PVC film slows down shrivelling and weight loss during 30 days of storage at 10 °C (Arjona et al., 1994b), this could be attributed to the high RH of 85% of the modified atmosphere (13% O2 and 0.5% CO2) in the packaging. Pongjaruvat (2008) also found that packaging of purple passion fruit reduced weight loss and shrivelling, slowed down the changes in colour, pH, TA, sweetness, and sourness, maintained fruit firmness, and extended shelf life. However, again it was not clear if this was due to the altered gas composition (1–4 kPa O2 and 6 kPa CO2) or purely the increase in RH.



135

Care must be taken when using modified atmosphere packaging since condensation and adverse atmosphere conditions can cause disorders like an increase in fungal growth and red bleeding. 7.4.4 Controlled atmosphere storage Pruthi (1963) noted that purple passion fruit could be kept in 5% O2 and 5% CO2 for six weeks. 7.4.5 Ethylene Purple passion fruit is sensitive to exogenous ethylene as it accelerates endogenous ethylene production (Shiomi et al., 1996a) and can thus accelerate ripening. This sensitivity is not clearly present at harvest since application of 1000 ppm ethylene for 24 h did not induce earlier onset of ethylene production when applied on harvest day, but was effective when applied one day or five days after harvest (Shiomi et al., 1996a). This has to be taken into account when using MAP packaging because it can result in accumulation of ethylene thus counteracting the beneficial effects on ripening delay. Ethylene can also be used to improve colour development of fruit harvested at the mature-green stage (Arjona and Matta, 1991). 7.4.6 Waxing The application of paraffin wax coating to purple passion fruit reduced weight loss and enhanced fruit appearance for five weeks (Pruthi, 1963). This is different from findings in purple passion fruit by Dagame et al. (1991) and Pongjaruvat (2008) where adding wax on the fruit surface did not improve storage life. Pachón et al. (2006) had the same experience in purple passion fruit but stated that even though the effects of the treatment are minimal, this would be a good general practice for fruit that does not have to be transported far if only for the effect on the external appearance for the fruit going to the local markets.

7.5

Crop losses

7.5.1 Chilling injury Below 6.5 °C fruit is affected by chilling injury resulting in red discolouration on the surface (Pruthi, 1963). This was also noted in trials by Pongjaruvat (2008) who recorded red bleeding but attributed this more to development of atmospheric conditions within MAP. 7.5.2 Pathological disorders One of the most important disorders in passion fruit is woodiness or ‘bullet’ with incidences of 71.8–73.1% in commercial orchards in Brazil (Novaes and


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

136 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Rezende, 2003), which is caused by the passion fruit woodiness virus (PWV) (Inch, 1978) or by the cucumber mosaic virus. Affected leaves are stunted, curled and discoloured, while the fruits are often under-sized, misshapen, hard and dry (Griesbach, 1992). The virus is easily transmitted by mechanical means and by aphids, especially Myzus persicae Sulz. and Aphis gossypii Glover (Chagas et al., 1981). In Australia, the disorder has been successfully controlled by introducing hybrid cultivars since these are tolerant of the common strains of woodiness virus (Taylor and Greber, 1973; Inch, 1978). After massive wilting in commercial plantations of purple passion fruit, grafting on wilt-resistance seedlings of the yellow passion fruit has proven to be the only satisfactory method to control soilborne diseases such as fusarium wilt (F. oxysporum f. passiflorae) (Inch, 1978; Nakasone and Paull, 1998). The often used harvest method to gather from the ground as the fruit naturally drops when it ripens (Chavan and Kadam, 1995) also results in fruit that is highly contaminated with soil-borne pathogens. Additionally, the use of polyethylene bags to ensure high RH does not reduce fungal attack (Pruthi, 1963). However, adding a 5% Lysol solution to the polyethylene bag successfully reduced fungal attack. The common fungal attacks are by Alternaria passiflorae with circular, sunken, and brown spots on the fruit surface, and septoria blotch caused by Septoria passiflorae (Rodriguez-Amaya, 2003). Pruthi (1963) noted that during long term storage at 6.5 °C, passion fruit was attacked by white (Fusarium oxysporum), blue (Penicillium expansum), and black (Aspergillus niger and Rhyzopus nigricans) fungus. Experiments with yellow passion fruit from conventional and organic orchards started at ambient temperature (25 °C) and high RH, revealed that all fruit contracted anthracnose, caused by Colletotrichum gloeosporioides and presenting as light-brown patches that increase in size and evolve into a soft rot. Fusarium rot affected 25.5% and 19% and Phomopsis rot 11% and 2% of conventional and organic fruit, respectively (Fischer et al., 2007). Phomopsis rot can be found as a stem end rot on the passion fruit. Cladosporium herbarum and Cladosporium oxysporum cause powdery spot and fruit scab in cooler moist areas, but so far no fungicidal measures have been found. Fytosanitary actions to prevent these diseases include foliar fungicide application with Mancozeb + cupper oxychloride or thiophanate methyl, and sporadically the insecticide Fenthion. In the search for biological control measures against anthracnose, Cymbopogon citratus essential oil has been evaluated for the control of postharvest decay in yellow passion fruit but it could not prevent anthracnose in yellow passion fruit (Anaruma et al., 2010). 7.5.3 Insect pests and their control Thrips (Trips spp.) can damage plants, mainly during dry weather. Damage by thrips while feeding leads to mottled punctures on the leaves and fruit which may shrivel and drop prematurely (Ondieki, 1975).



137

Mites (Tetranychus urticae) cause brown coloured abrasions on the rind because they puncture the cells and drain their contents, especially close to the stalk (Mora and Benavides, 2009). Various types of flies can attack passion fruit. In Colombia, a complex of Dasiops sp. and Hexachaeta sp. cause severe damage. They cause flower and fruit abortion by consuming the content of the ovarian or the fruit itself. The affected fruit progressively wrinkle depending on the number of larvae present in the fruit and eventually drop. When cut open, the fruit is empty and shows initiation of fungal growth (Mora and Benavides, 2009). Suggested control measures include trapping, removal of pupae and larvae by destroying fallen flower buds and fruits. Passion fruit can also be a host to Mediterranean fruit fly so all quarantine measures related to this pest will apply when exporting to countries imposing quarantine measures for Mediterranean fruit fly. Additionally, since PWV is transmitted by aphids, especially Myzus persicae Sulz. and Aphis gossypii Glover (Chagas et al., 1981), it is important to control these. Care should be taken to apply only those insecticides and acaricides which are recommended for use on fruit crops and which will not interfere with the canning quality of the juice (Ondieki, 1975).

7.6

Processing

Passion fruit juice is the third most wanted exotic flavour after mango and pineapple and can be provided as juice at 14 °Brix or in concentrated form at 50 °Brix, which is more in demand (Isaacs, 2009). Fruit for processing is collected daily or weekly and transported to the processing plant, where rotten and unfit are removed. Then the fruit are washed with strong sprays of water to remove all dirt and leaves and other substances adhering to the fruit. The entire fruit is dropped between two rotating converging cones and when it bursts open, skins are carried through the cones whereas the pulp drops into a finisher (Hui et al., 2006). In another method, rotating, circular knives slice open the fruit and all is put in a continuous basket centrifuge, or the juice, pulp and seeds are forced through the holes in the wall and the rind stays behind. Afterwards, the seeds are removed from the pulp and juice by a screened pulper followed by a screened finisher leaving only clean juice (Hui et al., 2006). The main concern is the extreme heat sensitivity of the aroma and flavour components of the juice, making pasteurization difficult. Additionally, the high starch content of the juice can cause accumulation on the surfaces of the processing equipment, affecting efficiency (Hui et al., 2006). The juice can be consumed pure or diluted into a nectar or in mixes with other fruit juices. Additionally it can be concentrated to a juice of 43.5–50 °Brix but about 39% of the volatile components are lost in the process (Shaw et al., 2001). For yellow passion fruit, research has been directed to determine the ideal maturity stage for processing, and even though some changes may occur, fruit from stage 4 onwards (see Table 7.2) are suitable for processing (De Marchi et al., 2000).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

138 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Another important consideration in passion fruit processing is the waste production, which constitutes almost 75% of the raw material. Of this, 90% is the peel which can be used for the production of pectin (Schieber et al., 2001), which is used as a gelling agent and stabilizer. Pectin can be extracted successfully from passion fruit peel with citric acid (Pinheiro et al., 2008). Oil from passion fruit seeds is high in linoleic and linolenic acid, making passion fruit seed a valuable non-conventional source for high-quality oil (Liu et al., 2008).

7.7

Conclusions

Passiflora edulis (sour passion fruit), native from Brazil, is known in two forms, the purple and the yellow passion fruit. Both behave similarly during flowering, fruit growth, maturation and ripening but they mainly differ in colour, SSC and TA level as well as their aroma components. They are both climacteric fruit with high respiration and ethylene production. The main quality changes during storage and ripening include decrease of acidity resulting in higher apparent sweetness and weight loss resulting in shrivelling. The latter is not appreciated by consumers who prefer a smooth fruit. Another important difference is the temperature requirement during storage. Where purple passion fruit is best stored at 4–5 °C, yellow passion fruit prefers a higher temperature of 10 °C. The main market for both forms is the processing industry and most of the export consists of juice.

7.8

References

Akamine E K and Girolami G (1959), ‘Pollination and fruit set in the yellow passion fruit’, Hawaii Agr Expt Sta Tech Bul, 59, 44. Anaruma N D, Schmidt F L, Duarte M C T, Figueira G M, Delarmelina C, et al. (2010), ‘Control of Colletotrichum gloeosporioides (Penz.) Sacc. in yellow passion fruit using Cymbopogon citratus essential oil’, Braz J Microbiol, 41, 66–73. Arjona H E and Matta F B (1991), ‘Postharvest quality of passion fruit as influenced by harvest time and ethylene treatment’, HortScience, 26, 1297–1298. Arjona H E, Matta F B and Garner J O (1992), ‘Temperature and storage time affect quality of yellow passion fruit’, HortScience, 27, 809–810. Arjona H E, Matta F B and Garner J O (1994a), ‘Wrapping in polyvinyl chloride film slows quality loss of yellow passion fruit’, HortScience, 29, 295–296. Arjona H E, Matta F B and Garner J O (1994b), ‘Wrapping in polyvinyl chloride film slows quality loss of yellow passion fruit’, HortScience, 29, 295–296. Benincá J P, Montanher A B, Zucolotto S M, Schenkel E P and Fröde T S (2007), ‘Evaluation of the anti-inflammatory efficacy of Passiflora edulis’, Food Chem, 104, 1097–1105. Bernacci L C, Soares-Scott M D, Junqueira N T V, Passos I R d S and Meletti L M M (2008), ‘Passifora edulis Sims.: The correct taxonomic way to cite the yellow passion fruit (and of others colors)’, Rev Bras Frut, 30, 566–576. Bezerra J A F, Campos A C L, De Vasconcelos P R L, Nicareta J R, Ribeiro E R, et al. (2006), ‘Extrato de Passiflora edulis na cicatrização de anastomose colônica em ratos: estudo morfológico e tensiométrico’, Acta Cirurg Bras, 21, 16–25.



139

Chagas C M, Kitjima E W, Lin M T, Gama M I C S and Yamashiro T (1981), ‘Grave moléstia em maracujá amarelo (Passiflora edulis f. flavicarpa) no Estado da Bahia, causado por um isolado do vírus do “woodiness” do maracujá’, Fitopatol Bras, 6, 259–268. Chavan U D and Kadam S S (1995), ‘Passion fruit’, in Salunkhe D K and Kadam S S Handbook of Fruit Science and Technology: Production, composition, storage, and processing, New York, M. Dekker. Coleta M, Batista M T, Campos M G, Carvalho R, Cotrim M D, et al. (2006), ‘Neuropharmacological evaluation of the putative anxiolytic effects of Passiflora edulis Sims., its sub-fractions and flavonoid constituents’, Phytotherapy Res, 20, 1067–1073. Dagama F S N, Manica I, Kist H G K and Accorsi M R (1991), ‘Additives and polythene bags in the preservation of passion fruit stored under refrigeration’, Pesqu Agropecu Bras, 26, 305–310. De Marchi R, Monteiro M, Benato E A and Silva C A R d (2000), ‘Uso da cor da casca como indicador de qualidade do maracujá amarelo (Passiflora edulis Sims. f. flavicarpa Deg.) destinado à industrialização’, Ciencia e Tecnologia de Alimentos, 20, 381–387. De Neira C M (2003), ‘The effects of yellow passion fruit, Passiflora edulis flavicarpa, phytochemicals on cell cycle arrest and apoptosis of leukemia lymphoma molt-a cell line’, MSc Thesis. University of Florida. Ferreres F, Sousa C, Valentão P, Andrade P B, Seabra R M and Gil-Izquierdo Ã N (2007), ‘New C-deoxyhexosyl flavones and antioxidant properties of Passiflora edulis leaf extract’, J Agric Food Chem, 55, 10187–10193. Fischer G, Casierra-Posada F and Piedrahíta W (2009), ‘Ecofisiología de las especies pasifloráceas cultivadas en Colombia’, in Miranda D, Fischer G, Carranza C, Magnitskiy S, Casierra-Posada F, Piedrahíta W and Flórez L E, Cultivo, poscosecha y comercialización de las Pasifloráceas en Colombia: maracuyá, granadilla, gulupa y curuba, Bogotá, Sociedad Colombiana de Ciencias Hortícolas. Fischer I H, De Arruda M C, De Almeida A M, Garcia M, Jeronim E M, et al. (2007), ‘Doenças e características físicas e químicas pós-colheita em maracujá amarelo de cultivo convencional e orgânico no centro oeste paulista’, Rev Bras Frut, 29, 254–259. Fonseca D I and Ospina N M (2007), ‘Relacion semilla/fruto en dos pasifloras: granadilla (Passiflora liguralis Juss.) y gulupa (Passiflora edulis Sims.)’, Facultad de Agronomía. Bogotá, Universidad Nacional de Colombia. Gomes C S, Campos A C L, Torres O J M, Vasconcelos P R L d, Moreira A T R, et al. (2006), ‘Efeito do extrato de Passiflora edulis na cicatrização da parede abdominal de ratos: estudo morfológico e tensiométrico’, Acta Cirurg Bras, 21, 9–16. Gonçalves Filho A, Torres O J M, Campos A C L, Tâmbara Filho R, Rocha L C d A, et al. (2006), ‘Efeito do extrato de Passiflora edulis (maracujá) na cicatrização de bexiga em ratos: estudo morfológico’, Acta Cirurg Bras, 21, 3–8. Griesbach J (1992), ‘A guide to propagation and cultivation of fruit-trees in Kenya’, GTZ, Technical Cooperation, Eschborn, Germany. Harker F R, Marsh K B, Young H, Murray S H, Gunson F A and Walker S B (2002), ‘Sensory interpretation of instrumental measurements 2: Sweet and acid taste of apple fruit’, Postharvest Biol Technol, 24, 241–250. Hernández M S and Fischer G (2009), ‘Cosecha y poscosecha en las frutas pasifloráceas’, in Miranda D, Fischer G, Carranza C, Magnitskiy S, Casierra-Posada F, Piedrahíta W and Flórez L E, Cultivo, Poscosecha y comercialización de las Pasifloráceas en Colombia: maracuyá, granadilla, gulupa y curuba, Bogotá, Sociedad Colombiana de Ciencias Hortícolas. Hui Y H, Barta J, Cano M P, Gusek T W, Sidhu J S and Sinha N K (Eds.) (2006), Handbook of Fruits and Fruit Processing, Ames, Blackwell Publishing. IBRAF (2007), ‘Instituto Brasileiro de Frutas’, www.ibraf.org.br/estatisticas/ ProducaoBrasileiradeFrutas2007.pdf [accessed May 2011].


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

140 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Ichimura T, Yamanaka A, Ichiba T, Toyokawa T, Kamada Y, et al. (2006), ‘Antihypertensive effect of an extract of Passiflora edulis rind in spontaneously hypertensive rats’, Bioscience, Biotechnol Biochem, 70, 718–721. Inch A J (1978), ‘Passionfruit diseases’, Qld Agric J, 104, 479–484. Isaacs M (2009), ‘Mercados nacionales e internacionales de las frutas pasifloráceas’, in Miranda D, Fischer G, Carranza C, Magnitskiy S, Casierra-Posada F, Piedrahíta W and Flórez L E, Cultivo, poscosecha y comercialización de las Pasifloráceas en Colombia: maracuyá, granadilla, gulupa y curuba, Bogotá, Sociedad Colombiana de Ciencias Hortícolas. Kishore K, Bharali R, Pathak K A and Yadav D S (2006), ‘Studies on ripening changes in purple passion fruit (Passiflora edulis Sims.)’, J Food Sci Technol–Mysore, 43, 599–602. Knight R J J and Winters H F (1962), ‘Pollination and fruit set of yellow passionfruit in Sourthern Florida’, Fla State Hort Soc Proc, 75, 412–418. Lam S K and Ng T B (2009), ‘Passiflin, a novel dimeric antifungal protein from seeds of the passion fruit’, Phytomedicine, 16, 172–180. Leterme P, Buldgen A, Estrada F and Londoño A M (2006), ‘Mineral content of tropical fruits and unconventional foods of the Andes and the rain forest of Colombia’, Food Chem, 95, 644–652. Liu S, Yang F, Li J, Zhang C, Ji H and Hong P (2008), ‘Physical and chemical analysis of Passiflora seeds and seed oil from China’, Int J Food Sci Nutr, 59, 706–715. Meletti L M M, Soares-Scott M D and Bernacci L C (2005), ‘Caracterização fenotípica de três seleções de maracujazeiro-roxo (Passiflora edulis Sims.)’, Rev Bras Frut, 27, 268– 272. Menzel C M and Simpson D R (1994), ‘Passion fruit’, in Schaffer B and Andersen P C Handbook of Environmental Physiology of Fruit Crops: Sub-tropical and tropical crops, Boca Raton, FL, CRC Press. Mercadante A Z, Britton G and Rodriguez-Amaya D B (1998), ‘Carotenoids from yellow passion fruit (Passiflora edulis)’, J Agric Food Chem, 46, 4102–4106. Mita S, Kawamura S, Yamawaki K, Nakamura K and Hyodo H (1998), ‘Differential expression of genes involved in the biosynthesis and perception of ethylene during ripening of passion fruit (Passiflora edulis Sims.)’, Plant Cell Physiol, 39, 1209–1217. Montanher A B, Zucolotto S M, Schenkel E P and Fröde T S (2007), ‘Evidence of anti– inflammatory effects of Passiflora edulis in an inflammation model’, J Ethnopharmacol, 109, 281–288. Mora H and Benavides M (2009), ‘Plagas de importancia económica asociados a las pasifloráceas y su manejo en Colombia’, in Miranda D, Fischer G, Carranza C, Magnitskiy S, Casierra-Posada F, Piedrahíta W and Flórez L E, Cultivo, poscosecha y comercialización de las Pasifloráceas en Colombia: maracuyá, granadilla, gulupa y curuba, Bogotá, Sociedad Colombiana de Ciencias Hortícolas. Morley-Bunker M (1999), ‘Passionfruit’, in Jackson D I and Looney N E, Temperate and Subtropical Fruit Production, Wallingford, Cabi Publishing. Morton J (1987), ‘Passionfruit’, Fruits of Warm Climates, Winterville, Creative Resource Systems Inc. Nakasone H Y and Paull R E (1998), Tropical Fruits, Wallingford, CAB International. Narain N, Almeida J d N, Galvao M d S, Madruga M S and Brito E S d (2004), ‘Compostos voláteis dos frutos de maracujá (Passiflora edulis forma Flavicarpa) e de cajá (Spondias mombin L.) obtidos pela técnica de headspace dinâmico’, Ciencia e Tecnologia de Alimentos, 24, 212–216. Nascimento W M O d, Tomé A T, Oliveira M d S P d, Müler C H and Carvalho J E U d (2003), ‘Seleção de progênies de maracujazeiro-amarelo (Passiflora edulis f. flavicarpa) quanto à qualidade de frutos’, Rev Bras Frut, 25, 186–188. Novaes Q S d and Rezende J A M (2003), ‘Selected mild strains of Passion fruit woodiness virus (PWV) fail to protect pre-immunized vines in Brazil’, Sci Agric, 60, 699–708.



141

Ocampo Pérez J A, Coppens d’Eeckenbrugge G, Restrepo M, Jarvis A, Salazar M and Caetano C (2007), ‘Diversity of Colombian Passifloraceae: biogeography and an updated list for conservation’, Biota Colomb, 8, 1–45. Ondieki J J (1975), ‘Diseases and pests of passion fruit in Kenya’, Acta Hortic, 19, 291–293. Pachón A, Montaño A and Fischer G (2006), ‘Efecto del empaque, encerado y temperatura sobre las características fisicoquímicas y organolépticas de la gulupa (Passiflora edulis f. edulis) en postcosecha’, in Salamanca G Propiedades fisicoquímicas y sistemas de procesado: productos hortofrutícolas en el desarrollo agroalimentario, Bogotá, Ed. Guadalupe. Petry R D, Reginatto F, de-Paris F, Gosmann G, Salgueiro J B, et al. (2001), ‘Comparative pharmacological study of hydroethanol extracts of Passiflora alata and Passiflora edulis leaves’, Phytotherapy Res, 15, 162–164. Pinheiro E s R, Silva I M D A, Gonzaga L V, Amante E R, Teófilo R F, et al. (2008), ‘Optimization of extraction of high-ester pectin from passion fruit peel (Passiflora edulis flavicarpa) with citric acid by using response surface methodology’, Bioresour Technol, 99, 5561–5566. Pinzón I M d P, Fischer G and Corredor G (2007), ‘Determinación de los estados de madurez del fruto de la gulupa (Passiflora edulis Sims.)’, Agron Colomb, 25, 83–95. Pocasangre Enamorado H E, Finger F L and Puschmann R (1995), ‘Development and ripening of yellow passion fruit’, J Hortic Sci, 70, 573–576. Pommer C V and Barbosa W (2009), ‘The impact of breeding on fruit production in warm climates of Brazil’, Rev Bras Frut, 31, 612–634. Pongjaruvat W (2008), ‘Effect of modified atmosphere on storage life of purple passion fruit and red tamarillo’. MSc Thesis. Massey University, Palmerston North. Pruthi J S (1963), ‘Physiology, chemistry, and technology of passion fruit’, Adv Food Res, 12, 203–282. Pruthi J S, Susheela R and Girdhari L A L (1961), ‘Anthocyanin pigment in passion fruit rind’, J Food Sci, 26, 385–388. Rodriguez-Amaya D B (2003), ‘Passion fruits’, in Caballero B, Encyclopedia of Food Sciences and Nutrition, Oxford, Academic Press. Romero-Rodriguez M A, Vazquez-Oderiz M L, Lopez-Hernandez J and Simal-Lozano J (1994), ‘Composition of babaco, feijoa, passion-fruit and tamarillo produced in Galicia (NW Spain)’, Food Chem, 49, 251–255. Schieber A, Stintzing F C and Carle R (2001), ‘By-products of plant food processing as a source of functional compounds–recent developments’, Trends Food Sci Technol, 12, 401–413. Schotsmans W C, Nicholson S E, Pinnamaneni S and Mawson A J (2008), ‘Quality changes of purple passion fruit (Passiflora edulis Sims.) during storage’, Acta Hortic, 773, 239–244. Shaw P E, Lebrun M, Dornier M, Ducamp M N, Courel M and Reynes M (2001), ‘Evaluation of concentrated orange and passionfruit juices prepared by osmotic evaporation’, LWT-Food Sci Technol, 34, 60–65. Shiomi S, Kubo Y, Wamocho L S, Koaze H, Nakamura R and Inaba A (1996a), ‘Postharvest ripening and ethylene biosynthesis in purple passion fruit’, Postharvest Biol Technol, 8, 199–207. Shiomi S, Wamocho L S and Agong S G (1996b), ‘Ripening characteristics of purple passion fruit on and off the vine’, Postharvest Biol Technol, 7, 161–170. Silva J R, Campos A C, Ferreira L M, Aranha Jr. A A, Thiede A, et al. (2006), ‘Efeito do extrato da Passiflora edulis na cicatrização de gastrorrafias em ratos: estudo morfológico e tensiométrico’, Acta Cirurg Bras, 21, 52–60. Silva S R d and Mercadante A Z (2002), ‘Composição de carotenóides de maracujá– amarelo (Passiflora edulis flavicarpa) in natura’, Ciencia e Tecnologia de Alimentos, 22, 254–258.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

142 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Singh A, Yadav D S, Patel R K and Mousumi B (2007), ‘Effect on shelf-life and quality of passion fruit with polyethylene packaging under specific temperature’, J Food Sci Technol–Mysore, 44, 201–204. Taylor R H and Greber R S (1973), ‘Passion fruit woodiness virus.’, CMI/AAB, Description of Plant Viruses, 122. Ulmer T and MacDougal J M (Eds.) (2004), Passiflora: Passionflowers of the World, Cambridge, Timber Press, Inc. Vasco C, Ruales J and Kamal-Eldin A (2008), ‘Total phenolic compounds and antioxidant capacities of major fruits from Ecuador’, Food Chem, 111, 816–823. Vianna-Silva T, Resende E D d, Viana A P, Pereira S M d F, Carlos L d A and Vitorazi L (2008), ‘Qualidade do suco de maracujá-amarelo em diferentes épocas de colheita’, Rev Bras Frut, 28, 545–550. Vianna-Silva T, Resende E D d, Viana A P, Rosa R C C, Pereira S M d F et al. (2005), ‘Influência dos estádios de maturação na qualidade do suco do maracujá-amarelo’, Rev Bras Frut, 27, 472–475. Watson R R, Zibadi S, Rafatpanah H, Jabbari F, Ghasemi R, et al. (2008), ‘Oral administration of the purple passion fruit peel extract reduces wheeze and cough and improves shortness of breath in adults with asthma.’, Nutr Res, 28, 166–171. Westerkamp C and Gottsberger G (2000), ‘Diversity pays in crop pollination’, Crop Sci, 40, 1209–1222. Zibadi S, Farid R, Moriguchi S, Lu Y, Foo L Y, et al. (2007), ‘Oral administration of purple passion fruit peel extract attenuates blood pressure in female spontaneously hypertensive rats and humans’, Nutr Res, 27, 408–416. Zibadi S and Watson R R (2004), ‘Passion fruit (Passiflora edulis): Composition, efficacy and safety’, Evidence-Based Integrative Medicine, 1, 183–187.



Plate XIII

(Chapter 7) Maturity index/colour scale for purple passion fruit with six maturity stages from totally red (0) to over mature (6) (with permission from Pinzón et al., 2007).

8 Pecan (Carya illinoiensis (Wangenh.) K. Koch.) A. A. Gardea and M. A. Martínez-Téllez, Research Center for Food and Development, Mexico and E. M. Yahia, Autonomous University of Queretaro, Mexico

Abstract: A native species of North America, pecans are grown in several countries around the world. The nuts are well known for their important benefits for consumers’ health, including properties to prevent heart disease. Pecan quality attributes are well defined and set the standards not only for marketing issues, but also for breeding programs as well. Because of their low respiration rates, pecans are suitable for long-term storage, providing that conditions to prevent oxidation reactions are minimized. Both kernel darkening and rancidity development are oxidative reactions, which can be prevented by proper cold storage and limited exposure to air; however cold storage by itself reduces the reaction rate significantly. This chapter describes the guidelines for the management of pecans from harvesting to storage. Key words: Carya illinoiensis, pecan, postharvest, nutrition, processing.

8.1

Introduction

Public perception about the importance of selecting appropriate foods to support healthy lifestyles dictates particular attention not only to nutritional contents, but also to all of the nutraceutical properties found in foods. The nuts of the pecan tree are particularly rich in compounds that offer such positive impacts in our body (Yahia, 2010). It is recommended that regular intake of these nuts has protective effects against several maladies related to our modern sedentary life. Endemic to North America, pecans have been the staple of natives for centuries. Today, they are also grown in many countries, and although most of the crop is still produced in its original region, their marketing is expanding. Oleic and linoleic fatty acids are the main constituents of pecan oils and their content of unsaturated lipids is ten times higher than their saturated fats, not to mention a


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

144 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


wide series of other protective mechanisms related to their nutrients, micronutrients, vitamins, tocopherols, and diverse phytochemicals (Yahia, 2010). Pecan nuts, like all nuts, have very low respiration rates and quality deterioration. This chapter describes general guidelines for proper management of pecans from the moment they are harvested, through their postharvest handling and storage. 8.1.1 Origen and distribution Although native to North America, at present pecans are widely distributed in Australia, Brazil, China, Israel, Peru and South Africa; the largest acreage being found in the USA, followed by Mexico. Commercial pecan growing started in the United States, where the oldest groves are found, although Australian orchards have been under cultivation for the last forty years (Wakeling et al., 2000). The Spaniards were the first Europeans to find pecans in northern Mexico in the sixteenth century and legend has it that the birth rate of local natives was closely associated with the biannual bearing cycle characteristic of this species, implying its important role as a staple food. Pecans are a conspicuous element of the gallery forests (Beard, 1955; Sparks, 2005), typical of the semiarid regions of both Southern USA and Northern Mexico, as well as the deciduous forests of the USA east of the Mississippi. Not surprisingly, the largest diversity in native pecans is found in the USA, a situation that was considered when the United States Department of Agriculture (USDA) established a breeding and selection program that has yielded results for the last seventy years. Many of the commercially important varieties were originated from such a program, and continue to provide the industry with improved germplasm (Thompson and Grauke, 2003). So far, breeding programs in the United States continue to lead the search for improved germplasm (Sparks, 1992), and a review of the initial parameters is in continuous demand by the industry (Heaton et al., 1975). Taxonomically classified in the Junglandaceae family, pecans (Carya illinoinensis (Wangenh.) K. Koch) (USDA, 2010b) are an American species related to English walnuts (Juglans regia L.), actually a Caucasian species, and other American species such as Arizona, Southern California and Northern California walnuts and black walnut (Juglans nigra L.), whose high quality wood and veneers are highly demanded. Also, 21 other hickory species are included in this family (USDA, 2010a). 8.1.2 Production and consumption Pecan consumption in its countries of origin, the USA and Mexico, is higher than elsewhere. In the United States, almonds (Prunus amygdalus Batsh) and English walnuts (Juglans regia L.) are the nuts recording the highest consumption, followed by pecans. Pecan consumption in the United States, with a ten year average production of 114.4 M kg (Hadjigeorgalis et al., 2005), is 218 to 375 g per capita (Geisler, 2010). In Mexico, official numbers report an annual consumption of 250 g per person (Milenio, 2008), however, the inclusion of temporal inventories (like temporal imports for shelling), may be artificially increasing an otherwise more realistic figure. The United States accounts for the


Pecan (Carya illinoiensis (Wangenh.) K. Koch.)

145

largest export and import of pecans; its top buyer being Hong Kong, while most of in-shell and shelled pecan imports are from Mexico (Geisler, 2010). Nonetheless, pecan consumption is expected to grow given an increase in plantings and an expanding market. The increase in consumption will depend on several factors, the most important of them being the extent of increasing trends in consumption of healthy foods.

8.2

Nutritional value of pecan nuts

Tree nuts are considered rich sources of different phytochemicals that may contribute to health benefits because of their antioxidant, anti-proliferative, antiinflammatory, anti-viral and hypocholesterolemic properties (Bolling et al., 2010; Yahia, 2010). Such compounds include carotenoids, hydrolysable tannins, lignans, naphtoquinones, phenolic acids, phytosterols, polyphenols and tocopherols (Bolling et al., 2010). Pecan meat is an excellent source of many nutrients and phytochemicals (Table 8.1). By contrasting those figures it is clear that, as compared with almonds and English walnuts, pecans are richer in calories, linoleic acid, some micronutrients (zinc, copper and manganese) and some vitamins (particularly vitamins A and K), as well as γ-tocopherol (Self Nutrition Data, 2010). Kernel protein content accounts for 9 g per 100 g−1 of meat, although it is considered as genotype related. Wakeling et al. (2001) found that protein content was the only significant difference between Western Schley and Wichita pecans grown in Australia as compared to higher contents found when grown in the United States. Therefore, the information below must be viewed as a reference rather than universal values, and differences due to genotype, environment and their interaction should be taken in account. Pecans are rich in mono and polyunsaturated fatty acids. According to Rudolph et al. (1992) the most abundant fatty acids in pecan kernels are: oleic>linoleic> palmitic>stearic> linolenic, although their concentration may vary with genotype, maturity and year crop (McMeans and Malstrom, 1982). Other works report up to ten different fatty acids (Senter and Hdrvat, 1976). Oleic and linoleic acids comprise from 90% (Villarreal-Lozoya et al., 2007) to 95% (Herrera, 2005) of total kernel oil content, the high oleic acid content being the source for biosynthesis of linoleic and linolenic acids, as occurs in oilseeds (Toro-Vazquez et al., 1999). It is during embryo and cotyledon expansion when fatty acids accumulate in kernels (Wood and McMeans, 1982). Another benefit for consumers’ health is that pecan oil has ten times more unsaturated than saturated fatty acids (Yao et al., 1992), besides up to 22 g and 1 g per serving of total omega-6 and total omega-3 fatty acids, respectively (Self Nutrition Data, 2010). It has been reported that consumption of pecans lowers the risk of heart disease (Yahia, 2010). Mukuddem-Petersen et al. (2005) concluded that consumption of 50 to 100 g d−1 of nuts, at least five times a week, as part of a heart-healthy diet with a total fat content of 35% of energy, significantly decreased total cholesterol and LDL-cholesterol in normo- and hyperlipidemic individuals.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

146 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Table 8.1 Nutrients and health improving compounds present in the three most consumed nuts in the USA Nutrients in 100 grams of meat

Calories, kcal Protein, g Total fat, g Saturated fat, g Monounsaturated fat, g Polyunsaturated fat, g Linoleic acid (18:2), g Linolenic acid (18:3), g Carbohydrates, g Fiber, g Calcium, mg Iron, mg Magnesium, mg Phosphorus, mg Potassium, mg Sodium, mg Zinc, mg Copper, mg Manganese, mg Selenium, μg Vitamin C, mg Thiamin, mg Riboflavin, mg Niacin, mg Pantothenic acid, mg Vitamin B6, mg Folate, μg Vitamin A, intl. units Vitamin K, μg Vitamin E Tocopherol, α, mg Tocopherol, β, mg Tocopherol, γ, mg Tocopherol, δ, mg

Phytochemicals in 100 grams of meat

Wal

Alm

Pec

650 15 65 6

580 21 51 4

690 9 72 6

9

32

41

47

12

22

38

12

21

9

0

1

14 7 98 2.91 158 346 441 2 3.09 1.59 3.41

20 12 248 4.30 275 474 728 1 3.36 1.11 2.53

14 10 70 2.53 121 277 410 0 4.53 1.20 4.50

4.90 1.30 0.34 0.15 1.12 0.57

2.80 0 0.24 0.81 3.92 0.35

3.80 1.10 0.66 0.13 1.17 0.86

0.54 98 20 2.70 0.70 0.15 20.8 1.89

Wal Carotenoids Carotene β, μg Lutein, μg Lutein + zeaxanthin, μg Cryptoxanthin, β

0

3 8.47 1

29 17.6 17

0

9

Total phytosterols, mg 72

120

97

Stigmasterol, mg Campestrol β-sitosterol

4 5 111

3 5 89

Phytosterols

Flavonoids Catechin, mg Cyanidin, mg Delphinidin, mg Epicatechin, mg Epigallocatechin, mg Epigallocatechin gallate, mg Proanthocyanidins Monomers, mg Dimers, mg Trimers, mg 4–6mers, mg

0.13 0.21 7–10mers, mg 29 22 Polymers, mg 5 56 0

12 7.1 9

Alm Pec

1 7 64 0 2.47 0 0 0 0

7.34 6.0 7.62 23.3

2.47 0 0 0.35 2.12 0.70

6.70 9.88 6.70 0.70 5.29 2.12

8.22 18.23 10.1 44.6 9.35 27.6 42.3 107.3

5.71 39.9 21.2 84.9

89.1 235.9

3.50

25.9 1.40 0.43 0.39 0.89 24.4 0.25 0.47

Sources: Nutrients. USDA National Nutrient Database for Standard Reference, Release 16, last update 2005. International Tree Nut Council Nutrition Research and Education Foundation, September, 2003. Phytochemicals. USDA Phytochemical Study (2004), USDA Nutrient Database Standard Reference, Release 17, 2006. USDA database for the Proanthocyanidin Content of Selected Foods (2004), www.nal.usda.gov/fnic/foodcomp. All data were normalized from original units to 100 g of meat. Wal: walnuts, Alm: almonds, Pec: pecans



147

A close look at the data in Table 8.1 also shows that pecans represent the highest source of antioxidants of these three species, confirming earlier findings by Villarreal-Lozoya et al. (2007), who demonstrated that phenolic compounds with high antioxidant capacity in both kernels and shells make pecan nuts an important dietary source of antioxidants. Villarreal-Lozoya et al. (2007) reported that phytochemical constituents and antioxidant capacity (ACORAC values) of pecan varieties ranged from 372 to 817 mu mol trolox equivalents g−1 defatted kernels, while total phenolics ranged from 62 to 106 mg of chlorogenic acid equivalents g−1 defattened kernels. They also reported that condensed tannins varied from 23 to 47 mg catechin equivalents g−1 defattened kernels. Phenolic compounds with high antioxidant capacity in kernels and shells indicate that pecans can be considered as an important dietary source of antioxidants. Another important consideration when determining phenolic compounds and antioxidant capacity of pecan kernels is that samples must be previously defattened and measured in the acetone fraction, since different solvents deplete the samples and allow a more precise measurement (Pinheiro do Prado et al., 2009a, b). Importantly, pecans are rich in carotenoids, flavonoids and proanthocyanidins, having high content of phytosterols as well (Bhagwat et al., 2004). All of these are associated with improving the antioxidant capacity of our body. For the reasons described above, health specialists recommend the inclusion of nuts in diets to achieve a healthier feeding style (Mukuddem-Petersen et al., 2005; López-Uriarte et al., 2009). Observational studies suggest that nut consumption is inversely associated with the incidence of cardiovascular disease and cancer (Oliver-Chen and Blumenberg, 2008). These facts may explain why nowadays pecans are receiving a wider attention from health-caring consumers. It must be emphasized also that pecans, like other nuts and almost any foodstuff, may trigger allergic reactions in susceptible individuals and specific antigens have been developed for accurate diagnosis (Venkatachalam et al., 2007).

8.3

Harvesting, handling and storage

Harvest is accomplished in different ways, and in an increasing fashion. Mechanization is becoming the most common way, varying depending on the financial resources available to growers. Figure 8.1 shows a typical sequence common to heavily mechanized operations. 8.3.1 Soil preparation Since the nuts are picked directly from the ground, soil preparation is very important and its objective is getting a surface as flat and smooth as possible. 8.3.2 Tree shaking Once the soil is prepared, the next step is getting the nuts off the tree. This is accomplished by shaking the trees with machinery specially developed for


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

148 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Fig. 8.1

Description of typical mechanized harvest operations in a commercial pecan orchard.

nut crops (see Plate XIV in the colour section between pages 238 and 239). Growers have the choice of having their own machinery or hiring a contractor. Many prefer the latter since they avoid the high investment and maintenance costs involved, as well as the problem of having to train personnel every season, not to mention the highest risk of inflicting mechanical injuries to trunks and limbs because of a careless operation or an unskilled operator. By shaking the main trunk and limbs, the nuts are separated and fall to the soil or onto canvas previously spread underneath the trees. In the latter case, the nuts are collected from the canvas and loaded directly into containers to be transported to the sorting facility (Figs 8.2–8.5 and Plate XV in the colour section). If felled directly onto the soil, then the next procedure is followed. 8.3.3 Wind row formation Wind roads are rows of nuts between the tree lines, leaving them ready to be picked by a harvester, and specially designed implements named V-rakes are connected to the front of tractors to create these wind roads of pecans.



149

Fig. 8.2 Manual collection, an alternative to mechanization (courtesy of Dr Humberto Núñez).

Fig. 8.3

Nuts in a row ready for pick up (courtesy of Dr Humberto Núñez).

8.3.4 Nuts pick up and initial transport The harvester outputs the nuts into containers to be transported to the sorting facility and separates leaves and light debris by blowing them away to the sides. It must be pointed out that normally harvest should follow shuck dehiscence, but


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

150 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Fig. 8.4

Picking up of nuts and loading for transport to sorting facility (courtesy of Dr Humberto Núñez).

Fig. 8.5 Manual selection, sizing and grading of in-shell pecans (courtesy of Dr Humberto Núñez).

under particular circumstances it may be desirable to harvest as soon as the endosperms are ripe, without regard to shucks still being closed. Therefore they must be eliminated in an intermediate step, before sorting and grading can be attempted. Since a wide range of technologies are available, the above procedure is adjusted accordingly, but the final objective remains the same: getting the nuts



151

off the trees and collecting and transporting them to the storage facility, as fast as possible. 8.3.5 Immediate nut management Once the nuts are in the storage facility, they are handled either in sacs or metal containers that hold up to 1000 kg of in-shell pecans. Commercial storing conditions commonly used are −13.8 to −9.4 °C and 40% relative humidity (RH). Given the necessity that nuts may be stored for up to three years (more commonly for up to 10 months) the rancidity index must stay below 0.1% of free fatty acid content. 8.3.6 Preparing nuts for processing Once the nuts are ready for process, they are tempered at ambient temperature for 24 to 36 hours, which brings some moisture back into the nuts. Before pasteurization may be attempted, the nuts must be conditioned at room temperature for 4 to 8 hours in tanks, while water is sprayed on top. Pasteurization is achieved by hot water baths with a temperature range between 71.1 to 76.6 °C and an exposure time that varies widely within the industry. Since this is considered a critical control point, it is important that if any microbial assessment is to be considered, sampling should be done right after this step. 8.3.7 Shelling At this point the nuts are ready to be shelled and this is accomplished by a two step process. First, the nuts are mechanically cracked and second, the shells are removed by aspiration. Another alternative is by running everything on water and separating materials by flotation, although this causes water intake by kernels, which has to be adjusted later on. 8.3.8 Sizing and grading Afterwards the nuts are sorted by size, and arrays of several electronic sorters guarantee a good separation. Grading according to color may be achieved through a wide spectrum ranging from manual to infrared technologies depending on the operation size and financial resources. As a final selection step, sizing is done by running the meats through screens, although it can also be done along a band and manually picked. Before packing, the meats may be screened for metal debris using magnets and metal detectors. This process may be repeated two or three times to ensure the absence of this type of physical contaminant, which may include ferrous, non-ferrous and stainless steel particles. 8.3.9 Packing A 13.6 kg box is the industry standard for packing pecans, but bags of 226.8, 453.6 and 907.2 g (8, 16 and 32 ounces, respectively) are also commonly found


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

152 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


at retailers. Even when boxes are used, the meats are first bagged in food grade polyethylene bags, heat sealed under vacuum. Box dimensions are 38.7 × 28.6 × 25.7 cm (15¼ × 11¼ × 10⅛ inches) (L × W × D) and preferred construction is single-wall corrugated Kraft fiberboard, wax-coated inside to delay oil penetrations. When using boxes, palletizing standards are ten boxes per layer by five boxes high for a total of 50 boxes on a 121.9 × 101.6 cm (48 × 40 inches) standard GMA pallet. 8.3.10 Early season harvest Seed testa color is a quality attribute of paramount economical significance in the pecan industry. It is negatively affected by exposure to high temperatures, as occurs while ripenned nuts are left on the tree waiting for shuck dehiscence to start harvesting. Therefore, early season harvest is becoming popular, particularly in those places where fall temperatures are still high. Herrera (1994) found that Western Schleys grown at Las Cruces, New Mexico can be harvested up to four weeks in advance and artificially dried without deleterious effects on flavor. However, this creates a different problem as shucks must be mechanically removed from nuts, so specific equipment has needed to be designed (Verma et al., 1991). Also, nut water content must be lowered to 4% from as high as 24% (Herrera, 2005) since it has been noted that nuts with a 6% water content do not store well (LSU, 2009). Early harvest is a common practice in the southern Sonoran Desert of Mexico, which advances harvest for up to 40 days as compared with its counterparts in the Mexican highlands growing at the same latitude.

8.4

Current quality grading system

The following account summarizes the quality expected for export pecan halves and pieces in the American industry as followed by The Green Valley Pecan Company of Southern Arizona (www.greenvalleypecan.com) and is based on outlines defined elsewhere. 8.4.1

Quality standards

Microbiological A total plate count of less than 10 000 cfu g−1, yeast and mold below 1000 cfu g−1, and coliforms below 100 cfu g−1, while E. coli, Staphylococcus and Salmonella should not be detectable. Chemical To ensure minimum rancidity, a maximum free fatty acid content of 0.4% and a maximum peroxide value of 5 meq kg−1 are required. As for contaminants, on aflatoxin level of 2 ppb is set as the maximum limit.



153

Physical contaminants Since shell pieces may escape detection and become a physical contaminant, the maximum standard allowed for each 45.4 kg (100 lbs) has been set at three hard shells for pecan halves, for large to medium pieces up to four hard shells and no more than five hard shells in the case of small pieces. As described before, magnets and metal detectors are used to avoid metal contaminants, both ferrous and nonferrous, as well as stainless steel pieces. Although no particular mention is made regarding insects and insect parts, it is advisable to avoid their presence and it is in the smallest pieces where their detection may become more difficult. 8.4.2 Color As for physical characteristics, nut color must be a characteristic golden or amber, while meat texture should be firm and crispy. No musky or rancid odors should be present. The high linoleic acid content of pecan kernels make them highly susceptible to becoming rancid (Herrera, 2005), thus every attempt to avoid this defect must be taken into consideration. 8.4.3 Sizing Classification for halves and pieces according to size is accomplished through screens of different sizes, and these are shown in Table 8.2. First, there are three broad categories, Halves, Pieces and Meal, and each is subdivided in Table 8.2 Size classification of pecan halves and pieces according to industry standards in the USA and equivalents in the metric system Category

Units

Nut halves Mammoth Jr. Mammoth Jumbo

per pound 200–250 250–300 300–350

per kilogram 440–550 550–660 660–770

Pieces Extra large Large Large/medium Medium Small/medium Small Midget

Screen size in inches 36/64 to 28/64 28/64 to 19/64 26/64 to 19/64 22/64 to 16/64 19/64 to 16/64 16/64 to 12/64 12/64 to 8/24

in mm 14.3 to 11.1 11.1 to 7.5 10.3 to 7.5 8.7 to 6.4 7.5 to 6.4 6.4 to 4.8 4.8 to 3.2

Meal Granule Meal

Screen size in inches 8/64 to 5/64 5/64

in mm 3.2 to 2.0 2.0

Source: The Green Valley Pecan Company (2010) (http://www.greenvalleypecan.com).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

154 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


smaller categories. For example, in descending order, nut halves are divided into Mammoth, Jr. Mammoth and Jumbo. Nut pieces are comprised by Extra Large, Large, Large/Medium, Medium, Small/Medium, Small and Midget. Finally, Meal can be either Granule or Meal. The count of units per pound of meat implies that the smaller the count, the bigger the kernel parts; therefore, the Mammoth class includes the biggest halves, while Meal includes the smallest particles, basically the finest pieces capable of going through a very small mesh.

8.5

In-shell and shelled pecans

Once harvested, pecans can be managed in-shell or shelled, depending on several factors as described below. 8.5.1 In-shell nuts Although the shell itself represents a good barrier for gas exchange, it does not prevent air from coming in contact with kernels and eventually triggering oxidation processes, leading to oil rancidity and skin darkening. It should also be taken into account that in-shell pecans use more storing space than shelled kernels, therefore in-shell pecans are less efficient in space use in the cold room and during transport. However, very often pure economic reasons are the sole basis to define if the nuts are to be shelled or not, since extra infrastructure is required, and that implies expensive facilities and equipment, as well as trained labor. Often, because individual growers do not have the resources or do not meet the volumes for a profitable cost/benefit ratio, cooperative associations are formed to make a more efficient investment. Otherwise the crop is sold to middlemen, with obvious disadvantages and repercussions for growers but without the need for further investment and the concomitant risks. Advantages associated with in-shell pecans include that they can be stored longer than shelled kernels, and that the shells are natural barriers protecting kernels from bruising and delaying kernel oxidation and rancidity (LSU, 2009), as mentioned before. 8.5.2 Shelled kernels If shelling is an option, then the nuts are sorted according to size and color and cracked open to harvest the meals, following specific schedules according to market demands. If shelling is not an option, then the nuts must be cold stored anyway to avoid quality deterioration, which, although slow, occurs anyway. Often, however, cold storage is not possible and rancidity will develop depending directly on temperature. It must be considered that shelled kernels become darker and develop red colorations quicker than in-shell pecans (Grauke et al., 1998). When temperatures are higher (warmer sites) rancidity develops quicker. Hence, the need for marketing such a crop is greater and the likeliness of getting a fair price declines drastically. From the sanitary standpoint, since shelled pecans are



155

more likely to harbor pests like pecan weevil and others, avoiding transport of in-shell pecans must be part of any quarantine effort, making shelling part of an integrated pest control strategy.

8.6

Description of main quality attributes

Florkowski et al. (1992) acknowledged the complexity of communicating on quality issues in the pecan industry, so that standard grades could be related to quality attributes and prices. Quality pecans are defined by several factors, among the most important being kernel size and color, nutmeat-to-shell ratio, freedom from rancidity, and lack of defects, either physical or caused by insects. These factors, along with specific gravity and shell thickness, are useful not only to grade nuts but are also important factors for the design of handling and processing equipment (Kotwaliwale et al., 2004). Not restricted to processing, they have also been helpful in defining trait targets in breeding programs as well (Florkowski et al., 1992). Using direct gas chromatography (GC) as an objective measurement of several volatile compounds and a trained panelist to assess flavor scores as subjective variables, Forbus et al. (1980) reported that the best correlation coefficients were found when comparing flavor score vs. total volatiles (−0.95) and flavor score vs. tridecane levels (−0.93). Kernel size defines the best possible use for each product. While the biggest sizes are usually used to improve the visual appearance of the final product, the smallest are demanded for baking purposes, with a whole range of uses and demands for the intermediate sizes. Prices correspond accordingly. Kernel color is an indication of quality, since the darker colors are associated with rancidity development, the result of oxidation processes. Oxidation of endogenous leucoanthocyanidin to phlobaphe, cyanidin and delphinidin has been pointed out to be the cause of the red-brown discoloration of kernel testa (Senter et al., 1978). Kernel color is one of the parameters to estimate quality and value, before actual shelling and processing (Heaton et al., 1975), and a simplified color rating system, based on the Munsell Color System but with only six classes, was developed for the pecan industry (Thompson et al., 1996). When kept at room temperature, most color changes occur during the first 18 weeks (Kanamangala et al., 1999), therefore avoiding exposure to such conditions delays the onset of color deterioration. Kernel color transitions change from yellow to red hues and from lighter to darker values, although it changes very little in chroma. Color is also dependent upon genotype, and different years yield different colors for the same variety (Grauke et al., 1998). Therefore, environmental conditions during nut ripening, around harvest and after harvest have a decisive influence in color development. The warmer the temperature, the darker color the kernel develops. Higher elevations and latitudes (cooler temperatures) tend to produce light colored kernels, while the opposite occurs at lower elevations and latitudes where both day and night temperatures will be warmer. However, for the


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

156 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


same latitude, elevation plays a key role in defining quality, and it is expected to find the lightest colored kernels at high elevations, but as a convenient trade off, lower sites may achieve an earlier ripening, as is commonly noted in Northern Mexico, where Western Schleys and Wichitas are grown along 28° NL, but with differences in elevation up to 1000 m. The nutmeat-to-shell ratio describes how much of the total crop is usable. It is the result of orchard management, as much as it is a genetic trait, and nuts from improved varieties have higher ratio than native trees, which are typically thickshelled and small. Also, careful management with appropriate technologies will result in bigger ratios. Although the current nut and kernel evaluation system was developed by the USDA-ARS, and it has been in use for decades to evaluate shelling efficiency, data suggest that there is still room for improvement and other variables should be taken into consideration (Thompson and Grauke, 2003).

8.7

Storage

An efficient strategy for pecan storage calls for a fast and effective drying after harvest, followed by cooling of nuts or kernels, in order to delay kernel quality deterioration (Heaton et al., 1982), regardless if the crop will be shelled or not. In general, benefits of low temperature storage are a better retention of fresh flavor, followed by color, aroma and texture (Herrera, 2005). A brief description of some of the recommended practices follows. 8.7.1 Nut moisture content Nut moisture content during harvest is in the order of 24%, and it should be lowered to 4%, since a 6% water content may lead to mold development and the nuts do not store well (Herrera, 2005; LSU, 2009). Besides the regular gravimetric methods to determine water content, pecan kernel moisture has also been measured by rf-impedance methods with promising results (Nelson et al., 1992). To achieve appropriate moisture content, growers may artificially induce nut dehydration by means of adding heat and dry air. When nuts are harvested early in the season, this practice is a must and is commonly done in processing facilities. However, without access to such infrastructure, a common practice is letting the nuts dehydrate while still on the tree, which leads to a late harvest season. Depending on whether this may pose a risk, since losses of quality are inherent. For example, Heaton et al. (1982) when comparing Stuart, Wichita and Schley nuts harvested in late season, found no color differences on these cultivars, but the latter has less flavor stability. 8.7.2 Appropriate temperature and humidity Having access to pecan samples stored in hermetically sealed containers for 25 years at 20 °C, Hao et al. (1989) were able to compare them with nuts kept



157

under the same conditions but for only ten months. They evaluated sensory, microbial and compositional characteristics, finding that the only significant change was in texture, concluding that pecan can be stored for up to 25 years under those particular conditions. However, achieving those conditions is both difficult and costly for the industry, and appropriate adjustments must be done under commercial conditions. Studying changes in pecans stored at 0.6 °C and 75% RH for 12 months, Yao et al. (1992) did not detect changes in kernel color, oil quality, tocopherols nor conjugated diene levels. Color changes in kernels frozen for up to a year were followed by Grauke et al. (1988) finding that, compared with unfrozen controls, frozen kernels were more red in hue but could not be distinguished on the basis of lightness; also, samples frozen for 12 months had reduced chroma compared to those frozen for six months or unfrozen. Present knowledge leads extension programs to advise that in-shell pecans can be stored for longer periods than shelled nuts, because of the shell protective effect. Also, native pecans storage life can be extended from three months at 21 °C up to eight years at −18 °C (LSU, 2009). Varieties like Western Schley can be kept at 21 °C for up to four months when in-shell, but only three months when shelled, but no difference were found at −18 °C lasting between two and five years (Herrera, 2005). Differences like those may be attributed to unsaturated oil contents, which along with temperature and moisture content are the main factors defining storability (Herrera, 2005). Nonetheless, other conditions should be taken into account, like the fact that pecan pieces have shorter shelf life than halves because of their larger surface/size ratio. As a result, nutmeats may be expected to last only for one or two months at 0 °C (Herrera, 2005). 8.7.3 Packaging materials Refrigerated or frozen pecans should be placed in airtight containers (LSU, 2009). Since shells are a natural barrier protecting kernels from oxidizing faster, very often the situation calls for storing shelled kernels, which requires packaging materials of specific conditions. Dull and Kays (1988) found that kernels packaged in polyvinylidenechloridecoated cellophane packaging films with low oxygen transmission rates were of acceptable quality after six months storage at 24 °C and 60% RH. Later Kanamangala et al. (1999) found that reducing fatty acid content of kernels by partial lipid extraction, resulted in a longer shelf life. They assumed that in addition to decreasing the total amount of lipid available for oxidation, the free fatty acid lipid component that correlated with the development of rancidity was reduced by extraction, most likely the linoleic fraction (Herrera, 2005). Although interesting from the analytical standpoint, implementing a strategy like this would represent an extra task that industry must consider. Using either polypropylene plastic containers or nylon-polyethylene plastic films under vacuum, Oro et al. (2008) evaluated kernels at 23 °C for up to 150 days without significant differences between the two packages. Shelf life was estimated at 120 days, although kernel darkening was detected.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

158


8.8

Postharvest physiology factors affecting nut quality

8.8.1 Respiration Pecans, like all nuts, have a very low respiration rate [about 1 mL kg−1h−1 at 10 °C] (Kader, 2002; Kader et al., 2010), as dormant embryos metabolism is very low, a situation accentuated when they are artificially dehydrated after harvest. Therefore, their shelf life is not threatened because of respirationdependent anabolic reactions, but because of the lipid oxidation process leading to rancidity and skin darkening (Senter and Hdrvat, 1976; Florkowski et al., 1992; Toro-Vazquez et al., 1999; Herrera, 2005).

8.8.2 Color Kernel color is one of the most important quality attributes and develops once shuck dehiscence starts (Kays and Wilson, 1977). Kernel darkening is associated with oxidation of oils (Woodroof, 1979) and rancidity development of free fatty acids (Oro et al., 2008). The seed testa, another designation for the kernel surface, may also become dark when shucks fail to open because of mechanical damage and insect injuries, particularly those caused by sucking insects like stink and coreid bugs, whose bite can penetrate through shells (Yates et al., 1991). There are varietal differences in hemipteran kernel damage susceptibility, but interestingly, it is the females that cause most of the injuries (Dutcher et al., 2001) and dark spots develop around the feeding site. Conditions during late harvests favor kernel darkening and to avoid such problem spraying with ethylene-liberating products in conjunction with auxins used after endosperm filling cause the shucks to open allowing uniform harvests without deleterious effects on foliage (Martínez-Téllez et al., 1995).

8.8.3 Rancidity As mentioned before, along with darkening, rancidity is the other major issue causing pecan quality deterioration. Both are the result of oxidation processes. In the first case is the oxidation of leucoanthocyanidins in kernels (Senter et al., 1978), while rancidity develops when pecan oils are oxidized (Toro-Vazquez et al., 1999). Because pecan oil is so rich in fatty acids (Santerre, 1994), particularly linoleic acid (Villarreal-Lozoya et al., 2007), this makes it particularly susceptible to becoming oxidized, thus getting rancid (Herrera, 2005). Oxidation of unsaturated fatty acids results in the development of undesirable aromas and flavors as well; when this occurs nut shells will have a dark and oily appearance. Peroxide content is the major variable used to measure rancidity and most standards call for a peroxide index value 60% of production), Japan, Korea, Brazil, Italy, Spain, Israel and Turkey, with over 90% of world production in Asia. Production is increasing in countries such as China, Korea, Brazil and Spain. 9.1.3 Culinary uses, nutritional value and health benefits Consumption is mostly in Asian countries where the sweetness, subtlety of flavour and lack of acidity is (generally) more appreciated. Persimmons can be consumed


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

168 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


fresh, are rarely used in cooking, or may be consumed dried. Drying fruit is the main form of processing, but is generally labour intensive, since fruit must first be peeled, then hung to dry. Astringency is lost as fruit ripen, or they can be treated to remove astringency rapidly after harvest (e.g. CO2 treatment, see later). There is a return of astringency when the latter are subjected to heating, or cooked. The high contents of tannins, polyphenols, carotenoids, ascorbic acid and sugars indicate the high potential for health benefit from persimmon consumption, and these compounds have been the subject of intensive study in the last decade. Although clinical studies still need to be conducted, diseases that are considered likely to benefit from persimmon ingestion are cardiovascular, high cholesterol, diabetes, cancer, stroke and even intoxification effects (see review of George and Redpath, 2008). The greater antioxidative activity of high versus low molecular weight tannins might indicate that astringent cultivars are likely to have superior health benefits (Gu et al., 2008), but the effect of removing astringency has not been studied in this respect. The re-solubilisation of polymerised tannin under simulated stomach conditions might make such a study superfluous. It should also be noted that this re-solubilisation might be a reason for caution in consuming excessive amounts of fruit that have had their astringency artificially removed, since the formation of phytobezoars may occur under certain conditions.

9.2


9.2.1 Fruit growth, development and maturation Generally, the growth, development and maturation of persimmon fruit do not differ substantially from those of most fleshy, climacteric fruit, be they from temperate deciduous trees or evergreen subtropical and tropical trees. They exhibit a double sigmoid growth curve, whether seeded or parthenocarpic, and demonstrate typical colouration and softening once they complete their growth cycle and begin to mature and ripen. A very comprehensive review of the development of nonastringent persimmons is also relevant for the astringent types (George et al., 1997). Special attention has been paid to the involvement of the calyx lobes in fruit growth and development (Yonemori et al., 1996). Removal of the calyx during stage I of the growth cycle inhibited fruit growth, indicating the importance of the contribution of assimilates produced in this organ. However, at stage III, fruit growth remained unaffected by calyx detachment, unless the scar was sealed with Vaseline®, in which case fruit growth rate decreased. Apparently, this decrease is due to inhibition of fruit respiration, which was shown to be necessary for photo-assimilate accumulation during the final fruit swell at growth stage III, required to maintain the sink strength of the fruit (Nakano et al., 1998). A unique feature of the persimmon fruit is the abundance of specified tannin cells and the varietal differences in their morphology and metabolism, resulting in the four distinct groups described above. Non-astringent cultivars contain fewer and smaller tannin cells than astringent cultivars (Itoo, 1986), have different cell wall characteristics (Gottreich and Blumenfeld, 1991; Yonemori and Matsushima,


Persimmon (Diospyros kaki L.)

169

1987), colour and shape (Yang et al., 2005). However, the PCNA group has been developmentally distinguished from the other three groups, with regard to its tannin content. Whereas in the latter the tannin content increases during stages I and II of fruit growth, in PCNA-type fruit its accumulation ceases during stage I and the tannin concentration therefore declines as the fruit continues to grow, resulting in a loss of astringency. Moreover, the tannin composition of PCNA fruit differs in that it does not coagulate in the presence of acetaldehyde. The loss of astringency in PVNA-type cultivars is related to the presence of the seeds that produce acetaldehyde and ethanol, thus causing a coagulation of the tannin, even before the fruit ripens. The PCNA-type cultivar is supposedly a recessive mutant of the astringent type and the cessation of condensed tannin accumulation at stage I of fruit development in these cultivars was shown to coincide with the gradual disappearance of DNA sequences of nine genes involved in flavonoid biosynthesis (Ikegami et al., 2005). 9.2.2 Respiration, ethylene production and ripening The ripe persimmon produces extremely low levels of ethylene (peaks below 5 nL g−1 h−1) and because of this, its climacteric status was initially questioned (Takata, 1983). The issue was more or less resolved when it was shown that postharvest fruit softening and colouration were accompanied by ethylene synthesis (Itamura et al., 1991). In the last decade, a number of molecular studies have demonstrated the involvement of the ethylene biosynthetic pathway and signal transduction in persimmon fruit ripening (Ortiz et al., 2006; Pang et al., 2007; Zheng et al., 2005). 1-MCP (a potent inhibitor of ethylene action that binds to the ethylene receptor site and applied commercially as SmartFreshSM) has been a valuable tool in elucidating the climacteric nature of the persimmon (Harima et al., 2003; Luo, 2007). The initiation of pseudo-climacteric ethylene production in detached young fruit (stage I) and in ripened mature fruit was shown to occur in the calyx, being modulated by water stress (Nakano et al., 2002, 2003). A water stress signal activates the expression of one of the three ACC-synthase genes (Dk-ACS2) in the calyx and the ethylene produced diffuses to the other fruit tissues, inducing autocatalytic ethylene production in the fruit by stimulating the expression of all three AC-synthase and two ACC-oxidase genes. Inhibition of ethylene production in the calyx by preharvest application of nickel, delayed ACC accumulation in the fruit, reduced on-tree fruit softening and prolonged the postharvest life of ‘Saijo’ persimmons by retarding softening (Zheng et al., 2006b). Other stresses that induce climacteric ethylene production, but without calyx involvement, are de-astringency treatments and wounding. Wounding also induces Dk-ACS2 expression, which is stimulated by 1-MCP, indicating a negative feedback response to ethylene (Zheng et al., 2005, 2006a). Ethylene perception and signal transduction in persimmon have been studied in relation to the expression of three ethylene receptor genes: Dk-ETR1, Dk-ERT2 and Dk-ERS1 (Pang et al., 2007). Dk-ETR1 is constitutive at a low basal level and independent of ethylene, although probably responsible for its perception.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

170 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Dk-ETR2 and Dk-ERS1 appeared to be regulated by ethylene during fruit development and ripening and were enhanced in response to exogenous ethylene, indicating a possible role in autocatalytic ethylene production, especially for Dk-ERS1, which was much more abundant than Dk-ETR2. This recent study suggests a possible answer to the question of differences in the ripening behaviour and sensitivity to ethylene between persimmon types and cultivars, which has so far not been addressed.

9.2.3 Cell wall metabolism and softening Persimmon fruit softening is associated with middle lamella degradation, loss of cell wall material, and cell wall separation (Shin et al., 1991). These cell wall changes result from the increasing activity of cell wall degrading enzymes common to most fleshy fruit: pectin methyl esterase, polygalacturonase, β-galactosidase and cellulase. These cause a reduction in high molecular weight carbohydrate polymers (pectin, hemicelluloses, and cellulose) and increases in soluble pectic fractions and neutral sugars. The direct involvement of these changes in fruit softening has been demonstrated by the inhibited softening incurred by gibberellins (Ben-Arie et al., 1996), 1-MCP (Luo, 2007) and heat treatment (Woolf et al., 1997; Luo, 2006), as opposed to ethylene-accelerated softening (Chang et al., 2009). However, in rapidly softening ‘Saijo’ fruit, α-L-arabinofuranosidase activity was more closely related to softening than that of the other hydrolases (Xu et al., 2004). This might possibly be a response to the CO2 treatment, since no comparison has been made between natural softening and that induced by artificial removal of astringency. Cell wall metabolism may also contribute to the natural loss of astringency concomitant with softening, because of complex formation between soluble tannin and solubilised cell wall fractions (Taira et al., 1997).

9.3

Maturity, quality at harvest and phytonutrients

9.3.1 Maturity and quality at harvest The most obvious feature of persimmon fruit maturation is the change in colour from light orange/yellow to deep orange and on to red, the result of chlorophyll degradation and carotenoid biosynthesis. The principal carotenoids are initially β-cryptoxanthin, zeaxanthin, antheraxanthin and violaxanthin (Ebert and Gross, 1985; Niikawa et al., 2007). The change to red is due to lycopene accumulation, especially after harvest. Its occurrence in fruit on the tree might be a good harvest index. However, the best objective method for assessing fruit maturity is the Hunter a value, although the Delayed Light Emission method might be more suitable for automated mechanical fruit sorting (Forbus et al., 1991). Chemical changes accompanying fruit maturation that contribute to the taste of the ripe fruit are sugar accumulation, acidity and a decline in soluble tannin. The



171

predominant sugars, in almost equal amounts, are glucose, fructose and sucrose, which increase throughout fruit development, reaching a constant level prior to harvest maturity. During postharvest ripening, the reducing sugars continue to increase due to invertase activity (Zheng and Sugiura, 1990), and a concurrent decline in sucrose levels (Del Bubba et al., 2009). Acidity in persimmons is relatively low even in immature fruit (c. 1%), but does not change with ripening. Malic acid, which is predominant, increases with maturity, accompanied by a decline in citric acid (Senter et al., 1991). Succinic, fumaric, isocitric, ascorbic, gallic and quinic acids have also been identified (Daood et al., 1992). The polymerisation of tannin during maturation of PVNA cultivars is evidently due to the production of ethanol and acetaldehyde by the seeds (Yonemori and Tomana, 1983), but in PCNA cultivars the early decline in soluble tannin is as yet unexplained, although the different tannin composition (Suzuki et al., 2005) is probably involved. Tannin polymerisation also accompanies maturation of astringent cultivars, but at values of around 1% at maturity, the fruit are still highly astringent (Del Bubba et al., 2009; Taira, 1996). A possible explanation for this decline in soluble tannin might be the formation of a glycoside with soluble sugars, proposed to occur during treatment with CO2 (Ittah, 1993). The constant concentration of total sugars maintained when fruit growth ceases might indicate that part of the products of increased invertase activity interact with the soluble tannin. Fruit softening is characteristic of maturation for many fruit species and a measure of firmness can be used as an index of maturity, as a criterion for when to harvest. In general, this is also true for many persimmon cultivars (Salvador et al., 2006). However, with a number of cultivars, fruit firmness as measured with a penetrometer (Magness-Taylor) has been found to be less related to maturity than is the Hunter a colour (Del Bubba et al., 2009; Forbus et al., 1991). Other modes of assessing firmness, such as an impact (Sinclair IQ Firmness Tester) or acoustic (Aweta Firmness Sensor) response, have been found to correlate better with perceived ripeness or postharvest keeping quality. 9.3.2 Phytonutrients Phytonutrients in persimmon include, in addition to the sugars, vitamins and fibre content characteristic of most fruit, large amounts of condensed tannins, polyphenols and carotenoids (Gorinstein et al., 2000), which contribute to the high antioxidative potential of these fruit. High molecular weight tannins have a greater antioxidative activity than low molecular weight tannins (Gu et al., 2008; Kondo et al., 2004), but the effect of removing astringency on antioxidative activity is not known. Maturation and ripening are associated with a reduction in polyphenol content, which might lead to a reduced antioxidant potential. Conversely, the increase in the carotenoid content associated with ripening is likely to raise it. Although varietal differences have not generally been addressed, non-astringent cultivars were found to have higher levels of vitamins A and C than astringent cultivars (Homnava et al., 1990).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

172 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


9.3.4 Taste Persimmon overall has a subtle taste with little or no acidity and the aroma is not strong compared with that of many fruit species. Fruit with good sun exposure will tend to have best flavour (higher SSC and more volatiles/flavour). The two most important taste aspects tend to be sweetness and astringency. Higher levels of sweetness are generally preferred by consumers, and warmer growing environments will result in higher SSC content (up to or above 20%; Cristosto, 2004), while fruit in cooler environments may struggle to achieve an average of even 15% (Mowat and Collins, 2000). In astringent-type persimmons under prolonged MA storage that enables loss of astringency, flavour can become bland if CO2 levels in storage are low, or develop off-flavours if CO2 is too high. In non-astringent persimmons, a possible negative attribute that can affect repeat sales is that of ‘residual astringency’. The key factor that affects this appears to be the fruit temperature during development (Mowat and Collins, 2000), particularly during the period of 10–14 weeks after full bloom (Chujo, 1982; Jackman and Woolf, unpublished data).

9.4

Preharvest factors affecting postharvest fruit quality

9.4.1 Minerals – nutrition Studies conducted with a non-astringent cultivar (‘Fuyu’ in New Zealand) and with an astringent cultivar (‘Triumph’ in Israel) have not indicated any apparent postharvest effects of mineral status of the fruit at harvest (although the New Zealand study did not include nitrogen in the analysis). This could, however, be the result of specific environmental effects on the mineral composition and/or physiology of the fruit, since the same cultivars grown in Brazil, Spain and Australia were found to respond to preharvest calcium by producing firmer or higher quality fruit (Agusti et al., 2004; Ferri et al., 2008) and Redpath et al. (2009) found a correlation of leaf calcium content and postharvest softening rate. The keeping quality of coolstored ‘Fuyu’ was improved by preharvest sprays of calcium chloride or nitrate (0.5%) and boron (0.3%), because of reduction of skin cracks, and browning (Ferri et al., 2008). Application of 2% Ca(NO3)2 to astringent ‘Triumph’ fruit before colour break retarded colour development, fruit softening and ethylene production and reduced postharvest fruit softening and deterioration. However, the incidence of soft-blossomend fruit, which appeared to be related to low calcium levels, was not affected by orchard sprays of calcium nitrate throughout the growing season (Ben-Arie et al., 2008). Repeated heavy foliar application of calcium sprays in New Zealand was not found to reduce chilling injury following storage (Woolf and colleagues, unpublished data). Convincing data as to the ability of cultural practices to affect the mineral composition and postharvest quality of persimmon fruit are scarce. 9.4.2 Plant growth regulators The objective of preharvest application of plant growth regulators is to control fruit maturation or improve postharvest ripening and quality. Advanced maturation



173

has been achieved by applying paclobutrazol (a gibberellin synthesis inhibitor), abscisic acid, ethychlozate or methyl jasmonate (presumably by stimulation of ethylene synthesis) and ethephon (an ethylene-releasing compound). These treatments enable earlier harvesting because of enhanced growth rate and fruit colouration, but may also accelerate the postharvest softening rate. This practice may be useful where limited storage/shelf life is acceptable (i.e. early season local or airfreight export markets). Paclobutrazol has been applied commercially with success, care being taken not to delay harvest from treated trees. It is applied to the soil in the spring, immediately retarding vegetative growth and the effect can last for 2–3 years. Conversely, delayed maturation is achieved by spraying GA3 (30–50 mg L−1), 10–20 days before harvest. Colour development and fruit softening are retarded, but the chief advantage of this treatment is an extended storage and shelf life. It is necessary to determine the optimum dose for each cultivar, since, although increasing the dose enhances the effect, it may be detrimental to fruit size and especially to the return bloom in the subsequent year. A similar effect can be obtained by spraying the cytokinin CPPU at a low concentration (2–10 mg L−1, ten days after full bloom (DAFB)). Combined with girdling, final fruit weight could be improved (Hamada et al., 2008). However, to the best of our knowledge, this treatment has yet to be adopted commercially. The delayed maturation induced by GA3 has been shown to increase the carbohydrate content, chiefly cellulose, together with reduced activity of PG and cellulase during fruit softening (Ben-Arie et al., 1996, 1997). It also reduces the rate of fruit respiration (Nakano et al., 1997) and the sensitivity of the fruit to ethylene ten-fold. 9.4.3 Climate and environment The persimmon is generally regarded as a crop that is highly adaptable to many soil types and conditions, as well as to a wide range of climatic conditions. Sunburn and abrasions caused by wind are easily recognised and can be dealt with to some extent, using appropriate training methods, wind-breaks (trees or artificial netting) and other methods of protection, such as net-houses or covering. Astringency is the most obvious of the fruit characteristics that is affected by climatic conditions during fruit development. As noted above, non-astringent cultivars require warmer conditions than astringent cultivars for maturation and may not lose their astringency when grown under relatively low temperatures (Mowat et al., 1997). On the other hand, excessively high temperatures may be detrimental to fruit size, partly because of accelerated maturation. Fruit can be susceptible to sunburn in mid-summer, particularly following pruning or leaf thinning. However, although net covering in a hot climate reduced the daily temperature and somewhat delayed maturation (chiefly because of a delay in colour development), it did not increase fruit size, which is positively affected only by increasing irrigation in both open and net-covered orchards. Nonetheless, net covering produced higher quality fruit because of reduced sunburn and wind abrasions, in addition to reduced bird damage (Ben-Arie et al., 2008).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

174 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Canopy management contributes significantly to overall fruit quality. In a review of Australian persimmon management practices, Nissen et al. (2003) reported that in Australian orchards, trellised trees produce higher yields of marketable fruit than do other training systems. Trellising increased planting density, improved light interception, and structures that stabilised the tree significantly reduced fruit blemishes. Light exposure of the fruit has an effect on fruit temperature (Mowat, 2003). In Japan, Takano et al. (1991) reported that the level of light exposure had a greater effect on fruit weight, colour and soluble solids content than did crop load. Exposed fruit had higher colour and lower soluble tannins than unexposed fruit in the mid-canopy in New Zealand ‘Fuyu’ (Mowat, unpublished data). Specific leaf weight is useful as an indicator of light conditions in ‘Fuyu’ canopies in New Zealand orchards, where higher values were correlated with improved fruit quality (Mowat, 2003). 9.4.4 Calyx separation In some cultivars and growing conditions, calyx separation or ‘calyx cavity’ develops (Glucina, 1987). This disorder occurs late in the season, during the final phase of the double sigmoidal growth curve. It is thought that the fruit expands faster than the calyx, and this results in the flesh separating from the calyx tissue, resulting in potentially large gaps (up to 5 mm or more), which may even encircle the whole calyx. This leads to more rapid softening of non-stored persimmons and increased levels of chilling injury in stored fruit. Thus, commercial recommendations are to remove these fruit during packing, although detection of all but the most severe disorders can be difficult. These cavities also provide a refuge for insects such as caterpillars, mealybugs and even earwigs. The problem is more common in ‘Fuyu’, but less so in some other cultivars such as ‘Triumph’ and ‘Suruga’. Larger fruit are more likely to have calyx separation, probably because of the greater fruit expansion. It is considered to occur more on young trees, and generally declines after about 15 years. 9.4.5 Skin cracking/black blotch An additional practical and economic challenge to persimmons is the propensity for the occurrence of large or small cracking (‘crazing’) of the skin. This can occur as ‘ring cracks’ around the fruit, most often at the distal end, or as discrete brown/black patches on the skin (‘black stain’, Fumuro and Gamo, 2001; or ‘black blotch’, Woolf et al., 2008). Depending on market requirements, these may or may not be acceptable. Large cracks are evident at harvest, but smaller cracks may only become evident after harvest, or during storage, although the actual cracking is most likely to have occurred preharvest during the final stage of fruit growth (Chujo et al., 1982; Woolf et al., 2008). Factors that may increase this problem are rainfall or presence of seeds, both of which lead to increased fruit expansion, presumably placing more stress on the skin. The resulting cracks may be visible to the naked eye or microscopic (Woolf et al., 2008), and it is the latter



175

ones that are likely to blacken after harvest or during storage. Thus, orchard management systems that avoid damage to the fruit skin (e.g. avoiding leaf contact with fruit; Woolf et al., 2008) or fruit bagging prior to harvest (Fumuro and Gamo, 2001) ensure development of continuous wax layers that will improve packout and final fruit quality.

9.5

Postharvest handling factors affecting fruit quality

Although there are significant differences between countries and cultivars, the maximum storage life of persimmons is generally in the order of 12–16 weeks. Typically this will only be achieved by use of a combination of treatments (such as optimised temperature, 1-MCP and MA storage) to overcome softening and/or chilling injury problems. The final limitation to long-term storage will typically be external quality due to skin browning, excessive softening or disease incidence. 9.5.1 Temperature management The standard recommended storage temperature is 0 °C (Crisosto, 2004; MacRae, 1987), and some countries recommend even lower temperatures such as −1 °C (Israel). Higher temperatures (3–8 °C) lead to increased chilling injury in ‘Fuyu’ (Collins and Tisdell, 1995), and at 5–15 °C for other cultivars (Crisosto, 2004). Since maintaining temperatures around or below 0 °C is important, determining the freezing point can be an important step in commercial temperature management. Crisosto (2004) suggests a freezing point of −2 °C and we have found freezing points as high as −1.25 °C (New Zealand) or as low as −3.2 °C (Israel), the variation being probably attributable to SSC level. 9.5.2 Physical damage An important problem with persimmons is that any puncturing or damage to the skin results in blackening that is very evident to consumers on the orange-red skin. Aside from the obvious deleterious visual effect, such damage can promote rots during storage. In some cultivars, bruising appears not to be important (‘Fuyu’ in New Zealand), but in other cultivars (‘Triumph’), careful handling at and after harvest is of major importance, to avoid the occurrence of blackened tissues beneath the skin. Fruit that have been treated with CO2 to remove astringency are especially susceptible. Therefore, the commercial recommendation is to pack the fruit prior to de-astringency treatment. 9.5.3 Water loss Unlike many crops, weight loss is not a key factor for persimmons, probably because little water loss occurs through the skin (Perez-Munuera et al., 2009), but


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

176 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Fig. 9.1 The relationship between weight loss, fruit shrivel and Alternaria decay development on ‘Triumph’ persimmons, after 14 weeks storage at −1 °C and RH levels ranging from 70 to 100%.

low RH can cause fruit shrivelling. For example, ‘Triumph’ fruit showed a linear relationship between increase in weight loss during storage and RH (Prusky et al., 1981), and the percentage of shrivelled fruit was unacceptable above 5% loss in weight, which occurred at 85% RH after 14 weeks at −1 °C (Ben-Arie and Prusky, unpublished data, Fig. 9.1). From the point of view of decay development, increased weight loss was accompanied by reduced infected area, so that optimum quality was achieved with 3–5% weight loss at 85–90% RH. However, maintenance of 90 to 95% relative humidity (RH) during storage has also been recommended (Crisosto, 2004). In terms of weight loss from the fruit, both before and during storage, no significant impacts on chilling injury have been noted for ‘Fuyu’ (Woolf, unpublished data). Softening of the tissue beneath and around the calyx after prolonged storage could possibly arise indirectly from water loss by the calyx lobe, which has been shown to trigger ethylene production (Nakano et al., 2002, 2003), as described above. Where there are cracks or punctures of the skin, water loss occurs more rapidly during storage and shelf life, and thus some shrivelling and sinking of tissue can become evident. In non-damaged fruit, the key area where weight loss may be commercially important is in the appearance of the calyx, where drying and browning of the green leafy tissue may affect retailer and consumer perceptions of freshness. 9.5.4 Atmosphere Controlled atmosphere (CA) storage Storage under low O2 of 2 to 5% delays ripening, and CO2 at 5 to 10% slows softening and can reduce chilling injury (CI) symptoms (Crisosto, 2004; Burmeister et al., 1997; Tanaka et al., 1971). The upper tolerable concentration of CO2 appears to be between 10% (Crisosto, 2004) and 20% (Haginuma, 1972),



177

although there clearly are cultivar differences. Excessive exposure can result in skin browning and/or flesh browning beginning in the fruit centre. CA storage of the astringent ‘Triumph’ has the triple benefit of delaying fruit softening, retarding decay development and, if extended beyond three months, removing astringency (Guelfat-Reich and Ben-Arie, 1976; Guelfat-Reich et al., 1975). The atmosphere required to achieve these advantages is 1.0–1.5% O2 and 1.5–3.0% CO2. At higher CO2 levels, Alternaria decay control is improved, but fruit softening is enhanced and at >5% CO2, internal flesh browning occurs. The disadvantage of long-term CA storage (exceeding three months) is the very short subsequent shelf-life, due to rapid fruit softening. Below 1.0% O2, ethanol and acetaldehyde accumulation are excessive and off-flavours develop after three months at −1 °C, although astringency is completely removed (Ben-Arie, unpublished data). ‘Rojo Brillante’ storage life was extended to 30 days at 15 °C under CA (3% O2, 97% N2) because of delayed softening, thus circumventing CI, also with removal of astringency (Arnal et al., 2008). In this case, increased CO2 was of no additional benefit. Modified atmosphere storage Use of modified atmosphere (MA, or MAP) is common commercial practice in Korea, Japan and New Zealand (Kim and Lee, 2005; Kawada, 1982; MacRae, 1987). Fruit are heat-sealed in a 60-μm polyethylene (PE) bag, which generates an atmosphere of approximately 0.5–1.5% O2 and 4–8% CO2 (MacRae, 1987; Kim and Lee, 2005) and this delays and ameliorates CI symptoms, but does not eliminate them. Fruit of an entire tray (e.g. 4–10 kg) tend to be stored in one bag, but individual fruit-bags, or fruit in lots of 3–5, may also be used in Japan. An additional benefit of the MA bag system is that fruit are maintained in the MA environment during storage at the packhouse facility, during shipment/ transport (e.g. seafreight container), and during the steps through the wholesale and retail chain. This has a range of advantages other than the continual MA atmosphere, including reduced temperature fluctuation, avoiding condensation and improved food safety. A key commercial challenge is the reliability of bagsealing, where even one pin-prick sized hole can compromise the MA atmosphere and result in chilling injury development. In addition, once sealed in the MA bag, exposure to higher temperatures than the target storage temperature may result in reduced O2 and elevated CO2 concentrations, which may damage fruit (‘glassy ring’ and calyx abscission). Ethylene Persimmons are climacteric and sensitive to ethylene and thus exposure to ethylene results in increased rates of softening and reduced storage and shelf life, and therefore marketability (Takata, 1983; Krammes et al., 2005; Park and Lee, 2005; Besada et al., 2010). Besada et al. (2010) examined the effect of a wide range of concentrations and durations of ethylene exposure on shelf and storage life of ‘Fuyu’ in simulated air (non-stored) and seafreight (MA-stored) commercial scenarios. Exposure of fruit at 20 °C for one day, at even 0.2 μL L−1, resulted in


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

178 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


an increased softening rate (non-stored fruit). If fruit were stored under MA for seven weeks after treatment, chilling injury was increased with ≥1 μL L−1 for 1 d, and slightly increased with ≤0.5 μL L−1 for 2 d. However, ethylene exposure of MA packed fruit during storage (0 °C), at either the beginning or end of the storage period, had either little or no influence on chilling injury (even with exposure times of seven days at 10 μL L−1). The lack of response of ‘Fuyu’ persimmons at low temperature is supported by results with ‘Triumph’, which (although this cultivar is not sensitive to CI), can be stored at −1 °C with ethylene levels up to 5 μL L−1, without any softening effect. Other treatments that will ameliorate the effects of exogenous ethylene are 1-MCP treatment. Krammes et al. (2005) showed that fruit treated with 1-MCP (0.1 and 1.0 μL L−1) were less responsive to even continuous exposure to ethylene (0.1 or 3 μL L−1) at 23 °C. Thus, although eliminating ethylene exposure before storage is critical, exposure during storage may be less important. However, Neuwald et al. (2009) reported benefits of ethylene scrubbing in terms of softening and skin browning under long-stored MA conditions. Thus, clearly commercial best practice is to minimise ethylene concentrations during storage. Anoxic tolerance of persimmons A remarkable characteristic of persimmons is their ability to tolerate nearcomplete anoxia (Tanaka et al., 1971). Storage of persimmons in flowing nitrogen (10 mm diam.), evident to the retailer at removal from storage. Rots caused by Botrytis cinerea, a wound parasite, can develop at three different sites on the fruit (Woolf et al., 2008). ‘Apex punctures’ that occur during harvest or handling due to puncturing of the skin by the ‘apex spike’ (the hard structure present at the stylar end of the fruit), enable fungal penetration. The apex spike itself can become infected



183

(during flowering) and these infections develop into rots during storage. ‘Calyx rots’ (around the calyx end of the fruit) occur sporadically and we have also found these to be caused by Botrytis cinerea. Keeping the amount of Botrytis inoculum low in orchards during the growing season is key to reducing the potential for storage rots. In addition to the postharvest impact of Botrytis, infection of the petal tissue at flowering can lead to cosmetic marking of the skin that causes rejection at packing. Postharvest treatments using a hot water drench at approximately 55 °C have been shown to be effective for control of postharvest diseases in long-stored ‘Fuyu’ (Woolf et al., 2008), and similar treatments (hot water brushing) are effective on ‘Triumph’ (Ben-Arie, pers. comm.). Other causes of decay in persimmons according to Crisosto (2004) and Palou et al. (2009) are Cladosporium, Colletotrichum, Mucor, Penicillium, Phoma and Rhizopus. Many of these infections take advantage of wounding or microscopic damage to the skin (e.g. Mucor, Kwong et al., 2004).

9.8


Insects are a significant problem for persimmons, which can host fruit fly in the subtropics, and are readily infested in temperate environments by a wide range of other pests, such as caterpillars, thrips, mealybug and scale. There is also a wide range of insects that cause significant preharvest problems, but may not be a significant problem from a postharvest perspective (e.g. various stink bugs: Halyomorpha halys, Plautia crossota stali, Riptortus clavatus, Son et al., 2009; and cut worms, Choi et al., 2008). 9.8.1 Fruit fly Fruit flies are important fruit pests that attack several cultivated species of high commercial value in subtropical and tropical areas of the world. Three species are prevalent on persimmon in different growing regions: the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), the Mexican fruit fly, Anastrepha ludens (Loew) and the oriental fruit fly, Bactrocera dorsalis (Wendel). Because of the continuity of hosts and the relatively short life cycle of the pests, their control is difficult and fruitgrowing regions that are infected have developed regional protocols for dealing with the problem. These include detailed recommendations for sanitation, weekly monitoring, pesticide-bait spray programmes, release of sterilised males and traps to kill. Sanitation recommendations include total removal and disposal of fruit from the trees and orchard ground after harvest. Monitoring with traps containing the attractant trimedlure begins around the time of colour break. Bait sprays are frequently applied from aircraft and supplemented with spot spraying in the orchards. In recent years an effective and environmentally friendly insecticide, Conserve®-SC (Spinosad; Dow AgroSciences), has replaced the organophosphate malathion as a bait spray (Stark et al., 2004). The dispersal of sterilised males is increasing and new traps to attract


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

184 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


and kill have been developed. In Hawaii a multi-lure trap (three attractants) with soapy water or sticky boards to kill, and in Israel two traps – Biofeed® and Protect® – based on attractant yellow boards, bait and Spinosad, are available. In the event that a combination of all treatments is not sufficiently effective and larvae are found in infected fruit, cover sprays with the organophosphate diviphos are recommended to achieve eradication (Thomas et al., 2007). Quarantine regulations in some persimmon importing countries are very strict, with zero tolerance. Cool storage at below 1 °C for two weeks kills all stages of the fly and is generally suitable for most cultivars. For chilling-sensitive astringent cultivars, it is possible that the high CO2 treatment at a high temperature to remove astringency could also be effective. 9.8.2 Other insects In more temperate environs, the most important pests of persimmon include mealybug (e.g. Pseudococcus longispinus, P. viburni, P. calceolariae and Phenacoccus graminicola) and various leafroller and other caterpillar species (e.g. Ctenopseustis obliquana, C. herana, Cnephasia jactatana, Planotortrix octo, Stathmopoda skelloni, Sperchia intractana and the lightbrown apple moth – Epiphyas postvittana). Postharvest treatments for such species include cold disinfestation and heat treatments either by hot air (Dentener et al., 1996) or hot water (Lee et al., 2008). Other important insects include thrips (e.g. Heliothrips haemorrhoidalis, Nesothrips propinquus) and scale insects (e.g. Hemiberlesia rapax, Hemiberlesia lataniae, Aspidiotus erii, Ceroplastes pseudoceriferus and Phenacoccus aceris). Scale insects can infest fruit or calyx, and where this occurs, it tends to result in an indentation in the fruit. Finally, various mites may also be an issue (e.g. Aceria diospyri, Oribatidae, Tetranychus urticae (TSM), Orthotydeus californicus and O. caudatus). 9.8.3 Passenger or ‘hitchhiker’ pests The issue of ‘passenger’ or ‘hitchhiker’ pests, including spiders, earwigs, centipedes, slaters, and even small snails, poses a problem. They often hide under the calyx or in the calyx cavity (if present). In this location, they are difficult to detect and are well protected from any preharvest insecticides and postharvest treatments (such as brushing). Some packhouses resort to checking under each lobe of the calyx, and use an air gun to remove insects, which is clearly an expensive practice and generally only practicable for very high value markets (such as Japan).

9.9


9.9.1 Harvest operations Different cultivars require different harvest techniques. For many cultivars (e.g. ‘Fuyu’ and ‘Triumph’), fruit must be cut from the tree using secateurs, leaving the



185

calyx attached to the fruit, since hand-pulling can injure the fruit and adjoining stem. However, other cultivars (e.g. ‘Kaki-Tipo’), may be hand-harvested (twisted) from the stem. Another factor that has a significant influence on the harvest technique is that of fruit shape and the location and structure of the ‘apex spike’ (black spike at distal end of the fruit). If the spike is prominent, it is more likely to damage other fruit during handling and packing and in this case fruit must be harvested into single-layer trays (e.g. Italy) or 20-kg crates with three layers (New Zealand) rather than larger harvest bins (350 kg, Israel). The ability to harvest by hand and not use small trays clearly has significant impacts on speed and economics, but enhances the danger of bruising while filling the bins and during transport. 9.9.2 Packinghouse practices Generally persimmons do not require any specific handling procedure other than the usual grading, sizing and packaging, adapted to the marketing outlets. Only fruit harvested into bulk bins are dumped into water to ensure gentle fruit handling. Astringent cultivars have to be treated to remove astringency. The most common method used is exposure to 80% CO2 for one to three days, depending on the cultivar. The preference for this treatment is because of the maintained fruit firmness (relative to ethanol). In Japan, the method has been refined with temperature control, shortening the time required – CTSD (controlled temperature short duration). In Italy, ‘Kaki-Tipo’ is treated with ethylene (>100 μL L−1), in spite of its softening effect, since the response to CO2 is not optimal and that market favours the softer fruit. The treatment is applied at 25–30 °C for 24–36 hours, depending on the stage of maturity, and thereafter temperature is reduced to 15 °C until the desired colour is achieved. Fruit that are intended for storage periods in excess of 8–10 weeks require treatment to inhibit Alternaria black spot development. The recommended treatment in Israel for ‘Triumph’ is a 30-second dip in 500 mg L−1 hypochlorite or Troclosene-Na. 9.9.3 Control of ripening and senescence Using refrigeration to delay persimmon ripening and senescence is limited by chilling injury (CI), which is the decisive factor in choosing the appropriate storage temperature for each cultivar. Thus, the non-susceptible ‘Triumph’ can be stored at −1 °C for four months, ‘Fuyu’ develops CI within two weeks below 8 °C (air-stored), and the highly susceptible ‘Rojo Brillante’ maintains best quality at 15 °C, but only for three to four weeks. CA storage has been shown to be beneficial in retarding both softening and black spot development, but the optimal levels need to be determined for each cultivar. Internal injury is likely to appear at higher CO2 levels, especially under MA conditions, where the build-up of CO2 is controlled by the balance between fruit respiration (affected by temperature) and the selective permeability of the


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

186 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


package material. Nonetheless, with films of suitable gas transmission, the storage life of ‘Fuyu’ persimmons can be tripled at 1 °C (Cia et al., 2006). The disadvantage of both storage methods is the rapid rate of fruit softening after removal of the fruit to shelf-life conditions. This has been shown to be remediable when CA storage follows 1-MCP treatment. Persimmon fruit respond very well to 1-MCP (commercially applied by AgroFresh as SmartFreshSM) at levels in the range of 0.3–0.6 mg L−1, at both storage and ambient temperatures, either before or after storage. In addition to alleviating CI in ‘Fuyu’ and ‘Rojo Brillante’, when applied before storage at 0 °C, the treatment extends the post-storage shelf life by retarding fruit softening. However, with long-term storage, decay development generally becomes the limiting factor. Hence, there is an advantage in combining 1-MCP pre-storage treatment with CA storage. Irrespective of this, it is convenient to apply 1-MCP in combination with the CO2 treatment to remove astringency (Harima et al., 2003), either before or after storage. Similarly, use of 1-MCP treatment prior to MA storage leads to near elimination of chilling injury for ‘Fuyu’ (Kim and Lee, 2005). This is typically carried out on only a small portion of the crop destined for long-term storage, because of the cost of treatment, additional handling and delays to packing, which generally make its universal use uneconomic. It should be noted that 1-MCP does not solve all physiological disorders, or pathological problems that typically result from storage for more than ten weeks. 9.9.4 Recommended storage and shipping conditions Optimum storage temperature is generally 0 °C, but variation between cultivars exists (e.g. ‘Rojo Brillante’ (see Section 9.5.1 above)). Ethylene scrubbing is generally not used under commercial conditions, but ethylene should be avoided where possible. Some cultivars respond well to MA storage (e.g. ‘Fuyu’) but CA is rarely used commercially (see Sections 9.5.4 and 9.9.3 above).

9.10

Processing

9.10.1 Fresh-cut processing Although there is potential for persimmons to be processed for fresh-cut, either as wedges or slices, there has been little development in this area. This is possibly because of the relative ease of preparation of persimmon fruit for serving and its relatively slow flesh browning in such situations. At 5 °C (a typical storage temperature for fresh-cut products), slices of ‘Fuyu’ have a shelf life of seven days in air, and eight days in a CA (2% O2 + 12% CO2; Wright and Kader, 1997). A longer shelf life can be expected at 0 to 2 °C (Crisosto, 2004). Itamura et al. (2009) found that ‘Saijo’ showed more softening when fruit were cut into vertical wedges rather than horizontal slices, and that fruit cut into small pieces softened the most rapidly. Application of 1-MCP slowed softening, but was not completely effective.



187

Use of antioxidants such as sodium ascorbate and cysteine were found to reduce browning of fresh-cut ‘Rojo Brillante’ (Peraz-Gago et al., 2009). 9.10.2 Other processing practices The most common processing of persimmons is that of drying, which has been carried out for many centuries (Testoni, 2002). Typically the skin is removed (by hand or chemically), and the fruit then air-dried. Chinese and Japanese traditionally hang fruit to dry on strings, resulting in a high value product (Sugiura and Taira, 2009). Additional processing include dried powders from purees to prepare traditional sherbets (Cortellino et al., 2009), and, of course as carried out in nearly all cultures, various alcoholic beverages (Khositashvili et al., 2008).

9.11

Conclusions

Persimmon is a challenging fruit to work with and has many unique characteristics. 1-MCP has provided a key tool for elimination of chilling injury and/or softening. Indeed, the reduction in softening and chilling injury in persimmons is something very close to a ‘silver bullet’. However, rots still remain a challenge for long-stored fruit, particularly given the desire for non-chemical solutions. There are also a number of unexplained physiological disorders that appear mainly on the fruit surface after prolonged storage, which will probably gain importance once the application of 1-MCP and effective disease control enable extension of the fruit’s storage life. The issue of residual astringency is a problem in PCNA cultivars, which needs development of a rapid, simple measure of astringency that correlates with human perception. If this tool could be used in the field and/or packhouse, this would be advantageous. There are opportunities to further research the healthfulness of persimmons. To this end, a worldwide industry initiative into funding and co-ordinating this area was made at the recent International Persimmon Symposium in Italy (Wells, 2009).

9.12

References

Agusti M, Juan M, Martinez-Fuentes A, Mesejo C and Almela V (2004), ‘Calcium nitrate delays climacteric of persimmon fruit’, Annals of Applied Biology, 144, 65–69. Arnal L, Besada C, Navarro P and Salvador A (2008), ‘Effect of controlled atmospheres on maintaining quality of persimmon fruit cv. “Rojo Brillante” ’, Journal of Food Science, 73, 826–830. Arnal L and Del Rio M A (2003), ‘Removing astringency by carbon dioxide and nitrogenenriched atmospheres in persimmon fruit cv. “Rojo Brillante” ’, Journal of Food Science, 68, 1516–1518. Ben-Arie E and Zutkhi Y (1992), ‘Extending the life of “Fuyu” persimmon by modifiedatmosphere packaging’, HortScience, 27, 811–813. Ben-Arie R, Saks Y, Sonego L and Frank A (1996), ‘Cell wall metabolism in gibberellintreated persimmon fruits’, Plant Growth Regulation, 16, 25–33.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

188 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Ben-Arie R and Sonego L (1993), ‘Temperature affects astringency removal and recurrence in persimmon’, Journal of Food Science, 58, 1397–1400. Ben-Arie R, Zhou H W, Sonego L and Zutkhi Y (1997), ‘Plant growth regulator effects on the storage and shelf-life of “Triumph” persimmons’, Acta Horticulturae, 436, 243–250. Ben-Arie R, Zilka S, Klein I and Gamrasni D (2008), ‘Persimmon and environment: soil and water management for high quality fruit production’, Advances in Horticultural Science, 22, 286–293. Besada C, Jackman R C, Olsson S and Woolf A B (2010), ‘Response of “Fuyu” persimmon to ethylene exposure before and during storage’, Postharvest Biology and Technology (accepted). Brackman A, de Freitas S T, Pinto J AV (2004), ‘Ripening control with 1- Methylcyclopropene on “Fuyu” persimmon in cold storage and controlled atmosphere’, Rev. Fac. Zootec. Vet. Agro, 11, 123–134. Burmeister D M, Ball S, Green S and Woolf A B (1997), ‘Interaction of hot water and controlled atmosphere storage on quality of “Fuyu” persimmons’, Postharvest Biology and Technology, 12, 71–81. Chang X X, Rao J P, Zhao B and Liu L (2009), ‘Effect of propylene on softening and postharvest cell wall metabolism of persimmon fruit’, Acta Horticulturae, 833, 299–304. Choi S T, Kang S M and Park C G (2008), ‘Integrated and organic production: insect pest management’, Advances in Horticultural Science, 22, 294–300. Chujo T (1982), ‘Studies on the thermal conditions on the growth and quality of fruits of “Fuyu” kaki’, Memoirs of Faculty of Agriculture, Kagawa University. Chujo T, Honma A, and Ashizawa M (1982), ‘Ultrastructural changes of fruit surface of kaki (Diospyros kaki Linn. f.) through developmental phase’, Technical Bulletin Faculty of Agriculture Kagawa University, 33, 95–101. Cia P, Benato E A, Sigrist J M M, Sarantopoulos C, Oliveira L M and Padula M (2006), ‘Modified atmosphere packaging for extending the storage life of “Fuyu” persimmons’, Postharvest Biology and Technology, 42, 228–234. Collins R J and Tisdell J S (1995), ‘The influence of storage time and temperature on chilling injury in “Fuyu” and “Suruga” persimmon (Diospyros kaki L.) grown in subtropical Australia’, Postharvest Biology and Technology, 6, 149–157. Cortellino G, Scalzo R L Testoni, Bertolo G and Maestrelli A (2009), ‘Persimmon puree: a new ingredient to improve technological and health benefits in sherbets’, Acta Horticulturae, 833, 77–82. Crisosto C (2004), ‘Persimmon’. In: KC Gross, CY Wang and M Saltveit (eds), Agriculture Handbook Number 66. The commercial storage of fruits, vegetables, and florist and nursery stocks. Available at: http://www.ba.ars.usda.gov/hb66/ Daood H G, Biacs P, Czinkotai B and Hoschke A (1992), ‘Chromatographic investigation of carotenoids, sugars and organic acids from Diospyros kaki fruits’, Food Chemistry, 45, 151–155. Del Bubba M, Giordani E, Pipucci L, Cincinelli A, Checchini L and Galvan P (2009), ‘Changes in tannins, acorbic acid and sugar content in astringent persimmons during on-tree growth and ripening in response to different postharvest treatments’, Journal of Food Composition and Analysis, 22, 668–677. Dentener P R, Alexander S M, Lester P J, Petry R J, Maindonald J H, and McDonald A M (1996), ‘Hot air treatment for disinfestation of lightbrown apple moth and longtailed mealy bug on persimmons’, Postharvest Biology and Technology, 8, 143–152. Ebert G and Gross J (1985), ‘Carotenoid changes in the peel of ripening persimmon (Diospyros kaki) cv. Triumph’, Phytochemistry, 24, 29–32. Eshel D, Ben-Arie R, Dinoor A and Prusky D (2000), ‘Resistance of gibberellin-treated persimmon fruit to Alternaria alternata arises from the reduced ability of the fungus to produce endo-1,4-glucanase’, Phytopathology, 90, 1256–1262.



189

Ferri V C, Rombaldi C V, Silva J A, Pegoraro C, Nora L, et al. (2008), ‘Boron and calcium sprayed on “Fuyu” persimmon tree prevent skin cracks, groove and browning of fruit during cold storage’, Ciencia Rural, 38, 2146–2150. Forbus W R, Payne J A and Senter S D (1991), ‘Nondestructive evaluation of Japanese persimmon maturity by delayed light emission’, Journal of Food Science, 56, 985–988. Fukushima T, Kitamura T, Murayama H and Yoshida T (1991), ‘Mechanisms of removal of astringency by ethanol treatment in “Hiratanenashi” kaki fruits’, Journal of the Japanese Society for Horticultural Science, 60, 685–694. Fumuro M and Gamo H (2001), ‘Effects of baggin on the occurrence of black stain on the skin of “Shinsyu” persimmon (Diospyros kaki L.) grown under film’, Journal of the Japanese Society for Horticultural Science, 70, 261–263. George A P, Mowat A D, Collins R J and Morley-Bunker M (1997), ‘The pattern and control of reproductive development in non-astringent persimmon (Diospyros kaki L.): a review’, Scientia Horticulturae, 70, 93–122. George A P and Redpath S (2008), ‘Health and medical benefits of persimmon fruit: a review’, Advances in Horticultural Science, 22, 244–249. Glucina PG (1987), ‘Calyx separation: a physiological disorder of persimmons’, Orchardist of New Zealand, 60, 161–163. Gorinstein S, Kulasek W, Bartnikowska E, Leontowicz M, Zemser M, et al. (2000), ‘The effects of diets, supplemented with either whole persimmon or phenol-free persimmon, on rats fed cholesterol’, Food Chemistry, 70, 303–308. Gottreich M and Blumenfeld A (1991), ‘Light microscopic observations of tannin cell walls in persimmon fruit’, Journal of Horticultural Science, 66, 731–736. Grant T, Macrae E A and Redgwell R J (1992), ‘Effect of chilling injury on physicochemical properties of persimmon cell wall’, Phytochemistry, 31, 3739–3744. Gu H F, Li C M, Xu Y J, Hu W F, Chen M H and Wan Q H (2008), ‘Structural features and antioxidant activity of tannin from persimmon pulp’, Food Research International, 41, 208–217. Guelfat-Reich S and Ben-Arie R (1976), ‘CA storage of “Triumph” persimmons’, Proceedings of the XIV Congress of the International Institute of Melbourne Refrigeration, 59–63. Guelfat-Reich S, Ben-Arie R and Metal N (1975), ‘Effect of CO2 during and following storage on removal of astringency and keeping quality of “Triumph” persimmons’, Journal of the American Society of Horticultural Science, 100, 95–98. Haginuma S (1972), ‘Controlled atmosphere storage of fruits in Japan’, Japan Agricultural Research Quarterly, 6, 175–180. Hamada K, Hasegawa K and Ogata T (2008), ‘Effects of CPPU and strapping on fruit size and maturity in “Hiratanenashi” Japanese persimmon’, Journal of Horticultural Science and Biotechnology, 83, 477–480. Harima S, Nakano R, Yamauchi S, Kitano Y, Yamamoto Y, et al. (2003), ‘Extending shelflife of astringent persimmon (Diospyros kaki Thunb.) fruit by 1-MCP’, Postharvest Biology and Technology, 29, 319–324. Homnava A, Payne J A, Koehler P and Eitenmiller R (1990), ‘Provitamin A (alphacarotene, beta-carotene and beta-cryptoxanthin) and ascorbic acid content of Japanese and American persimmons’, Journal of Food Quality, 13, 85–95. Ikegami A, Kitajima A and Yonemori K (2005), ‘Inhibition of flavonoid biosynthetic gene expression coincides with loss of astringency in pollination-constant, non-astringent (PCNA)-type persimmon fruit’, Journal of Horticultural Science and Biotechnology, 80, 225–228. Itamura H, Kitamura T, Taira S, Harada H, Ito N, et al. (1991), ‘Relationship between fruit softening, ethylene production and respiration in Japanese persimmon “Hirataneneshi” ’, Journal of the Japanese Society for Horticultural Science, 60, 695–701.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

190 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Itamura H, Nakamoto T, Hanaoka and Sun N (2009), ‘Improving shelf life of cut persimmon fruit’, Acta Horticulturae, 833, 295–298. Itoo S (1986), ‘Persimmon’. In: Monslise, S P (ed.) CRC Handbook of Fruit Set and Development, Boca Raton, FL: CRC. Ittah Y (1993), ‘Sugar content changes in persimmon fruits (Diospyros kaki L.) during artificial ripening with CO2: a possible connection to deastringency mechanisms’, Food Chemistry, 48, 25–29. Kato K (1984), ‘Astringency removal and ripening as related to ethanol concentration during de-astringency by ethanol in persimmon fruits’, Journal of the Japanese Society for Horticultural Science, 53, 278–289. Kato K (1987), ‘Large-scale trials for the short-term de-astringency in persimmon fruits by ethanol’, Journal of the Japanese Society for Horticultural Science, 56, 92–100. Kato K (1990), ‘Astringency removal and ripening in persimmons treated with ethanol and ethylene’, HortScience, 25, 205–207. Kawada, (1982), ‘Use of polymeric films to extend postharvest life and improve marketability of fruits and vegetables–Unipack: individually wrapped storage of tomatoes, oriental persimmons and grapefruit’. In: D.G. Richardson and M. Meheriuk (Eds), Controlled Atmospheres for Storage and Transport of Perishable Agricultural Commodities, Timber Press, Beaverton, OR, pp. 87–99. Khositashivili M, Vebliani M, Asashvili T, Papunidze G and Kobakhidze M (2008) ‘Persimmon production and processing in Georgia’. Poster Abstract, pg 51. IV International Symposium on Persimmon, Italy, Nov 8–13. Kim Y K and Lee J M (2005), ‘Extension of storage and shelf-life of sweet persimmon with 1-MCP’, Acta Horticulturae, 685, 165–174. Kondo S, Yoshikawa H and Katayama R (2004), ‘Antioxidant activity in astringent and non-astringent persimmons’, Journal of Horticultural Science and Biotechnology, 79, 390–394. Krammes, JG, Argenta, LC and Vieira, MJ (2005), ‘Postharvest control of ripening and quality maintenance of “Fuyu” persimmon fruit by ethylene handling’, Rev. Bras. Frutic., 27, 360–365. Kwong J H, Ahn G-H and Park C S (2004), ‘Fruit soft rot of sweet persimmon caused by Mucor piriformis in Korea’, Mycobiology, 32, 98–101. Lee Y-J, Park Y-H, Kang J-S, Choi Y-W and Son B-G (2008), ‘Short duration hot-water dipping to reduce skin blackening, decay and survival of insects in “Fuyu” persimmon during storage’. Poster Abstract, pg 77. IV International Symposium on Persimmon, Italy, Nov 8–13. Luo Z (2006), ‘Extending shelf-life of persimmon (Diospyros kaki L.) fruit by hot air treatment’, European Food Research and Technology, 222, 149–154. Luo Z (2007), ‘Effect of 1-methylcyclopropene on ripening of postharvest persimmon (Diospyros kaki L.) fruit’, Food Science and Technology, 40, 285–291. MacRae EA (1987), ‘Development of chilling injury in New Zealand grown “Fuyu” persimmon during storage’, New Zealand Journal of Experimental Agriculture, 15, 333–344. Matsuo T and Itoo S (1982), ‘A model experiment for de-astringency of persimmon fruit with high CO2 treatment: in vitro gelation of kaki-tannin by reacting with acetaldehyde’, Agricultural and Biological Chemistry, 46, 683–689. Mowat A (2003), ‘Fruit development patterns of persimmon (Diospyros kaki l.) grown under a cool climate’, Acta Horticulturae, 601, 113–119. Mowat A and Collins R (2000), ‘Consumer behaviour and fruit quality: supply chain management in an emerging industry’, Supply Chain Management: An International Journal, 5, 45–54. Mowat A D, George A P and Collins R J (1997), ‘Macro-climatic effects on fruit development and maturity of non-astringent persimmon (Diospyros kaki L. cv. Fuyu)’, Acta Horticulturae, 436.



191

Nakano M, Yonemori K, Sugiura A and Kataoka I (1997), ‘Effect of gibberellic acid and abscisic acid on fruit respiration in relation to final swell and maturation in persimmon’, Acta Horticulturae, 436, 203–214. Nakano R, Inoue S, Kubo Y and Inaba A (2002), ‘Water stress-induced ethylene in the calyx triggers autocatalytic ethylene production and fruit softening in “Tonewase” persimmon grown in a heated plastic-house’, Postharvest Biology and Technology, 25, 293–300. Nakano R, Ogura E, Kubo Y and Inaba A (2003), ‘Ethylene biosynthesis in detached young persimmon fruit is initiated in calyx and modulated by water loss from the fruit’, Plany Physiology, 131, 276–286. Nakano R, Yonemori K and Sugiura A (1998), ‘Fruit respiration for maintaining sink strength during final swell at growth stage III of persimmon fruit’, Journal of Horticultural Science and Biotechnology, 73, 341–346. Neuwald D A, Streif J, Sestari I, Giehl R F H, Weber A and Brackmann A (2009), ‘Quality of “Fuyu” persimmon during modified atmosphere storage’, Acta Horticulturae, 833, 227–238. Niikawa T, Suzuki T, Ozeki T, Kato M and Ikoma Y (2007), ‘Characterisitics of carotenoid accumulation during maturation of the Japanese persimmon “Fuyu” ’, Horticultural Research (Japan), 6, 251–256. Nissen R J, George A P, Collins R J and Broadley R H (2003), ‘A survey of cultivars and management practices in Australian persimmon orchards’, Acta Horticultuae, 601, 179–185. Ortiz G I, Sugaya S, Sekozawa Y, Ito H, Wada K and Gemma H (2006), ‘Expression of 1-aminocyclopropane-1-carboxylate synthase and 1-aminocyclopropane-1-carboxylate oxidase genes during ripening in “Rendaiji” persimmon fruit’, Journal of the Japanese Society for Horticultural Science, 75, 178–184. Oshida M, Yonemori K and Sugiura A (1996), ‘On the nature of coagulated tannins in astringent type persimmon fruit after an artificial treatment of astringency removal’, Postharvest Biology and Technology, 8, 317–327. Ozawa T, Lilley T and Haslam E (1987), ‘Polyphenol interactions: astringency and the loss of astringency in ripening fruit’, Phytochemistry, 26, 2937–2942. Palou L, Montesinos-Herrero A, Guardado A, Besada C and Del Rio MA (2009), ‘Fungi associated with postharvest decay of persimmon in Spain’, Acta Horticulturae, 833, 275–280. Pang J H, Ma B, Sun H J, Ortiz G I, Imanishi S, et al. (2007), ‘Identification and characterization of ethylene receptor homologs expressed during fruit development and ripening in persimmon (Diospyros kaki Thunb.)’, Postharvest Biology and Technology, 44, 195–203. Park Y M and Lee Y J (2005), ‘Ripening responses of “Fuyu” persimmon fruit to exogenous ethylene and subsequent shelf temperature’, Acta Horticulturae, 685, 151–156. Perez A, Ben-Arie R, Dinoor A, Genizi A and Prusky D (1995), ‘Prevention of black spot disease in persimmon fruit by gibberellic acid and iprodione treatments’, Phytopathology, 85, 221–225. Perez-Gago M B, del Rio M A, Argudo C, and Mateos M (2009), ‘Improving shelf life of cut persimmon fruit’, Acta Horticulturae, 833, 245–250. Perez-Munuera I, Quiles A, Larrea V, Arnal L, Besada C and Salvador A (2009), ‘Microstructure of persimmon treated by hot water to alleviate chilling injury’, Acta Horticulturae, 833, 251–256. Pesis E and Ben-Arie R (1984), ‘Involvement of acetaldehyde and ethanol accumulation during induced de-astringency of persimmon fruits’, Journal of Food Science, 49, 896–899. Pesis E and Ben-Arie R (1986), ‘Carbon dioxide assimilation during postharvest removal of astringency from persimmon fruit’, Physiologia Plantarum, 67, 644–648. Pesis E, Levi A and Ben-Arie R (1986), ‘Deastringency of persimmon fruits by creating a modified atmosphere in polyethylene bags’, Journal of Food Science, 51, 1014–1016.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

192 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Prusky D, Ben-Arie R and Guelfat-Reich S (1981), ‘Etiology of black spot disease caused by Alternaria alternata in persimmons’, Phytopathology, 71, 1124–1128. Prusky D, Kobiler I, Akerman M and Miyara I (2006), ‘Effect of acidic solutions and acidic prochloraz on the control of postharvest decay caused by Alternaria alternata in mango and persimmon fruit’, Postharvest Biology and Technology, 42, 134–141. Redpath S, George A P, Hofman P, Price S and Nissen R J (2009), ‘Premature f softening, a major physiological problem of persimmon in subtropical Australia’, Acta Horticulturae, 833, 289–294. Salvador A, Arnal L, Besada C, Larrea V, Hernando I and Perez-Munuera I (2008), ‘Reduced effectiveness of the treatment for removing astringency in persimmon fruit when stored at 15 °C: Physiological and microstructural study’, Postharvest Biology and Technology, 49, 340–347. Salvador A, Arnal L, Carot J M, Carvalho C and Jabaloyes J M (2006), ‘Influence of different factors on firmness and color evolution during the storage of persimmon cv. “Rojo Brillante” ’, Journal of Food Science, 71, 169–175. Salvador A, Arnal L, Monterde A and Cuquerella J (2004), ‘Reduction of chilling injury symptoms in persimmon fruit cv. “Rojo Brillante” by 1-MCP’, Postharvest Biology and Technology, 33, 285–291. Senter S D, Chapman G W, Forbus J W R and Payne J A (1991), ‘Sugar and nonvolatile acid composition of persimmons during maturation’, Journal of Food Science, 56, 989–991. Shin M L, Lee S K and Park Y M (1994), ‘Factors involved in discoloration of nonastringent “Fuyu” persimmon fruits’, Journal of the Korean Society of Horticultural Science, 35, 155–164. Shin, S-R, Song J-H, Kim, S-D and Kim K-S (1991), ‘Changes in the cell structure during maturation and postharvest of persimmon fruits’, Journal Korean Agricultural Chemistry Society, 34, 32–37. Son J-K, Yun J-E and Park C-G (2009), ‘Insect pest problems of sweet persimmon in Korea’, Acta Horticulturae, 833, 325–330. Stark J D, Vargas R and Miller N (2004), ‘Toxicity of spinosad in protein bait to three ecenomically important tepphritid fruit fly species (Diptera Tephritidae) and their parasitoids (Hymeneoptera Braconidae)’, Journal of Economic Entomology, 97, 911–915. Sugiura A and Taira S (2009), ‘Improving shelf life of cut persimmon fruit’, Acta Horticulturae, 833, 71–76. Suzuki T, Someya S, Hu F and Tanokura M (2005), ‘Comparative study of catechin compositions in five Japanese persimmons (Diospyros kaki)’, Food Chemistry, 93, 149–152. Taira S (1996), ‘Astringency in persimmon’. In: Linskens, H Fand Jackson, J F (eds.) Modern Methods of Plant Analysis, Berlin, Heidelberg: Springer-Verlag. Taira S, Kubo Y, Sugiura A and Tomana T (1987), ‘Comparative studies of postharvest fruit quality and storage quality in Japanese persimmon (Diospyros kaki L. cv. “Hiratanenashi”) in relation to different methods for removal of astringency’, Journal of the Japanese Society for Horticultural Science, 56, 215–221. Taira S, Ono M and Matsumoto N (1997), ‘Reduction of persimmon astringency by complex formation between pectin and tannins’, Postharvest Biology and Technology, 12, 265–71. Taira S, Sato A and Watanabe S (1992), ‘Relationship between differences in the ease of removal of astringency among fruits of Japanese persimmon (Diospyros kaki Thunb.) and their ability to accumulate ethanol and acetaldehyde’, Journal of the Japanese Society for Horticultural Science, 60, 1003–1009. Takano S, Nishino S and Kuraoka K (1991), ‘The establishment of a technique for producing high-quality fruits of Japanese cultivar “Fuyu” with two low branches. I. The relationship between the type of branch or shoot, degree of thinning and fruit quality with regard to exposure to sunlight’, Bulletin of the Nara Agricultural Experiment Station, 22, 29–33.



193

Takata M (1983), ‘Respiration, ethylene production and ripening of Japanese persimmon fruit harvested at different stages of development’, Journal of the Japanese Society for Horticultural Science, 52, 78–84. Tanaka Y, Takase N and Sato J (1971), ‘Studies on the CA-storage of fruits and vegetables, III. Effect of CA-storage on the quality of persimmons (Diospyros kaki LINN. f.)’, Research Bulletin of the Aichi Prefecture Agriculture Research Center, Series B, #3. Testoni A (2002), ‘Postharvest and processing of persimmon fruit’. Proceedings of the First Mediterranean Symposium on persimmon. CIHEAM, International Centre for Advanced Mediterranean Agronomic studies. Series 51; 53–70. Thomas M C, Heppner J B, Woodruff R E, Weems H V, Steck G J and Fasulo T R (2007), ‘Mediterranean Fruit Fly, Ceratitis capitata (Wiedemann).(Insecta: Diptera: Tephritidae).’ Available at http://creaturesifasufledu Wells L G (2009), ‘The persimmon “X” factor and merits of forming an international commercial persimmon association’, Acta Horticultura, 833, 63–67. Wright K P and Kader A A (1997), ‘Effect of slicing and controlled-atmosphere storage on the ascorbate content and quality of strawberries and persimmons’, Postharvest Biology and Technology, 10, 39–48. Woolf A B, Jackman R C, Olsson S, Manning M, Rheinlander P, et al. (2008), ‘Meeting consumer requirements from a New Zealand perspective’, Advances in Horticultural Science, 22, 274–280. Woolf A B, MacRae E A, Spooner K J and Redgwell R J (1997), ‘Changes to physical properties of the cell wall and polyuronides in response to heat treatment of “Fuyu” persimmon which alleviate chilling injury’, Journal of the American Society for Horticultural Science, 122, 698–702. Xu C, Nakatsuka A and Itamura H (2004), ‘Effects of 1-methylcyclopropene treatment on ethylene production, softening and activities of cell wall degrading enzymes in “Saijo” persimmon fruit after removal of astringency with dry ice’, Journal of the Japanese Society for Horticultural Science, 73, 184–188. Yamada M, Taira S, Ohtsuki M, Sato A, Iwanami H, et al. (2002), ‘Varietal differences in the ease of astringency removal by carbon dioxide gas and ethanol vapor treatments among oriental astrigent persimmons of Japanese and Chinese origin’, Scientiae Horticulturae, 94, 63–72. Yang Y, Ruan R, Wang R and Li G (2005), ‘Morphological characteristics under optical microscope of tannin cells in persimmon fruit’, Acta Horticulturae, 685, 135–141. Yonemori K, Itai A, Nakano R and Sugiura A (1996), ‘Role of calyx lobes in gas exchange and development of persimmon fruit’, Journal of the American Society for Horticultural Science, 121, 676–679. Yonemori K and Matsushima J (1987), ‘Changes in tannin cell morphology with growth and development of Japanese persimmon fruit’, Journal of the American Society for Horticultural Science, 112, 818–821. Yonemori K and Tomana T (1983), ‘Relationships of ethanol production by seeds of different types of Japanese persimmons and their tannin content’, HortScience, 18, 319–321. Zheng G H and Sugiura A (1990), ‘Changes in sugar composition in relation to invertase activity during growth and ripening of persimmon’, Journal of the Japanese Society for Horticultural Science, 59, 281–287. Zheng Q L, Nakatsuka A and Itamura H (2006a), ‘Involvement of negative feedback regulation in wound-induced ethylene synthesis in “Saijo” persimmon’, Journal of Agricultural and Food Chemistry, 54, 5875–5879. Zheng Q L, Nakatsuka A, Matsumoto H and Itamura H (2006b), ‘Pre-harvest nickel application to the calyx of “Saijo” persimmon fruit prolongs postharvest shelf-life’, Postharvest Biology and Technology, 42, 98–103. Zheng Q L, Nakatsuka A, Taira S and Itamura H (2005), ‘Enzymatic activities and gene expression of 1-aminocyclopropane-1-carboxylic acid (ACC) synthase and ACC oxidase in persimmon fruit’, Postharvest Biology and Technology, 37, 286–290.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Plate XVI (Chapter 9) New Zealand persimmon orchard in late autumn. Note leaf colour and late season, highly coloured fruit and the reflective mulch which increases light, particularly in the lower canopy.

Plate XVII (Chapter 9) Photos of a range of chilling injury levels (0 to 5) in ‘Fuyu’ persimmons. From top (0, no chilling injury) to bottom right (5, complete, total gelling).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

10 Pineapple (Ananas comosus L. Merr.) A. Hassan and Z. Othman, Malaysian Agricultural Research and Development Institute (MARDI), Malaysia and J. Siriphanich, Kasetsart University, Kamphang Saen, Thailand

Abstract: The pineapple is the third most important tropical fruit in the world after banana and citrus; the world pineapple production in 2007 was estimated at 21 008 795 tonnes. This chapter discusses various aspects of postharvest biology and technology of pineapple. The chapter is divided into 11 sections covering postharvest physiology, physical and biochemical changes during maturation and ripening, preharvest and postharvest factors affecting quality, physiological disorders, pathological disorders, insect pests and their control, postharvest handling practices, and processing. Key words: Ananas comosus, pineapple, postharvest handling, storage, physiology.

10.1

Introduction

10.1.1 Origin, morphology and structure Pineapple (Ananas comosus L. Merr.) is believed to be originated from South America, in the region encompassing central and southern Brazil, northern Argentina and Paraguay. The fruit had already been domesticated by the native South Americans before the arrival of Christopher Columbus in 1493. Currently, pineapples are grown commercially over a wide range of latitudes from approximately 30° N in the northern hemisphere to 33°58′S in the south (Malezieux et al., 2003). The word ‘pineapple’ was used by the European explorers to describe the fruit, which resembles pinecones. ‘Ananas’, the original name of the fruit, comes from the Tupi word for pine ‘nanas’, and comosus means ‘tufted’ referring to the stem of the fruit (Collins, 1968). The pineapple is an herbaceous perennial plant of the Liliopsidae (monocotyledonous). The adult plant is 1–2 m high and 1–2 m wide, and it is inscribed in the general shape of a spinning top (d’Ecckenbruge and Leal, 2003). The main morphological structures are the stem, the leaves, the peduncle, the


Pineapple (Ananas comosus L. Merr.)

Fig. 10.1

195

Morphological structure of pineapple.

multiple fruit, the crown, the shoots and the roots (Fig. 10.1). The multiple fruit is the result from the fusion of individual fruitlets on a single stalk (Rohrbach and Apt, 1986). Multiple flowers, helically arranged along the axis each produce a fleshy fruitlet that becomes pressed against the fruitlets of adjacent flowers, forming what appears to be a single fleshy fruit. Early European experts recognized as many as 48–68 pineapple cultivars and classified them based on spininess, fruit shape and flower colour. Py et al. (1987) classified pineapple into five groups namely Spanish, Queen, Cayenne, Pernambuco and Perolera. 10.1.2 Worldwide importance and economic value Pineapple is the third most important tropical fruit in the international trade after bananas and citrus; the world pineapple production in 2007 was estimated at 21 008 795 tonnes. About 70% of the total production is consumed domestically, whereas 30% is exported. The most important producing country is Thailand producing 2 815 275 tonnes followed by Brazil (2 676 417), Indonesia (2 237 858), Philippines (2 016 462), Costa Rica (1 968 000), China (1 386 811), India (1 308 000), Nigeria (900 000), Mexico (671 131), Vietnam (470 000), Kenya (429 065),


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

196 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Colombia (342 014), Venezuela (363 075) and Malaysia (360 000) (FAO, 2009). Successful production is influenced by several factors especially low production cost, and availability of manpower and land resources. Costa Rica is the most important exporting country with an export quantity of 1 353 027 tonnes followed by the Philippines (270 054), Ecuador (99 581), Cote D’Ivoire (96 558), USA (89 269) and Panama (61 210). Other exporting countries include Honduras, Guatemala, Brazil, Mexico, Ghana and Malaysia (FAO, 2009). The USA is the largest pineapple importer totalling 696 820 tonnes in 2007, followed by Belgium (292 499), the Netherlands (200 026), Germany (167 416), Japan (165 794), Italy (142 168), United Kingdom (116 730), Spain (113 182) and Canada (102 064). The European Union is the largest export market for pineapple (FAO, 2009). For a very long time, the world production and marketing of pineapple has been dominated by the Smooth Cayenne both for fresh and processing. However, in 1996 the world’s pineapple fresh fruit industry went through a transformation when the Del Monte Corporation introduced hybrid ‘MD-2’ for the United States and European markets (Bartholomew, 2009). ‘MD-2’, produced from a cross between the PRI hybrids 58–1184 and 59–443 (Chan et al., 2003), is now grown by many companies and growers in the world and believed to be the most important pineapple cultivar for the fresh market. It is being exported to many countries including the United States, Europe, United Kingdom, Japan, Korea, Hong Kong, China, Singapore and the Middle East (Bartholomew, 2009). 10.1.3 Culinary uses and nutritional value Pineapple is produced for both fresh consumption and processing. Pineapple for fresh consumption is marketed in whole or minimally processed form with a short marketable period. Besides being consumed as desserts, fresh pineapple is also eaten as salad where some spices or sauces may be added according to taste preference. Pineapple can be cooked into various forms or used as an ingredient in cooking. Various processed products from pineapple were described by Abd Shukor et al. (1998), Collins (1968) and Dev and Ingel (1982). Fresh pineapple is a good source of carbohydrate, fibre and minerals especially Ca, P, Fe, Na and K. It also contains some vitamins including A, B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B9 (folate) and C (ascorbic acid). The nutritional content is influenced by several factors including varieties, soil, climatic condition, maturity stage and handling. Processing may result in the nutritional components being altered in the final processed products (Tee et al., 1988).

10.2


10.2.1 Fruit growth, development and maturation The pineapple fruit and their components, including core, flesh and shell, show similar sigmoid development (Py et al., 1987; Singleton, 1965) and the maturation period of



197

fruit is influenced by several factors, including cultivars, climatic condition, altitude and cultural practices. During the maturation period, the increase in fruit weight slows down while the accumulation of dry matter speeds up as well as the soluble solids content. The peduncle itself starts to dry out. At the same time, the quantity of air in the intercellular space as well as in the locule of each fruitlet reduces progressively (Py et al., 1987). When the intercellular space or pocket of air between cells disappears late in the fruit development, the translucency appearance may occur in some cultivars. Because of this development, specific gravity of the fruit increases (Smith, 1984). Artificial flower induction substances such as ethylene and α-naphthaleneacetic acid (NAA) could delay fruit development. NAA at 100 ppm and 2-chloroethylphosphonic acid (CPA) at 200 ppm applied to the developing inflorescence less than 2.5 cm in diameter can delay fruit maturity by one to four weeks, while increasing fruit size by 25% (Bartholomew and Criley, 1983; Gortner, 1969). The Smooth Cayenne normally takes 100–150 days to develop from flowering to maturation with a shorter maturation period in lower altitude and equatorial regions. Pernambuco takes a longer developmental period, while Red Spanish and Queen take shorter time (Py et al., 1987). The first sign of pineapple maturation is around seven weeks before harvest when the development of new leaves in the crown slows down and four weeks later shell colour begins to change (Gortner, 1965). The yellow colour formation at the base of the fruit starts at around 100 days after flowering and this shell colouring is the most common criteria to judge pineapple maturity. In cooler seasons, the yellow shell colour develops well and coincides with the development of flesh colour and translucency of the flesh. However, in warmer periods, pineapple can reach maturity when it is still green, especially in Smooth Cayenne. The flatness of the eye is also used as a maturity indicator in this cultivar, but not in Queen where the eyes are prominent (Py et al., 1987). 10.2.2 Respiration and ethylene production Pineapple is a non-climacteric fruit (Dull et al., 1967) and has a moderate respiration rate around 10 to 20 ml CO2.kg−1.h−1 at 20 °C. Ethylene production rate in pineapple is low, ranging between 9 and 300 nl.kg−1.h−1. However, ethylene production is higher in more mature fruit. Internal ethylene concentration ranged from 80 to 1140 μl. l−1 with lower concentration in the upper part of the fruit (Dull et al., 1967). Cazzonelli et al. (1998) showed that during ripening, the expression of 1-aminocyclopropane-1-carboxylic acid (ACC) synthase increased by 16 fold, while there was no increase in ACC oxidase. The study shows a significant role of ethylene in the control of pineapple ripening.

10.3

Physical and biochemical changes during maturation and ripening

10.3.1 Colour During maturation, there is no change in both the shell and the flesh colour. As ripening begins, the chlorophyll in the shell degrades resulting in the yellowing of


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

198 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


the fruit without any increase in carotenoid pigment except late in the senescence stage. During shell yellowing, the flesh also turns from white to yellow in concomitance with accumulation of carotenoids (Gortner, 1965; Py et al., 1987). There is similar change in shell and flesh colour and their chemical components between fruit harvested green and those attached on the plant (Dull et al., 1967).

10.3.2 Texture Pineapple texture changes gradually from firm to soft as the fruit advances in maturity and ripeness. There are some variations in the texture of different groups of pineapple where Smooth Cayenne are fibrous, Red Spanish and Pernambuco are non-fibrous while Queen and Perolera are crispy in texture (Py et al., 1987). In the case of Queen pineapple, the core can also be consumed. These textural variations could be due to the differences in the chemical compositions of the cell wall in different pineapple groups. Textural differences can also be influenced by maturity stage and growing location (Bartolome et al., 1995). Vidal-Valverde et al. (1982) reported that hemicellulose was the major pineapple cell wall component (41.8%) followed by cellulose 33.6 % and pectin 21.2%. Lignin was found to be only 0.05%. Alcohol insoluble solid (AIS) of pineapple fruit declined with their maturity (Singleton and Gortner, 1965; Dull, 1971). The fibre content, a component of the AIS, also increased up to the onset of ripening and then decreased (Dull, 1971). They also reported that a large amount of unaccounted material, probably hemicellulose, increased during maturation and could play a major role in pineapple texture.

10.3.3 Starch Pineapple fruit does not accumulate starch (Py et al., 1987; Dull, 1971) which explains the small changes in chemical composition and taste of the fruit during ripening. The starch content is very low throughout fruit development where the highest value is less than one per cent, achieved 60 days before ripeness (Dull, 1971).

10.3.4 Sugars The major sugar components in pineapple fruits are sucrose, fructose, and glucose (Flath, 1980). During the early stage of fruit development, glucose and fructose are the major sugar component with low content of sucrose. Around six weeks prior to full ripeness, sucrose abruptly accumulates up until harvesting (Chen and Paull, 2000). The accumulation of sugars up until harvesting was suggested to be due to the high activity of the cell wall enzyme, invertase. At harvest, soluble solids content in pineapple varied a great deal depending upon maturity, season, and cultural practices. A variation from 7 to 21% soluble solids content was reported in a study covering three seasons in Australia (Smith, 1988b). Sugar



199

continues to accumulate if the fruit remains attached. However, soluble solids declined when the translucent area developed higher than 50 to 60% (Bowden, 1969). After harvest, there is only a small decline in sugar or soluble solids content. High storage and handling temperature enhances the decrease in sugar content (Paull and Rohrbach, 1982). There is a gradient of sugar concentration in an individual fruit where it is highest at the base and decreases towards the top. The difference between the base and the top portions could be up to four per cent. There is also different sugar distribution in a horizontal direction, sugar content is highest in the flesh near the core and decreases outward to the shell. Sugar in the core is slightly lower than that in the flesh nearby (Miller and Hall, 1953). Soluble solids content is the most correlated parameter with eating quality and always used as a quality criterion for selecting fruit suitable for fresh market (Smith, 1988a). Under commercial practice, a minimum soluble solids content requirement of 12% is used in both Hawaii and Australia. 10.3.5 Acids The major non-volatile organic acids are malic and citric, with a ratio of about 1 to 2–3 (Chan et al., 1973). During the first half of fruit development, the acidity remains quite stable at around 0.1–0.3%, and the malic acid content remains low throughout fruit development. Citric acid increases around six weeks to a maximum at 10 days before the fully ripe stage then declines as the fruit becomes more translucent (Singleton and Gortner, 1965). After harvest, the acid content may increase, particularly at temperatures below 20 °C, but at 29 °C and higher, the acid content decreases quickly. At intermediate temperatures, the acid content remains relatively stable (Dull, 1971). At harvest, the acid content can vary between 0.28 to 1.6%, depending on season, growing conditions, maturity stage and cultivar (Py et al., 1987). Acid distribution in individual fruit is reverse to that of sugar; lowest at the bottom and increases towards the top; high in the core, lowest in the flesh and intermediate near the shell (Miller and Hall, 1953). The acid content does not correlate well with the consumer acceptance of fresh fruit. As a result, sugar to acid ratio, which varies from 5.4 to 66.4 in three seasons’ study with Smooth Cayenne, is also not related to consumer acceptance (Smith, 1988b). 10.3.6 Ascorbic acid During the first half of fruit development, ascorbic acid content in pineapple is low then increases as the fruit becomes more mature, but declines later (Singleton and Gortner, 1965). At harvest, the ascorbic acid content varies according to maturity stage. For ‘Mauritius’ pineapple, the ascorbic acid content harvested between 120 to 130 days from flower induction varies from 23 to 40 mg.100−1 g flesh (Abdullah and Rohaya, 1997). The content in an individual fruit also varies and positively correlates with acid content. It is lowest at the bottom, which may be only half of that at the top, while it is intermediate at the middle (Miller and


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

200 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Hall, 1953). After harvest, the amount of ascorbic acid increases slightly or remains relatively constant for a few days, but ascorbic acid contents decrease gradually under prolonged storage at low temperature (Paull and Rohrbach, 1982). Upon exposure to higher ambient temperature following low temperature storage, ascorbic acid contents decrease very quickly (Abdullah and Rohaya, 1997; 1983; Abdullah et al., 1985; 1986; 1996). 10.3.7 Phenolic compounds Pineapple contains phenolic compounds, the major contributor to the antioxidant potential besides ascorbic acid (Gardner et al., 2000). The phenolic compounds include p-coumaric acid, ferulic acid, caffeic acid, sinapic acid, p-coumaroyl quinic acid, p-hydroxybenzoic acid, and p-hydroxy benzoic aldehyde (de Simon et al., 1992; van Lelyveld and de Bruyn, 1977). Each phenol, except sinapic acid, increases in concentration in pineapple fruitlets affected by blackheart disorder. 10.3.8 Protein Pineapple, like many other fruits, is very low in protein but contains bromelain, a glycoprotein having protease activity commonly used in the food industry. The amount of bromelain is roughly half of the protein found in pineapple where the content is much less in the fruit than the stem (Heinicke and Gortner, 1957), and it is higher at the top of the fruit and lower in the middle and the base (Miller and Hall, 1953). Bromelain activity remains relatively high during fruit development and declines at the ripening stage (Lodh et al., 1973) along with the total protein content (Gortner and Singleton, 1965). Another enzyme that received much attention in pineapple is polyphenol oxidase (PPO). Its activity is normally low at harvest, but following chilling stress, higher activity is induced (van Lelyveld and de Bruyn, 1977; Teisson et al., 1979b). PPO activity varies between different parts of the fruit at harvest, with significantly higher levels in the skin and crown leaves but negligible in any parts of the fruit pulp (Zhou et al., 2003). PPO activities increase in pineapple fruits affected by blackheart, a low temperature-related physiological disorder (Abdullah et al., 2009), and has also been implicated in black spot infected fruitlets of pineapple caused by Penicillium funiculosum and Fusarium monoliforme (Avallone et al., 2003). Peroxidase is another pineapple enzyme where the activity decreases during fruit development and during storage (Gortner and Singleton, 1965; Teisson et al., 1979b). Most amino acids decline during the development of the fruit, and those found are alanine, aspartic acid, asparagines, glycine and glutamic acid (Flath, 1980; Kermasha et al., 1987). However, aspartic acid is only found in high amounts at the mature stage. Histidine, the sulphur-containing amino acid methionine, and cystine are present in small amounts but increase abruptly during the ripening of the fruit (Gortner and Singleton, 1965).



201

10.3.9 Mineral Pineapple contains some minerals including calcium, iron, magnesium, phosphorus, potassium and zinc. Variation in mineral content observed in pineapple could depend on the type of soil where the plants were grown, the water used for irrigation and the fertilizer applied (Flath, 1980). Deficiency of molybdenum may cause high nitrate levels in fruits, which leads to detinning in canned pineapple (Chairidchai, 2000; Chongpraditnun et al., 2000). 10.3.10 Volatile compounds Similar to other fruits, pineapple aroma increases with its maturity and ripening stages. More than 200 compounds have been identified including esters, lactones, aldehydes, ketones, alcohols, carbonyl acids, hydrocarbons, phenol and sulphur compounds. Summer fruit have more volatiles, especially ethyl alcohol and ethyl acetate, than winter fruit. More volatiles are produced as the fruit become more mature on the plant as well as during ripening after harvest (Flath and Forrey, 1970). As pineapple fruit turns from green to yellow, some volatiles increase while others decrease (Umano et al., 1992). Some volatiles are bound with sugar and released during the preparation of pineapple flesh with the reaction of β-glucosidase (Wu et al., 1991). Table 10.1 lists some of the major volatiles found in pineapple. Those with asterisk are identified as major contributors to pineapple aroma. Flavourist had already made available formulas of synthetic chemicals used to imitate pineapple aroma. Among the earlier compounds used are vanillin, n-dodecanal, allyl and amyl esters, maltol, ethyl maltol and isobutylfuryl propionate (Broderick, 1975).

10.4


10.4.1 Soil Pineapple have been grown on many types of soils including organic peat soil in Malaysia (see Plate XVIII in the colour section between pages 238 and 239); volcanic ash soil in Hawaii, many Caribbean islands and parts of the Philippines; and very sandy soils found in parts of southern Queensland and northern South Africa (Hepton, 2003). Pineapples grown on different types of soil may have different postharvest quality, for example in Malaysia, the pineapple grown on mineral soil is sweeter than those grown on organic peat. However, ‘Josapine’ pineapple grown on mineral soil is more susceptible to bacterial heart rot disease. 10.4.2 Climatic condition Fruit produced in winter in sub-tropical regions is known to be of poor quality as the fruit acidity is high (Bartholomew, 2009). The winter fruits are also subject to developing blackheart, a chilling-related physiological disorder, either in the field or after harvest (Leverington, 1968). Climatic conditions influence the nutritional


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

202 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Table 10.1

Major volatiles found in pineapple

Volatiles

References

Odour description

Methyl-3-(methylthio) propanoate*

Berger et al. (1985); Teai and Claude-Lafontaine (2001); Umano et al. (1992) Berger et al. (1985); HaagenSmit et al. (1945); Teai and Claude-Lafontaine (2001); Umano et al. (1992) Ohta et al. (1987); Umano et al. (1992) Ohta et al. (1987); Rodin et al. (1965); Umano et al. (1992) Takeoka et al. (1991); Teai and Claude-Lafontaine (2001) Ohta et al. (1987); Umano et al. (1992) Umano et al. (1992) Berger et al. (1983) Berger et al. (1985) Berger et al. (1985)

Pineapple-like

Ethyl-3-(methylthio) propanoate

3-hydroxy-2-butanone 2,5-dimethyl-4-hydroxy3-(2H) furanone Ethyl-2methylbutanoate* Ethyl acetate* Butane 2, 3 diol diacetate α-patchoulene 1-(E,Z)-3,5-undecatriene 1-(E,Z,Z)-3,5,8undecatriene

Fruity, pineapple-like

Burnt pineapple

Honey-like Fruity, spicy Balsamic, spicy, pinewood Balsamic, spicy, pinewood, more fruity

* Major contributors to pineapple aroma

content of fruit including ascorbic acid (Chan et al., 1973) and the acid content fluctuates markedly and consistently according to the weather variation before harvest, where there is a two-week lag before the effects of the weather factors become obvious. Ascorbic acid content is also influenced by the amount of sunlight received during the development as fruit under strong sunlight contains higher ascorbic acid (Singleton and Gortner, 1965). 10.4.3 Cultural practices Crown removal increases fruit size and the fruit becomes more cylindrical in shape, however, they become subject to sunburn (Py et al., 1987). Chemical application such as 3-chlorophenoxyacetic acid (3-CPA) at the early stage of crown development can reduce crown size and increase fruit size and yield (Bartholomew and Criley, 1983) and the size of the crown itself can be controlled by mechanically removing the apex at least two months before harvest to allow wound healing (Py et al., 1987). The use of 3-CPA for crown control may cause injury to the base of pineapple slips and the crown causing them to be easily detached from the fruit (Abd Shukor et al., 1998). The detached areas serve as entry points for disease causing microorganisms such as Thielaviopsis paradoxa and fruits with detached crowns have shorter storage life than those with the crown intact.



10.5

203

Postharvest factors affecting quality

10.5.1 Physical damage Like other horticultural commodities, physical damage on pineapple may occur at any point throughout the handling chain right from harvesting until consumption. Physical damages are caused by mechanical factors such as cuts, abrasions, compaction and impact. The damages may appear immediately after the injury took place or in many cases they only become noticeable after some time during handling or marketing. Mechanical damage may affect fruit quality in terms of poor appearance, uneven fruit ripening and shorter storage life. Damaged fruits usually have higher respiration rates and the leakage cell content leads to infection by microorganisms (Paull and Chen, 2003). 10.5.2 Temperature The recommended optimum storage temperature for pineapple is between 7 and 13 °C (Hardenburgh et al., 1986; Paull, 1997). Temperatures lower than the optimum level may induce chilling injury. More mature fruits are more adaptable to lower temperature, but lower storage temperature and a longer storage period may induce acid accumulation. Up to 35% increase in titratable acidity has been found in pineapple stored for ten days at 8 °C. Prolonged exposure to lower temperatures may cause poor organoleptic quality, but under good handling practices, maintenance of the cold chain is necessary as interruptions may cause the development of internal browning, fungal diseases and shorter storage life (Paull, 1997). Exposure to extremely high temperature above 35 °C should be avoided as it may also affect fruit quality. Exposure to high temperature speeds up the deterioration process and increases weight loss due to excessive moisture loss through the fruit surface. Extremely high temperature may result in the shell and crown becoming dry, especially when fruits are transported without refrigeration. 10.5.3 Relative humidity The recommended range of relative humidity (RH) for storage of pineapple is 85–95% (Hardenburgh et al., 1986; Paull and Chen, 2003). Higher RH reduces water loss, which helps maintain the fruit appearance and freshness, while lower RH encourages moisture loss from the surface and affects fruit appearance. Loss of moisture causes physiological weight loss, but a reduction of water loss helps in maintaining the fruit external appearance. Wrapping the fruit in a perforated polyethylene (PE) sleeve helps the maintenance of the fruit external appearance by creating a moisture barrier, which slows down moisture loss. However, storing fruits under very high RH favours the growth of microorganisms on the shell and peduncle. 10.5.4 Atmosphere There is very limited use of controlled or modified atmosphere (CA or MA) for pineapple commercially (Yahia, 1998). The recommended condition is 2–5% O2


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

204 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


and 5–10% CO2 (Kader, 1992). ‘Mauritius’ pineapple stored for more than three weeks under MA in sealed PE bags at 10 °C are affected by off-odour and off-flavour development (Abdullah et al., 1985), but waxing the fruit and high humidity during cold storage would give equal benefits as demonstrated by atmosphere modification.

10.6


10.6.1 Common chilling injury Chilling injury (CI) affects fruits exposed to temperatures below the optimum level for storage for sufficient time to cause injury. The symptoms of CI in pineapple include failure of the green shell to turn yellow, yellow-shelled fruit turning a brown or dull colour, wilting, drying and discolouration of crown leaves and a breakdown of internal tissue, giving a pale watery appearance (Dull, 1971; Abdullah et al., 2008). In bad cases, severe fungal diseases might infect the fruit. Visual symptoms of CI develop faster when the fruits are transferred to higher temperatures between 20 and 30 °C following exposure to low temperature, as different parts of the fruit have different levels of sensitivity towards CI (Abdullah et al., 2002). CI can be reduced or controlled through temperature manipulations. Pre-storage preconditioning at 15 and 10 °C also allows pineapple to be stored at sub-optimal temperature. The storage life of ‘N36’ pineapple is extended from five weeks at optimal temperature of 10 °C to more than eight weeks with less chilling injury at sub-optimal temperature of 5 °C (Abdullah et al., 2008). Similar treatments can also extend storage life of ‘Josapine’ pineapple. 10.6.2 Blackheart ‘Blackheart’, also known as ‘endogenous brown spots’ and ‘internal browning’, is another temperature-related physiological disorder of pineapple and has been comprehensively reviewed by Abdullah et al. (2010). The characteristic symptom of the disorder is the development of dark spots in the flesh area close to the core. In its early stage of development, the spots appear watery but they then enlarge and turn brown as the severity of the disorder increases. In severe cases, the entire flesh and core tissue of a fruit may be visibly affected. Fruits affected by blackheart appear normal externally and its presence is only detectable once the fruit has been cut open (Akamine, 1976; Akamine et al., 1975). The lack of detectable external symptoms creates substantial problems in the marketing of fresh fruit, as they have to be examined destructively. Blackheart may occur before harvest in the field or after harvest following exposure to low temperature and has been reported in fruits stored at temperatures as low as 4 °C and as high as 21 °C (Wills et al., 1985; Smith, 1983). Thus, in addition to the chilling at temperatures below the optimum, blackheart induction may also take place at temperatures higher than the normal range that causes CI. Blackheart has been associated with an increase in polyphenol oxidase (PPO)



205

activity and reduction in ascorbic acid content in affected fruits (Teisson et al., 1979a,b). However, the initial PPO activity and ascorbic acid content do not necessarily indicate fruit susceptibility to blackheart (Stewart et al., 2002; Abdullah et al., 2010; Pauziah et al., 2005). Partial control of blackheart can be achieved by preharvest applications of chemicals such as parachlorophenoxyacetic acid (PCPA), α-naphthaleneacetic acid (ANA), potassium and calcium (Abdullah et al., 2009). Harvesting fruit at an earlier maturity can delay the appearance of blackheart symptoms but they can still appear at postharvest when exposure at ambient temperature is prolonged after low-temperature storage (Abdullah and Rohaya, 1997). After harvest, blackheart can be partially controlled by several methods including thermotherapy (Abdullah et al., 1983; Akamine et al., 1975), MA packaging (Abdullah et al., 1985; Haruenkit and Thompson, 1994; Mizuno et al., 1982), surface coating (Abdullah et al., 1983; Nimitkeatkai et al., 2006; Pimpimol and Siriphanich, 1993; Rohrbach and Paull, 1982; Zaulia et al., 2007) and 1-methylcyclopropene (1-MCP) (Selvarajah et al., 2001). Development of pineapple hybrids resistant to blackheart is the most practical approach to overcome the problem and some have been successfully developed in Hawaii and Malaysia (Abdullah et al., 2010). The Pineapple Research Institute of Hawaii has successfully developed two hybrid cultivars, ‘73–50’ and ‘53–116’ from Smooth Cayenne that show significant levels of resistance to blackheart. The ‘MD-2’, a superior hybrid developed by the Del Monte Corporation, is also resistant to blackheart (Bartholomew, 2009). Research on blackheart control through molecular breeding approaches has been conducted in Australia (Graham et al., 2000; Zhou et al., 2002) and Malaysia (Abu Bakar et al., 2008). 10.6.3 Flesh translucence Flesh translucence in pineapple is regarded as a physiological disorder by Py et al. (1987) and Paull (1997). The flesh affected by translucency shows water-soaking symptoms (Paull and Chen, 2003). It occurs together with fruit ripening when the shell colour at the base of pineapple fruit of some cultivars begins to turn yellow. It may also occur in green-ripe fruit where the whole flesh is affected while the skin is still green (Py et al., 1987). In the translucent flesh, the air space is filled with liquid where highly translucent fruit has a flat taste and might be off-flavour (Bowden, 1969). This off-flavour taste could be the result of anaerobic respiration of the flesh which is blocked from exchanging gases through the intercellular network. These fruits are very fragile and easily damaged during handling and transportation and are also susceptible to disease and preharvest sunburn (Paull and Reyes, 1996). The causes of flesh translucence are not well understood, but large fruit and fruit with small crowns tend to develop more symptoms of flesh translucence. High temperature, high radiation and high nitrogen fertilizer facilitate translucent flesh development, so shading the fruit may eliminate the translucency development (Py et al., 1987; Soler, 1993). Both crown weight and flesh translucency were


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

206 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


reported to be correlated with monthly average air temperature two to three months before harvest (Paull and Reyes, 1996). However, crown removal does not influence translucency occurrence (Chen and Paull, 2001). After harvest, flesh translucency increases in stored fruits and it could be reduced by waxing (Rohrbach and Paull, 1982) and thermotherapy (Akamine et al., 1975).

10.7


The most important postharvest disease in pineapple is black rot, which can be found in all production areas around the world and the disease incidence could be as high as 70% of the inspected shipments to the New York market (Cappellini et al., 1988). The disease is caused by Thielaviopsis paradoxa (de Seynes) von Hohn which infects through a wound or cracked surface. The flesh of infected fruit becomes soft and watery and later turns dark due to the growth of the fungal mycelium and its chlamydospore. Postharvest control can be achieved by careful harvest and handling to prevent wounding or bruising and treating the fruit with suitable fungicides (see Table 10.2) within six to 12 hours after harvest (Rohrbach and Schmitt, 1994). Other pineapple diseases (Table 10.2) are caused by fungi or bacteria already present on the fruit at preharvest. Infection usually occurs through wound or cracks on the surface or damage caused by insects. The incidence of these diseases after harvest is rather limited as compared to black rot, and mostly cannot be controlled after harvest (Rohrbach and Schmitt, 1994). In addition to these infectious diseases, pineapple can be damaged by yeast and bacteria trapped inside the fruit during fruit development when individual fruitlets fuse together (Rohrbach and Apt, 1986). If fruit are damaged or overripe, the yeast and bacteria start growing leading to fermentation with bubbles of gas and juice escaping through cracks on the skin. The skin turns brown and leathery and the fruit becomes spongy with bright yellow flesh (Paull, 1997). Moulds on the cut surface of the peduncle are saprophytes but give an unsightly appearance (Paull, 1997). Dipping the fruit with a fungicide listed in Table 10.2 or adding coating material to the fungicide can control the mould growth.

10.8


No major insects attack pineapple fruit, but a butterfly, Thecla basilides (Geyer) may lay eggs on the inflorescence. The larva penetrates and digs out holes causing misshapen fruit, and the fruit reacts by exuding an amber coloured gum which makes it impossible to sell. The existence of this insect is limited to Central and South America (Py et al., 1987). The Smooth Cayenne pineapple is resistant to all tropical fruit flies, namely the Mediterranean fruit fly (Ceratitis capitata Wiedemann), the melon fly (Dacus cucurbitae Coquillett) and the oriental fruit fly (D. Dorsalis Hendel) (Macion et al., 1968; Seo et al., 1970; 1973). The cultivar is not regarded as host and therefore quarantine treatment is not required for


© Woodhead Publishing Limited, 2011 Fusarium subglutinans (Wollenweb. & Reinking)

Light to dark brown discolouration of fruitlet, sunken fruitlet, profuse pink sporulation and exudation of gum

Yellowish, reddish brown, to very dark, dull brown discolouration of fruit tissue. Infected tissues generally become harden, granular, brittle and speckled with colour variation

Fruit turns brown or black when cooked during canning process. Uncooked may be symptomless or light pink to brown and may smell like cantaloupe

Fusariosis

Marbling

Pink disease

Through open flower by nectar feeding, insects remain latent until fruit ripening

Usually low incidence, found mostly in cool area where air temperature does not exceed 29 °C

Compiled from: Damayanti et al. (1992); Lim (1985); Rohrbach and Phillips (1992); Rohrbach and Schmitt (1994); Py et al. (1987).

Erwinia herbicola, Erwinia sp. Gluconobacter oxyden (Henneberg) de ley Acetobacter aceti (Pasteur) (Syn. Acetobacter liquefaciens)

No postharvest control

No postharvest control

No postharvest control Worldwide but epidemic in lowland tropics where temperature remains above 21 °C

Flower through South America caterpillar wound

Brazil, Hawaii, South Africa

Low temperature 8–9 °C; gamma radiation 50–250 Gy; use of fungicides within 6–12 hours after harvest such as benomyl 1200–1400 ppm, triademenol 250 ppm, imazalil 250 ppm, triademefon 500 ppm, sodium salicyl anilide 1%, o-phenylphenol, captan, salicylic acid, benzoic acid No postharvest control, endosulfan at forcing and 3 weeks after forcing

Worldwide, especially in lowland tropics

Through wounds or cracks within 8–12 hours

Unopen flower through mite injured trichome

Control

Distribution

Infection

Open flower and Acetobacter peroxydans Visser’t Hooft, Acetobacter cracks on the fruit sp. and Erwinia herbicola var. ananas (Serrano)

Penicillium funiculosum Thom, Fusarium subglutinan (Wollenweb. & Reinking)

Thielaviopsis paradoxa (de Seynes) von Höhn (Syn. Chalara paradoxa (de Seynes) Sacc.)

Soft watery flesh later turn dark from the growth of mycellium and chlamydospore

Black rot, water rot, water blister, soft rot, or Thielaviopsis fruit rot

Centre part of an individual Fruitlet core rot, leathery pocket, eye rot, interfruitlet fruitlet becomes brown to black, distorted fruit shape corking, black spot, or fruitlet brown spot

Pathogen

Symptom

Nature and control of postharvest diseases in pineapple

Name

Table 10.2

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

208 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


importation into fruit fly-free countries (Paull, 1997). For other cultivars, vapour heat treatment at 44.6 °C for 8.75 hours is required in mainland United States (Armstrong, 1994). Surface insects including mealy bug, scale and mite cause some postharvest problems. These insects should be well controlled before harvest since they can easily miss detection or removal during postharvest handling, by hiding underneath the bract on individual fruitlets and in the crown. They can be removed by using a brush or water jet during the washing procedure. If these surface insects are found upon entry to the United States, the fruit must be fumigated with methyl bromide at concentrations depending on the temperature at the time of fumigation (Armstrong, 1994). Exporting pineapple to China also requires the control of surface insects besides fumigation with methyl bromide.

10.9


10.9.1 Harvesting Pineapple is harvested once it has already achieved its optimum maturity for consumption. A minimum total soluble solids (TSS) level of 12% is the requirement under the worldwide Codex standard for fresh pineapple (Codex Alimentarius, 2007). Changes on the skin colour and shape of the eyes can be used to estimate fruit maturity. For ‘Mauritius’, the fruit are harvested at breaker stage, i.e. 120 days after flower induction. Fruits for nearby market are harvested at a more advanced stage as customers prefer ripe pineapple. Being a non-climacteric fruit, the taste and flavour of pineapple are better developed in the tree-ripened fruit and they will not improve after harvest (Dull, 1971). During harvesting, pineapple is cut off the plant with a machete. Harvesting should be done carefully to prevent bruising, especially for large fruit. Harvested fruits are placed inside the basket on the back of workers (see Plate XIX in the colour section). When the basket is full, the fruit are piled up at the end of rows or directly loaded on to a truck, for transportation to the packinghouse as soon as possible. The use of crates while in the field is encouraged to reduce mechanical injury. In large-scale plantations, carrying fruit by hand is avoided by using a harvesting aid. In this case, harvesting crews walk between rows of pineapple following the ‘harvester’, which has a boom with a conveyer belt extended to the side. Pickers harvest the fruit and place them on the belt, but fruit is better placed by hand in the field bin upside down to avoid injury (Py et al., 1987). While in-field it is also important to leave the fruits under shaded conditions for protection from the sun. 10.9.2 Packinghouse operations Harvested fruits are prepared for the markets at packinghouses which may be located either inside or outside the farm. Packinghouse operations for pineapple may include cleaning, washing, grading, sizing, fungicide treatment, surface coating, drying and



209

packaging (Abd Shukor et al., 1998; Abdullah et al., 2000). Suitable operations conducted would depend on the market, method of transportation and duration to reach the market as the operations for the domestic market are usually simpler than for the export markets. Once arrived at the packinghouse, pineapple can be unloaded by hand, dumped, sliding or submerging the whole container into a water tank to remove dirt and surface insects. A water jet or brush could also be used for cleaning. Bracts at the base of the fruit should be removed by hand, since insects could be hiding underneath, and the fruit stem is trimmed to about 5–20 mm for vertical packing. Sorting for green-ripe fruit could also be done at this stage since they sink while others float in water (Py et al., 1987). Specific gravity may be used as an index of eating quality. Smith (1988a) suggested the use of two water tanks containing water and a 2.5% salt solution to grade pineapple into three groups: floated in water, sunk in water but floated in salt solution, and those sunk in salt solution. Due to the natural progressive development of flesh translucency from the base to the top of the fruit, the angle of fruit floating in water could also be used to separate fruit with different degrees of translucency. Those that float in an upright position are most translucent, while those that float at 45 degree or lay horizontal are less translucent (Songprateep, 1990). After washing, pineapples are sorted to remove defected ones such as malformed, bruised or insect damaged. Fruit with black rot can also be removed judging from early degreening of some fruitlets. Fruit with an under- or over-developed crown could also be removed (Py et al., 1987). In Hawaii, crown to fruit size ratio should be within 0.33 to 1.5 (Paull, 1997). Large crowns could also be reduced by ‘gouging’ in which part of the crown is removed. This technique leaves a wound, may reduce overall appearance, and could cause disease development during subsequent transport or storage. Gouging can also be done in the field two months before harvest to allow proper healing (Py et al., 1987). A fungicidal treatment such as thiabendazol (TBZ) is applied by dipping or spraying to control black rot disease caused by Thielaviopsis paradoxa. In small-scale operations, pineapple is classified manually according to sizes by experienced workers and a simple balance is used to check fruit weight when in doubt. Sizing machines either by diameter or by weight are also available in large-scale operations including diverging belt and rotary weighing sizer. Under Codex standards, pineapple is classified into three classes, namely ‘Extra Class’, ‘Class I’ and ‘Class II’ according to fruit quality. Size is determined by the average weight of the fruit with a minimum weight of 700 g, except for small size varieties, which can have a minimum weight of 250 g (Table 10.3). 10.9.3 Packaging and transportation Pineapple for local markets in some developing countries are transported either in bulk without container or placed in traditional containers such as bamboo baskets. In some countries, the use of traditional baskets has been replaced with returnable plastic baskets or containers with improved features including better strength and stackable. Corrugated fibreboard cartons with specific design, dimension and capacity are most commonly used for export markets. In Hawaii, large cartons of


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

210 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Postharvest biology and technology of tropical and subtropical fruits Table 10.3 Size classification of pineapple under the Codex standard for pineapple Size code

A B C D E F G H

Average weight (+/− 12%) (in grams) With crown

Without crown

2 750 2 300 1 900 1 600 1 400 1 200 1 000 800

2 280 1 910 1 580 1 330 1 160 1 000 830 660

Source: Codex Alimentarius (2007).

20 kg containing six to ten fruits are used for surface or sea shipment, whereas smaller cartons of 10 kg containing five to six fruits are used for air shipment (Paull and Chen, 2003). Fruits in the cartons are arranged either vertically or horizontally with cushioning pads placed at the inner bottom and in between layers for protection from mechanical injury during handling and transportation. 10.9.4 Recommended storage and shipping conditions The recommended optimum temperatures for pineapple are 7–13 °C with relative humidity of 85–95% (see Sections 10.5.2 and 10.5.3). Under this condition, mature green fruit can remain fresh for four to five weeks. Fruits of more advanced maturity have shorter storage life than those of lesser maturity. The same temperatures are used for shipping pineapples in refrigerated containers. For shipping by sea, matured green fruits are stored or transported at 10 °C, whereas a temperature of 7.5 °C is used for fruits of more advanced maturity. For air shipment, fruit harvested at advanced maturity can be used and stored temporarily at 7.5 °C before being transported. MA or CA is not needed for transportation, as the benefit is minimal for storage life extension. Pineapple is compatible with many types of non-climacteric fruits and vegetables when transported under mixed load conditions. The most important consideration in mixed loads is compatibility with respect to their requirements for temperature, relative humidity, atmosphere, protection from odours, and protection from physiologically active gases, such as ethylene (Wilson et al., 1998; Mohd Salleh et al., 2008). 10.9.5 Control of ripening and senescence Storage life extension by preconditioning and storage at sub-optimal temperature are discussed in Section 10.6.1. Suitable postharvest treatments are covered in Sections 10.6.2 and 10.7 of this chapter.



10.10

211

Processing

10.10.1 Fresh-cut processing Being a large size fruit and relatively hard to peel, pineapple is well suited to be prepared and sold as fresh cut or minimally processed (Siriphanich, 1994). Good handling practices for minimally processed pineapple involve the use of high quality fruits, high sanitation in preparation, good packaging and maintenance of a cold chain. The common temperatures used are 1–4 °C. Tissue injuries in freshly cut pineapple lead to a higher metabolic rate and shorter storage life than for the whole fruit. The use of very sharp knifes for cutting is necessary as fruit with fewer cuts have a lower metabolic rate than those with more cuts (Iverson et al., 1989). Fresh cut pineapple is also subjected to spoilage by microorganism. Yeast and fungi are of primary concern, while bacteria are secondary due to the low pH of the pineapple flesh. Sanitation during the preparation of fresh cut pineapple should be of primary concern for quality and safety. Newly prepared fresh cut pineapple, under careful preparation, could have as much as 105 cfu.g−1 total plate counts of microbial contamination (O’Conner-Shaw et al., 1994). The count could also vary up to 100 fold between preparations. The two most important microorganisms are Listeria monocytogenes, a saprophyte able to grow at low temperature and Escherichia coli, which is acid resistant. Contamination by microorganisms in the flesh may originate from the fruit before cutting but the level of contamination could be reduced by washing the fruits with clean and chlorinated water. With careful preparation, fresh cut pineapple can be stored for up to three weeks at 4 °C (Fadrigalan et al., 2000; Latifah et al., 1999; 2000). Powrie et al. (1990) claimed that fresh cut pineapples sealed in plastic bags and flushed with 15–20% oxygen and 3% argon can be stored for up to ten weeks at 1 °C. Another food preservation technique by using ultra-high pressure has also been studied on fresh cut pineapple (Aleman et al., 1994). However, browning can still proceed after this high-pressure treatment where PPO is relatively resistant to inactivation under high-pressure treatment (Aleman et al., 1998). The addition of ascorbic acid and storage at low temperature could delay the browning (Chen and Paull, 2001; Chen et al., 2000).

10.10.2 Other processed products Various processed products from pineapple were described by Abd Shukor et al. (1998). The products include juice, canned flesh, fruit cocktail, crushed pineapple, fruit punch, frozen pineapple, yoghurt, pineapple powder, freeze-dried pineapple, wines, sauces, jams, marmalades and confectionery. Collins (1968) has comprehensively reviewed by-products from pineapple fruit. The possible by-products include syrup from a cannery, alcohol, feed yeasts, organic acids such as citric acid and malic acid from the mill juice, and starch, protease and fibres from the plant residues of pineapples. Other pineapple by-products include bromelain, vinegar, wine and feed (Dev and Ingel, 1982).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

212 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


10.11

Conclusions

The pineapple has become one of the most established tropical fruits in world trade. The global pineapple industry continues to play very important roles for the future in meeting consumers needs and providing a good source of income and livelihood for many people. Many aspects of pineapple production and postharvesting have been studied and investigated by producing beneficial results but the vast knowledge and technologies that have been generated need further expansion in order to face new challenges. Research on the aspects of quality, safety, health and highly efficient technology, besides greater concern for environment, should be given stronger emphasis in the future.

10.12 Acknowledgements The authors wish to express their sincere thanks to Mrs Rohaya Md Atan and Mr Md Syahril Md Khalil of MARDI for their kind assistance in the preparation of the manuscript.

10.13

References

Abd Shukor A R, Faridah A, Abdullah H and Chan Y K (1998), ‘Pineapple’, in Shaw P E, Chan H T and Nagy S, Tropical and Subtropical Fruits, Auburndale, Florida, Agscience Inc., 137–190. Abdullah H and Rohaya M A (1983), ‘The development of black heart disease in pineapple (Ananas comosus cv. Mauritius) during storage at lower temperatures’, MARDI Res Bull, 11, 309–319. Abdullah H and Rohaya M A (1997), ‘Influence of maturity stage on quality of stored pineapple (Ananas comosus cv. Mauritius)’, J Biosci, 8, 119–126. Abdullah H, Rohaya M A and Abd Aziz I (1996), ‘Quality changes in pineapple (Ananas comosus cv. N36) stored at low temperatures’, MARDI Res J, 24, 39–47. Abdullah H, Rohaya M A and Engku Hasmah E A (2008), ‘Increasing pineapple fruit resistance to chilling injury by temperature preconditioning’, Acta Hort, 768, 217–224. Abdullah H, Rohaya M A, Latifah M N, Mohamed Selamat M and Underhill S J (2002), ‘Respiration rates, ethylene production and chlorophyll content of the fruit and crown of pineapple stored at low temperatures’, J Trop Agric Food Sci, 30, 99–107. Abdullah H, Rohaya M A, Rosli H and Mohamed Selamat M (2000), ‘Handling and transportation trial of pineapple by sea shipment from Malaysia to the United Kingdom’, Acta Hort, 529, 317–328. Abdullah H, Rohaya M A and Zaipun M Z (1985), ‘Effect of modified atmosphere on black heart development and ascorbic acid contents in Mauritius pineapple (Ananas comosus cv. Mauritius) during storage at low temperature’, ASEAN Food J, 1, 15–18. Abdullah H, Rohaya M A and Zaipun M Z (1986), ‘Storage study of Sarawak pineapple with special emphasis on black heart disorder’, MARDI Res Bull, 14, 132–138. Abdullah H, Subari S and Rohaya M A (1983), ‘Pengawalan penyakit teras hitam di dalam nanas Moris dengan perlakuan haba’, Teknol Pertanian, 4, 189–196. Abdullah H, Wills R B H, Rohaya M A, Zaulia O, Lam P F and Smith M K (2010), ‘Blackheart disorder in fresh pineapple’, Fresh Produce, 4, 29–35.



213

Abu Bakar U K, Lam P F, Hamidah G, Pillai V, Marzukhi H (2008), ‘Success stories and challenges in promoting plant biotechnology products’, Proceedings of the National Horticulture Conference 2007, MARDI, Serdang, 55–62. Akamine E K (1976), ‘Postharvest control of endogenous brown spot in fresh Australian pineapples with heat’, HortSci, 11, 586–588. Akamine E K, Goo T, Steepy T, Greidanus T and Iwaoka N (1975), ‘Control of endogenous brown spot of fresh pineapple in postharvest handling’, J Amer Soc Hort Sci, 100, 60–65. Aleman G, Farkas D F, Torres J A, Wilhelmsen E and Mcintyre S (1994), ‘Ultra-high pressure pasteurization of fresh cut pineapple’, J Food Protection, 57, 931–934. Aleman G, Ting E Y, Farkas D F, Mordre S C, Hawes A C O and Torres J A (1998), ‘Comparison of static and step-pulsed ultra-high pressure on the microbial stability of fresh cut pineapple’, J Sci Food Agric, 76, 383–388. Armstrong J W (1994), ‘Tropical and subtropical fruits’, in Paull R E and Armstrong J W, Insect Pests and Fresh Horticultural Products: Treatments and Responses, Wallingford, CAB International, 275–290. Avallone S, Guiraud J P, Brillouet J M and Teisson C (2003), ‘Enzymatic browning and biochemical alterations in black spots of pineapple [Ananas comosus (L.) Merr.]’, Current Microbiology, 47, 113–118. Bartholomew D P (2009), ‘ “MD-2” pineapple transforms the worlds pineapple fresh fruit industry’, Pineapple News, 16, 2–5. Bartholomew D P and Criley R A (1983), ‘Tropical fruit and beverage crops Vol 2’, in Nickell, L G, Plant Growth Regulating Chemicals, Boca Raton, CRC Press, 1–11. Bartolome A P, Ruperez P and Fuster C (1995), ‘Pineapple fruit: morphological characteristics, chemical composition and sensory analysis of Red Spanish and Smooth Cayenne cultivars’, Food Chemistry, 53, 75–79. Berger R G, Drawert F, Kollmannsberger H, Nitz S and Schraufstetter B (1985), ‘Novel volatiles in pineapple fruit and their sensory properties’, J Agric Food Chem, 33, 232–235. Berger R G, Drawert F and Nitz S (1983), ‘Sesquiterpene hydrocarbons in pineapple fruit’, J Agric Food Chem, 31, 1237–1239. Bowden R P (1969), ‘Further studies on ripeness in pineapples’, Food Technol Australia, 21, 160–162. Broderick J J (1975), ‘Pineapple some distance to go’, Flavours, Nov/Dec, 351. Cappellini R A, Ceponis M J and Lightner G W (1988), ‘Disorders in avocado, mango and pineapple shipments to the New York market, 1972–1985’, Plant Disease, 72, 270–273. Cazzonelli C I, Cavallaro A S and Botella J R (1998), ‘Cloning and characterisation of ripening-induced ethylene biosynthetic genes from non-climacteric pineapple (Ananas comosus) fruits’, Aust J Plant Physiol, 25, 513–518. Chairidchai P (2000), ‘The relationships between nitrate and molybdenum contents in pineapple grown on an inceptisol soil’, Acta Hort, 529, 211–216. Chan, Jr H T, Chenchin E and Vonnahme P (1973), ‘Nonvolatile acids in pineapple juice’, J Agric Food Chemistry, 21, 208–211. Chan Y K, Coppens d’Eecckenbrugge G and Sanewski G M (2003), ‘Breeding and variety improvement’, in Bartholomew D P, Paull R E and Rohrbach K G, The Pineapple – Botany, Production and Uses, Wallingford, CABI, 33–55. Chen C and Paull R E (2000), ‘Changes in sugar contents and activities of sugar metabolizing enzymes in pineapple fruit flesh during development’, Acta Hort, 529, 191–195. Chen C and Paull R E (2001), ‘Fruit temperature and crown removal on the occurrence of pineapple fruit translucency’, Scientia Hort, 88, 85–95. Chen N J, Paull R E and Hodgson A (2000), ‘High pressure treatment of pineapple slices’, Pineapple News #7. Available from: http://agrss.sherman.hawaii.edu/pineapple/ pnews7.htm [accessed May 2011].


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

214 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Chongpraditnun P, Luksanawimol P, Limsmuthchaiporn P and Vasunun S (2000), ‘Effect of fertilizers on the content of nitrate in pineapple fruit’, Acta Hort, 529, 217–220. Codex Alimentarius (2007), Fresh fruits and vegetables, Rome, WHO and FAO, 101–106. Collins J L (1968), The Pineapple. Botany, Cultivation and Utilization, London, Leonard Hill. Damayanti M, Sharma G J and Kundu S C (1992), ‘Gamma radiation influences postharvest disease incidence of pineapple fruits’, HortSci, 27, 807–808. d’Eckenbruge G C and Leal F (2003), ‘Morphology, anatomy and taxonomy’, in Bartholomew D P, Paull R E and Rohrbach K G, The Pineapple – Botany, Production and Uses, Wallingford, CABI, 13–32. de Simon B F, Perez-Ilzarbe J, Hernandez T, Gomez-Cordoves C and Estrella I (1992), ‘Importance of phenolic compounds for the characterization of fruit juices’, J Agric Food Chem, 40, 1531–1535. Dev D K and Ingel U M (1982), ‘Utilization of pineapple by-products and wastes – a review’, Indian Food Packer, 36, 15–22. Dull G G (1971), ‘The pineapple: general’, in Hulme A C, The Biochemistry of Fruits and Their Products Vol 2, London, Academic Press, 303–331. Dull G G, Young R E and Biale J B (1967), ‘Respiratory patterns in fruit of pineapple, Ananas comosus, detached at different stages of development’, Physiologia Plantarum, 20, 1059–1065. Fadrigalan E N, Lustre A O, Natividad A C, Matienzo V T and Garcia M M (2000), ‘Evaluation of washing, chlorine treatment and storage conditions to control Listeria monocytogenes in minimally processed pineapple’, in Alexander G I and Gartner R, Quality Assurance Systems for ASEAN Fruits, Brisbane, Palamere Pty. Ltd., 96–104. FAO (2009), FAOSTAT. Available from: http://faostat.fao.org/site/567/DesktopDefault. aspx?PageID=567#ancor (accessed 29 December 2009). Flath R A (1980), ‘Pineapple’, in Nagy S and Shaw P E, Tropical and Subtropical Fruits: Composition, Properties and Uses, Westport, AVI, 157–183. Flath R A and Forrey R R (1970), ‘Volatile components of Smooth Cayenne pineapple’, J Agric Food Chem, 18, 306–309. Gardner P T, White T A C, McPhail D B and Duthie G G (2000), ‘The relative contributions of vitamin C, carotenoids and phenolics to the antioxidant potential of fruit juices’, Food Chem, 68, 471–474. Gortner W A (1965), ‘Chemical and physical development of the pineapple fruit. IV. Plant pigment constituents’, J Food Sci, 30, 30–32. Gortner W A (1969), ‘Relation of chemical structure to plant growth-regulator activity in the pineapple plant: retarding senescence of pineapple fruit with applications of 2,4,5-trichlorophenoxyacetic acid and 1-naphthaleneacetic acid’, J Food Sci, 34, 577–580. Gortner W A and Singleton V L (1965), ‘Chemical and physical development of the pineapple fruit III. Nitrogenous and enzyme constituents’, J Food Sci, 30(1): 24–29. Graham M, Ko L, Hardy V, Robinson S, Sawyer B, et al. (2000), ‘The development of blackheart resistant pineapples through genetic engineering’, Acta Hort, 529, 133–136. Haagen-Smit A J, Kirchner J G, Prater A N and Deasy C L (1945b), ‘Chemical studies of pineapple (Ananas sativus Lindl). I. The volatile flavor and odor constituents of pineapple’, J Amer Chem Soc, 67, 1646–1650. Hardenburgh R E, Watada A E and Wang C Y (1986), The Commercial Storage of Fruits, Vegetables, and Florist and Nursery Stocks. US Dept of Agr, Agr Handbook No. 66 (revised), Washington DC, USDA. Haruenkit R and Thompson A K (1994), ‘Storage of fresh pineapple’, in Champ B R, Highley E and Johnson G I, Postharvest Handling of Tropical Fruits, ACIAR Proceedings #50, 422–426. Heinicke R M and Gortner W A (1957), ‘Stem bromelain – A new protease preparation from pineapple plants’, Economic Botany, 11, 225–234.



215

Hepton A (2003), ‘Cultural system’, in Bartholomew D P, Paull R E and Rohrbach K G, The Pineapple – Botany, Production and Uses, Wallingford, CABI, 109–142. Iversen E, Wilhelmsen E and Criddle R S (1989), ‘Calorimetric examination of cut fresh pineapple metabolism’, J Food Sci, 54, 1246–1249. Kader A A (1992), ‘Modified atmosphere during transport and storage’, in Kader A A, Postharvest Technology of Horticultural Crops, Oakland, University of California, 85–92. Kermasha S, Barthakur N N and Alli I (1987), ‘Changes in chemical composition of the Kew cultivar of pineapple fruit during development’, J Sci Food Agri, 39, 317–324. Latifah M N, Abdullah H, Mohd Selamat M, Habsah M, Talip Y and Rahman K M (2000), ‘Modified atmosphere packing of minimally processed pineapple’, J Trop Agric Food Sci, 28, 77–86. Latifah M N, Abdullah H, Mohd Selamat M, Talip Y and Rahman K M (1999), ‘Quality of minimally processed pineapple using two packing systems’, J Trop Agric Food Sci, 27(1): 101–107 Leverington R E (1968), ‘Problems associated with pineapple products’, Food Technol Australia, 20, 20–29. Lim W H (1985), ‘Diseases and disorders of pineapples in peninsular Malaysia’, MARDI Report No. 97. Lodh S B, Divakar N G, Chadha K L, Melanta K R and Selvaraj Y (1973), ‘Biochemical changes associated with growth and development of pineapple fruit variety Kew. III. Changes in plant pigments and enzyme activity’, Indian J Hort, 30, 381–383. Macion E A, Mitchell W C and Smith J B (1968), ‘Biophysical and biochemical studies on the nature of resistance of pineapples to the oriental fruit fly’, J Econ Entomology, 61, 910–916. Malezieux E, Cote F and Bartholomew D P (2003), ‘Crop environment, plant growth and physiology’, in Bartholomew D P, Paull R E and Rohrbach K G, The Pineapple – Botany, Production and Uses, Wallingford, CABI, 69–108. Miller E V and Hall G D (1953), ‘Distribution of total soluble solids, ascorbic acid, total acid and bromelin activity in the fruit of the natal pineapple (Ananas comosus L. Merr.)’, Plant Physiol, 28, 532–534. Mizuno S, Terai H and Kozukue N (1982), ‘Studies on the endogenous brown spot of pineapple in postharvest handling’, Science Reports of Faculty of Agriculture, Kobe University, 15, 47–53. Mohd Salleh P, Ahmad Tarmizi S and Pauziah M (2008), ‘Shipping tropical fruits in mixed loads container’, Proceeding of the National Horticulture Conference 2007, MARDI, 55–62. Nimitkeatkai H, Srilaong V, Kanlayanarat S (2006), ‘Effect of edible coating on pineapple fruit quality during cold storage’, Acta Hort, 712, 643–648. O’Connor-Shaw R E, Roberts R A, Ford L and Nottingham S M (1994), ‘Shelf life of minimally processed honeydew, kiwifruit, papaya, pineapple and cantaloupe’, J Food Sci, 59, 1202–1206 & 1215. Ohta H, Kinjo S and Osajima Y (1987), ‘Glass capillary gas chromatographic analysis of volatile components of canned Philippine pineapple juice’, J Chromatography, 409–412. Paull R E (1997), ‘Pineapple’, in Mitra S K, Postharvest Physiology and Storage of Tropical and Subtropical Fruits, 123–143. Paull R E and Chen C C (2003), ‘Postharvest physiology, handling and storage’, in Bartholomew D P, Paull R E and Rohrbach K G, The Pineapple – Botany, Production and Uses, Wallingford, CABI, 253–280. Paull R E and Reyes M E Q (1996), ‘Preharvest weather conditions and pineapple fruit translucency’, Scientia Hort, 66, 59–67. Paull R E and Rohrbach K G (1982), ‘Juice characteristics and internal atmosphere of waxed “Smooth Cayenne” pineapple fruit’, J Amer Soc Hort Sci, 107, 448–452. Pauziah M, Abdullah H, Ahmad Tarmizi S, Mohd Salleh P, Mohamed Selamat M and Norhayati M (2005), ‘Association of polyphenoloxidase (PPO) and peroxidase (POD)


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

216 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


with blackheart development of Malaysian pineapples’. MARDI Horticulture Research Centre Technical Report, 172–175. Pimpimol J and Siriphanich S (1993), ‘Factors effecting internal browning disorder in pineapples and its control measures’, Kasetsart Journal (Nat. Sci.), 27, 421–430. Powrie W D, Chiu R, Wu H and Skura B J (1990), ‘Preservation of cut and segmented fresh fruit pieces’, U.S. Pat. #4, 895, 729. Py C, Lacoeuilhe J J and Teisson C (1987), The Pineapple Cultivation and Uses, Editions G-P Maisonneuve & Larose, Paris, 568 p. Rodin J O, Himel C M, Silverstein R M, Leeper R W and Gortner W A (1965), ‘Volatile flavor and aroma components of pineapple. I. Isolation and tentative identification as 2,5-dimethyl-4-hydroxy-3(2H)-furanone’, J Food Sci, 30, 280–285. Rohrbach K G and Apt W J (1986), ‘Nematode and disease problems of pineapple’, Plant Disease, 70, 81–87. Rohrbach K G and Paull R E (1982), ‘Incidence and severity of chilling induced internal browning of waxed “Smooth Cayenne” pineapple’, J Amer Soc Hort Sci, 107, 453–457. Rohrbach K G and Phillips D J (1992), ‘Postharvest diseases of pineapple’, Acta Hort, 269, 503–508. Rohrbach K G and Schmitt D P (1994), ‘Part IV. Pineapple’, in Ploetz R C, Nishijima W T, Zentmyer G A, Rohrbach K G and Ohr H D, Compendium of Tropical Fruit Diseases, St Paul, APS Press, 45–55. Selvarajah S, Bauchot A D and John P (2001), ‘Internal browning in cold-stored pineapples is suppressed by a postharvest application of 1-methylcyclopropene’, Postharvest Biology and Technology 23, 167–170. Seo S T, Chambers D L, Kobayashi R M, Lee C Y L and Komura M (1970), ‘Infestations of oriental fruit flies in 53–116 and Smooth Cayenne pineapple varieties grown near supporting guava or other host fruits’, J Econ Entomology, 63, 1830–1831. Seo S T, Chambers D L, Lee C Y L, Komura K, Fujimoto M and Kamakahi (1973), ‘Resistance of pineapple variety 59–443 to field populations of oriental fruit flies and melon flies’, J Econ Entomology, 66, 522–523. Singleton V L (1965), ‘Chemical and physical development of the pineapple fruit. I. Weight per fruitlet and other physical attributes’, J Food Sci, 30, 98–104. Singleton V L and Gortner W A (1965), ‘Chemical and physical development of the pineapple fruit. II. Carbohydrate and acid constituents’, J Food Sci, 30, 19–23. Siriphanich J (1994), ‘Minimal processing of tropical fruit’, in Champ B R, Highley E and Johnson G, Postharvest Handling of Tropical Fruit, ACIAR Proceedings, No. 50, pp. 127–137. Smith L G (1983), ‘Causes and development of black heart in pineapples, Trop Agric (Trinidad), 60, 31–35. Smith L G (1984), ‘Pineapple specific gravity as an index of eating quality’, Trop Agric (Trinidad), 61, 196–199. Smith L G (1987), ‘Quality improvements for Australian fresh market pineapples’, Food Technol Australia, 39, 64–68. Smith L G (1988a), ‘Indices of physiological maturity and eating quality in Smooth Cayenne pineapples. I. Indices of Physiological maturity’, Queensland J Agric Animal Sci, 45, 213–218. Smith L G (1988b), ‘Indices of physiological maturity and eating quality in Smooth Cayenne pineapples. II. Indices of eating quality’, Queensland J Agric Animal Sci, 45, 219–228. Soler A (1993), ‘Enzymatic characterization of stress induced translucence of pineapple flesh in the Ivory Coast’, Acta Hort, 334, 295–304. Songprateep P (1990), ‘The relationship of floating characteristics on maturity and chilling injury of pineapple cv. Smooth Cayenne’, Bachelor Special Problems, Department of Horticulture, Kasetsart University, Bangkok, Thailand, 26 p.



217

Stewart R J, Sawyer B J B and Robinson S P (2002), ‘Blackheart development following chilling in fruit of susceptible and resistant pineapple cultivars’, Aust J Exp Agric, 42, 195–199. Takeoka G R, Buttery R G, Teranishi R, Flath R A and Guntert M (1991), ‘Identification of additional pineapple volatiles’, J Agric Food Chem, 39, 1848–1851. Teai T and Claude-Lafontaine A (2001), ‘Volatile compounds in fresh pulp of pineapple (Ananas comosus (L.) Merr.) from French Polynesia’, Journal of Essential Oil Research, 13, 314–318. Tee E S, Mohd Ismail N, Mohd Nasir A and Khatijah I (1988), Nutrient Composition of Malaysian Foods, Kuala Lumpur, ASEAN-Australia Economic Cooperation Programme. Teisson C, Lacoeuilhe J J and Combres, J C (1979b), ‘Le brunissement interne de l’ananas. V. Recherches de moyens de lutte’, Fruits, 34, 399–415. Teisson C, Martin-Prevel P and Marchal J (1979a), ‘Le brunissement interne de l’ananas. IV. Approche biochimique du phenomene’, Fruits, 34, 329–339. Umano K, Hagi Y, Nakahara K, Shoji A and Shibamoto T (1992), ‘Volatile constituents of green and ripened pineapple (Ananas comosus (L.) Merr.)’, J Agric Food Chem, 40, 599–603. van Lelyveld L J and de Bruyn J A (1977), ‘Polyphenols, ascorbic acid and related enzyme activities associated with black heart in Cayenne pineapple fruit’, Agrochemophysica, 9, 1–6. Vidal-Valverde C, Herranz J, Blanco I and Rojas-Hidalgo E (1982), ‘Dietary fiber in Spanish fruits’, J Food Sci, 47, 1840–1845. Wills R B H, Abdullah H, Scott K J (1985), ‘Effect of storage time at low temperature on the development of blackheart in pineapples’, Trop Agric (Trinidad), 62, 199–200. Wilson L G, Boyette M D and Estes E A (1998), ‘Part IV: Mixed loads’, in Postharvest Handling and Cooling of Fresh Fruits, Vegetables and Flowers for Small Farmers, North Carolina State University. Available from http://www.ces.ncsu.edu/hil/hil803html (accessed 12 December 1998). Wu P, Kuo M, Hartman T G, Rosen R T and Ho C (1991), ‘Free and glycosidically bound aroma compounds in pineapple (Ananas comosus L. Merr.)’, J Agric Food Chem, 39, 170–172. Yahia E M (1998), ‘Modified and controlled atmospheres for tropical fruits’, in Janick J, Horticultural Reviews, 22, 123–183. Zaulia O, Suhaila M, Azizah O, Mohamed Selamat M (2007), ‘Effect of various coatings on the chemical changes of different pineapple cultivars (N36 and Gandul) at low temperature storage’, J Trop Agric Food Sci, 35, 107–120. Zhou Y, Jobin-Decor M, Dahler J, Wills R, Underhill S, Graham M W (2002), ‘Optimising transient assays for studying the regulation of PPO gene expression in pineapple blackheart’, Acta Hort, 575, 595–601. Zhou Y, Dahler J M, Underhill S J R, Wills R B H (2003), ‘Enzymes associated with blackheart development in pineapple fruit’, Food Chem, 80, 565–572.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Plate XVIII

Plate XIX

(Chapter 10) Pineapple production on peat soil in Johor, Malaysia.

(Chapter 10) Harvesting pineapple for processing in Johor, Malaysia.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

11 Pistachio (Pistacia vera L.) M. Kashaninejad, Gorgan University of Agricultural Sciences and Natural Resources, Iran and L. G. Tabil, University of Saskatchewan, Canada

Abstract: The pistachio nut (Pistacia vera L.) is one of the most popular tree nuts in the world and is valued globally for its nutritional value, health and sensory attributes and economic importance. It is high in unsaturated fatty acids and low in saturated fatty acids, a rich source of proteins, dietary fibers, vitamins, minerals and antioxidants, and is an increasingly important nut crop consumed raw, salted or roasted. In common with other tree nuts, pistachios are rich in nutrient content and beneficial for the human diet. Careful harvesting, appropriate postharvest handling and proper processing, storage and packaging, all contribute to achieve optimum yield of high quality nuts. Pistachio nuts should be processed as soon as possible after harvest and stored in appropriate conditions to avoid mold growth and undesirable chemical reactions such as oxidative rancidity. This chapter will provide information about the botany, worldwide importance, postharvest pathology, harvesting, handling, processing and storage of pistachio nut. Key words: Pistacia vera, pistachio nut, processing, drying, roasting, aflatoxin.

11.1

Introduction

11.1.1 Origin and history The word pistachio is a loanword from the Zendor Avestan (ancient Persian language) pista-pistak (Joret, 1976) and is a cognate to the modern Persian word Peste. According to Dioskurides, the pistachio is derived from pissa (means resin) and aklomai (means to heal), i.e. a plant with healthy resin. The common name of pistachio in different languages is: Peste (Persian), Pistache (French), Pistazie (Germany), Pistacchio (Italian), Pistacho (Spanish), Pista (Indian), Pistasch (Swedish), Fustuq (Arabic) and Pisutachio (Japanese). The origins of the pistachio are Asia Minor (now Turkey), Iran, Syria, Lebanon, the Caucasus in southern Russia and Afghanistan (Zohary, 1952). It probably developed in interior desert areas because it requires long, hot summers for fruit maturation, is drought and salt tolerant, and has a high winter chilling requirement.


Pistachio (Pistacia vera L.)

219

Archeologists have found evidence in a dig site at Jarmo, near northeastern Iraq, that pistachio nuts were a common food as early as 6750 BC (Kirkbride, 1966; Kramer, 1982). The history of pistachio nuts reflects their ‘royal character’, endurance and pride. Especially fine pistachios are said to have been a favorite delicacy of the Queen of Sheba, who confiscated all Assyrian deliveries for herself and for her royal court (Whitehouse, 1957). Nebuchadnezzar, the ancient king of Babylon, had pistachio trees planted in his fabled hanging gardens around the 8th century BC (Brothwell and Brothwell, 1969). In the 2nd century BC, Nicander found pistachio in Susa, a village in southwestern Iran close to the border with Iraq (Joret, 1976). In the 1st century BC, Poseidonius recorded cultivated pistachio in Syria (Joret, 1976), and the nuts traveled from Syria to Italy in the 1st century AD and spread throughout the Mediterranean from there (Banifacio, 1942; Moldenke and Alma, 1952). Pistachio has been spread eastward from its center of origin and was reported in China around the 10th century AD (Lemaistre, 1959). It was introduced to USA in 1854 but commercial plantings did not develop until 1970 (Rieger, 2006). More recently pistachio has been cultivated in Australia. 11.1.2 Botany Pistachio is the only commercially edible nut among the 11 species in the genus Pistacia that all exude turpentine or mastic. Pistacia vera L. (Latin name of pistachio) is by far the most economically important and a member of the Anacardiaceae or cashew family. Other important members of this family are cashew, mango, mombins (Spondias spp.), poison ivy, poison oak, pepper tree and sumac. P. nigricans Crantz, P. officinarium Ait, P. reticulate Willd and P. terebinthus Mill are the synonyms of P. vera L. Pistachio trees are small to medium size and can grow to 12 m, but are generally smaller in the cultivation period. Leaves are compound-pinnate and generally with three and sometimes five leaflets. Their shapes vary from ovoid to oblongovoid with dark green above and paler below on entire margins and obtuse tips. The flowering behavior of pistachio trees depends on their location, which can be steppe-forests, steppe or semi-desert. Floral bud differentiation takes place before blossoming. Shoot elongation usually commences at the end of March and ends between April and May (Crane and Iwakiri, 1981). One or two axillary buds located on the new growth are vegetative. Inflorescence buds which are conspicuously larger than vegetative buds expand at the following March, and anthesis generally takes place at the end of May and after about three weeks they grow and differentiate very fast. The pistachio tree is dioecious, meaning that male and female flowers are borne on separate trees. Therefore, both male and female trees are required to produce nuts. The pistachio tree has about 13 primary branches with each bearing one terminal and five to 19 lateral flowers. The flowers are apetalous and include up to five sepals. Male flowers have five small stamens and females include a single tricarpellate, superior ovary. Since the female flowers are nectarine-free they cannot attract bees, although they may be attracted to male


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

220 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


flowers for pollen. Therefore, the pollen is spread by wind. Pistachios grow on trees in grape-like clusters on first-year-old wood (see Plate XX in the colour section between pages 238 and 239). Based on location and variety, fruit development occurs at different times. For ‘Kerman’ variety following proper and successful pollination, fruit set and endocarp (nut shell) begins to enlarge in late April until May, while the kernel does not grow. During this period, the shell is very soft and sensitive to insect attacks. The shell begins to harden in June and from late June until early August the kernel grows and fills the shell. Nut ripening takes place during late August and September and the shell splits more and more along the ventral suture, hull color changes from green to red and abscission of the individual nut begins from the rachis (Hendricks and Ferguson, 1995). Fruiting takes place four to five years after transplanting but full bearing and economically significant crops happen around ten years of age. The pistachio fruit (nut) is a drupe and almost oval shape. It consists of a single seed (kernel), encased by a thin soft and edible seed coat (testa or skin), enclosed by a hard smooth inedible shell (endocarp), which is further surrounded by the fleshy hull (mesocarp and epicarp), which is also inedible (see Plate XXI in the colour section). The hull is thin and fleshy, pale green in color, with a red blush at maturity. The shell dehisces along the ventral suture with kernel growth and progresses along both sutures until physiological maturity reaches maximum size. The seeds range in color from light to dark green or greenish-yellow (called pistachio kernel green) and contain two cotyledons surrounded by a thin coating. Physiological maturity is manifested by loosening and easy separation of the hull from the shell and changing of the hull color from green to red (Crane, 1978). 11.1.3 Varieties Many cultivated varieties of pistachio are available in different countries with significant variation in their characteristics particularly in terms of size, shape, color, taste and splitting. Maggs (1973) reported that the main pistachio varieties in the world have been spread from Iran, Turkey and Syria. These varieties were obtained through seedling selection in the field. Pistachio is cultivated in different regions of Iran but Kerman province is the largest and most important pistachio growing area with much higher genetic diversity of pistachio than other regions. More than 70 varieties have been recorded in this province. ‘Ohadi’ or ‘Fandoghi’, ‘Kalle-Ghuchi’, ‘AhmadAghaei’, ‘Badami’, ‘Rezaei’ and ‘Momtaz’ are the major varieties grown in Kerman province (Fig. 11.1). ‘Ohadi’ cultivation has been increased during the last 40 years and now includes about 70% of pistachio orchards in this region. It is round-shaped with a light yellow to green kernel, bearing large bunches of green hulled and high splitting nuts. It produces attractive and good quality nuts suitable for export. Large fruit, high yield and good split percentage are the main reasons for the popularity of ‘Kalle-Ghuchi’ variety. It is also round-shaped with light green kernel (Esmail-pour, 2001).



221

Fig. 11.1 Pictorial view of nut (left) and kernel (right) of five Iranian pistachio varieties; from top to bottom: ‘Akbari’, ‘Badami’, ‘Kalle-Ghuchi’, ‘Momtaz’ and ‘Ohadi’.

There are about 20 female pistachio varieties in Syria of which ‘Ashouri’ (‘Red Aleppo’), ‘Red Oleimy’ and ‘White Batoury’ are three main varieties. ‘Ashouri’ accounts for about 85% of the total pistachio area in Syria. A 40-year-old tree of ‘Ashouri’ variety produces up to 200 kg of fresh nuts per year. It is the best Syrian variety in terms of splitting (with 99%) and excellent as a table variety. ‘Ashouri’ nuts are elongated and red with dark spots and medium size (27 mm length, 15 mm width and 14.5 mm thickness) (Hadj-Hassan, 2001). In Turkey, there are eight main domestic varieties including ‘Uzun’, ‘Kirmizi’, ‘Halebi’, ‘Siirt’, ‘Beyazben’, ‘Sultani’, ‘Degirmi’ and ‘Keten Gomlegi’ and five foreign varieties from Iran including ‘Ohadi’, ‘Bilgen’, ‘Vahidi’, ‘Sefidi’ and ‘Momtaz’. Most of the harvested crop consists of ‘Uzun’ and ‘Kirmizi’ varieties. The ‘Uzun’ variety is long (19 to 21 mm) and plump; some of the nuts are half as wide as they are long with a splitting percentage of 69%. ‘Kirmizi’ is a red-hulled, thin-shelled, free-splitting, green kernel nut of medium size. All Turkish varieties except ‘Siirt’ have elongated nuts while ‘Siirt’ has ovoid nut shape. ‘Siirt’ is the best Turkish variety in terms of splitting with 92%. Domestic varieties generally have yellowish green kernels (Ak and Acar, 2001). About 20 varieties have been imported as seed from other countries to the United States and tested to develop as a local variety but the results have demonstrated that a special variety’s success in another country does not mean a successful performance in the United States. ‘Kerman’, a developed California variety, named after the main pistachio area in Iran (Kerman province) was introduced in the 1950s after testing for several years in California. Now, it is the main commercial variety grown in California consisting of about 99% of pistachio production in this state. It produces high yields of large nuts but it has a strong alternate-bearing habit and many blanks and non-split nuts. It has light greenish-yellow kernel with minimum flavor particularly after drying in commercial dryer. American consumers prefer pistachios from other countries because of better flavor and color attributes. ‘Joley’ is another female variety that was introduced from Damghan, Iran and has been planted mainly in New Mexico and a few orchards in California. It is smaller than ‘Kerman’ variety with greener kernel and better taste. It has almond-shaped nuts with high non-split percentage in some years.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

222 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


11.1.4 Uses Pistachio is cultivated for nut production and the nuts are mainly used for eating out of hand as fresh, dried, and roasted with or without salt and flavorings. The pistachio is unique in the nut trade because of shell splitting naturally before harvesting. This advantage allows pistachio nuts to be marketed extensively in-shell for fresh consumption, because their kernels can be easily separated without mechanical cracking. It also enables the processor to roast and salt the kernel without shell removal while almonds, walnuts and pecans are generally sold shelled to the industrial trade. In the United States, after roasting and salting of raw pistachio nuts, the shell is colored with a red dye to cover shell stains and blemishes and sold as ‘Red’ pistachios. Pistachio nuts are also used in pastries, cakes, ice creams, confections, baked goods, candies, sausages and desserts. Pistachio is an excellent taste enhancer and can be added to many food products to improve nutrition, color and flavor. The utilization of pistachio nuts in the producing countries are more varied than in the importer countries. In Iran, the hulls are used for fertilizer, feed for ruminants and small amounts are made into a flavorful marmalade (Mohammadi Moghaddam et al., 2009). A small amount of pistachio oil is produced for eating and use in cosmetics, while a limited amount of pistachio is also used for production of pistachio butter (Taghizadeh and Razavi, 2009). This butter, a semisolid paste, is made from ground and roasted pistachio kernels with addition of some flavorings and sweeteners. Pistachio butter is a nutritive product rich in lipids, proteins, carbohydrates and vitamins, and can be used in different food products such as cookies, ice creams and cakes. The hull is used for dyeing and tanning in India. 11.1.5 Worldwide importance and economic value World commercial production of pistachio nuts increased more than tenfold, from 47 584 tonnes in 1970 to 517 823 tonnes in 2007 (FAOSTAT, 2009). Pistachio nuts are produced commercially in 18 countries on 608 729 hectares. According to the Food and Agriculture Organization (FAO), the top six pistachio producers in 2007 were Iran at 230 000 tonnes (44.4% of the world’s production), followed by the United States (108 598 tonnes, 20.97% share), Turkey (73 416 tonnes, 14.18% share), Syria (52 066 tonnes, 10.05% share), China (38 000 tonnes, 7.34% share) and Greece (9 000 tonnes, 1.7% share). Pistachio production in Iran, Turkey, Syria, China and Greece increased 4.14, 1.56, 3.93, 1.15 and 7.14-fold, respectively from 1970 to 2007. As shown in Fig. 11.2, Iran’s production has been the key factor driving the global growth trend. However, production of the United States increased from 0 in 1970 to 108 598 tonnes in 2007, making it the second highest world producer after Iran. Alternate bearing, blanking and non-splitting are three physiological disorders that affect the fluctuation of commercial yield. Plantings have recently increased dramatically in the major producer countries of Iran, United States and Turkey. For example, pistachio production in the United States has increased from 688 bearing hectares in 1977 to 46 136 in 2007. In Iran,



Fig. 11.2

223

Global, Iran and United States pistachio production from 1970 to 2007.

it increased from 47 000 to 440 000 hectares during the same period. Although pistachio production has been initiated in countries such as Australia, Mexico, Argentina and South Africa, their production numbers have not reached competitive levels. Average yield per tree ranges from 2 to 22.5 kg/year. An average 3 kg of unshelled nuts yield 1 kg shelled. In 2000, world yields varied from 500 kg.ha−1 to 3037 kg.ha−1 with an average of 1117 kg.ha−1 (Kaska, 2002). Duke (2001) reported yields from 2 to 8 kg unshelled nuts per tree or 200 to 800 kg.ha−1 for 8 to 15 year old trees and 8 to 30 kg per tree or 800 to 2400 kg.ha−1 for 16 to 30 year old trees. Global pistachio export has increased from 13 531 tonnes (valued $1.36 million) in 1970 to 313 372 tonnes (worth $1.36 billion) in 2007. Iran and Turkey has been the major exporter in 1970 with 74 and 25% of world exports, respectively. Figure 11.3 shows the major exporters of pistachio nuts in 2006. According to FAO, Iran was the leading exporter of pistachio nuts in 2006 with 163 431 tons or 55% of global export followed by the United States with 48 571 tonnes or 17% of world export. Most export of Iranian pistachio is bound for Hong Kong, Germany, United Arab Emirates, Russia, Spain, Italy and India. Some of Iranian pistachio markets are also major exporter such as Hong Kong and Germany although they were among the top global pistachio importers in 2006 (Fig. 11.4). As many of these countries are not pistachio producers, it proves that trans-shipment or further processing occurs often with this commodity. Hong Kong and Germany are the major trans-shipper of pistachio nuts. In 2006, Germany imported pistachio valued at $199 million, primarily from Iran and the United States and exported pistachios valued at $106 million to other European countries.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

224 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Fig. 11.3 The leading global exporters of pistachio nuts 2006.

Fig. 11.4 Top global importers of pistachio in 2006.



225

11.1.6 Composition, nutritional value and health benefits Pistachio nuts are highly valued for their nutritional, sensory and health attributes. In addition to being high in unsaturated fatty acids and low in saturated fatty acids, they are good sources of proteins, dietary fibers, vitamins, minerals and antioxidant phytochemicals. Nutritionally, pistachio nuts are better than other tree nuts and peanut because they are lower in calories and fat content and higher in protein, carbohydrate and potassium. The composition of pistachio nut may vary depending on variety and maturity at harvest time. Tables 11.1–11.3 present the chemical composition and nutritional value, fatty acid and amino acid profiles of two varieties of pistachio nut. Mono- and poly-unsaturated fatty acids constitute more than 80% of pistachio oil. Carbohydrate analysis of pistachio has indicated the predominant sugar to be sucrose followed by raffinose, glucose, fructose, maltose and stachyose with traces of isomaltose and cellobiose (Kashani and Valadon, 1984). The globulin fraction is the major protein in the pistachio, contributing about two-third of the total protein (66%). Albumins are second in predominance to globulins, contributing 25% of the total protein, followed by glutelins (7.3%) and prolamins (2%) (Shokraii and Esen, 1988). All essential amino acids are present in pistachio where lysine is present at a high level and with only cystine in a limited amount. Pistachio nut contains substantial levels of a diverse range of phytochemicals such as carotenoids (lutein), phytosterols and phenolic compounds (flavonoids and resveratrol) in the kernel and skin. The presence of anthocyanins in pistachio nut is a unique characteristic that causes the red-purple color in the skin of the pistachio. Anthocyanins are water-soluble pigments that impart the attractive red, Table 11.1 Chemical composition of two varieties (‘Ohadi’ from Iran and ‘Kerman’ from the USA) of pistachio nut Component (unit)

Moisture (%) Oil (%) Protein (%) Carbohydrates (%) Crude fiber (%) Ash (%) Potassium (mg 100 g−1) Phosphorus (mg 100 g−1) Iron (mg 100 g−1) Calcium (mg 100 g−1) Magnesium (mg 100 g−1) Sodium (mg 100 g−1) Copper (mg 100 g−1) Energy (kcal 100 g−1)

Variety Ohadi

Kerman

2.54 57 20.8 13.8 1.93 2.6 1170 560.5 10.3 179.3 102.6 10.7 1.3 570

3.97 44.44 20.61 27.97 1.03 3.02 1025 490 4.15 107 121 1 ______ 557

Source: Shokraii (1977); USDA (2006).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

226 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Postharvest biology and technology of tropical and subtropical fruits Table 11.2 Fatty acid profile of two varieties (‘Ohadi’ from Iran and ‘Kerman’ from the USA) of pistachio nut Amount (%)

Fatty acid

C14:0 C16:0 C16:1 C18:0 C18:1 C18:2 C18:3 C18:4 C20:0 C22:0

Ohadi

Kerman

____ 13.4 2.0 1.0 49.5 31.8 Trace 2.2 _____ _____

Trace 12.59 0.52 0.90 57.48 27.93 0.57 _____ Trace Trace

Source: Shokraii (1977); Clarke et al. (1976).

Table 11.3 Amino acid profile of two varieties (‘Ohadi’ from Iran and ‘Kerman’ from the USA) of pistachio nut Percent total amino acids

Amino acid

Alanine Arginine Aspartic acid Cystine Glutamic acid Glycine Histidine lsoleucine Leucine Lysine Methionine Phenyl-alanine Proline Serine Threonine Tryptophan Tyrosine Valine

Ohadi

Kerman

4.00 9.70 8.80 2.60 20.60 4.50 2.30 4.10 7.00 5.70 1.50 4.90 3.80 5.60 3.20 1.40 2.90 5.60

5.46 1.91 9.54 1.72 22.70 5.23 1.94 4.79 8.11 11.04 2.07 4.74 4.64 3.71 3.95 _____ 2.80 6.46

Source: Shokraii (1977); Clarke et al. (1976).

blue and purple colors of various fruits and many colorful vegetables. Pistachio anthocyanins are present as glycosides of cyanidin and include cyanidin-3galactoside (major; 696 μg.g−1) and cyanidin-3-glucoside (minor; 209 μg.g−1) (Seeram et al., 2006).



227

Many studies have indicated that a diet containing pistachio nut can reduce the risk of coronary heart disease (CHD). Aside from their mono-unsaturated fatty acids and fibers, pistachio nuts are rich sources of antioxidant phytochemicals, which promote heart health by inhibiting the absorption of cholesterol from the intestine through direct competition with uptake mechanisms. Recent studies have shown that a diet that incorporates pistachio nuts can reduce the total cholesterol, total cholesterol/HDL cholesterol ratio, and low density lipoprotein/ high density lipoprotein ratio significantly, and also decrease the plasma malondialdehyde, an important indicator of lipid peroxidation (Sheridan et al., 2007). Several studies have indicated that regular consumption of pistachio nuts does not lead to remarkable weight gain. The results have shown that those who eat pistachio nut more frequently are leaner and have a lower body mass index (BMI) than the infrequent nut eaters, even though their energy intake is higher (Cotton et al., 2004). It has also been proven that regular consumption of pistachio nuts lowers the blood pressure and therefore might be recommended for hypertension. They reduce the absorption of glucose and lower the blood sugar. As a result of many vitamins and minerals, they are especially recommended for children for a healthy physical and mental development. Pistachio nuts are also a good source of vitamin E which boosts the immune system and alleviates fatigue. These days, it is strongly recommended to consume foods with minimal processing in order to gain maximum health benefits. Other than drying at low temperatures and sometimes roasting, no other treatment is commonly applied to pistachio. Therefore, fatty acids, minerals, vitamins and other nutritional compounds are retained at a maximum level. Pistachios have been reported as a folk remedy for scirrhus of the liver, abdominal ailments, abscess, amenorrhea, bruises, sores, trauma and dysentery. 11.1.7 Physical, mechanical and thermal properties of pistachio nuts Physical, mechanical and thermal properties of pistachio nut and its kernel are important in the design of equipment for harvesting, handling, processing, transportation, sorting, separation, packaging and storage. Designing equipment without taking these into consideration may yield poor results. Size, shape and dimensions of pistachio nut and kernel are important in sizing, sorting, sieving and other separation processes. Densities of pistachio nut and kernel are necessary to design the equipment for processing and storage such as hullers, dryers and bins. The porosity affects the resistance to airflow through bulk pistachio nuts and packing characteristics. Physical properties also affect the hydrodynamic and pneumatic conveying characteristics of pistachio nut and kernel. During harvesting, handling, processing and storage of pistachio nut, the product exerts frictional forces on machinery components or storage structures. The magnitude of these frictional forces affects the amount of power required to


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

228 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Fig. 11.5 Schematic of three major perpendicular dimensions of pistachio. The dotted lines represent the kernel inside the nut.

convey the material. The static coefficient of friction is useful to determine the angle at which chutes must be positioned to achieve a consistent flow of material through the chute. Terminal velocity is very critical in the design of the pneumatic conveyor, transporting pistachio nut and kernel using air and separation of pistachio nut and kernel from undesirable materials such as shells, hulls, leaves, blank pistachios and small branches. The terminal velocity is affected by the density, shape, size and moisture content of pistachio nuts. Mechanical properties such as rupture force, deformation and rupture energy are used to design equipment for shelling and grinding of pistachio nut. Thermal properties of pistachio nut, in particular specific heat, are used to design a new unit operation or to analyze current processes such as drying and storage. Moisture content and variety are the most important factors affecting the physical, mechanical and thermal properties of pistachio nut and kernel. Table 11.4 describes some physical properties of pistachio nut as a function of moisture content. The mathematical relationship between physical properties and moisture content are also presented in this table. In these measurements, length, width and height have been defined as the distance from the calyx end to the stem, the maximum diameter, and the distance from the highest point to the lowest point of pistachio nut when positioned on a horizontal plate, respectively (Fig. 11.5).

11.2


Blanking, non splits and alternate bearing are the three main physiological disorders related to fruiting of pistachio nuts. Blanks are nuts without kernels and occur when the embryo fails to develop and can take place during nut setting and nut filling. Promotion of shell development from ovary tissues without successful fertilization causes blanking in nut setting phase. Blanking may also occur during kernel growth when the tree cannot provide sufficient assimilate to complete



Length (L) (mm) Width (W) (mm) Height (H) (mm) Sphericity (φ) (%) Unit mass (M) (g) Volume (V) (cm3) True density (ρt) (kg m−3) Bulk density (ρb) (kg m−3) Porosity (ε) (%) Emptying angle of repose (θe) (°) Filling angle of repose (θf) (°) Static coefficient of friction for rubber (μ) Rupture force (N) along the length (FL) Rupture force (N) along the width (FW) Rupture force (N) along the height (FH) Rupture energy (mJ) along the length (EL) Rupture energy (mJ) along the width (EW) 58.61–42.94 37.24–25.57 42.65–35.14 69.17–46.95 40.48–28.73

6.31–35.57

FW = −0.8965 Mc + 97.24

90.31–60.57

112.31–82.59 FH = −0.9348 Mc + 118.08 6.31–35.57 256.78–182.66 EL = −2.3512 Mc + 272.63 6.31–35.57 157.46–101.39 EW = −1.7335 Mc + 170.98 6.31–35.57

5.77–39.11

5.77–39.11

5.77–39.11

5.77–39.11

l = 0.0170Mc + 12.9176 w = 0.0447Mc + 8.8088 h = 0.0384Mc + 8.6632 φ = 0.0026Mc + 0.7432 M = 0.520 + 0.011Mc V = 0.622 + 0.011Mc ρt = 858.7 + 0.13Mc ρb = 572.73 + 0.19Mc ε = 33.24–0.04Mc θe = 0.1367Mc + 25.330

Equation

(Continued)

Ew = −0.3667 Mc + 42.88

El = −0.6261 Mc + 72.75

Fh = −0.2440 Mc + 44.42

Fw = −0.3398 Mc + 38.90

Fl = −0.4946 Mc + 61.93

24.50–27.02 θf = 0.0855Mc + 24.030 0.393–0.647 μ = 0.0083Mc + 0.3505

136.23–98.84 FL = −1.0904 Mc + 143.01 6.31–35.57

5.33–34.78 5.44–34.78

5.77–39.11

θf = 0.0896Mc + 15.155 μ = 0.0044Mc + 0.4687

13.1–13.6 8.1–9.8 8.8–9.7 82.5–74.8 0.547–0.873 0.634–1.013 860–864 574–581 61.65–49.86 26.17–30.39

15.72–18.47 0.497–0.633

5.30–34.80 5.30–34.80 5.30–34.80 5.30–34.80 5.33–34.77 5.33–34.77 5.33–34.77 5.33–34.77 5.33–34.77 5.33–34.78

5.44–34.78 5.44–34.78

L = 0.0335Mc + 16.6630 W = 0.0178Mc + 11.8664 H = 0.0251Mc + 11.954 ----------------M = 0.94 + 0.019Mc V = 1.13 + 0.020Mc ρt = 857.6 + 0.29Mc ρb = 551.38 + 2.56Mc ε = 35.30–0.24Mc θe = 0.2148Mc + 20.345

16.9–17.8 12.1–12.7 12.3–12.7 79.3–79.8 1.105–1.680 1.291–1.873 860–869 573–649 60.59–47.75 21.54–28.32

Value

5.40–34.80 5.40–34.80 5.40–34.80 5.40–34.80 5.33–34.77 5.33–34.77 5.33–34.77 5.33–34.77 5.33–34.77 5.44–34.78

MC (% w.b.)

Equation

MC (% w.b.)

Value

Kernel

Nut

Some physical, mechanical and thermal properties of pistachio nut and kernel of the ‘Ohadi’ variety as function of moisture content

Property (unit)

Table 11.4

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Continued

9.8–12.0 0.705–2.567 2.4–1.1 38.26 43.54

4.00–36.30 5.12–33.86

5.40–34.80

56.35–42.28

Value

Eh = −0.4929 Mc + 59.83

Equation

S = −0.0407Mc + 3.0342

--------------- ----------------- -----------------

Vt = 0.23Mc + 10.56 3.50–36.30 9.0–10.0 Vt = 0.17Mc + 9.53 Cp = 0.9310 ln(Mc)–0.7748 --------------- ----------------- -----------------

213.92–145.07 EH = −2.1427 Mc + 226.97 6.31–35.57

5.77–39.11

MC (% w.b.)

Equation

MC (% w.b.)

Value

Kernel

Nut

MC = moisture content (% w.b.). Source: Kashaninejad et al. (2006); Razavi and Taghizadeh (2007); Razavi et al. (2007a; 2007b; 2007c; 2007d); Nazari Galedar et al. (2009).

Rupture energy (mJ) along the height (EH) Terminal velocity (Vt) (m s−1) Specific heat (Cp) (kJ kgK−1) at 25 °C Shell splitting (S ) (mm) Hull/nut ratio Shell/nut ratio

Property (unit)

Table 11.4

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X



231

development of its entire crop. Insufficient irrigation and inadequate boron leaf levels were also reported as causes of blank formation in pistachio nuts (Freeman and Ferguson, 1995). Shell splitting is a unique characteristic of pistachio nuts compared with other nuts and significantly important for pistachio quality because it affects the price and marketability of the product. Splitting is one of the maturation criteria and continues with kernel growth through maturity. Nut splitting can be reduced by water stress late in the growing season. Harvest time and boron nutrition are also important factors affecting nut splitting. Heating in the drying process will decrease the moisture content of shells and increase the splitting of nuts. Non-split nuts are usually separated after processing of fresh nuts and cracked and sold as kernels for processing into mixed nuts or ice cream. Pistachios are strongly alternate bearing and produce heavy crops every other year, fluctuating with no or little crops in ‘off’ years. Carbohydrate competition is probably the cause of this phenomenon so that carbohydrate depletion prevents floral initiation in the summer of an ‘on’ year. Inflorescence buds develop partially but abscise during heavy crop years and inhibit to produce a heavy crop in the next year. Like blank production, rootstock has a significant effect on alternate bearing. Studies indicated that blanking and shells splitting are related to ‘on’ and ‘off’ crop years. Blanking is much higher in ‘off’ years and non-split nuts are much more common in ‘on’ years, while crop load is much higher in ‘on’ years (Freeman and Ferguson, 1995).

11.3

Postharvest pathology and mycotoxin contamination

Several fungi have been identified to infect pistachios and some of them cause considerable damage to the hull and kernel. Alternaria causes black spots on the hull that are sometimes surrounded by red margins causing shell staining and mold in the kernel in early split nuts or fruits with cracked hull. Saprophytic fungi such as Alternaria, Aspergillus, Cladosporium, Fusarium and Penicillium are associated with shell staining, consequently infecting and causing decay to kernels of pistachio nuts (Michailides et al., 1995). The greatest postharvest damage of pistachio nuts is from Aspergillus flavus and Aspergillus parasiticus. These fungi produce aflatoxin. They are among the most potent mutagenic substances known to result in liver cancer. As the pistachio nuts grow on the trees, aflatoxin producing fungi can infect the kernels. However, the hull covering the shell usually remains intact and protects the kernel from invasion by molds and insects. Damaged hulls or nuts with poor protection by hulls are most prone to fungal infection. Sometimes the hull is attached to the shell and both split together. This hull rupture often referred to as ‘early splitting’, exposes the kernel to mold and insect infestations. The proportion of early split pistachio nuts is usually 1–5%, although it can be as high as 30% in some situations. The navel orangeworm (Amyelois transitella) is the major insect problem that usually infests nuts with ruptured hulls, and high levels of aflatoxin


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

232 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


contamination have been reported in insect-damaged kernels. Doster and Michailides (1994) in their study on California pistachios reported that early split nuts had over 99% of the aflatoxin detected and navel orangeworm infected nuts had substantially more infection by several Aspergillus species as well as over 84% of the aflatoxin detected. Very late harvest, bird damage and cracking also result in hull rupture and infection of kernels with Aspergillus molds at low levels. In addition to increasing aflatoxin production in infected nuts after harvest, early split and damaged nuts that are not infected on the trees may become infected during harvest, transport, handling and storage. High temperature and humidity within the bulk pistachio nuts during transport and storage can provide the best conditions for infection of early split and damaged nuts. Infected nuts will provide a source of inoculum for the spread of fungi to sound nuts under inappropriate storage conditions or during inadequate processing, thus increasing the incidence and level of aflatoxin contamination. Mold contamination and aflatoxin production can be prevented to ensure that contaminated nuts do not enter the food chain (Joint FAO/WHO Food Standards Program, 2002). This prevention program should consider the different steps before and after harvest until the nuts reach the consumers. Using cultivars with lower early split nuts, reducing inoculum sources such as fallen fruits and inflorescence from trees, burying or removing pistachio litter, manipulation of irrigation, application of microorganisms or saprophytic yeasts as biocontrol agents and minimizing insect damage such as navel orangeworm are the main approaches to prevent contamination of nuts before harvest. At harvest, pistachios should not be in contact with the orchard floor to avoid infection. Delaying harvest should be avoided to prevent more aflatoxin production in the infected pistachio nuts. The nuts should be transported to the processing plant and hulled and dried as soon as possible after harvest because of high temperature and relative humidity within the bulk pistachio nuts that provide the best conditions for further contamination. If temporary storage of fresh pistachio nuts at the processing plant is necessary, they should be stored at 0 °C and lower than 70% relative humidity. Drying at high temperature will probably kill the aflatoxin-producing fungi but it has little effect on the aflatoxin already present. Drying to appropriate moisture content (5–7%) or water activity (less than 0.7) will prevent the growth of these fungi. Aflatoxin producing fungi will not be able to grow and produce aflatoxin in dried pistachio nuts stored at 25 °C and relative humidity lower than 70% for a long time. Since nuts infected by molds and contaminated with aflatoxin have some distinct physical properties such as dark stain and hull adhesion compared to sound nuts, they can be easily machine sorted.

11.4


11.4.1 Maturity criteria and harvest time Although pistachios are traditionally harvested when the hull separates easily from the shell, ideal harvest time and optimum maturity is determined by



233

several criteria such as compositional and visible changes. Moisture content of the kernels decreases continually throughout maturation and stabilizes at full maturity, while fresh and dry weights of the kernel increase with maturity and reach a peak at harvest time. Respiration rate and total protein content decrease throughout maturation, and ether-extractable fat and total sugar content reach a peak at optimum maturity. These compositional changes coincide with shell splitting and changing from translucent to opaque, although they are invisible because the fleshy hull covers the shell in the developing nuts. Color change of the hull is a visible evidence of maturation, which is green in immature nuts and progresses to ivory to rose with optimum maturation (Labavitch et al., 1982). The percent of blank and immature fruits decrease throughout maturation and is minimal at optimum maturity. When fully mature, the nut will be separated from the hull easily when the fruit is pressed between the thumb and fingers at the hull’s distal end. Activity in the abscission zones between the nuts and the rachis is another evidence of maturation. At this status, fruit removal force will decrease and nuts will easily detach by gentle shaking (Ferguson et al., 1995). Like other fruits, maturation does not occur evenly throughout the tree. Therefore, the optimum harvest time is when the maturity criteria are observed at 70 to 80% of fruits. Based on all mentioned criteria, mid- to end of September was determined as the best harvest time for ‘Ohadi’, ‘Kalle-Ghouchi’, ‘Ahmad-Aghaei’ and ‘Badami’ varieties in Kerman province, Iran. The harvest time for these varieties may be different in other regions. Optimum harvest time is very important in maintaining nut quality; harvest should not be delayed because this will increase losses to navel orangeworm (NOW, Amyelois transitella), birds and fungi (in particular Aspergillus flavus), as well as shell staining due to breakdown of the phenolic compound-rich hull tissues. Early harvest leads to weight loss and decreases the shelf life of freshly harvested pistachios. 11.4.2 Harvest operations Pistachio trees are grown on traditional plantations and the lack of space between trees and rows necessitates harvesting by hand in Iran, Turkey and Syria. Pistachio clusters are harvested by laborers and dumped into sacks. The sacks are collected into plastic bins and transported to processing plants by trucks or trailers. In the United States, young trees (less than six years old) are hand harvested by knocking the trunk or striking the branches onto tarps spread under the trees, while mature pistachios are mechanically harvested onto a catching frame. Since orchard soils have potential to contaminate the pistachios with Aspergillus flavus, it is very important to prevent dropping the pistachios to the floor during mechanical harvesting. As well, any mechanical damage during harvesting should be avoided because pistachio hulls are fragile and susceptible to injury; shell staining will intensively increase in pistachios with damaged hulls. Pistachios also require more careful handling due to their higher moisture content at harvest than other tree nuts.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

234 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


11.4.3 Postharvest storage Shell staining and decay incidence are the major deterioration after harvest if the nuts are left in the hull for a long time, particularly at high temperatures. Most of the heating of bulk freshly harvested pistachio nuts is due to respiration. The maximum respiration rate of unhulled pistachio nuts is 125 mLCO2.kg−1.h−1 at 20 °C (Thompson et al., 1997). This level of respiration would produce a heating rate of about 0.7 °C per hour. Roughly handled, pistachio nuts can be held for at least 32 hours at 25 °C without significant increases in light or dark shell staining. At 30 and 40 °C, shell staining can occur in 24 hours and less than 16 hours, respectively, and accelerates specially beyond these time durations. Gently handled pistachio nuts with intact hulls may be held for up to 48 hours at ambient conditions without significant increase in staining. Ambient air circulation in bulk pistachio nuts or keeping them in a cold place are the best methods to prevent heat increase and retard shell staining if delays are unavoidable before processing (Thompson et al., 1997). Fresh unhulled pistachio nuts can be stored up to six weeks at 0 °C and 70–75% relative humidity without any significant effects on appearance, flavor quality, composition and hull removal. Storage at higher temperatures results in more incidence of surface molds and shell staining. An adequate air flow rate (0.1 Ls−1kg−1) through nuts during storage is essential to minimize losses. Sorting the nuts before storage to eliminate defective nuts (which are much more susceptible to decay), leaves and debris helps to increase the shelf life of fresh pistachio nuts. Hulled pistachio nuts have a shorter shelf life because the hull protects the nut from decay organisms without affecting shell quality. Hulled fresh pistachio nuts can be held for up to three weeks at the best storage conditions (0 °C and 40–50% relative humidity). Increasing the relative humidity to 90% shortens the storage of hulled pistachio nuts to 2 weeks at 0 °C, 1 week at 5 °C, 4 days at 10 °C, 2 days at 20 °C and 1 day at 30 °C. After two weeks storage at 0 °C and less than 10% relative humidity, the moisture content decreases to 7% and hulled nuts are almost completely dry. Although freezing has no significant effects on kernel texture, its influence on flavor quality eliminate it as an alternative for extending shelf life of fresh hulled nuts (Kader et al., 1978; 1979).

11.5

Processing of fresh pistachio nuts

Proper and quick processing after harvest is very important for pistachio quality and its marketability. For hundreds of years, pistachio nuts were processed manually. After harvesting the ripe pistachios, are hulled by hand. Workers perform this job so fast and skillfully that it is very difficult to see the procedure even at close observation. In some regions pistachio nuts are hulled right away after harvest, but in other regions they are dried in the hull for later hulling at a convenient time. Sometimes the pistachio nuts are immersed in water to separate the hull easily when squeezed between fingers. Pistachio nuts are then spread on



235

a concrete or earth floor in the sun to dry. These processing methods usually result in nuts with stained shells and lower quality. During the last 30 years, traditional methods have extensively been improved in the leading producer countries and now pistachios are mechanically hulled and processed within a short time. Figure 11.6 indicates the processing procedures using two methods when freshly harvested pistachios arrive at the processing plant (Nakhaeinejad, 1998). Separation of blank pistachios is the main difference in these methods. Further processing of dried pistachio nuts may be accomplished immediately at harvest season or later as indicated in Fig. 11.7. 11.5.1 Hulling Hulling must be accomplished as soon as possible to reduce the chances for fungal growth and to avoid shell staining. The hull of the freshly harvested and mature pistachio nuts slip off fairly easily. Generally, different types of machines are used satisfactorily for hulling pistachios. Cylindrical hullers are more popular and economic and are used at different sizes and capacities to hull pistachios in various regions of Iran. The cylindrical huller consists of two concentric metallic cylinders and the inner cylinder rotates inside the stationary outer cylinder. The outside surface of the inner cylinder and inside surface of the outer cylinder are covered by parallel rings or slabs that are positioned at certain points. Pistachio nuts are fed continuously between the two cylinders and the hulls are separated from nuts

Fig. 11.6 Scheme processing procedures of freshly harvested pistachio nut. Left: processing by air flow tank. Right: processing by water float tank.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

236 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Fig. 11.7

Processing procedures of dried pistachio nut.

after impacting the rings. Basically, this is a dry hulling method wherein pistachio nuts are hulled without water, an important advantage for pistachio growers and processors in dry regions. In rubber machines, the pistachios are rubbed between two rubber drums and the hulls are separated from the nuts. This machine does not damage mature pistachios but is unable to peel unripe pistachios, which are easily separated in the next stages. The abrasive peeler is another machine that produces an attractive product but is limited to a batch of nuts at a time. This small machine is suitable for small-scale production because it is unable to hull large volumes of pistachios that are being produced currently in pistachio orchards. It consists of a vertical cylinder with its inside coated by an abrasive material; a rotating disc at the bottom of the cylinder is also coated with the same abrasive. Pistachios are thrown by the centrifugal force of the rotating disc against the abrasive wall surface; the disintegrated hulls are removed from the peeler by a water stream that is introduced from the top of the cylinder. In the United States, pistachios are hulled in machines that consist of two parallel rubberized belts rotating in the same direction but at different speeds. After the hulling process, undesirable materials including hulls, branches, leaves, shells, broken nuts and kernels, blank and unripe pistachios, unpeeled pistachios and small pistachios are separated from the hulled nuts quickly to promote quality and marketability of the final product and also to avoid fungal growth. The separation of undesirable materials takes place at several stages using proper devices such as air leg, water or air flow tank, a stick tight separator and picking or inspection tables. 11.5.2 Trash and debris removal Although most of the hulls, branches and leaves are separated from the nuts in the hulling process, a small amount of hull pieces, debris and bunches remain; they



237

are separated at this stage using the air leg or air flow system. The remaining trash and debris do not exceed more than one percent of total materials separated in the huller. This process is based on the capacity of an air stream to lift particles against gravity. The effect depends on air velocity and the particle moisture content, shape, size and specific gravity. This apparatus contains a vertical column and a blower at the bottom that regulates the air flow rate and velocity. The air flows upward in the column from the bottom to the top and fractionates the undesirable materials and blank pistachios from hulled nuts based on their terminal velocity. 11.5.3 Washing Shell appearance is one of the most important characteristics of pistachio quality and marketability. Hull latex extracted after the hulling process includes some components that cause blemished appearance and consequently raise the cost and time for separation of stained nuts after the drying process. Shell staining can be greatly decreased by appropriately washing the hulled nuts and removing the latex from the shell after the hulling process. As the pistachios are moved forward in a layer by a particular steel conveyor during the washing process, high pressure water is sprayed on the pistachios. In addition to cleaning the nuts and removing the latex from shells, the remaining debris and trashes are also separated. Water consumption is minimal in this washing process which is an advantage for dry regions. 11.5.4 Separation of blank pistachio nuts The kernels of blank and immature pistachio nuts are usually not fully developed and most of them are empty. Thus, the ratio of kernel to nut and the mass of 100 nuts, particularly, the specific gravity of blank and immature pistachios is lower than fully mature pistachios. Water has been used as a media for separation of blank pistachios from ripe ones for many years. When hulled pistachio nuts after the washing process are immersed in the water tank, all blank pistachios will float and most (about 60 to 80%) of the split and fully mature nuts will sink. The floaters also consist of unsplit nuts with less than 15% meat content (Woodroof, 1979). The air entrapped between the shell and the kernel of some fully split pistachio nuts reduces their specific gravity and consequently they float with blank pistachios. Separation efficiency can be improved by the installation of a stirrer or propeller in the water tank to remove the air entrapped between the shell and the kernel in the split and mature nuts. The floaters will be removed by water stream from the top of water tank and the sinkers will be taken out from the bottom of the tank employing a steel conveyor. In some processing plants or regions where enough water is not available for the separation of blank pistachios, this process is accomplished by an air flow float tank called a ‘dry tank’ machine. Blank and immature pistachio nuts, small, undersized and broken pistachios, debris and tiny trashes are separated in this machine using air flow and vibration.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

238 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


11.5.5 Drying Drying is an important operation in pistachio processing. The moisture content which is as high as 40% (wet basis) in the freshly harvested nuts is reduced to about 4–6%. Drying time is a function of many parameters including dryer air temperature, ambient relative humidity, initial moisture content of pistachio nuts, drying stage, variety and drying method. Figure 11.8 shows the drying time and behavior of pistachio nut (‘Ohadi’ variety) at different temperatures in a thin layer dryer (Kashaninejad et al., 2007). The increase in the drying air temperature decreases drying time rapidly and consequently increases the drying rate. Drying curves shown in Fig. 11.9 demonstrate that drying of pistachio nuts occurs in the falling rate period. At higher air temperatures, two distinct drying periods can be detected, namely, an initial transitional nut warm-up period wherein a slight increase in the drying rate takes place, and a falling rate period characterized by a rapid decrease of the drying rate. At lower air temperatures, the falling rate period is only detected which suggests predominance of the internal diffusion phenomenon as the mass transfer controlling process. In the falling rate period, a high initial drying rate (with higher rates at higher temperatures) is observed followed by a gradual decrease as the material approaches the dried state. Initially, the drying rate is higher because the initial water for evaporation comes from regions near the surface. As the drying progresses, the drying rate decreases with decrease of moisture content because the water to be evaporated comes from parenchymal cells within the structure and must be transported to the surface. The falling rate region is indicative of an increased resistance to both heat and mass transfer through the inner cells. Table 11.5 shows the characteristics of different commercial dryers that are used for drying of pistachio nuts. Nowadays most processors prefer to use a

Fig. 11.8 Drying pattern of pistachio nut (‘Ohadi’ variety) at different air temperatures (air velocity = 1.5 m/s, relative humidity = 20%).



239

Fig. 11.9 Drying rate of pistachio nut (‘Ohadi’ variety) at different air temperatures (air velocity = 1.5 m/s; relative humidity = 20%).

Table 11.5

Characteristics of commercial pistachio dryers

Dryer type

Average air temperature (°C)

Drying time (h)

Dimensions (m)

Bed depth (cm)

First stage

Second stage

Flat bottomed bin dryer

65

-------------

8

L = 2.0 W = 1.2 H = 0.5

40

Continuous column dryer

45

40

10

L = 5.0 W = 2.0 H = 4.0

30

Continuous belt dryer

55

40

9

L = 10.5 W = 6.7 H = 6.5

30

Vertical cylindrical dryer

55

-------------

8

H = 4.0 D1 = 0.5 D2 = 1.5

50

Funnel cylindrical dryer

80

-------------

5.5

H = 3.5 D = 2.0

300

L: length, W: width, H: height, D1: internal cylinder diameter, D2: external cylinder diameter, D: diameter.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

240 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


two-stage drying process as it uses less energy and increases the uniformity of drying of the nuts compared with the single stage process. Chemical composition and quality of pistachio nuts do not change significantly during the drying process but shell splitting increases and some of the closed shells split during drying because of moisture loss. In dryers with high nut depth, the pressure exerted by nuts in the upper layers may prevent the splitting of the shells in the lower layers (Kashaninejad et al., 2003). Drying air temperatures above 80 °C cause shells to split so widely that the nut drops out. Appropriate air temperature and uniform air flow distribution is very important to prevent potential of fungal growth during the early stage of drying. In some processing plants, sun drying may be used. Pistachio nuts are spread out in a thin layer 2–3 cm thick on a concrete floor under the sun and this requires about 48 hours at temperatures near 26 °C. Sun drying should be accomplished with protective cover to prevent access by birds and rodents. Pistachio nuts are planted in regions with plenty of sunshine during the harvest season. Therefore, solar energy is an advantageous alternative for drying of pistachio nuts in order to decrease the dependence of the drying process on fossil fuels. Ghazanfari et al. (2003) dried pistachio nuts by a forced air solar dryer to 6% moisture content for 36 hours. The maximum temperature in the solar collector reported was 56 °C, which was 20 °C above the ambient temperature. When air is forced through a layer of bulk pistachio nuts, resistance to the flow (the so-called pressure drop) develops as a result of energy lost through friction and turbulence. The resistance to airflow through bulk pistachio nut is an essential parameter to optimally design the forced ventilation systems for drying and also cooling the stored bulk. As well, the uniform and proper airflow distribution can prevent fungal growth during the drying process. Figure 11.10 shows the resistance

Fig. 11.10

Pressure drop of pistachio nut at different airflow rates and moisture contents.



241

of bulk pistachio nuts at various airflow rates and moisture contents. Airflow resistance across a column of pistachio nuts increases linearly with increasing depth. The pressure drop through pistachio nut beds increases more rapidly with increasing airflow rate compared with bed depth (Kashaninejad et al., 2010). Airflow rate, moisture content and fill method affect the pressure drop, however airflow rate and fill method have greater influence on pressure drop of pistachio nut than moisture content. An increase in the moisture content in the range of 4.08–38.40% (wet basis) results in a 55% increase in the pressure drop across pistachio nut beds. The dense fill increases the bulk density which results in an increase in the airflow resistance of bulk pistachio nuts by 97% than that of loose fill (Kashaninejad and Tabil, 2009). 11.5.6 Storage of dried pistachio nuts Generally, nuts may be held for a long time (up to 2–5 years) if they are stored under optimum conditions but at unfavorable storage conditions, they may become inedible even within one month because of mold growth, off-flavor, rancidity, discoloration, absorption of undesirable flavors and insect infestation. Pistachio nuts dried to appropriate moisture content (4–6%) are very stable and can be stored for up to one year at 20 °C and 65–70% relative humidity without significant losses in quality attributes (Kader et al., 1982). No differences in chemical composition and sensory attributes were observed among nuts stored at different temperatures (0, 5, 10, 20 and 30 °C) for 12 months. Nuts held at 30 °C had lower moisture content and higher sugar content and rancid flavor than those stored at lower temperatures. Long storage potential of pistachio nut is a result of high oleic acid, natural antioxidants and reduction of moisture to monolayer moisture content during the drying process. Pistachios are more stable to rancidity and have a longer storage potential than other tree nuts such as almonds, pecans or walnuts. All these nuts are high in fat content, but walnut and pecan oils have a much higher content of polyunsaturated fatty acids than pistachio oil. For longer storage of pistachio nuts, low temperatures (between 0–10 °C) are recommended. Exclusion of oxygen, insect control through fumigation, vacuum packaging or N2 injection in packages and controlled atmospheres can maintain nut quality during storage. Storage under high concentration of CO2 (98%) and reduced O2 (less than 0.5%) provides good stability in terms of fatty acid loss and formation of peroxide and free fatty acids (Maskan and Karatas, 1998). Oxygen scavenger packaging is an efficient method to eliminate the oxygen content and retard the oxidation of pistachio nut during long storage. It has been reported that pistachio nuts stored in an oxygen scavenger system have a lower hexanal content than those in vacuum and atmospheric packaging (Leufven et al., 2007). Hexanal is an indicator of oxidation progress and is applied in various products to monitor quality deterioration. Wheat starch-based edible films are alternative packaging materials for pistachio nuts or kernels to improve the shelf life. The main advantage of edible films is the reduction of synthetic packaging materials, but they also retard peroxide formation and minimize water absorption during storage. Addition of


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

242 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


PEG (polyethylene glycol) to wheat starch films enhances tensile and mechanical properties of the films (Forghani, 2008). Insect infestation is a potentially important problem during storage because the fungal infections often accompany insect damage. Fumigation with methyl bromide or phosphine has been used for disinfestation. Storage of nuts at temperatures near freezing (0 °C) or in 0.5% oxygen and 10% carbon dioxide also effectively kill all insects.

11.6

Processing of dried pistachio nuts

11.6.1 Separation of split from non-split pistachio nuts Non-splitting is one of the shell defects that affects marketability and the price of processed product, therefore the non-split nuts should be separated from split nuts before selling. Although some of the closed shells split during the drying process, non-splitting may comprise up to 30% depending on the variety. Closed shell nuts are separated from the open shell ones by mechanical devices called pinpicker or needle picking drums. In this machine, raw nuts are fed into a rotating drum that is covered by tiny needles or pins. Open shell nuts are picked by needles and lifted away with drum rotation and separated at the top of the drum by a brush. Closed shells nuts that are not picked by needles pass through the bottom of the drum and are collected at the other side of the rotating drum. 11.6.2 Grading of pistachio nuts Grading requirements for pistachio nuts in the shell, shelled pistachio nuts, artificially opened pistachio nuts and non-split pistachio nuts are available and used by the industry. The basic requirements of grading should be that nuts are free from foreign materials, loose kernels, shell pieces, particle and dust, and blank nuts. The grading criteria are divided into shell and kernel defects. Shell defects include any blemish affecting the appearance, edibility and/or marketing of pistachio nuts such as adhering hull material, light or dark stained shell, nonsplitting or splitting other than the suture, deformity and/or other damage. Kernel defects include immature kernels, rancidity, mold or decay and any damage or evidence of insects. Size and degree of dryness are also important quality attributes affecting grading. 11.6.3 Salting and roasting Pistachio nuts are mostly consumed salted and roasted in-shell. Salting and roasting tremendously enhance the flavor, color and texture of pistachio nuts and increase overall palatability of the valued products. Improvement of sensory attributes of pistachio nuts during roasting is a result of non-enzymatic browning or Maillard reaction which takes place between the reducing sugars and nitrogenous compounds, in particular amino acids and proteins. Nuts become



Fig. 11.11

243

Roasting procedures in a continuous nut roaster.

more crumbly and brittle during the roasting process, which are typical characteristics of roasted products. Figure 11.11 shows the roasting process diagram in a continuous pistachio roaster (Dadgar, 1998). Pistachio nuts are salted by soaking in salt solution in a rotary salting machine and rotation of the drum and appropriate residence time provide uniform salting. Seyhan (2003) reported that 20% (W/V) salt solution and 20 min soaking may be used for salting of pistachio nuts. The higher concentration of salt solution results in lower moisture absorption throughout the soaking process. Other additives such as lemon juice or saffron may be added to the salt solution to enhance flavor of the roasted product. The excess salt solution entrapped between the shell and the kernel is removed by vibration to promote efficiency of the dryer. As the pistachio nuts are turned around and moved forward on the steel belt dryer, surface salt solution and the moisture absorbed during salting are evaporated. Then pre-dried pistachio nuts are fed to the top of a threelayer steel belt roaster and discharged from the bottom to the steel belt cooler. Pistachio nuts are roasted at 145 °C and cooled at ambient temperature. The outlet air of the cooler is utilized in the dryer to improve efficiency of the system. Kashani and Valadon (1983, 1984) have investigated the effect of the common roasting method (drying at 70 °C for 1 hr and roasting at 145 °C for 20 min) on components and quality of pistachio nut. After roasting, an obvious increase in fatty acids (from 2.7 to 5.5 mg.g−1) and phosphatidic acid (from 0.8 to 2.7 mg.g−1) and a slight decrease in triglycerides (from 437.6 to 434.9 mg−1g) and choline compounds took place, while most of the other lipid components did not change. Although iodine value or malonaldehyde did not change significantly, peroxide value clearly increased (from 0.73 to 1.04 meqkg−1) during roasting. Increase in the peroxide value demonstrates that some of the pistachio oil was degraded during roasting. After roasting, the total available carbohydrates, starch, dextrin, and in particular total free sugars decreased significantly. Reducing sugars such as glucose and fructose almost disappeared. No significant effect was observed in


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

244 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


total protein, but about 40% of free amino acids were degraded. Some free amino acids such as cysteine, histidine, arginine, methionine and tyrosine disappeared totally. Reduction in free amino acids and reducing sugars might be a result of taking part in a Maillard reaction.

11.7

References

Ak B E and Açar I (2001), ‘Pistachio production and cultivated varieties grown in Turkey’, in Padulosi S and Hadj-Hassan A, Project on Underutilized Mediterranean Species. Pistacia: Towards a Comprehensive Documentation of Distribution and Use of its Genetic Diversity in Central & West Asia, North Africa and Mediterranean Europe, Rome, Italy, IPGRI. Banifacio P (1942), II Pistacchio: Coltivazione, Commercio, Uso, Rome, Ramo Editoriale degli Agricoltori. Brothwell D and Brothwell P (1969), Food in Antiquity: A Survey of the Diet of Early Peoples, New York, Frederik A. Praeger. Clarke J A, Brar G S and Procopiou J (1976), ‘Fatty acid, carbohydrate and amino acid composition of pistachio (Pistacia vera) kernels’, Pl Food Hum Nutr, 25 (3/4), 219–225. Cotton P A, Subar A F, Friday J E and Cook A (2004), ‘Dietary sources of nutrients among US adults, 1994 to 1996’, J Am Diet Assoc, 104, 921–930. Crane J C (1978), ‘Quality of pistachio nuts as affected by time of harvest’, J Am Soc Hort Sci, 103, 332–333. Crane J C and Iwakiri B T (1981), ‘Morphology and reproduction of pistachio’, Hort Rev, 13, 376–393. Dadgar F (1998), Salting and Roasting Pistachios in Iran, Kerman, Momtazan Industrial Co. Doster M A and Michailaides T J (1994), ‘Aspergillus molds and aflatoxins in pistachio nuts in California’, Phytopathol, 84, 583–590. Duke J A (2001), Handbook of Nuts, Boca Raton, Florida, CRC Press. Esmail-pour A (2001), ‘Distribution, use and conservation of pistachio in Iran’, in Padulosi S and Hadj-Hassan A, Project on Underutilized Mediterranean Species. Pistacia: Towards a Comprehensive Documentation of Distribution and Use of its Genetic Diversity in Central & West Asia, North Africa and Mediterranean Europe, Rome, Italy, IPGRI. FAOSTAT (2009), FAOSTAT database, FAO statistics database on the World Wide Web. Available from: http://apps.fao.org (accessed December 2009). Ferguson L, Kader A A and Thompson J (1995), ‘Harvesting, transporting, processing and grading’, in Ferguson L, Pistachio Production, Center for Fruit and Nut Crop Research and Information, Pomology Dept., Univ. Calif., Davis, CA, pp. 110–114. Forghani M (2008), ‘Moisture uptake, rancidity and physical properties of wheat starchbased edible films as a new package’, Int J Food Safety, 10, 65–71. Freeman M and Ferguson L (1995), ‘Factors affecting splitting and blanking’, in Ferguson L, Pistachio Production, Center for Fruit and Nut Crop Research and Information, Pomology Dept., Univ. Calif., Davis, CA, pp. 106–109. Ghazanfari A, Tabil L G and Sokhansanj S (2003), ‘Evaluating a solar dryer for in-shell drying of split pistachio nuts’, Dry Technol, 21 (7), 1357–1368. Hadj-Hassan A (2001), ‘Cultivated Syrian pistachio varieties’, in Padulosi S and HadjHassan A, Project on Underutilized Mediterranean Species. Pistacia: Towards a Comprehensive Documentation of Distribution and Use of its Genetic Diversity in Central & West Asia, North Africa and Mediterranean Europe, Rome, Italy, IPGRI. Hendricks L and Ferguson L (1995), ‘The pistachio tree’, in Ferguson L, Pistachio Production, Center for Fruit and Nut Crop Research and Information, Pomology Dept., Univ. Calif., Davis, CA, pp. 7–9.



245

Joint FAO/WHO Food Standards Program (2002), Discussion paper on aflatoxins in pistachios, 34th session, Rotterdam, The Netherlands, 11–15 March. Joret C (1976), Les plantes dans l’antiquité et au moyenvâge; histoire, usages et symbolisme, Genève, Slatkine Reprints. Kader A A, Heintz C M, Labavitch J M and Rae H L (1982), ‘Studies related to the description and evaluation of pistachio nut quality’, J Amer Soc Hort Sci, 107, 812–816. Kader A A, Labivitch J M, Mitchell F G and Sommer N F (1978), Quality and safety of pistachio nuts as influenced by postharvest handling procedures, The Pistachio Association Annual Report, CA, pp. 45–51. Kader A A, Labivitch J M, Mitchell F G and Sommer N F (1979), Quality and safety of pistachio nuts as influenced by postharvest handling procedure, The Pistachio Association Annual Report, CA, pp. 45–56. Kashani G G and Valadon L R G (1983), ‘Effect of salting and roasting on the lipids of Iranian pistachio kernels’, J Food Technol, 18, 461–467. Kashani G G and Valadon L R G (1984), ‘Effect of salting and roasting on the carbohydrates and proteins of Iranian pistachio kernels’, J Food Technol 19, 247–253. Kashaninejad M and Tabil L G (2009), ‘Resistance of bulk pistachio nuts (Ohadi variety) to airflow’, J Food Eng, 90, 104–109. Kashaninejad M, Maghsoudlou M, Khomeini M and Tabil L G (2010), ‘Resistance to airflow through bulk pistachio nuts (Kalleghochi variety) as affected by the moisture content, airflow rate, bed depth and fill method’, Powder Technol., 203, 359–369. Kashaninejad M, Mortazavi A, Safekordi A and Tabil L G (2006), ‘Some physical properties of Pistachio (Pistachia vera L.) nuts and its kernel’, J Food Eng, 72, 30–38. Kashaninejad M, Mortazavi A, Safekordi A and Tabil L G (2007), ‘Thin layer drying characteristics and modeling of Pistachio nuts’, J Food Eng, 78, 98–108. Kashaninejad M, Tabil L G, Mortazavi A and Safekordi A (2003), ‘Effect of drying methods on quality of pistachio nuts’, Dry Technol, 21(5), 821–838. Kaska N (2002), ‘Pistashio nut growing in the mediterranean basin’, Acta Hort, 591, 443–451. Kirkbride D (1966), ‘Beidha: an early neolithic village in Jordan’, Archaeol, 19, 199–207. Kramer C (1982), Village Ethnoarchaelogy: Rural Iran in Archaeological Perspective, New York, Academic Press. Labavitch J M, Heintz C M, Rae H L and Kader A A (1982), ‘Physiological and compositional changes associated with maturation of “Kerman” pistachio nuts’, J Amer Soc Hort Sci, 107, 688–692. Lemaistre J (1959), ‘Le pistachier (étude bibliographique)’, Fruits 14, 57–77. Leufven A, Sedaghat N and Habibi M B (2007), ‘Influence of different packaging systems on stability of raw dried pistachio nuts at various conditions’, Iranian Food Sci Technol Res J, 3 (2), 27–36. Maggs D H (1973), ‘Genetic resources in pistachio’, FAO Plt Genet Resources Newsletter 29, 7–15. Maskan M and Karatas S (1998), ‘Fatty acid oxidation of pistachio nuts stored under various atmospheric conditions and different temperatures’, J Sci Food Agric, 77, 334–340. Michailides T, Morgan D P and Doster M A (1995), ‘Foliar and fruit fungal diseases’, in Ferguson L, Pistachio Production, Center for Fruit and Nut Crop Research and Information, Pomology Dept., Univ. Calif., Davis, CA, pp. 148–159. Mohammadi Moghaddam T, Razavi M A, Malekzadegan F and Shaker Ardekani A (2009), ‘Chemical composition and rheological characterization of pistachio green hull’s marmalade’, J Texture Studies, 40, 390–405. Moldenke H N and Alma L (1952), Plants of the Bible, Waltham, Chronica Botanica. Nakhaeinejad M (1998), Pistachio Hulling and Processing in Iran, Kerman, Momtazan Industrial Co. Nazari Galedar M, Mohtasebi S S, Tabatabaeefar A, Jafari A and Fadaei H (2009), ‘Mechanical behavior of pistachio nut and its kernel under compression loading’, J Food Eng, 95, 499–504.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

246 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Razavi M A and Taghizadeh M (2007), ‘The specific heat of pistachio nuts as affected by moisture content, temperature and variety’, J Food Eng, 79, 158–167. Razavi M A, Emadzadeh B, Rafe A and Mohammad Amini A (2007a), ‘The physical properties of pistachio nut and its kernel as a function of moisture content and variety: Part I. Geometrical properties’, J Food Eng, 81, 209–217. Razavi M A, Emadzadeh B, Rafe A and Mohammad Amini A (2007b), ‘The physical properties of pistachio nut and its kernel as a function of moisture content and variety: Part II. Gravimetrical properties’, J Food Eng, 81, 218–225. Razavi M A, Mohammad Amini A, Rafe A and Emadzadeh B (2007c), ‘The physical properties of pistachio nut and its kernel as a function of moisture content and variety: Part III. Frictional properties’, J Food Eng, 81, 226–235. Razavi M A, Rafe A and Akbari R (2007d), ‘Terminal velocity of pistachio nut and its kernel as affected by moisture content and variety’, African J Agric Res, 2 (12), 663–666. Rieger M (2006), Introduction to Fruit Crops, New York, Food Product Press. Seeram N P, Zhang Y, Henning S M, Lee R, Niu Y, et al. (2006), ‘Pistachio skin phenolics are destroyed by bleaching resulting in reduced antioxidative capacities’, J Agric Food Chem, 54, 7036–7040. Seyhan F G (2003), ‘Effect of soaking on salting and moisture uptake of pistachio nuts (Pistachia vera L.) from Turkiye’, GIDA, 28 (4), 395–400. Sheridan M J, Cooper J N, Erario M and Cheifetz C E (2007), ‘Pistachio nut consumption and serum lipid levels’, J Am Coll Nutr, 26, 141–148. Shokraii E H (1977), ‘Chemical composition of the pistachio nuts of Kerman, Iran’, J Food Sci, 42, 244–245. Shokraii E H and Esen A (1988), ‘Composition, solubility, and electrophoretic patterns of proteins isolated from Kerman pistachio nuts (Pistacia vera L.)’, J Agric Food Chem, 36 (3), 425–429. Taghizadeh M and Razavi M A (2009), ‘Modeling time-independent rheological behavior of pistachio butter’, Int J Food Properties, 12, 331–340. Thompson J F, Rumsey T R and Spinoglio M (1997), ‘Maintaining quality of bulk-handled, unhulled pistachio nuts’, App Eng Agric, 13, 65–70. USDA (2006), ‘National Nutrient Database for Standard Reference’, Release 19, National Technical Information Service, USDA, Springfield, VA. Whitehouse W E (1957), ‘The pistachio nut – a new crop for the western United States’, Economic Botany 11, 281–321. Woodroof J G (1979), Tree Nuts: Production Processing Products, Westport, Conn., AVI. Zohary M (1952), ‘Amonographical study of the genus Pistacia’, Palest J Bot, 5, 187–228.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Plate XX

Plate XXI

(Chapter 11) Grape-like clusters of pistachio fruits on a tree.

(Chapter 11) Kernel, skin, shell and hull of pistachio nut.


12 Pitahaya (pitaya) (Hylocereus spp.) F. Le Bellec and F. Vaillant, Centre for Agricultural Research and Development (CIRAD), France

Abstract: While pitahaya (Hylocereus spp.) was originally domesticated by preColumbian Americans, it was still practically unknown until the mid-1990s in most parts of the world. Pitahaya is now a member of the ‘small exotic fruits’ category in many shops, though it remains a minor player. This chapter gives an initial evaluation of the advantages and disadvantages of this new fruit. Commercially, pitahaya appear to have numerous selling points; pitahaya’s fruit is attractive in shape and color, and it has very good internal properties of high interest for the food industry. Key words: Hylocereus, pitahaya, botany, agronomy, chemical composition, storage, postharvest technology, uses, markets.

12.1

Introduction

Practically unknown fifteen years ago, pitahaya1 today occupies a growing niche in the exotic fruit market as well as in the domestic markets of producer countries, such as Vietnam, Malaysia, Colombia, Mexico, Costa Rica and Nicaragua. Elsewhere, pitahaya is considered to be a new, promising fruit species; it is cultivated on different scales in Australia, Israel, and Reunion Island (Le Bellec et al., 2006). This success can be explained in part by the fruit’s appealing qualities and characteristics (attractive color and shape) and by the commercial policies of some producing and exporting countries (e.g., Vietnam, Colombia and Israel). The generic term ‘pitahaya’ includes several different species, which can often be a source of confusion. Currently, only a few species of pitahaya are commonly found on the market: yellow pitahaya (Hylocereus megalanthus Bauer), a fruit with yellow skin and white pulp, and red pitahaya (Hylocereus spp. Britt & Rose), a fruit with a red skin and either white or red pulp. These species are native to tropical 1

Different spellings are used : pitaya, pitahaya, pitajaya, pitajuia, pitalla or pithaya


248


and sub-tropical America. Up to now, available publications have dealt with very specific topics on the difficulties of introducing pitahaya as a commercial fruit, the principal research topics being genetics, floral biology, ecophysiology and fruit characterization (physico-chemical composition). The aim of our work was to draw up an exhaustive list of literature currently available on Hylocereus and to group the references by discipline (uses and marketing, botany, biogeography, floral biology, agronomy, postharvesting and composition).

12.2

Uses and market

The pulp of the fruit is refreshing and possesses a texture close to that of kiwi fruit. It is much appreciated, especially if chilled and cut in halves so that the flesh can be eaten with a spoon. The juice is enjoyed as a cool drink, while syrup made of the whole fruit is used to color candy and the pulp is also used in sorbet and fruit salads. Flowers can be cooked and eaten as a vegetable. Hylocereus spp. are also used for medicinal purposes and their leaves and flowers have traditionally been used by the Mayas in Latin America as a hypoglycemic, diuretic, and cicatrizant agent (Pérez et al., 2007). The medicinal uses are increasingly sought as reported in recent studies. An aqueous extract of Hylocereus exhibited positive protective microvascular activity and wound-healing properties in diabetic rats (Pérez et al., 2005), while Pérez et al. (2007) isolated and showed properties of two triterpenes from H. undatus in the protection against increased skin vascular permeability in rabbits. Khalili et al. (2009) suggested that the consumption of red pitahaya play a role in the prevention of cardiovascular disease. Pitahaya is widely consumed in South America and Asia, but it was unknown in the European Union and North America until the mid-1990s. The fruit is still a niche product, but imports have increased considerably in the last two years and pitahaya now has its place in the displays of retailers devoted to rare exotic fruits (Le Bellec et al., 2006) and the range of supplier countries is growing rapidly. Israel, with a major cost price advantage thanks to sea transport, competes with Asian suppliers during the second half of the year. The fruit attracts two different market segments. Asian customers purchase it quite regularly, with a peak at the Chinese New Year. On this occasion, it is not usually bought for its taste, but for its fine appearance because it is displayed as an offering to ancestors. The greatest demand is for large fruits. This success can be explained in part by the fruit qualities and characteristics and also by the commercial policies of some producing and exporting countries.

12.3

Botany, origin and morphology

12.3.1 Botany and genetic Pitahaya belongs to the vine cacti of the genera Hylocereus (Berger) Britt and Rose of the botanical family Cactaceae. Hylocereus is characterized as a climbing plant


Pitahaya (pitaya) (Hylocereus spp.)

249

with aerial roots that bears a large, scaly, glabrous berry (Britton and Rose, 1963). Hylocereus spp. are diploid (2n = 22) except H. megalanthus (allotetraploid, 2n = 4x = 44) (Lichtenzveig et al., 2000; Tel-Zur et al., 2004b). In Latin America, many different cultivated species and fruits are referred to as ‘pitahaya’, a generic and vernacular name that renders their botanical classification difficult. However, all pitahaya are grouped into four main genera: Stenocereus Britton & Rose, Cereus Mill., Selenicereus (A. Berger) Riccob and Hylocereus Britton & Rose (Mizrahi et al., 1997). We focused particularly on the Hylocereus species (see Plate XXII in the colour section between pages 238 and 239). There are many contradictions concerning the botanical classification of Hylocereus that are reflected in the difficulty of characterization. This is due to similar morphological characteristics and/or environmental conditions between species. For example, Britton and Rose (1963) have created a genus (Mediocactus) to classify the yellow pitahaya (actually H. megalanthus) due to a description of the morphology of a species which has a triangular stem like that of Hylocereus, and spiny fruits like those of Selenicereus. Accordingly, they classified it into a separate genus named Mediocactus, thereby implying both an intermediate morphology and an intermediate taxonomic status. Recent studies help to clarify this botanical classification (Bauer, 2003; Tel-Zur et al., 2004b). In our paper, we use Bauer’s nomenclature. Thus, there are 15 species of Hylocereus, whose ornamental value is due to the beauty of their large flowers (15–25 cm) that bloom at night (see Plate XXII in the colour section). Even if all these species can potentially produce fruits, only five are cultivated for this purpose and our study was limited to those. The characteristics of these species are presented below and summarized in Table 12.1:

•

•

H. costaricensis (Web.) Britton & Rose is characterized by vigorous vines, perhaps the most robust of this genus. Stems are waxy white and flowers are margined; the outer perianth sediments are reddish, especially at the tips; and stigma lobes are rather short and yellowish. Its scarlet fruit (diameter: 10–15 cm; weight: 250–600 g) is ovoid and covered with scales that vary in size; it has a red purple flesh with many small black seeds, pleasant texture and good taste. H. megalanthus Bauer (syn. Selenicereus megalanthus) has long, slender and green stems; not horned. The areoles are white. Its yellow fruit (diameter: 7–9 cm; weight: 120–250 g) is oblong, covered with clusters of deciduous spines, black seeds; its edible flesh has a pleasant, sweet flavor.

Table 12.1

Peel and flesh colors of Hylocereus spp.

Species

Weight

Peel color

Flesh color

Common name

H. costaricensis H. megalanthus H. purpusii H. monocanthus H. undatus H. undatus subsp. luteocarpa

250–600 g 120–250 g 150–400 g 200–400 g 300–800 g 100–480 g

Red Yellow Red Purple Rosy-red Clear yellow

Red purple White Red Red purple White White

Red pitaya Yellow pitaya Red pitaya Red pitaya Dragon fruit –


250

•

•

•


H. ocamponis (Weing.) Britton & Rose (syn. H. purpusii) has very large (25 cm) flowers with margins; outer perianth segments are more or less reddish; middle perianth segments golden, and inner perianth segments white. It produces scarlet, oblong fruit covered with large scales (length: 10–15 cm; weight: 150–400 g); red flesh with many small black seeds; and has pleasant flesh texture though not very pronounced. H. monocanthus Bauer (including H. polyrhizus) has very long (25–30 cm) flowers with margins; outer reddish perianth segments, especially at the tips; and rather short and yellowish stigma lobes. Its scarlet fruit (length: 10–15 cm; weight: 200–400 g) is oblong and covered with scales that vary in size; it has a red flesh with many small black seeds, pleasant flesh texture and good taste. H. undatus (Haw.) Britton & Rose (see Fig. 12.1) has long and green stems, more or less horned in the age margins. Flowers are very long (up to 29 cm), outer perianth segments are green (or yellow-green) and inner perianth segments

Fig. 12.1

Fruit of Hylocereus undatus (© F. Le Bellec).



251

pure white. Its rosy-red fruit (length: 15–22 cm; weight: 300–800 g) is oblong and covered with large and long scales, red and green at the tips; it has a white flesh with many small black seeds, pleasant flesh texture and a good taste. A new subspecies of H. undatus subsp. luteocarpa from Mexico has been recently described, having yellow fruit with large foliaceous scales (De Dios, 2005). Many varieties of Hylocereus exist throughout the world, selected or not by humans. The custom of regarding fruit morphology and color is often the sole criterion for defining species. For example, a few varieties of H. costaricensis are known in Costa Rica as: ‘Lisa’, ‘Cebra’ and ‘Rosa’ (Vaillant et al., 2005). Recently, morphological variation was studied in 21 pitahaya genotypes in Mexico which allowed discriminating, by vegetative criteria, four groups within the species H. undatus (Grimaldo-Juárez et al., 2007). These authors conclude: ‘The variability of this group represents greater capacity to change in response to its environment, demonstrating different phenotypes, which are selected by man as suggested for yellow, red and magenta pitahaya’. This study has not been complemented by genetic analyses; perhaps they would have discovered subspecies as described by De Dios (2005) or hybrids. Indeed, reciprocal crosses among diploid Hylocereus species and the ease of obtaining partially fertile hybrids facilitates the creation of new variety (for natural or voluntary hybridization). For examples, Tel-Zur et al. (2004b) have created many hybrids for their experiment; to overcome the problems associated with self-incompatible varieties that are grown on Reunion Island, we have easily created a hybrid H. undatus × H. costaricensis, see Fig. 12.2 that allows the pollination of these two parents (Le Bellec et al., 2004). In conclusion, few studies seek to describe and characterize pitahaya varieties. The market reduces this apparent diversity to two colors of fruits: yellow and red!

Fig. 12.2

Hybrid of H. undatus (right) × H. costaricensis (left) (© F. Le Bellec).


252


12.3.2 Origin, distribution and ecology of Hylocereus Most Hylocereus species originate principally from Latin America (probably from Mexico and Colombia), with others possibly from the West Indies (Britton and Rose, 1963). In these regions, pitahaya has been cultivated for many years. Ethnobotanical studies (Mesoamerican region) indicate Hylocereus species were domesticated by pre-Columbian cultures (Casas and Barbera, 2002) and have been a food source for inhabitants. Today they are distributed all over the world (in tropical and subtropical regions), but H. undatus is the most cosmopolitan species. In their region of origin, the fruits of Hylocereus sp. are the main traditional fruit and the most widely consumed local fruit (Mizrahi et al., 1997). The Hylocereus species is at present cultivated for fruit production in Cambodia, Colombia, Costa Rica, Ecuador, Guatemala, Indonesia, Malaysia, Mexico, Nicaragua, Peru, Taiwan and Vietnam, with more recent cultivation in Australia, Israel, Japan, New Zealand, Philippines, Spain, Reunion Island and the southwestern United States (Valiente-Banuet et al., 2007, Le Bellec et al., 2006). The robustness of Hylocereus species enables them to prosper under different ecological conditions. For example, in Mexico, they are found in very rainy regions (340 to 3500 mm year) and at altitudes of up to 2750 m above sea level (Mizarhi et al., 1997). They can survive in very hot climates, with temperatures of up to 38–40 °C (Le Bellec et al., 2006); nevertheless, in some species, temperatures below 12 °C can cause necrosis of the stems (Bárcenas, 1994). Hylocereus species are semi-epiphytes and consequently usually prefer to grow in half-shaded conditions (conditions provided in nature by trees). Some species tolerate sites totally exposed to solar radiation (H. undatus, H. costaricensis and H. purpusii, for example), however, gas exchange and growth or flowering are often inhibited (Nerd et al., 2002; Andrade et al., 2006) and very hot sun and insufficient water may lead to burning of the stems. In the Neveg Desert in Israel, the most favorable conditions for growth and fruit production are found to be 30% shade for H. polyrhizus (Raveh et al., 1996), while in the French West Indies (Guadeloupe and Saint-Martin), cultivation of H. trigonus is only possible with about 50% shade (Le Bellec et al., 2006). H. undatus tolerates prolonged drought, up to six weeks, without any effect on growth (Nobel, 2006). In Mexico, the rainy season provides optimal conditions for photosynthesis in H. undatus, due to low air temperature and, small deficit of vapor pressure during the night (Andrade et al., 2006) but excess water systematically results in the abscission of flowers and young fruits (Le Bellec et al., 2006). Hylocereus species can adapt to different types of welldrained soil (Bárcenas, 1994). 12.3.3 Morphology and reproductive biology of Hylocereus Few studies have been published on the floral biology of H. undatus and H. costaricensis, the two most widely cultivated Hylocereus species in the world. Some researchers are interested in them, in some cases to study the cultivation potential of this new fruit (Weiss et al., 1994), and in other cases to study the floral biology of this species that is endemic to Costa Rica and Mexico (Castillo et al.,



253

2003). The flowers of Hylocereus appear under the areoles; they are large (more or less 30 cm), in the shape of a funnel, and nocturnal. The ovary is located at the base of a long tube carrying the foliaceous scales to the exterior and there are numerous stamens on a slender anther stalk. The unusually large, tubular style is 20 cm in length and 0.5 cm in diameter; the stigmas have 24 slender lobes, and are creamy green in color. Floral growth does not depend on water availability, but on day length; in Vietnam, floral induction is often triggered using artificial light to increase day length. On Reunion Island, it has been demonstrated that the number of flowers obtained using artificial light at night is proportional to the distance between the receiving point and the light source. The floral buds can remain in the latent stage for many weeks (Le Bellec et al., 2006), and the beginning of flowering generally occurs after the rainy season (Le Bellec et al., 2006). In the southern hemisphere, H. undatus and H. costaricensis flower from November to April, and in the northern hemisphere from May to October (Weiss et al., 1994; Le Bellec, 2004). Flowering episodes are cyclic and spread out over the whole period and the number of flowering episodes or flushes depends on the species: for example, seven to eight for H. costaricensis and five to six for H. undatus. There is a period of three to four weeks between flowering flushes (Le Bellec, 2004), which makes it possible to see floral buds, flowers, young fruits and mature fruits on the same plant at the same time. The periods between the appearance of floral buds (lifting of the areole) and flowering (stage 1), and between flower anthesis and fruit harvest (stage 2) are very short: around 15 to 20 days for the first stage and 30 days for the second stage. In their native countries, pollination of flowers occurs during the night by nectar-feeding bats such as Leptonycteris curasoae and Choeronycteris mexicana (Herrera and Martinez Del Rio, 1998; Valiente-Banuet et al., 2007) or by a species of butterfly belonging to the Sphingideae family, of the genus Maduca. During the day bees (Apis melifera) pollinate flowers (Le Bellec, 2004; Valiente-Banuet et al., 2007). There seems to be no major problems connected with fruit yields in the main producing countries in Latin America and Asia (Valiente-Banuet et al., 2007). Dehiscence takes place a few hours before the complete opening of the flower. Pollen is very abundant, heavy and not powdery. Flowers open at between 20:00 and 20:30; the stigma dominates the stamens (the position of the stigma at this stage encourages allogamy). Flowers bloom only for a day and then close (whether fertilized or not) in the morning of the day after anthesis. The following day, petals become soft and then slowly dry. The lower part of a non-fertilized flower becomes yellowish and the whole flower falls off four to six days later, while the lower part of a fertilized flower remains greenish and increases enormously in volume, indicating that the fruit has set. In some countries (Israel, South Africa, Madagascar, Reunion Island and French West Indies), natural production of fruits from clones introduced from H. undatus and H. costaricensis is practically non-existent (Le Bellec et al., 2006). The autoincompatibility (Weiss et al., 1994) of the clones of these species and the absence of efficient pollinators – interspecific crossing is possible – appear to be responsible for this lack of productivity. Honeybees are very attracted to the pollen of these flowers and the repeated visits of these insects can contribute to pollination (Weiss


254


et al., 1994). However, the quality of the fruits resulting from free pollination is generally lower than that of those obtained by manual cross-pollination (Le Bellec, 2004). The origin of the pollen can also influence the time lapse between pollination and harvest of the fruit (known as the phenomena of metaxenia, this was previously only observed on H. polyrhizus) (Mizrahi et al., 2004).

12.4

Cropping system

Pitahaya has only been cultivated for a short time and the first published references to serious cultivation practices date back only to around 15 years ago (Le Bellec et al., 2006). Little agronomic knowledge has been acquired from the traditional cultivation of these species in tropical America, or this knowledge has perhaps not been published. Traditional methods of cultivation have changed considerably in new production areas, as they have been adapted and improved to overcome the problems encountered there (Weiss et al., 1994). Two major pitahaya production systems are considered: the undergrowth cropping system with a well-established ecology (of the forest type, see Plate XXIII in the colour section), and the intensive system where optimum conditions for pitahaya production (shade, feeding, and irrigation) are created and managed. The undergrowth cropping system can only be effective in the natural ecological area of pitahaya. It is appropriate for plantation projects emphasizing natural production (biological production, low input, production with labels, etc.). The intensive system, on the other hand, makes it possible to enlarge the pitahaya production zone. It is particularly appropriate for projects where potential extension surfaces are limited and/or the high cost of the workforce is a limiting factor. Each system carries advantages and disadvantages. The farming of pitahaya under a natural vegetable cover that was not established for shading purposes for this same pitahaya is practiced in many areas of production (Rondón, 1998). It is probably the most used system since it is the cheapest one. This undergrowth pitahaya production method is referred to as the ‘traditional’ method, which generally provides conditions that are favorable to pitahaya production: shade, organic matter resulting from the decomposition of the leaves and branches of the vegetable cover, hygrometry, etc. However, these conditions can vary notably according to the season and undergrowth type (Andrade et al., 2006). For these reasons, regular upkeep is essential in these pitahaya plantations in order to maintain optimum growing conditions. To improve production with this method, it is possible to recreate this environment by planting tutors specifically for this culture (De Dios and Castillo Martinez, 2000). This production system allows a better control of the shade through the choice of an adapted tutor as the shade is not always adequate or at least not easily controlled. The need for water is also not always provided for. The intensive production system of the pitahaya – including artificial shade, dead tutors and an irrigation system – make it possible to meet the exact requirements of the pitahaya production. Cropping system intermediaries can also be designed. For example, pitahaya can be cultivated on dead tutors between hedges, with the trees providing



255

the necessary shade. If these cropping systems are different, the specific techniques of production will not change. Only investment, labor mobilization and quantities of inputs will be different from one system to another.

12.5

Cultivation techniques

12.5.1 Multiplication and planting density Hylocereus can be multiplied naturally and very easily by cutting off the stem as soon as it touches the ground. Its sequential stem segments can develop adventitious roots, so each rooted stem segment can act as an individual unit for water uptake (Nobel, 2006). The sowing of seeds and the in vitro multiplication of young shoots of mature plants are also possible (Yassen, 2002). However, in agriculture, multiplication by cuttings is preferable, as it allows reliable reproduction of the variety. In addition, the fruiting stage is reached more rapidly with cuttings, less than one year after planting, as opposed to three years for plants grown from seed. Finally, the robustness of these species enables cuttings to be taken directly in the field; provided cuttings are at least 50 to 70 cm in length and are regularly watered in order to ensure satisfactory rooting. Given these conditions and the plant’s characteristics, around 90% of the cuttings will grow (Le Bellec et al., 2006). The distance between plants depends on the type of support used. With an artificial vertical support (see Fig. 12.3), a 2–3 m distance between planting lines is required (between 2000 and 3750 cuttings.ha−1), at a rate of three cuttings per support. With horizontal or inclined supports, the density can be

Fig. 12.3

Plant and flowers of Hylocereus costaricensis (© F. Le Bellec).


256


much higher since the cuttings are planted every 50–75 cm around the production table (6500 cuttings.ha−1) or along the inclined support (6500 cuttings.ha−1) (Le Bellec et al., 2006). The height of these different types of support should be between 1.40 and 1.60 m for vertical supports and between 1 and 1.20 m for horizontal and inclined supports to facilitate management of the crop. 12.5.2 Cultivation practices Pitahaya are semi-epiphytic plants, which crawl, climb and attach naturally to any natural or artificial support they meet (trees, wood or cement posts, stone walls, etc.) thanks to their aerial roots. Growing them flat on the ground is not recommended, first because it makes cultivation more difficult (pollination, harvest, etc.), and secondly because contact with the ground causes damage to the vines. Pitahaya are thus best grown on living or dead supports (De Dios and Castillo Martinez, 2000). Many different types of support are used, but we focus on vertical supports made of wood (or cement and iron posts) and on horizontal and inclined supports (Le Bellec et al., 2006). Plant growth is rapid and continuous, though possibly with a vegetative rest period when the climatic conditions are unfavorable (such as drought and very low temperatures). When vertical and horizontal supports are used, pruning is important and the stems should be selected in such a way as to force the plant to climb over the entire support. All lateral growth and parts of the plant facing the ground should be removed, while the main stems and branch stems are kept, except those that touch the ground. Major pruning is carried out the first year after planting. Whatever the support used, the stem must be attached to it with a clip. The aim of maintenance pruning is to limit bunch growth and this should be carried out as early as the second year after planting. In practice, the extent of pruning depends on the type of support and its strength. For example, a three-year-old plant weighs around 70 kg (Le Bellec et al. 2006). Even if this weight is not in itself a problem for the different types of support, bunches may not be able to withstand violent winds. Pruning consists of removing all the damaged stems from the plant in addition to those that are entangled with one another. The postharvest pruning encourages the growth of new young shoots that will bear flowers the following year. 12.5.3 Nutrition and irrigation In natural conditions, the pitahaya feeds exclusively on the organic matter that is contained in the superficial layers of the soil. In order to create ideal conditions of production, it is important to complete this natural nutrition. Yields vary as a function of the nutritive elements supplied. The pitahaya’s root system is superficial and can rapidly assimilate even the smallest quantity of nutrients. Mineral and organic nutrition is particularly advantageous and, when combined, their effect is even more beneficial (López and Guido, 1998; Le Bellec et al., 2006). Even if pitahaya can survive with very low rainfall – many months of drought – when good quality fruits are required, a regular water supply is needed. Regular irrigation is



257

important, because it enables the plant to build sufficient reserves not only to flower at the most favorable time, but also to ensure the development of the fruits. To ensure good fruit production, irrigation is often necessary, and local microirrigation is particularly recommended. In addition to the efficiency of the water supplied by this system, micro-irrigation avoids uneven and excess watering that can result in flowers and young fruits falling off the vines. 12.5.4 Weed management Weed management is an important point of the pitahaya production; the pitahaya’s root system is superficial and is particularly sensitive to competition for water. Orchards are traditionally planted on sloping grounds or in the forest; this prevents the development of weeds. Then, the use of herbicides regularly sprayed on the whole farm is a common practice. Consequently, such a practice involves some impact on the environment and the production profit (for herbicides and labor costs). Introduction of cover crops on these orchards may be an interesting alternative. A vegetative cover plant established on the inter-row can be very advantageous: it allows near total control of erosion in the event of strong rains, ensures water conservation, restores soil fertility thanks to its biological reactivation and makes it possible to limit, and even control, the proliferation of adventitious. This weed management can be supplemented by a mulching around pitahaya. 12.5.5 Pollination The lack of genetic diversity and/or the absence of pollinating agents in certain production areas means that manual cross-pollination is needed to ensure fruit setting and development (Weiss et al., 1994; Catillo et al., 2003). Manual pollination (see Fig. 12.4) is simple and this operation is facilitated by the floral characteristics of Hylocereus, as the different floral parts are very large. Finally, manual pollination may be carried out from before anthesis of the flower from 4:30 p.m. until 11:00 a.m. the next day. These manual pollinations are worth undertaking and the fruits obtained are of excellent quality (Le Bellec, 2004). Pollination is accomplished by opening the flower by pinching the bulging part. This reveals the stigmata, which are then covered with pollen with a brush. Alternatively, the anthers can be directly deposited (with minimal pressure) on the stigmata with the fingers. The pollen can be removed from a flower of a different clone (or from another species) and stored in a box until needed. The pollen removed from two flowers will be enough for around 100 pollinations with a brush. It can be stored for 3 to 9 months at −18 to −196 °C without risk of damage. Fruits obtained after pollination using pollen stored at 4 °C for 3 to 9 months are usually very small (Metz et al., 2000). The activity of bees (Apis mellifera) can make manual pollination difficult, but it must nevertheless be accomplished (Le Bellec, 2004). Bees can be extremely efficient and, after only a few hours of activity, they will have harvested all the pollen. The pollen must thus be collected before the bees arrive and manual pollination carried out the next morning as soon as the bees have left the plantation.


258


Fig. 12.4

Manual pollination of Hylocereus spp. (© F. Le Bellec).

12.5.6 Harvesting Fruits from Hylocereus species are non-climacteric and have a low respiration rate when mature and after being picked (ranging between 50 and 120 mg CO2 kg−1. h−1) (Hoa et al., 2006; Nerd et al., 1999; To et al., 2002), therefore fruits should be harvested when they have attained full maturity and development is complete. Up to now the only practical harvest indexes have been the color of the epidermis and fruit firmness (To et al., 2002) which are usually assessed subjectively by fruitpickers. For both Hylocereus species (H. undatus and H. polyrhizus) it has been shown that when the color of the epidermis turns fully red, the size, fruit weight, pulp content, total soluble solids, pulp betacyanins and flavor rating reach maximum values while firmness, mucilage content, starch and total titrable acidity are at a minimum (Nerd et al., 1999). For example, in previous studies, firmness reduced rapidly from values of up to 12 kg.cm−2 at 16–20 days after anthesis to 1.2 ± 0.5 kg cm−2 at the stage when fruit epidermis is fully red (Nerd et al., 1999; To et al., 2002). This firmness value remains high and decreases only slightly during storage. Therefore, the practice of picking fruits earlier to let them better withstand transport is counterproductive as they will never develop full flavor or proper texture. In Vietnam and Mexico, this optimal maturity stage is reached within 28–31 days after anthesis for Hylocereus undatus (To et al., 2002; Yah et al., 2008), while in Israel, fruits from both Hylocereus undatus and polyrhizus grown under



259

greenhouse conditions reached optimum maturity between 33–37 days after anthesis (Nerd et al., 1999). Yields vary between 5 and 30 t.ha−1, being closely related to the density of planting and practice, type of pollination, etc.

12.6

Pests and diseases

The development of the culture of pitahaya in recent years has been accompanied by the appearance of some diseases, such as anthracnose caused by Colletotrichum gloeosporioides (Palmateer et al., 2007), basal rot caused by Fusarium oxysporum (Wright et al., 2007), stems necrotic lesions caused by Curcularia lunata (Masratul Hawa et al., 2009), stem spots caused by Botryosphaeria dothidea (ValenciaBotin et al., 2003). Different viral (Cactus virus X) and bacterial (Xanthomonas sp. and Erwinia sp.) diseases are also reported in the literature and can have major consequences (Liou et al., 2004). Several factors influence the development of these diseases: rainfall, badly decomposed compost, too humid or too dry soil, successive periods of continuous rain and dryness involving asphyxiates and lack of water. On the other hand, the eradication of these diseases seems unlikely, only preventive and prophylactic measures seem suitable. The sanitary quality of plant material is dominant and determines the life of the plantation. Few pests have been recorded on Hylocereus. Ants belonging to the genera Atta and Solenopsis (Le Bellec et al., 2006) can cause major damage to the plants as well as to the flowers and fruits (see Fig. 12.5). Cotinus mutabilis perforates the stem and Leptoglossus zonatus sucks the sap, leaving stains and some deformation. Different species of aphids and scales have also been observed on fruits and flowers. Rats and

Fig. 12.5 Ant damage on fruit (© F. Le Bellec).


260


birds can cause serious damage, mainly to flowers and fruits, but also to ripe fruits. The marketing of fruit may be affected by various diseases as fruit rot caused by Bipolaris cactivora (Taba et al., 2007). In some regions, pitahaya fruits are hosts of fruit fly species (Bactrocera spp.), and thus export to many markets require a disinfestation treatment (Hoa et al., 2006). Hot air treatments (46.5 °C for 20 min) (Hoa et al., 2006) and irradiation with X-rays can be successfully applied to ensure a stable visual and compositional quality during storage (Wall and Khan, 2008).

12.7

Quality components and indices

The edible part of pitahaya fruit corresponds to the mesocarp which yields a viscous juice containing many small seeds. The main physico-chemical properties of pitahaya juice (without seeds) are reported in Table 12.2. Juice contains approximately 12 ± 2% dry matter, mainly composed of reducing sugars, glucose and fructose (sucrose was only detected in traces). The amount of reducing sugars ranges from 50 to 130 g l−1 depending on varieties and cultivars (see Table 12.2). In mature fruit, a gradual increase of total soluble solids (TSS) concentration is Table 12.2

Main physico-chemical composition of Hylocereus fruit pulp

Characteristics pH-valuea Dry matter Density (20 °C) Total titratable acidsa,b Malic acid Citric acid Total soluble solidsa Protein content Lipid Glucose

Unit % g.cm−3 g.l−1 g.l−1 g.l−1 °Brix g.l−1 g.l−1

Fructose Minerals Pectin L-Ascorbic acid Dehydroascorbic acid Total vitamin C Betacyanin

g.l−1 g.l−1 mg.100 g−1 g.100 ml−1 g.100 ml−1 g.100 ml−1 mg.l−1

Total dietary fiber Total phenolics

g.100 gl−1 μM GACb equ.g−1

Hylocereus spp. 4.3–4.7 (Stintzing et al., 2003) 12 ± 1 1.04 ± 0.01 2.4 (Vaillant et al., 2005) to 3.4 (Stintzing et al., 2003) 6.2–8.2 (Esquivel et al., 2007a) 0.95–1.2 (Esquivel et al., 2007a) 7.1–10.7 1.2–1.25 1.17–1.43 30–103 (Esquivel et al., 2007a; Stintzing et al., 2003) 19–29 (Esquivel et al., 2007a) 65–136 (Esquivel et al., 2007a) 1.6–3.5 (Esquivel et al., 2007a) 1.1–3.6 (Esquivel et al., 2007a) 3.2–5.8 (Esquivel et al., 2007a) 530–717a (Esquivel et al., 2007c; Stintzing et al., 2003; Vaillant et al., 2005) 3.2 ± 0.1 (Mahattanatawee et al., 2006) 5.6–7.4 (Vaillant et al., 2005)

Notes: a Hylocereus polyrhizus. b Gallic acid equivalent.



261

observed from the external section of mesocarp to the center of the fruit (Nomura et al., 2005) though TSS concentration rarely reaches more than 140 g.100 g−1 in Hylocereus species, with common values ranging generally between 8 and 13 g TSS.100 g−1 (Esquivel et al., 2007a; Vaillant et al., 2005; Yah et al., 2008). In the white flesh fruits (H. undatus), TSS content in mature fruit is slightly higher (up to 190 g TSS.100 g−1) as reported for fruits grown in temperate climate (Ming Chang and Chin Shu, 1997). Total titratable acidity is also always relatively low in pitahaya species, ranging between 2.4 and 3.4 g.L−1 according to genotype (Le Bellec et al., 2006), with malic acid as the predominant acid present in the pulp (Esquivel et al., 2007a; Nomura et al., 2005; Yah et al., 2008). Protein content varies considerably depending on methods used (from 0.3% to 1.5%) because betalain, the nitrogen-containing pigment responsible for the red color, may interfere with results. The main amino acid present in pitahaya juice appears to be proline with a remarkably high content of 1.1 to 1.6 g.L−1 in juice (Stintzing et al., 1999). Mineral content is relatively high, with potassium the most prevalent mineral in juice, and followed by sodium and magnesium (Stintzing et al., 2003). Total dietary fiber content of pitahaya fruits is reported to be 3.2 ± 0.1 g.100 g−1 (FW) (Mahattanatawee et al., 2006), a relatively high value which is probably due to mucilage, a complex polymeric substance of carbohydrate nature with a highly branched structure. Nonetheless, mucilage has been reported to be only around 0.5% of fresh pulp for mature fruit from both Hylocereus undatus and polyrhizus (Nerd et al., 1999). Pectin was reported to be only 0.27% of fresh pitahaya pulp (Mahattanatawee et al., 2006). To our knowledge, no characterization of the mucilage of Hylocereus species has been reported so far, but it can be assumed that it displays similar characteristics of other cactus species, as recently reviewed for Opuntia sp. In this case, mucilage has been characterized as a complex mixture of at least five types of polysaccharides, less than 50% of which corresponds to a pectin-like polymer. The arabinogalactan backbone is apparently predominant but other branched polysaccharides are also associated (Matsuhiro et al., 2006). Residual starch is reported even in mature fruits but concentration is below 0.5% for both H. undatus and H. polyrhizus species (Nerd et al., 1999). Hylocereus species, both white and red flesh, appear to be surprisingly poor in total ascorbic acid, ranging between 12–17 mg.100 g−1 (FW) (Nerd et al., 1999; To et al., 2002) while other cactus species, for example prickly pear, have a much higher vitamin C content which is comparable to that of citrus. Other vitamins may be present but have not been reported. Betalains is predominant in the red flesh from Hylocereus species while non-colored phenolic compounds are predominant in the white flesh of H. undatus. The red color of flesh in Hylocereus species is due to the presence of betalains, a pigment that replaces anthocyanins in fruit-bearing plants belonging to most families of caryophyllales (Stintzing et al., 2003; Strack et al., 2003). Betalains are watersoluble pigments that comprise red-purple betacyanin and yellow betaxanthins, and are an immonium conjugate of betalamic acid with cyclo-dopa and amino acids or amines, respectively. In contrast to red beet and other cactus fruits, red-purple pitahaya (H. polyrhizus) is a pure source of betacyanin as betaxanthins have not been


262


detected (Strack et al., 2003), which explains the deep glowing red-purple color of the flesh. In red flesh pitahaya, the average content of total betalain ranges from 40–70 mg.100 ml−1. Structural studies on H. polyrhizus pigments reveal the presence of many betalains, but the three main betacyanins identified are betanin, phyllocactin and hylocerenin (Stintzing et al., 2006; Wybraniec et al., 2009). Betalain pigments present in red-flesh pitahaya display a red color with an absorbance peak around 536 nm (Stintzing et al., 2002). Betalains are of high commercial interest for food coloring but also for their functional properties as they present high antioxidant (Vaillant et al., 2005; Wu et al., 2006; Tesoriere et al., 2009;), anti-inflammatory (Allegra et al., 2005; Gentile et al., 2004), anti-cancer (Asmah et al., 2008), and anti-hypercholesterolemia properties (Khalili et al., 2009), reported in both chemical and cellular-based tests. Nonetheless, little is known on the real bioavailability of betacyanin (Tesoriere et al., 2004a). Betacyanins are absorbed from the digestive tract into the systemic circulation in their intact forms, yet the extent of in vivo absorption remains unknown (Frank et al., 2005) although average absorption of betalains simulated during in vitro gastro-intestinal digestion depends on the individual betalain compounds. For example, the bio-accessible fraction of betanin is only 40% in cactus fruits (O. ficus indica L. Mill.), slightly lower than for betanin from red-beet (Tesoriere et al., 2008). Pitahaya juice displays high antiradical activity; around 8–12 μmole of Trolox equivalent assessed by the ORAC method for the red flesh Hylocereus, a value very similar to beetroot (Ou et al., 2002). The white flesh Hylocereus species has a much lower ORAC value (around 3.0 ± 0.2) (Mahattanatawee et al., 2006), indicating a high participation of betacyanin compounds in the total antioxidant capacity. In most studies, a positive correlation between antioxidant capacity to total betalain content is generally observed (Esquivel et al., 2007b). Total phenolic compounds in white flesh (52.3 ± 33.6 mg GAE.100 g−1 puree) (Mahattanatawee et al., 2006). The main phenolic identified is gallic acid which is detected in various Hylocereus genotypes and tyrosine, a precursor in betalain biosynthesis (Esquivel et al., 2007b). The small granny seeds that account for about 1.3–1.5% of fruit yield 32–39% oil. The main fatty acids of pitahaya seed oil are palmitic acid (18%), oleic acid (22%), and linoleic acid (50%). The content of unsaturated fatty acids is high, around 75%, with polyunsaturated fatty acid around 50% which make the pitahaya oil comparable to flaxseed or grape seeds (Ariffin et al., 2009).

12.8


As a non-climacteric crop, the quality of pitahaya fruits picked at optimum maturity tends to decrease during storage. Several factors affect fruit quality, unfortunately this knowledge is not published. Here is a review to date. 12.8.1 Temperature management Pitahaya fruits harvested close to full color stage can undergo low storage temperature up to 6 °C. However, chilling injury can occur after long period storage at 6 °C, and



263

fruits present wilting and darkening of the scales and browning of the outer layer of the pulp. Fruits from Israel keep their visual acceptance and marketing quality for at least three weeks at 6 °C, two weeks at 14 °C or one week at 20 °C (Nerd et al., 1999). Throughout storage at all these temperatures, the concentration of soluble solids remained fairly constant. Fruits stored at 6 °C maintain their eating quality (flavor) for at least three weeks but deteriorated rapidly when transferred to room temperature (Nerd et al., 1999). Both varieties Hylocereus undatus and H. polyrhizus respond to storage in a similar manner (Nerd et al., 1999). During storage at 20 °C respiration rate decreases, remaining relatively low, ranging between 0.52 to 0.78 ml.CO2.kg−1.h−1, with the production rate of ethylene ranging from 0.025 to 0.091 ml.kg−1.h−1 (Nerd et al., 1999). 12.8.2 Water loss Due to scales, important thickness of peel and high mucilage content in flesh, fruit preserve high water content during storage even though water loss increases at higher storage temperature. After one week of storage at 20 °C, water loss reach only 4.2% and 3 weeks of storage at 6 °C water loss is generally reported below 6% (Nerd et al., 1999). Both species H. undatus and H. polyrhizus respond in a similar manner. 12.8.3 Atmosphere Only modified atmosphere packaging (MAP) was assessed to extend shelf life of pitahaya fruits. The shelf life of pitahaya has been extended in this case up to 35 days when stored at 10 °C, using polyethylene bags with average oxygen transmission rates of 4 l.m2.h−1 (To et al., 2002).

12.9

Processing

Pitahaya fruits can be marketed as ready-to-eat (fresh-cut) products after being peeled and/or sliced and packed in microperforated polyethylene bags. At these conditions, quality is maintained for about two weeks at either 4 or 8 °C, though an additional treatment should be implemented to prevent slices from sticking together (Goldman et al., 2005). Pure pitahaya juice is marketed in some countries and even exported. Fruits are washed, halved, and manually pulped, generally using a spoon. In Nicaragua, the pitahaya pulp obtained (with seeds) is then frozen at −20 °C, stored and directly exported to ethnic markets in the United States (Vaillant et al., 2005). Pulp can be also sieved on appropriate screens (0.5 to 1.0 mm) using a pulper with soft paddle or brushes to separate the juice from particulate matter, including seeds. However, the highly gelatinous mucilage which envelops every seed is difficult to remove by simple sieving without significantly decreasing juice yield (Esquivel et al., 2007a; Schweiggert et al., 2009). The same occurs when complete separation of mesocarp fibbers and seeds is implemented through centrifugation (Mosshammer et al., 2005). Thus, the


264


compromise between juice yield and quality dictates the juicing and subsequent steps. An enzyme-assisted process for the liquefaction of pitahaya pulp can be added to degrade mucilage and make easier separation of seeds. Partial degradation of mucilage can be achieved with pulp maceration at 40 °C for two hours with very high concentration of previously selected enzymes (2000 ppm) (Herbach et al., 2007) or at 8 °C for three days with 1% ascorbic acid and 1000 ppm enzyme preparation (Schweiggert et al., 2009). The last process allows for the decrease of juice viscosity by 50%, enabling overall juice yields of 48–60% and 80% betalain recovery (Schweiggert et al., 2009), compared to 25–39% overall juice yields when no enzyme treatment is implemented. However, when compared to other fruit, the concentration of enzyme needed is extremely high, and even though the cost of enzyme can be offset by an increase of juice yields, additional research efforts are needed to develop cheaper alternatives. Traditionally, reduction of viscosity is achieved by adding ½ to ¼ (v/v) of water, sieving the slurry on cotton or synthetic cloth for the removal of seeds, and adding sugar and citric acid (TSS = 15 g.100ml−1 and pH = 3.5). The beverage is then pasteurized in glass bottles (Campos-Hugueny et al., 1986). To increase yield substantially, crushing of the whole fruit (with peel) has been also tested, not for Hylocereus species but for cactus fruits possessing similar characteristics. Cactus peel can be palatable and the mash obtained pressed using a cone screw expresser or paddle pulper fitted with appropriate screens (Mosshammer et al., 2006). An enzymatic maceration step can be implemented prior to pressing in order to increase yields, then, vacuum concentration, freezedrying or spray drying can be implemented to yield fruit juice extracts with good overall pigment retention (71–83%). Additionally, microfiltration, a membrane process, was also tested to stabilize at ambient temperature the juice but flux density was very low (825 g (vp: 300 g).

20.8.2

Control of ripening and senescence

Modified atmosphere (MA) Modified atmosphere storage has been used to extend the storage life of many perishable crops including sugar apple and atemoya. However, storing fruit in an improper atmosphere may result in some disorders. Some studies on MA storage of sugar apple and cherimoya are described below. Coating ‘Nang’ sugar apple with 0.5 and 1.0% chitosan or individually wrapping the fruit with linear low density polyethylene (LLDPE) did not delay fruit softening when the fruit was stored at 13 °C and 95% RH. Modified atmosphere packaging (MAP) with 6 μM and 15 μM PE bags, though, reduced weight loss and maintained skin and pulp colour. Fruit kept in 6 μM PE bags had a storage life of at least 18 days whereas after day 12, fruit kept in 15 μM PE bags showed skin darkening (Fig. 20.8(c, d)) after removal from the bags due to the high CO2 inside (Chunprasert et al., 2006). Fully mature and freshly harvested sugar apple (Annona squamosa L.) stored in fibreboard boxes had a shelf life of four days at ambient (27 ± 2 °C) and eight days in cool storage conditions (15 ± 2 °C). The post-harvest combination of coating with 6% waxol + 0.1% carbendazim and forced-air precooling (at 10 °C) extended shelf life up to 14 days under cool storage (Kamble and Chavan, 2005). There were reports of the synergistic effects of ethylene absorbents and MAP when used in combination to extend storage life. Sugar apple placed in PE bags containing KMnO4 had a storage life of nine days while untreated fruit could be stored for five days (Babu et al., 1990). Sugar apple packed in 0.1 mm thick polyvinylchloride (PVC) film plus KMnO4 absorbent and stored at 16 °C with 90–100% RH delayed fruit ripening (Chaves et al., 2007). MAP by individual packing in PVC film and placing the fruit in polyester trays wrapped in PVC film did not influence the skin colour of ‘Gefner’ atemoya, but it preserved pulp brightness and reduced weight loss compared to non-packed fruit. Silva et al. (2009) found that MAP and storage at low temperature effectively preserved atemoya and maintained the fruit’s appearance after 15 days of storage. Atemoya cv. ‘PR3’ fruit individually sealed in copolymer (PD-955) and


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

418 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


low-density polyethylene (LDPE) bags were stored for 21 days at 15 °C or 25 °C and then were unwrapped and maintained at 25 °C for ripening. Weight loss in the packaged atemoyas was lower than in the control (non-wrapped fruit). Fruit sealed in LDPE did not ripen, probably due to development of an injurious atmosphere inside the package. Atemoyas packaged in PD-955 film stored at 15 °C had a shelf life of 17 days compared to the 13 days of the control fruit (Yamashita et al., 2002). Negative physical and chemical changes and deterioration in eating quality was delayed in ‘Pet Pakchong’ fruit wrapped with PVC film and stored at 14 °C. However, the PVC film wrapping caused abnormal ripening. Unwrapped fruit stored at 14 °C had the longest shelf life (12 days) while fruit stored at room temperature had the shortest shelf life (three days) (Oumsomniang, 2005). 1-Methylcyclopropene (1-MCP) 1-MCP is used for extension of postharvest life in many types of fresh produce, in particular climacteric or ethylene-sensitive produce. It inhibits ethylene responses by competitively binding to ethylene receptor in plant cells. 1-MCP is not only practical as vapour fumigation, but it can also be used in small volumes, making the treatment safe from the point of view of human health. It is mostly used as a pretreatment before long periods of storage. Sugar apples treated with 810 ppb 1-MCP for 12 hours at 25 °C and then stored at 25 °C for four days were firmer than the control. Both sugar apples treated with 1-MCP at 30 or 90 ppb and the control fruit ripened faster than fruit treated with 1-MCP at higher concentrations (Benassi et al., 2003). ‘African Pride’ atemoya fruit were fumigated with 25 ppb 1-MCP for 14 hours at 20 °C, treated with 100 ppb ethylene for 24 hours, then ripened at 20 °C. Fruit treated with ethylene alone generally ripened 50% faster than untreated fruit, while 1-MCP treatment alone increased the number of days to ripening by 3.4 (58%). Applying 1-MCP to the fruit prior to ethylene prevented accelerated ripening, so that the ripening time was similar to fruit treated with 1-MCP alone. However, 1-MCP treatment was associated with slightly higher severity of external blemishes in atemoya and slightly higher rotting severity in atemoya, compared to non-treated control (Hofman et al., 2001). Thus, additional precautions may be necessary to reduce disease severity associated with 1-MCP treatment. ‘Fai’, ‘Nang’ sugar apples and ‘Pet Pakchong’ atemoya were fumigated with 500 ppb 1-MCP to study fruit ripening behaviour (Noichinda et al., 2009a). Climacteric peaks at 25 °C were dramatically reduced in 1-MCP treated ‘Nang’ and ‘Pet Pakchong’ (Fig. 20.11(a)) while ethylene production peaks were slightly decreased and delayed following all 1-MCP treatments (Fig. 20.11(b)). The ripening and softening of 1-MCP treated fruit was postponed for 2–3 days (Fig. 20.12). Calcium carbide (CaC2) After harvest most sugar apples and atemoyas in Thailand are traditionally allowed to ripen naturally during transport to the consumer, usually for several days at ambient temperature. The traditional way to hasten fruit ripening is the application of CaC2 which releases acetylene (C2H2) gas to induce fruit ripening.


Sugar apple (Annona squamosa L.) and atemoya

419

Fig. 20.11 Respiration (a) and ethylene production (b) rates of non-treated (solid lines) and 500 ppb 1-MCP-treated fruit (dashed lines) of ‘Nang’ ({), ‘Fai’ (Δ), and ‘Pet Pakchong’ (×) at 25 °C.

Using CaC2 to hasten ripening effectively reduced fruit cracking and fruit weight loss during ripening in ‘African Pride’, but did not affect soluble solids, SS/TA, and vitamin C contents (Kosiyachinda and Kasiolarn, 1989; Kasiolarn, 1991). Flavonoid levels of CaC2-treated sugar apple fruits in ‘Fai’ and ‘Nang’ varieties were slightly lower than those of naturally ripened ones. As far as antioxidant activity abilities were concerned, ferrous ion chelating in both ripened groups was quite low (0.01–0.02%), whereas DPPH free radical scavenging ability, in contrast, was high at 83–92% (Noichinda et al., 2010b). Chemicals Some chemicals, such as plant growth regulators, have been applied to improve postharvest quality of sugar apples. Salicylic acid (SA) is an endogenous hormone that mediates in plant defence against pathogens. It has been reported to reduce decay and extend storage life of various fruits. Treating sugar apple with SA increased activities of antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX), decreased lipoxygenase (LOX) activity and correspondingly lowered malondialdehyde (MDA) contents in treated fruit, compared to the control. SS, total soluble sugars, softness and decay rate were significantly lowered in treated fruit, and fruit ripening was achieved after ten days of storage (Mo et al., 2008). SA has positive effects in maintaining membrane integrity and in delaying fruit ripening process.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

420 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Fig. 20.12 Fruit firmness of non-treated (solid lines) and 500 ppb 1-MCP-treated fruit (dashed lines) of ‘Nang’ ({), ‘Fai’ (Δ), and ‘Pet Pakchong’ (×) at 25 °C.

Furthermore, several regulating substances were used to investigate their role in the respiratory climacteric and ripening of sugar apple fruit. Dipping sugar apple fruit in a solution of indole acetic acid (IAA) at concentrations between 10−4 and 10−2 M accelerated ripening (Broughton and Guat, 1979). 1-Aminocyclopropene1-carboxylic acid (ACC) and IAA enhanced the softening and electrolyte leakage of treated-fruit. Respiration of IAA-treated fruit was enhanced. In contrast, aminoethoxyvinylglycine (AVG) and 2, 4-dinitrophenol (DNP) delayed softening. Cycloheximide (CHI), which inhibits de novo synthesis of the cell proteins, caused the fruit to remain harder than the untreated fruit (Tsay and Hong, 1988). 20.8.3 Recommended storage and shipping conditions Mature sugar apple and atemoya fruits can be stored at temperatures above 13 °C to facilitate shipment to distant markets. Lower temperatures cause chilling injury



421

with subsequent shrivelling and abnormal ripening (Kasiolarn, 1991; Campbell and Phillips, 1994). Pre-cooling of sugar apples by room- or forced-air cooling at 10 to 13 °C and maintaining controlled atmosphere (CA) conditions at 3–5% O2 + 5–10% CO2 can result in a storage life of four weeks (Kader, 2001; Cantwell, 2002). On the other hand, others have recommended storing sugar apple at temperatures between 15 and 20 °C (Broughton and Guat, 1979; Vishnu Prasanna et al., 2000) and with low O2 and ethylene tensions coupled with 10% CO2 and a relative humidity of 85%–90% in the storage atmosphere (Broughton and Guat, 1979).

20.9

Processing

20.9.1 Fresh-cut processing As atemoya are bigger than sugar apples and contain fewer seeds, they can be used to make fresh-cut products, before they become too soft. However, quick flesh browning is a major concern. Fresh atemoya pulp treated with 0.4–0.5% ascorbic acid and stored in MAP consisting of a 65 μM LLDPE/nylon/ LLDPE five-layer co-extruded bag at 0 °C for four weeks retained the desired creamy colour during storage and after exposure to ambient conditions for three hours. Sensory and microbiological properties of the ascorbic acid-treated atemoya pulp were acceptable throughout the storage period of four weeks (Gamage et al., 1997). 20.9.2 Other processing practices In Thailand, sugar apples are rarely processed. They are mostly consumed fresh as a dessert and are considered to be of poor quality and of little commercial importance. However, the pulp is sweet and has an excellent flavour that can be processed into many products including ice cream, sweet desserts, nectar, jelly, jam, conserves, sherbet, syrup, tarts, juice and fermented drinks (wine/liquors) (Ojha et al., 2005; Wanichkul, 2009b). Heat is commonly used to preserve processed products, but care should be taken with respect to its effect on quality, especially flavour. The flavour spectrums of sweet and flavoured pulp from mature ripe fruit of sugar apple heated to 55 °C (critical temperature) and 85 °C (pasteurization temperature) for 20 minutes each, and spray dried with skim and whole milk powders and stored for 12 months, did not differ from those in the fresh pulp. However, heating fresh pulp has the tendency to increase flavour production. Both heat treatments significantly increased the quantities of aroma compounds in the isoprenoid group such as α-pinene, β-pinene, linalool, spathulenol, cineole, limonene, α-copaene, α-farnecene and δ-cadenene, while germacrene, α-cubebene, caryophyllene were found in the 55 °C treatment and aromadendrene, ε-cadenene were found in the 85 °C heated pulp (Shashirekha et al., 2008). Freezing is an alternative method to preserve the quality of fresh produce for long storage durations. Individually quick frozen (IQF) vacuum packaged and


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

422 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


non-vacuum packaged sugar apples were stored at −18 °C for 12 months. Little discolouration was observed in vacuum packaged fruit, whereas serious discolouration was found in the non-vacuum packaged control. The main phenolic compounds, catechin, chlorogenic acid, eugenol and gallic acid, were higher in the pulp packaged under a vacuum. The discolouration of the pericarp of frozen sugar apple is thought to be O2-involved browning (Wu et al., 1997).

20.10

Conclusions

Sugar apples (Annona squamosa Linn.) and the hybrid atemoyas (A. cherimola Mill. × A. squamosa Linn.) are tropical aggregate fruits with attractive appearance due to their protruding areoles. Sugar apples and atemoya contain high levels of sugars and vitamin C. While fruit softening and fruitlet separation during ripening are the main concern for some sugar apple varieties, fruit cracking and skin blackening are concerns for atemoyas. Fruit softening behaviour during ripening separates sugar apples into two groups: fruit carpel splitting and fruit carpel gelling. Enzymes associated with cell wall degradation need to be investigated to understand their participation in the softening processes. Storage temperatures above 13 °C are ideal and lower temperatures cause chilling injury. Controlled and modified atmosphere storage could effectively extend the storage life, with the optimum atmosphere being 3–5% O2 + 5–10% CO2. 1-MCP fumigation is a practical and promising technique to maintain quality of sugar apple. Sugar apple and atemoya plants can be programmed to produce fruit throughout the year by branch pruning techniques. However, due to their short postharvest shelf life and probably also due to quality problems such as fruit splitting, pulpy flesh and skin blackening and the fact that they contain multiple seeds due to their biological morphology, sugar apples are only a minor fresh commodity in international markets. Research is on-going in the areas listed above and, although there have been some promising results, further research is still needed. Fundamental research using molecular biology to understand and to control ripening is needed. Proper breeding programmes are required to satisfy consumer preferences. New cultivars are needed, with a lower calorie content but with high antioxidant levels. Qualities admired by consumers include a minimum number of seeds, firm fruit, lack of woodiness, consistent flavour, improved external shape and appearance, and lack of skin blackening. Breeding programmes and other research efforts should aim to produce fruit with these properties.

20.11 Acknowledgements We most appreciate Assoc. Prof. Dr Kavit Wanichkul and Mr Ruangsak Komkhuntod, official staff from Kasetsart University, Thailand, for providing us with both informative data and materials of sugar apple and atemoya.



20.12

423

References

Anon. (2002a), Artificial Pollination of Sugar Apple and Atemoya: Fruit and Vegetables, Food and Fertilizer Technology Center, Taipei, Taiwan, PT2002–2036. Anon. (2002b), Fruits for the Future – Annona: Factsheet, Vol 5 of the Institute of Irrigation and Development Studies, International Centre for Underutilized Crops, University of Southampton, Southampton. Anon. (2006), Custard Apple (Annona spp. also Rollinia) collective name for atemoya, cherimoya, sugar apple or sweetsop, ramphala and soursop: Conditions of Entry Index, ed, Vol Section G: General Provisions. Primary Industries and Resources, South Australia. Babu K H, Zaheeruddin M and Prasad P K (1990), ‘Studies on postharvest storage of custard apple’, Acta Horticulturae, 269, 299–300. Bartley J P (1987), ‘Volatile constitutents of custard apple’, Chromatographia, 23, 129–131. Benassi G, Correa G A S F, Kluge R A and Jacomino A P (2003), ‘Shelf life of custard apple treated with 1-methylcyclopene – an antagonist to the ethylene action’, Brazilian Archives of Biology and Technology, 46, 115–119. Bolívar-Fernández N, Saucedo-Veloz C, Solís-Pereira S and Sauri-Duch E (2009), ‘Ripening of sugar apple fruits (Annona squamosa L.) developed in Yucatán, México’, Agrociencia, 43, 133–141. Broughton W J and Guat T (1979), ‘Storage conditions and ripening of the custard apple Annona squamosa L’, Scientia Horticulturae, 10, 73–82. Brown B I, Wong L S, George A P and Nissen R J (1988), ‘Comparative studies on the postharvest physiology of fruit from different species of Annona (custard apple)’, Journal of Horticultural Science, 63, 521–528. Campbell C W and Phillips R L (1994), The Atemoya: Fact Sheet HS-64 of the Florida Cooperative Extension Service, University of Florida. Cantwell M (2002), ‘Appendix: Summary table of optimal handling conditions for fresh produce’, in Kader A A, Postharvest Technology of Horticultural Crops, 3rd edn, University of California, Agriculture and Natural Resources Publication 3311, 511–518. Chaves M A, Bonomo R C F, Silva A A L, Santos L S, Carvalho B M A, et al. (2007), ‘Use of potassium permanganate in the sugar apple postharvest preservation’, Ciencia Y Technologia Alimentaria, 5, 346–351. Charoensiri R, Kongkachuichai R, Suknicom S and Sungpuag P (2009), ‘Beta-carotene, lycopene, and alpha-tocopherol contents of selected Thai fruits’, Food Chemistry, 113, 202–207. Chuakul W and Sornthornchareonon N (2003), ‘Ethnomedical uses of Thai Annonaceous plant (1)’, Thai Journal of Phytopharmacy, 10, 25–32. Chungsamarnyart N, Mahatheeranont S, Rattankkreetakul C, Jiwajinda S and Jansawan W (1992), ‘Isolation of acaricidal substances against tropical cattle ticks from sugar apple seed’, Kasetsart Journal, 26, 41–45. Chunprasert A, Uthairatanakij A and Wongs-Aree C (2006), ‘Storage quality of “Nang” sugar apple treated with chitosan coating and MAP’, Acta Horticulturae, 712, 857–864. Gamage T V, Yuen C M C and Wills R B H (1997), ‘Minimal processing of custard apple (Annona atemoya) pulp’, Journal of Food Processing and Preservation, 21, 289–301. Hofman P J, Jobin-Decor M, Meiburg G F, Macnish A J and Joyce D C (2001), ‘Ripening and quality responses of avocado, custard apple, mango and papaya fruit to 1-methylcyclopropene’, Australian Journal of Experimental Agriculture, 41, 567–572. Iqbal M P, Kazim S F and Mehboobali N (2006), ‘Ascorbic acid contents of Pakistani fruits and vegetables’, Pakistan Journal of Pharmaceutical Sciences, 19, 282–285. Kader A (2001), Fruits other than apples and european pears: Optimal Controlled Atmospheres for Horticultural Perishables, Vol 22A of the Postharvest Technology Research and Information Center, UC DAVIS – Department of Plant Sciences, 26–70.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

424 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Kamble P B and Chavan J K (2005), ‘Effects of post-harvest treatments and storage temperature on shelf-life of custard apple fruits’, Journal of Food Science and Technology, 42, 253–255. Kasiolarn H (1991), ‘Postharvest physiology of sugar apple (Annona squamosa Linn.) and the storage of atemoya (Annona × “African Pride”) fruit’, Master thesis, Kasetsart University, Bangkok, Thailand. Kosiyachinda S and Kasiolarn H (1989), Effect of GA3 on postharvest physiology and fruit crack of atemoya cv. African Pride. Paper presentated in the workshop on development and application of postharvest technology of fruit and vegetables in ASEAN, 16–19 October, Penang, Malaysia. Morita H, Sato Y., Chan K-L, Choo C-Y, Itokawa H, et al. (2000), ‘Samoquasine A, a benzoquinazoline alkaloid from the seeds of Annona squamosa’, Journal of Natural Products, 63, 1707–1708. McMillan R T Jr. (1986), ‘Serious diseases of tropical fruits in Florida’, Proceedings of the Florida State Horticultural Society, 99, 224–227. Mo Y, Gong D, Liang G, Han R, Xie J and Li W (2008), ‘Enhanced preservation effects of sugar apple fruits by salicylic acid treatment during post-harvest storage’, Journal of the Science of Food and Agriculture, 88, 2693–2699. Monkong J, Komkhuntod R and Wanichkul K (2009), ‘Effect of bagging materials on fruit quality of Annona hybrid cv. “Petch Pakchong”,’ in Proceeding of the 6th national conference of Kasetsart University – Kampaengsan, Plant and Biotechnology session, 8–9 December, Nakornpathom, 110–117. Monkong J, Komkhuntod R and Wanichkul K (2010), ‘Effect of bagging materials on fruit growth of Annona hybrid cv. “Petch Pakchong”,’ in Proceeding of the 48th national conference of Kasetsart University, Plant session, 3–5 Febuary, Bangkok, 16–23. Mossler M A and Crane J (2002), Florida crop/pest management profile: Atemoya and sugar apple, CIR 1417, a series of the Environmental Horticulture Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Nakasone H Y and Paull R E (1998), Tropical Fruits, Wallingford, Oxon, CAB International. Nissen R J, Smith L G, Broadley R H, George A P and Sisson C S (2002), ‘Marketing of custard apple in Australia: from grower to consumer’, Acta Horticulturae, 575, 437–442. Noichinda S, Bodhipadma K, Wongs-Aree C and Komkhuntod R (2009a), ‘Influence of 1-methylcyclopropene on the delaying respiration rate and pulp softening in hybrid sugar apple (Annona cherimola × Annona squamosa) cv. Pet-Pakchong’, Journal of Applied Science, 8(2), 1–5. Noichinda S, Bodhipadma K, Wongs-Aree C, Komkhuntod R and Sirisukchaitavorn H (2009b), ‘Differences in antioxidant properties among cultivated sugar apples (Annona spp.)’, Agricultural Science Journal, 40(3), 265–269. Noichinda S, Bodhipadma K, Wongs-Aree C and Komkhuntod R (2010a), ‘Ripening behavior of sugar apple between “Fai” and “Nang” cultivars’ (unpublished data). Noichinda S, Bodhipadma K, Wongs-Aree C, Komkhuntod R, Sirisukchaitavorn H, et al. (2010b), ‘Evaluation of antioxidant properties in naturally and artificially ripening sugar apple (Annona squamosa L.) fruits’, Acta Horticulturae, 875, 377–381. Nonta P (2009), ‘Grading evaluation of sugar apple (Annona squamosa Linn.) fruit from Pakchong district Nakhon Ratchasima province’. Master thesis, Kasetsart University, Bangkok, Thailand. Nwokocha L M and Williams P A (2009), ‘New starches: Physicochemical properties of sweetsop (Annona squamosa) and soursop (Anonna muricata) starches’, Carbohydrate Polymers, 78, 462–468.



425

Ojha S, Chakraborty M R, Chakrabarti J and Chatterjee N C (2005), ‘Fruit-rot of custardapple (Annona squamosa) – a new disease from Burdwan, West Bengal’, Journal of Mycopathological Research, 43, 143–144. Oumsomniang Y (2005), ‘Growth and development, harvesting indices, and effects of plastic film wrap and low temperature on quality and storage life of atemoya fruits (Annona atemoya Hort.cv.Petpakchong)’, Master thesis, Suranaree University of Technology, Nakhon Ratchasima, Thailand. Pereira M C T, Bandeira N, Antunes Júnior R C, Nietsche S, de Oliveira Júnior M X, et al. (2009), ‘Bagging effect upon either quality of the fruits and incidence of the fruit borer in atemoya and sweetsop’, Bragantia, 68, 389–396. Pino J A and Rosado A (1999), ‘Volatile constituents of custard apple (Annona atemoya)’, Journal of Essential Oil Research, 11, 303–305. Phillips R L and Campbell C W (1994), The sugar apple: Fact Sheet HS-38 of the Florida Cooperative Extension Service, University of Florida, p 3. Preungvate O (1982), ‘Starch, sucrose, glucose, fructose and titratable acidity in various Thai fruits’, Journal of the National Research Council of Thailand, 14, 29–53. Rao N S, Sharma K and Sharma R K (2005), ‘Anti-feedant and growth inhibitory effects of seed extracts of custard apple, Annona squamosa against Khapra Beetle, Trogoderma granarium’, Journal of Agricultural Technology, 1, 43–54. Rasai S, George A P and Kantharajah A S (1995), ‘Tissue culture of Annona spp. (cherimoya, atemoya, sugar apple and soursop): A review’, Scientia Horticulturae, 62, 1–14. Sanewski G M (1988), Growing custard apples: Queensland Department of Primary Industries Information Series, QI 87014, Brisbane, Australia. Sanewski G M (1989), ‘Custard apples: sweet taste of success?’, Queensland Agricultural Journal, 115, 299–303. Shashirekha M N, Baskaran R, Rao L J, Vijayalakshmi M R and Rajarathnam S (2008), ‘Influence of processing conditions on flavour compounds of custard apple (Annona squamosa L.)’, LWT, 41, 236–243. Silva A V C, de Andrade D G, Yaguiu P, Carnelossi M A G, Muniz E N and Narain N (2009), ‘Packing and refrigeration for atemoya preservation’, Ciencia Y Technologia Alimentaria, 29, 300–304. Sloper B (2007), Thailand study tour considers new varieties, rootstocks, in Custard Apple: Annual industry report of Australian Custard Apple Grower Association (ACAGA), Inc, Vol 07/08 of the Horticulture Australia Limited (HAL), Sydney, p 5. Swinbourne A (2007), Custard apple marketing program, in Custard Apple: Annual industry report of Australian Custard Apple Grower Association (ACAGA), Inc, Vol 06/07 of the Horticulture Australia Limited (HAL), Sydney, p 2. Thongteera Y, Wanichkul K and Komkhuntod R (2006a), ‘Fruit development of Annona hybrid (Annona cherimola Mill. × Annona squamosa Linn.) cv. Petch Pakchong’, Journal of Science and Technology, 14, 46–54 (English abstract). Thongteera Y, Wanichkul K and Komkuntud R (2006b), ‘Postharvest changes of Annona hybrid fruits (Annona cherimola Mill. × Annona squamosa Linn.) cv. Petch Pakchong’, Agricultural Science Journal, 37, 303–310 (English abstract). Thongteera Y, Wanichkul K and Komkuntud R (2007a), ‘A study on floral biology of Annona hybrid (Annona cherimola Mill. × Annona squamosa Linn.) “Petch Pakchong”,’ in Proceeding of 44th Kasetsart University Annual Conference: Plants, Kasetsart University, Bangkok, pp. 303–310 (English abstract). Thongteera, Y, Wanichkul K and Komkuntud, R (2007b), ‘Harvesting indices of Annona hybrid fruits (Annona cherimola Mill. × Annona squamosa Linn.) cv. Petch Pakchong’, King Mongkut’s Agricultural Journal, 25 (1), 11–21 (English abstract). Tsay L M and Hong Y S (1988), ‘Effects of several physiologically-active regulating substances on the ripening of sugar apple fruits’, Journal of the Japanese Society for Horticultural Science, 57(3), 538–543.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

426 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Tsay L M and Wu M C (1990), ‘Studies on the physio-chemical properties of postharvest sugar apple’, Acta Horticulturae, 269, 241–247. UN/ECE (2002), Annonas: UNECE Standard FFV-47 Concerning the Marketing and Commercial Quality Control of the Economic Commission for Europe, United Nations/ Economic and Social Council, p. 7. Vishnu Prasanna K N, Sudhakar Rao D V and Krishnamurthy S (2000), ‘Effect of storage temperature on ripening and quality of custard apple (Annona squamosa L.) fruits’, Journal of Horticultural Science and Biotechnology, 75, 546–550. Wanichkul K (2009a), ‘Species and cultivated Annona spp.’, Advanced Agriculture, 22, 35–52 (in Thai). Wanichkul K (2009b), ‘Sugar apple: An interesting fruit’, Advanced Agriculture, 22, 14–26 (in Thai). Wyllie S G, Cook D, Brophy J J and Richter K M (1987), ‘Volatile flavor components of Annona atemoya (custard apple)’, Journal of Agricultural Food and Chemistry, 35, 768–770. Wu M C, Tsay L M and Chen C S (1997), ‘Improving color preservation of frozen sugar apple by vacuum packaging’, Proceedings of the Florida State Horticultural Society, 110, 238–240. Wu M C and Tsay L M (1998), ‘Activity of softening enzymes during storage of sugar apple (Annona squamosa L.) at different temperatrures’, Food Preservation Science, 24, 319–323. Wu M C, Chen C H and Chen C S (1999), ‘Effects of different storage temperatures on change of fruit composition of sugar apple (Annona squamosa L.)’, Food Preservation Science, 25, 149–154. Yamashita F, Miglioranza L Hd S, Miranda Ld A and Souza C Md A (2002), ‘Effects of packaging and temperature on postharvest of atemoya’, Revista Brasileira de Fruiticultura, 24, 658–660. Yan L Y, Teng L T and Jhi T J (2006), ‘Antioxidant properties of guava fruit: Comparison with some local fruits’, Sunway Academic Journal, 3, 9–20. Yang Y-L, Hua K-F, Chuang P-H, Wu S-H, Wu K-Y, et al. (2008), ‘New cyclic peptides from the seeds of Annona squamosa L. and their anti-inflammatory activities’, Journal of Agricultural and Food Chemistry, 56, 386–392.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Plate XXXV (Chapter 20) Appearances of ripe sugar apples cultivated in Thailand: ‘Green Fai’ (a), ‘Purple Fai’ (b), ‘Green Nang’ (c), ‘Purple Nang’ (d), ‘Golden Nang’ (e), ‘Seedless’ (f), ‘Golden Flesh’: atemoya (g) and ‘Pet Pakchong’: atemoya (h).


21 Tamarillo (Solanum betaceum (Cav.)) W. C. Schotsmans, Institute of Agricultural Research and Technology, Spain, A. East, Massey University, New Zealand and A. Woolf, The New Zealand Institute for Plant & Food Research Limited, New Zealand

Abstract: The tamarillo is a subtropical non-climacteric fruit that produces fruit throughout the year, with fruit production peaking in late summer or autumn. The fruit has an attractive deep red skin and flesh, and a distinctive somewhat acidic flavour. Tamarillos are optimally stored at 3 to 4.5 °C, and 90–95% relative humidity. Lower temperatures will increase the risk of chilling injury. As the fruit mature, the colour changes from green to purple, red, amber and gold, while firmness and titratable acidity decline and the juice yield, soluble solids content (mainly sugars) and pH increase. Stem and calyx quality are important factors from a commercial marketing perspective although they do not affect flavour. Key words: Solanum betaceae, Cyphomandra, tamarillo, tree tomato, tomate de árbol, anthocyanins, stem quality.

21.1

Introduction

21.1.1 Origin, botany, morphology and structure The tamarillo (Solanum betacea, previously known as Cyphomandra betaceae) belongs to the plant family Solanaceae, genus Solanum (Bohs, 1995). The fruit are egg-shaped berries, with attractive, glossy, purple-red to golden yellow skins and orange-red to cream-yellow succulent flesh surrounding the seed locules (see Plate XXXVI in the colour section between pages 238 and 239). Other names commonly used are tree tomato, ‘tomate de palo’, and ‘tomate de árbol’. The name tamarillo was developed in New Zealand as recently as 1970 (Morton, 1987). The exact origin of tamarillo is at present unknown (Popenoe et al., 1989), but it can be found in the Andean regions of Peru, Chile, Ecuador and Bolivia (Morton, 1987) and is categorised in the same Solanaceae family as tomato, eggplant and capsicum (Sale and Pringle, 1999). The plant has spread to Central


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

428 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


America and the West Indies and New Zealand (Slack, 1976). In the wild, the fruit are generally small, splotchy and yellow or pale red in colour (Popenoe et al., 1989). The large purple-red strains currently found in commercial plantings were developed by nurserymen in New Zealand around 1920, from the then existing yellow and purple strains (Sale and Pringle, 1999) that were introduced by D. Hay & Sons in 1891 (Morton, 1987). The plant is a small, fast-growing and brittle tree, with shallow roots. It grows to a height of 3–5.5 m with a single upright trunk that branches into a few lateral branches (Morton, 1987; Popenoe et al., 1989) which bear the flowers and fruit. The evergreen leaves are large (17 to 30 cm long, 12 to 19 cm wide), shiny, hairy, with prominent veins, and a pungent musky odour. The tree reaches maturity three years after planting and is commercially productive for seven to eight years (Clark and Richardson, 2002). Tamarillo has a modular growth pattern, with each module consisting of three to four leaves with a terminal inflorescence. The inflorescence has a compound structure of up to 50 pale pink or lavender flowers distributed alternately (Lewis and Considine, 1999a). The flowers have five pointed lobes, five yellow stamens and green-purple calyx (Morton, 1987) and open sequentially at two- to three-day intervals, with individual flowers closing at night and reopening each day for up to five days (Lewis and Considine, 1999a). Flowering is continual but usually peaks in late summer or autumn. Tamarillo flowers are self-pollinating but require wind or an insect pollinator to transfer the pollen. The fruit take around 21 to 26 weeks to mature from flowering and since flowering is continual, fruit are also formed year round, with a peak in late autumn and winter (April to November in New Zealand) (Sale and Pringle, 1999). Fruit do not mature simultaneously and several harvests are necessary (Morton, 1987; Popenoe et al., 1989). The fruit is egg-shaped, 4–10 cm long and 3–5 cm wide; it is pointed at both ends and has a long stalk that is left attached for marketing. The skin is smooth, thin and yellow or orange to deep red or almost purple, sometimes with dark, longitudinal stripes. The flesh has the same variation in colour as the skin, ranging from yellow to deep red, or purple. The skin is tough and has an unpleasant flavour. The fruit has a firm texture and numerous thin, nearly flat, circular, large, hard and distinctly bitter seeds in two lengthwise compartments (Morton, 1987). The pulp surrounding the seeds is soft, juicy, subacid to sweet and flavourful, whereas the outer layer of flesh is slightly firm, succulent and bland. In the outmost layers of the flesh, small, hard, irregular, ‘stones’, containing large amounts of sodium and calcium, can appear (Popenoe et al., 1989). Tamarillo is a subtropical fruit and flourishes in regions where temperatures in the growing season are between 16 and 22 °C (Popenoe et al., 1989), while frost (−2.2 °C) will kill all but the larger branches (Morton, 1987). There are no altitude limitations, as they can be found at 1100–2300 m at the equator and near sea level in New Zealand (Popenoe et al., 1989). Fertile, light, well drained soils are needed (Morton, 1987; Popenoe et al., 1989), with good drainage and irrigation, since the trees cannot tolerate drought nor standing water.


Tamarillo (Solanum betaceum (Cav.))

429

21.1.2 Worldwide importance and economic value The tamarillo is cultivated extensively in most of South America but is mainly used for local consumption and often in a processed form; it is not promoted, resulting in lower quality fruit unsuitable for export. In Ecuador, 3000 ha produce 25 000 tonnes that are consumed within the country at a rate of approximately 1.5 kg/ capita/year (Ojeda et al., 2009). In Colombia about 120 000 tonnes of tamarillo are produced per year on 6500 ha of which the majority is locally consumed (Márquez et al., 2007), but 500 tonnes were exported in 2008 to The Netherlands, France, Canada, Germany and Spain, representing a value of circa €870 000 (Legiscomex, 2008). Infrequent reports indicate the presence of the plant in Kenya (Mwithiga et al., 2007), Uganda (Stangeland et al., 2009), Malaysia (Tee and Lim, 1991), Taiwan (Tseng et al., 2008) and Cuba (Tejeda and Cortes, 1997). Thanks to selection efforts and the development of shipping and storage techniques, tamarillo has been successfully grown in New Zealand (Janet, 2005). Commercial production is located in the north of the North Island, with about 175 growers producing 740 tonnes of fruit on 194 ha, representing a value of circa €700 000 in domestic sales and €550 000 in export sales in 2008 (Aitken and Hewett, 2008). The main export markets for tamarillo from New Zealand are the USA (mainly California), Australia, Hong Kong, Japan, Singapore, and the Pacific Islands. Tamarillo is exported fresh, packed in a cardboard box with each fruit sitting in an individual cup within a tray covered by a polyliner. 21.1.3 Cultivars and genetic variability Although named cultivars seem to exist only in New Zealand, two to four types of tamarillo are distinguished according to their skin colour: purple-red (often divided into purple and red) and yellow (often divided into amber and gold) (Popenoe et al., 1989; Sale and Pringle, 1999; Prohens and Nuez, 2000). Growers often relate the yellowish green leaf colour to the production of yellowish fruit and the purple-green foliage with the production of orangey-red fruit. In New Zealand, the red cultivar ‘Red Beau’ was the standard cultivar but it has significantly declined because of virus sensitivity, being replaced by varieties like ‘Ted’s Red’ and ‘Laird’s Large’. Other named red cultivars include: ‘Oratia’, ‘Red Delight’, ‘Kerikeri Red’, ‘Andy’s Sweet Red’, ‘Red Beauty’, ‘Red Chief’ and ‘Seccombe Red’ (Sale and Pringle, 1999). In the yellow strains, ‘Bold Gold’ is one of the most common cultivars (Sale, 2006) with other named cultivars being ‘Goldmine’, ‘Amberlea Gold’ and ‘Kaitaia Yellow’. The most serious disease affecting tamarillo in New Zealand is tamarillo mosaic potyvirus (TaMV), which results in production of blotchy, streaked unattractive fruit, limiting the production of export grade fruit. Therefore, great effort is going into the development of resistant cultivars (Cohen et al., 2000). 21.1.4 Culinary uses, nutritional value and health benefits The fruit is eaten raw or cooked and can be used as a vegetable like tomato but is also often used in desserts. The skin is always removed, being bitter.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

430 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


The red strain is preferred for fresh consumption because of its stronger, more acid flavour. Yellow fruit have a milder flavour and are preferred for canning. The nutritional characteristics (see Table 21.1) of yellow and purple-red cultivars are all within the same range, although significant differences are found between cultivars (Boyes and Strübi, 1997). The main difference between the yellow and purple-red cultivars can be found in the anthocyanin content, which is considerably higher in the purple-red cultivars (Vasco et al., 2008). Tamarillos are low in fat and carbohydrate, low in sodium, and rich in iron, potassium and

Table 21.1 Nutritional characteristics of tamarillo from New Zealand, Ecuador, Spain, Colombia and Uganda. Ranges are presented Parameter

Purple red Min

Diameter (cm) 4.6 Length (cm) 5.5 pH 3.5 Soluble solids content (°Brix) 9.4 Titratable acidity (%) 0.76 Moisture (%) 87 Proteins (%) 2.2 Fat (%) 0.08 Glucose (%) 0.454 Fructose (%) 0.615 Sucrose (%) 0.604 Citric acid (%) 0.77 Malic acid (%) 0.05 Ash (%) 0.69 0.2 Sodium (mg 100 g−1 FW) 238 Potassium (mg 100 g−1 FW) 7.3 Calcium (mg 100 g−1 FW) 14 Magnesium (mg 100 g−1 FW) 0.35 Iron (mg 100 g−1 FW) 14 Vitamin C (mg 100 g−1 FW) 1.31 Antioxidant activity FRAP (mmol 100 g−1 FW) 4.2 Antioxidant activity (μmol TROLOX g−1 FW) 81 Total phenolic content (mg GAE 100 g−1 DM) 163 Anthocyanins (mg 100 g−1 DM) 94.4 Hydroxycinnamic acids (mg 100 g−1 DM) β-carotene (mg g−1 FW) 5.1

Yellow Max

Min

7 8 3.6 13.6 1.71 92 2.2 0.6 1.4 1.412 2.5 2.7 0.53 1.26 8.9 524 26 25.4 0.9 42 1.96 10.3 187 167 96.2 5.2

3.9 5 5.6 7 3.2 3.5 9.3 12.3 1.48 4 86 88 2.4 2.5 0.05 0.72 0.5 1.7 0.7 1.6 1.125 2.979 1.02 2.5 0.07 0.32 0.7 0.82 0.06 4.96 311 440 10.4 25 16 22.5 0.22 0.6 14 33.15 2.6 81 ND 59.44 3.4

Max

6.8 125 ND 60.36 4.6

ND= not detected; where FW = fresh weight: DM = dry matter; FRAP = ferric reducing antioxidant power; GAE = gallic acid equivalents; TROLOX = 6-hydroxy-2,5,7,8-tetramethylchroman-2carboxylic acid Sources: Dawes and Callaghan (1970), Romero-Rodriguez et al. (1994), Boyes and Strübi (1997), Manzano (2005), Leterme et al. (2006), Vasco et al. (2008; 2009), Mertz et al. (2009b) and Stangeland et al. (2009).



431

vitamin C (see Table 21.1), and they contribute significantly to the daily intake of vitamins A, B6 and E (Lister et al., 2005). They have a high antioxidant activity, comparable to that of mango (Stangeland et al., 2009), mainly due to the high vitamin C content but low total soluble phenolic content (< 200 mg gallic acid equivalent (GAE) 100 g−1 fresh weight (FW)), and low antiradical efficiency against the 1,1-diphenyl-2-picrylhydrazyl (DPPH•) free radical (Vasco et al., 2008). A full mineral analysis of the fruit is provided by Leterme et al. (2006) and characterisation of the combination of sugars and acids is provided by Heatherbell et al. (1975). The fruit is generally eaten by scooping the flesh from cut halves. Tamarillos can be used in any meal the same way tomatoes would be used: they are poached, fried, grilled, baked, added to stews or casseroles. They are also used to make compote, chutneys, and curries or to add taste or a decorative touch to salads or cheese platters. In Colombia, Ecuador and Sumatra, the fresh fruit are eaten less often, but they are frequently juiced or blended with water and sugar to make a fruit drink. In Ecuadorian folk medicine, the fruit, and more specifically the peel, is considered to be a cholesterol-lowering food and is used as an antimicrobial/ anti-inflammatory treatment for sore throats and inflamed gums (Vasco et al., 2009). An Argentinean community uses the boiled roots of the plant as a treatment for hepatic disorders (Hilgert, 2001).

21.2


21.2.1 Flowering and pollination In tamarillo, vegetative growth, flower production and fruit set continue over an extended period throughout the warmer months (Clark and Richardson, 2002). Flowering is continual but usually peaks in late summer or autumn, thus leading to an extended harvest period (generally three months for a given cultivar). Tamarillo flowers are self-pollinating but need wind or an insect vector to transfer the pollen. Both honey bees and bumble bees visit tamarillo flowers in New Zealand, but the effective pollination period is only three days, and pollination and fertilisation are essential for fruit development as flowers will drop prematurely if they are not pollinated. Because up to 50 flowers can be found in an inflorescence and flowers open sequentially at two- to three-day intervals, individual inflorescences have open flowers for up to 60 days, and flower buds, flowers and fruitlets can be present simultaneously in an individual inflorescence (Lewis and Considine, 1999a). Only 12% of the flowers set fruit and only 3% develop into mature fruit, and this was not improved if hand pollination was added to the natural pollination. In general, the probability of fruit set decreases with the amount of fruit that has already set in an inflorescence (Lewis and Considine, 1999b). Because of the high level of flower and fruit abscission, yield is very low (Lewis and Considine, 1999b), and a high producing orchard can yield 15 tonnes per ha, which is much lower than, for instance, apples and oranges, which can yield 70 tonnes per ha (Richardson and Patterson, 1993).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

432 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


21.2.2 Fruit growth, development and maturation Tamarillo has a double sigmoidal growth curve, with initial slow fruit growth from 20 to 45 days after anthesis (DAA), followed by an accelerated growth phase from 45 to 95 DAA, during which most of the dry matter is accumulated (Ordóñez et al., 2005). After this, growth slows down again. The fruit changes colour at about 60 DAA and soluble solids content (SSC) is maximal around 90 DAA (the red-ripe stage for red fruit), as is the reducing sugar content, with hexoses making up the main part (Ordóñez et al., 2005). Sucrose is not accumulated in tamarillo fruit. The malic acid content is low throughout maturation, whereas the citric acid content increases rapidly during the initial stage of growth, reaching a peak value around 60 DAA (Heatherbell et al., 1982). Starch accumulation is maximal (15.1 mmol kg−1) just before the fruit changes colour (55 DAA) and minimal (2.7 mmol kg−1) at fruit maturity (95 DAA) (Ordóñez et al., 2005). Interestingly, unlike tomatoes, starch accumulation is not correlated with fruit growth or SSC. The best indicator of fruit maturity for red tamarillo is the skin colour, as immature fruit are green, mature fruit are purple, and ripe fruit turn a deep red. With the exception of ‘Bold Gold’, which converts directly from green to yellow, yellow cultivars change from green to red to yellow (Sale and Pringle, 1999). Changes in colour start at the apex, with the flesh around the calyx being the last to change colour. The fruit continues to develop the red colour after harvest, with an increase in SSC and a decrease in titratable acidity (TA) (El-Zeftawi et al., 1988). The anthocyanin concentration in the flesh increases rapidly (up to 1.4 mg g−1 FW) during the early stages of fruit growth, while the anthocyanin concentration in the skin stays low (< 0.1 mg g−1 FW). This accounts for the unpleasant taste of immature tamarillo. As tamarillos mature, the anthocyanin content of the pulp substantially decreases and the content in the skin increases (Heatherbell et al., 1982). If tamarillo fruit are harvested immature, they will have a shorter shelf life, shrivel quickly during storage, and not develop the full red colour (Pratt and Reid, 1976; Sale and Pringle, 1999). Pectins decrease during fruit growth from 1% to 0.75% (Heatherbell et al., 1982). Firmness, juice content and SSC can provide useful complementary information (El-Zeftawi et al., 1988) for assessment of fruit maturity. As with many other fruits, the aroma and typical flavour are the last to develop. In total, 49 aroma and flavour components have been identified, the majority being non-terpenoid alcohols and esters and more specifically, methyl hexanoate, (E)-hex-2-enal, (Z)-hex-3-en-1-ol, eugenol, 4-allyl-2,6-dimethoxyphenol (Torrado et al., 1995), (Z)-3-hexenol, ethyl butyrate (14.8%), methyl butyrate and methyl hexanoate (Wong and Wong, 1997).

21.3

Postharvest physiology and quality

21.3.1 Respiration and ethylene production Tamarillo is a non-climacteric fruit with little respiration and ethylene production after harvest, resulting in a relatively long shelf life (Pratt and Reid, 1976; Sale



433

and Pringle, 1999). The respiration rate of tamarillo (0.19–0.25 μmol CO2 kg−1s−1 at 4 °C) slowly decreases after harvest, while the ethylene production (< 0.001 nmol kg−1s−1 at 4 °C) remains low (Pongjaruvat, 2008). Both respiration rate and ethylene production increase at the onset of fruit senescence (Pratt and Reid, 1976), and during shelf life at 20 °C (Pongjaruvat, 2008). 21.3.2 Ripening, quality components and indices As the fruit ripens, its skin develops a full red (or yellow or orange) colour, firmness decreases and the stem changes in colour from green to yellow and eventually detaches. The colour development of red tamarillo fruit is commercially used to assess fruit maturity in New Zealand (Sale and Pringle, 1999). The fruit is considered to be at optimum maturity for harvest and marketing when it is purple, as the red colour will continue to develop after harvest (El-Zeftawi et al., 1988) unless the fruit is harvested when it is still too immature (Pratt and Reid, 1976). In orange tamarillos, redness (a*), yellowness (b*) and lightness (L*) of the skin all increased with ripening (Márquez et al., 2007), whereas in ripe New Zealand ‘Mulligan Red’ red tamarillos (see Fig. 21.1), a*, b*, and C* all decreased while L* remained stable (Pongjaruvat, 2008). In contrast, in Kenyan tamarillos, redness (a*) of the skin increased as yellowness (b*) and lightness (L*) decreased; and the latter correlated well with a decrease in lightness of the pulp and an increase in the SSC of the juice (Mwithiga et al., 2007). Firmness (puncture, compression) decreased as tamarillos ripened (Márquez et al., 2007; Mwithiga et al., 2007; Pongjaruvat, 2008), and firmness (puncture) could be used to predict the internal fruit quality, as its decrease corresponds to an

Fig. 21.1 Changes in colour parameters of tamarillo fruit during storage at 4 °C without shelf life (—), and with three days of shelf life at 20 °C (---) (adapted from Pongjaruvat, (2008)).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

434 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


increase in juice yield (Mwithiga et al., 2007). This decrease can probably be related to the increase of soluble pectins during maturation, while pectic acid and protopectins decrease (Heatherbell et al., 1982). The SSC of tamarillo fruit increases during ripening to 10–12 °Brix (El-Zeftawi et al., 1988; Márquez et al., 2007; Mwithiga et al., 2007), pH increases from 3.2–3.7 to 3.4–4.7 (Márquez et al., 2007; Mwithiga et al., 2007) and TA slightly declines (Manzano and Diaz, 2002; Márquez et al., 2007). These changes result in an increase in the SSC/TA ratio (Pongjaruvat, 2008) and thus a higher sensory flavour rating (El-Zeftawi et al., 1988). As the fruit ripens, the stem changes in colour from green (see Plate XXXVIIE in the colour section) to yellow (see Plate XXXVIIF in the colour section) because of accelerated water loss and chlorophyll degradation, and eventually detaches (Pongjaruvat, 2008).

21.4


21.4.1 Handling and grading Because flower production and fruit set continue over an extended period, not all the fruit on a tree mature at the same time, and multiple harvests are needed. Tamarillo fruit are harvested by hand and packed with the stems attached. The healthy and intact green stems of tamarillo fruit influence consumer and marketing perception and are required to satisfy export standards (Sale and Pringle, 1999). Grading of fruit is generally done based on size, and misshapen and blemished fruit are removed. Fruit are generally packed into plastic pocket packs and placed inside polyethylene-lined single layer trays. Polyliners are essential to prevent excessive weight loss and fruit shrivelling during long-term storage, because they ensure a higher relative humidity (RH) surrounding the fruit. However, this is accompanied by a higher likelihood of fruit rots. 21.4.2 Temperature Cooling tamarillo fruit below 7 °C will slow softening, weight loss, TA reduction and colour change (Espina and Lizana, 1991; Manzano and Diaz, 2002; Pongjaruvat, 2008); however, the optimal temperature is lower, at 3 to 4.5 °C (Harman and Patterson, 1984). Temperatures below this optimal (e.g. 0–2 °C) will increase the risk of chilling injury (CI) and will cause more discolouration of the calyx and stem, while fungal decay occurs on the stem and calyx if stored above 4.5 °C (Espina and Lizana, 1991). Storage at 4 °C slows fruit metabolism, and the deterioration of the stem through a marked decrease in moisture loss and chlorophyll degradation and prevention of an increase in polyphenoloxydase activity (Pongjaruvat, 2008). The maximum storage duration will of course depend on a range of preand postharvest factors, but a storage duration of six weeks should be achieved relatively easily using optimum temperature management. Storage for up to nine weeks is possible, and the maximum generally limited by expression of



435

post-storage rots, these being significantly influenced by orchard factors (Woolf and Jackman, unpublished data).

21.4.3 Relative humidity A RH between 90% and 95% is optimal for tamarillo (Harman and Patterson, 1984). Lower RH, such as when tamarillo fruit are stored in open trays (23 °C, 65% RH), will result in considerable loss of moisture (12% in 14 days) and hence a decrease in marketable weight (Márquez et al., 2007). Using polyliners in the trays and thus increasing RH will reduce weight loss to 0.3–0.5% (in 14 days) when stored at 4 °C and will retain firmness (compression) better (Pongjaruvat, 2008).

21.4.4 Ethylene Applying ethylene will accelerate fruit ripening through a stimulation of respiration, a decrease in firmness, development of red skin colour and yellow flesh colour, and an increase in the ratio of SSC to TA (Pratt and Reid, 1976; Prohens et al., 1996).

21.4.5 Modified and controlled atmosphere Little information is available regarding modified atmosphere packaging (MAP) of tamarillo. MAP (3–4 kPa O2 and 4–7 kPa CO2) delayed the development of stem yellowing, but did not improve fruit quality, and increased stem blackening and ‘bleeding’ (diffusing red pigment) in the locule (Pongjaruvat, 2008).

21.4.6 Special treatments Submersion in a citric acid solution was effective in slowing down the SSC increase and TA decrease and increasing the shelf life (30 °C and 80% RH) of fruit from six to ten days (Moreno-Álvarez et al., 2007).

21.5

Crop losses

21.5.1


Chilling injury Tamarillos are sensitive to CI at temperatures lower than 3 °C. CI symptoms include scald (brown discolouration), surface pitting, and increased susceptibility to decay (Harman and Patterson, 1984; Espina and Lizana, 1991). Deterioration of the fruit stem and calyx As mentioned previously, deterioration of the fruit stem and calyx is a problem in tamarillo, since a healthy fruit calyx (see Plate XXXVIIA in the colour section)


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

436 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


and stem (see Plate XXXVIIE in the colour section) are requirements for export, and factors that are considered by importers and wholesalers, despite it being purely an aesthetic problem that does not affect the fruit flesh quality or taste. Calyx lifting (see Plate XXXVIIC in the colour section) and blackening (see Plate XXXVIID in the colour section) show up after 28 days of storage at 4 °C and increase rapidly during subsequent shelf life, whereas stem yellowing (see Plate XXXVIIF in the colour section) and blackening (see Plate XXXVIIG in the colour section) are already obvious from 14 days onwards. Physical damage and fast loss of moisture after harvest are the main reasons for these stem and calyx problems (Sale and Pringle, 1999). Physical abrasion, such as occurs during brushing during packing, can also promote browning and blackening. Additionally, the colour changes of the stem from green to yellow have been associated with accelerated chlorophyll degradation (Pongjaruvat, 2008), and stem blackening with increased polyphenol oxidase activity (Sale and Pringle, 1999; Pongjaruvat, 2008). Several treatments, such as the application of wax to the stem and MAP to reduce water loss, have been tested to reduce stem browning, with little success. Eugenol, an antibacterial additive, has been shown to delay stem dehydration browning in cherry (Serrano et al., 2005) and table grape (Valverde et al., 2005; Valero et al., 2006), keeping their stems healthy, but when tried in MAP for tamarillo it did not show the same beneficial effect (Pongjaruvat, 2008). Other Colour leaching from the locules into the pericarp can occur, making the pericarp more red. The circumstances in which this happens have not been determined, but adverse atmospheric conditions seem to be one of the elicitors. 21.5.2 Pathological disorders Fungal infections due to field contamination dramatically reduce storage life of tamarillo fruit and these have not been successfully prevented by preharvest treatments (Sale and Pringle, 1999). The common fungal attacks are bitter rots, as circular and brown-black spots caused by Glomerella cingulata, Colletotrichum acutatum, C. gleosporoides, Phoma exigua, or Diaporthe phaseolorum (Hampton et al., 1983; Blank et al., 1987; Sale and Pringle, 1999; Manning and Woolf, unpublished data), and stem-end rots, as a soft brown rot occurring around the base of the stem caused by Botrytis (Sutton and Strachan, 1971) and possibly Phomopsis (Manning and Woolf, unpublished data). Application of captafol and benomyl field sprays in combination with a prochloraz and imazalil postharvest dip has been shown to improve fruit storability (Blank et al., 1987). The use of irradiation successfully inhibited the stem-end rots during storage, but this method caused tamarillo fruit tissue to be sensitive to low temperature injury, resulting in tissue breakdown and discolouration during cold storage (Sutton and Strachan, 1971). Hot water dips (50 °C for 8 min) directly after harvest successfully remove latent infections but



437

can cause damage to the stem and the wax layer of the skin, which can result in higher levels of weight loss and susceptibility to invasion of secondary fungi (Yearsley et al., 1987). The commercial application of hot water dips is difficult, as tamarillo do not float (Hampton et al., 1983). When complementing these heat treatments with a postharvest fungicide dip (such as imazalil) and waxing, fruit can be stored for eight weeks at 3.5 °C followed by seven days at 20 °C (Yearsley et al., 1987). Although the hot water dip reduces fungal rots, it cannot prevent stem discolouration. Tamarillos produce a broad-spectrum invertase inhibitory protein that has antifungal and antibacterial activity and is involved in the plant defence mechanism (Ordóñez et al., 2000; 2006). 21.5.3 Insect pests and their control Tamarillos are generally regarded as pest-resistant, although they can be attacked by green aphids and fruit flies; and greenhouse thrips can cause damage to small fruit, which results in scaring (Rheinlander and colleagues, unpublished data). Aphids need to be controlled well, especially since they often spread viruses. Good orchard hygiene, pruning and weed control are the main techniques used to avoid aphid infection. Fruit fly can present a problem when exporting to countries with quarantine restrictions, but can be controlled using dimethoate or fenthion dipping or flood spraying, or using methyl bromide fumigation; but none of these is accepted in organic production.

21.6

Processing

Tamarillo fruit process extremely well. They can be frozen or canned and can be used for a range of products including jams, pulps, purees, chutneys, and juices. There is considerable potential for combining with milk products such as yogurts. The yellow cultivars are especially preferred for processing because of their average size, good flavour and because they contain fewer anthocyanins. The last factor is important to prevent reaction with the metal of the cans, which can cause blue discolouration of the product (Portela, 1999). More recently, tamarillo wine was produced in Venezuela with chemical and organoleptic characteristics similar to those of wine made from grapes (Alvarez et al., 2007). Processing is best carried out after removing the skin layer and the seeds because of the bitter nature of these components (Belén-Camacho et al., 2004). Extraction of carotenoids and anthocyanins from this material may be useful as a source of natural food colourants (Bobbio et al., 1983) or as functional food ingredients. Duran and Moreno-Alvarez (2000) optimised solvent mixtures and application to enable high carotenoid extraction from the pericarp. Belén-Camacho et al. (2004) characterised the oil content of both red and yellow cultivar seeds in order to assess their potential as raw material for a unique oil product manufacture. Thermal processing, such as pasteurisation, is often used to preserve fruit products. Thermal treatment of yellow tamarillo nectar can result in reduced


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

438 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


vitamin C and carotenoid content of the final product in comparison with that of fresh nectar (Mertz et al., 2009a). Extraction of the effective broad-spectrum invertase inhibitory protein produced by the fruit may also be a useful resource as a natural biocide for reduction of postharvest losses in horticultural products (Ordóñez et al., 2006). Tamarillo and its processed products (in the form of juice and pomace) are considered good sources of antioxidants that could be used to make nutraceutical or functional-food products (Ordóñez et al., 2010).

21.7

Conclusions

The tamarillo is a subtropical fruit from the Solanaceae family, originating probably from the Andes. Different types of tamarillo are distinguished according to their skin colour, ranging from red to yellow, but no major differences in physiology have been noted besides the presence of anthocyanins in the red types and the absence of them in the yellow types. Tamarillo has an extended flowering and fruiting period, with a peak in fruit production in late autumn and winter. It is a non-climacteric fruit with little respiration and ethylene production after harvest, but ethylene can be used to accelerate fruit ripening. Tamarillos are optimally stored at 3 to 4.5 °C, and 90–95% RH, and lower temperatures will increase the risk of chilling injury. As fruit mature, their skin colour changes, and the juice yield, SSC, pH and SSC/TA ratio increase and firmness and TA decline. Stem and calyx quality are important factors and these also represent the main quality problem and the main challenge for the future. Tamarillo fruit adapt very well to processing and can be used as a vegetable in a manner similar to tomato, but are also often used in sweet preparations.

21.8

References

Aitken A G and Hewett E W (2008), FreshFacts: New Zealand Horticulture 2008. Auckland, HortResearch – The Horticulture & Food Research Institute of New Zealand Ltd. Alvarez R A, Manzano J E, Materano W and Valera A (2007), ‘Caracterización química y organoléptica de vino artesanal de tomate de arbol Cyphomandra betaceae (Cav.) Sendth’, Proc Interamerican Soc Tropic Hortic, 51, 163–166. Belén-Camacho D R, Sánchez E D, Garcia D, Moreno-Álvarez M J and Linares O (2004), ‘Características fisicoquímicas y composición en ácidos grasos del aceite extraído de semillas de tomate de árbol (Cyphomandra betacea Sendt) variedades roja y amarilla’, Grasas Aceites, 55, 428–433. Blank R H, Dance H M, Hampton R E, Olson M H and Holland P T (1987), ‘Tamarillo (Cyphomandra betacea): effect of field-applied fungicides and post-harvest fungicide dips on storage rots of fruit’, N Z J Exp Agric, 15, 191–198. Bobbio F O, Bobbio P A and Rodriguez-Amaya D B (1983), ‘Anthocyanins of the Brazilian fruit Cyphomandra betacea’, Food Chem, 12, 189–195. Bohs L (1995), ‘Transfer of Cyphomandra (Solanaceae) and its species to Solanum’, Taxon, 44, 583–587. Boyes S and Strübi P (1997), ‘Organic acid and sugar composition of three New Zealand grown tamarillo varieties (Solanum betaceum (Cav.))’, N Z J Crop Hortic Sci, 25, 79–83.



439

Clark C J and Richardson A C (2002), ‘Biomass and mineral nutrient partitioning in a developing tamarillo (Cyphomandra betacea) crop’, Sci Hortic, 94, 41–51. Cohen D, van den Brink R C, MacDiarmid R M, Beck D L and Forster R L S (2000), ‘Resistance to tamarillo mosaic virus in transgenic tamarillos and expression of the transgenes in F1 progeny’, Proc XXV Internat Hortic Congress, Pt 11, 43–49. Dawes S N and Callaghan M E (1970), ‘Composition of New Zealand fruit. 1. Tamarillo’, N Z J Sci, 13, 447–451. Durán M G and Moreno-Álvarez M J (2000), ‘Evaluación de algunas mezclas de solventes en la extracción de carotenoides del pericarpio de tamarillo (Cyphomandra betacea Sendt)’, Cienc Tecnol Alim, 31, 34–38. El-Zeftawi B M, Brohier L, Dooley L, Goubran F H, Holmes R and Scott B (1988), ‘Some maturity indices for tamarillo and pepino fruits’, J Hortic Sci, 63, 163–169. Espina S and Lizana L A (1991), ‘Comportamiento de tamarillo (Cyphomandra betacea (Cav.) Sendtner) en almacenaje refrigerado’, Proc Interamerican Soc Tropic Hortic, 35, 285–290. Hampton R E, Blank R H, Dance H M and Olson M H (1983), ‘Tamarillo storage rot problems’, Proc 36th N Z Weed Pest Control Conf., 121–124. Harman J E and Patterson K J (1984), Kiwifruit, tamarillos and feijoas maturity and storage effects on keeping and eating quality, Wellington, New Zealand, Agrilink Horticultural produce and practice No. 103. Heatherbell D A, Reid M S and Wrolstad R E (1982), ‘The tamarillo-chemical composition during growth and maturation’, N Z J Sci, 25, 239–243. Heatherbell D A, Surawski J R and Withy L M (1975), ‘Identification and quantitative analysis of sugars and non-volatile acids in tamarillo fruit (Cyphomandra betacea)’, Confructa, 20, 17–22. Hilgert N I (2001), ‘Plants used in home medicine in the Zenta River basin, Northwest Argentina’, J Ethnopharmacol, 76, 11–34. Janet S (2005), Tariff and Trade Barriers. Wellington, New Zealand Horticulture Export Authority. Legiscomex (2008), ‘Frutas exóticas en Colombia/Inteligencia de mercados’, www. legiscomex.com/BancoMedios/Documentos%20PDF/est_col_frutas_exot_6.pdf [accessed May 2011]. Leterme P, Buldgen A, Estrada F and Londoño A M (2006), ‘Mineral content of tropical fruits and unconventional foods of the Andes and the rain forest of Colombia’, Food Chem, 95, 644–652. Lewis D H and Considine J A (1999a), ‘Pollination and fruit set in the tamarillo (Cyphomandra betacea (Cav.) Sendt.) 1. Floral biology’, N Z J Crop Hortic Sci, 27, 101–112. Lewis D H and Considine J A (1999b), ‘Pollination and fruit set in the tamarillo (Cyphomandra betacea (Cav.) Sendt.) 2. Patterns of flowering and fruit set’, N Z J Crop Hortic Sci, 27, 113–123. Lister C E, Morrison S C, Kerkhofs N S and Wright K M (2005), ‘The nutritional composition and health benefits of New Zealand tamarillos’, Crop & Food Research Confidential Report No. 1281. Manzano J E (2005), ‘Caracterización de frutos de tomate de arbol (Cyphomandra betaceae Cav. Sendtn.) y sus relativos en zonas montañosas de Venezuela’, Proc Interamerican Soc Tropic Hortic, 48, 149–151. Manzano J E and Diaz J G (2002), ‘Características de calidad en frutos almacenados de tomate de arbol [Cyphomandra betaceae (Cav.) Sendtn.]’, Proc Interamerican Soc Tropic Hortic, 46, 68–69. Márquez C J, Otero C M E and Cortés M R (2007), ‘Cambios fisiológicos, texturales, fisicoquímicos y microestructurales del tomate de árbol (Cyphomandra betacea S.) en poscosecha’, Vitae, 14, 9–16. Mertz C, Brat P, Caris-Veyrat C and Gunata Z (2009a), ‘Characterization and thermal lability of carotenoids and vitamin C of tamarillo fruit (Solanum betaceum Cav.)’, Food Chem, 119, 653–659.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

440 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Mertz C, Gancel A L, Gunata Z, Alter P, Dhuique-Mayer C, et al. (2009b), ‘Phenolic compounds, carotenoids and antioxidant activity of three tropical fruits’, J Food Compos Anal, 22, 381–387. Moreno-Álvarez M J, Pinto M G, García Pantaleón D and Belén-Camacho D R (2007), ‘Efecto del ácido cítrico sobre la madurez del tomate de árbol’, Rev Facultad Agron (LUZ), 24, 321–342. Morton J (1987), Tree Tomato, Fruits of Warm Climates, Miami, Florida: Morton, Julie F. Mwithiga G, Mukolwe M I, Shitanda D and Karanja P N (2007), ‘Evaluation of the effect of ripening on the sensory quality and properties of tamarillo (Cyphomandra betaceae) fruits’, J Food Eng, 79, 117–123. Ojeda A M, Bermeo S P, Bastidas A R and Muñoz C (2009), ‘Produccion y comercializacion de tamarillo (Cyphomandra betacea Sent), para el mercado internacional’, Escuela Superior Politécnica del Litoral, Quito, Ecuador. Ordóñez R M, Cardozo M L, Zampini I C and Isla M I (2010), ‘Evaluation of antioxidant activity and genotoxicity of alcoholic and aqueous beverages and pomace derived from ripe fruits of Cyphomandra betacea Sendt.’, J Agric Food Chem, 58, 331–337. Ordóñez R M, Isla M I, Vattuone M A and Sampietro A R (2000), ‘Invertase proteinaceous inhibitor of Cyphomandra betacea Sendt fruits’, J Enz Inhib Med Chem, 15, 583–596. Ordóñez R M, Ordóñez A A L, Sayago J E, Nieva Moreno M I and Isla M I (2006), ‘Antimicrobial activity of glycosidase inhibitory protein isolated from Cyphomandra betacea Sendt. fruit’, Peptides, 27, 1187–1191. Ordóñez R M, Vattuone M A and Isla M I (2005), ‘Changes in carbohydrate content and related enzyme activity during Cyphomandra betacea (Cav.) Sendtn. fruit maturation’, Postharvest Biol Technol, 35, 293–301. Pongjaruvat W (2008), Effect of Modified Atmosphere on Storage Life of Purple Passion Fruit and Red Tamarillo, Palmerston North, New Zealand, Massey University. Popenoe H L, King S R, León J, Kalinowski L S and Vietmeyer N D (1989), Lost Crops of the Incas: Little-known Plants of the Andes with Promise for Worldwide Cultivation, Washington, D.C., The National Academy Press. Portela S I (1999), ‘Fisiología y manejo de poscosecha del tamarillo (Cyphomandra betacea)’, Av Hortic, 4, 40–50. Pratt H K and Reid M S (1976), ‘The tamarillo: fruit growth and maturation, ripening, respiration, and the role of ethylene’, J Sci Food Agric, 27, 399–404. Prohens J and Nuez F (2000), ‘The tamarillo (Cyphomandra betacea): A review of a promising small fruit crop’, Small Fruits Review, 1, 43–68. Prohens J, Ruiz J J and Nuez F (1996), ‘Advancing the tamarillo harvest by induced postharvest ripening’, HortScience, 31, 109–111. Richardson A and Patterson K (1993), ‘Tamarillo growth and management’, Orchardist, 66, 33–35. Romero-Rodriguez M A, Vazquez-Oderiz M L, Lopez-Hernandez J and Simal-Lozano J (1994), ‘Composition of babaco, feijoa, passion-fruit and tamarillo produced in Galicia (NW Spain)’, Food Chem, 49, 251–255. Sale P (2006), ‘Some interesting developments and the odd hiccup in the 2006 tamarillo season’, Orchardist, 79, 52–55. Sale P and Pringle G (1999), The Tamarillo Handbook: A Guide for New Zealand Growers and Handlers, Kerikeri, New Zealand, New Zealand Tamarillo Growers Association Inc. Serrano M, Martínez-Romero D, Castillo S, Guillén F and Valero D (2005), ‘The use of natural antifungal compounds improves the beneficial effect of MAP in sweet cherry storage’, Inn Food Sci Emerg Technol, 6, 115–123. Slack J M (1976), ‘Growing tamarillos’, Agric Gazette, 86, 2–4. Stangeland T, Remberg S F and Lye K A (2009), ‘Total antioxidant activity in 35 Ugandan fruits and vegetables’, Food Chem, 113, 85–91. Sutton H C and Strachan G (1971), ‘An attempt to control Botrytis rot in tamarillos (Cyphomandra betacea (Cav). Sendt) by electron irradiation’, N Z J Sci, 14, 1097–1106.



441

Tee E S and Lim C L (1991), ‘Carotenoid composition and content of Malaysian vegetables and fruits by the AOAC and HPLC methods’, Food Chem, 41, 309–339. Tejeda T and Cortes S (1997), ‘Phenological behaviour of tree tomato (Cyphomandra betacea (Cav.) Sendt), in Cuba, during initial stages of establishment’, Cultivos tropicales, 18, 43–46. Torrado A, Suárez M, Duque C, Krajewski D, Neugebauer W and Schreier P (1995), ‘Volatile constituents from tamarillo (Cyphomandra betacea Sendtn.) fruit’, Flavour Fragr J, 10, 349–354. Tseng Y H, Liou C Y, Liu S C and Ou C H (2008), ‘Cyphomandra betacea (Cav.) Sendt. (Solanaceae), a newly naturalized plant in Taiwan’, Quarterly Journal of Chinese Forestry, 41, 425–429. Valero D, Valverde J M, Martínez-Romero D, Guillén F, Castillo S and Serrano M (2006), ‘The combination of modified atmosphere packaging with eugenol or thymol to maintain quality, safety and functional properties of table grapes’, Postharvest Biol Technol, 41, 317–327. Valverde J M, Guillén F, Martínez-Romero D, Castillo S, Serrano M and Valero D (2005), ‘Improvement of table grapes quality and safety by the combination of modified atmosphere packaging (MAP) and eugenol, menthol, or thymol’, J Agric Food Chem, 53, 7458–7464. Vasco C, Avila J, Ruales J, Svanberg U and Kamal-Eldin A (2009), ‘Physical and chemical characteristics of golden-yellow and purple-red varieties of tamarillo fruit (Solanum betaceum Cav.)’, Int J Food Sci Nutr, 60, 278–288. Vasco C, Ruales J and Kamal-Eldin A (2008), ‘Total phenolic compounds and antioxidant capacities of major fruits from Ecuador’, Food Chem, 111, 816–823. Wong K C and Wong S N (1997), ‘Volatile constituents of Cyphomandra betacea Sendtn. fruit’, J Essential Oil Res, 9, 357–359. Yearsley C W, McGrath H J W and Dale J R (1987), ‘Red tamarillos (Cyphomandra betacea): post-harvest control of fungal decay with hot water and imazalil dips’, N Z J Exp Agric, 15, 223–228.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

Plate XXXVI

(Chapter 21) Tamarillo fruit.

(a)

(b)

(c)

(d)

(e)

(f)

(g)

Plate XXXVII (Chapter 21) Healthy tamarillo calyx (a, b), calyx lifting (c) and blackening (d). Healthy stem (e), stem yellowing (f ), stem blackening (g) (pictures courtesy of The New Zealand Institute for Plant & Food Research Limited).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

22 Tamarind (Tamarindus indica L.) E. M. Yahia, Autonomous University of Queretaro, Mexico and N. K.-E. Salih, Agricultural Research Corporation, Sudan

Abstract: Tamarindus indica L., commonly known as tamarind, is a multipurpose long-lived tree best known for its fruit. It is indigenous to tropical Africa and exotic to Asia and Central America. India and Thailand are the major tamarind world producers, generating 300 000 and 140 000 tons annually, respectively. There are two main types of tamarind: sour (the most common) and sweet (mostly comes from Thailand). Tamarind can be eaten fresh (ripe or unripe) and it can be consumed processed into different products. In addition to the use of tamarind fruit in food it has many uses in the pharmacological industry and folk medicine. The ripe tamarind pods are susceptible to different pest and diseases, especially when grown in a big plantation. This chapter will describe the nutritional importance and the postharvest handling of tamarind. Key words: Tamarindus indica, postharvest, handling, nutrition, storage, processing.

22.1

Introduction

22.1.1 Origin, botany, morphology and structure Tamarindus indica L. (syns. T. occidentalis Gaertn, T. officinalis Hook, T. umbrosa Salisb) belongs to the family leguminaceae (syns. Fabaceae) and subfamily Caesalpinaceae. The genus Tamarindus is monotypic, i.e. it contains a single species. Commonly, Tamarindus indica is known as tamarind (the trade and English name). In Spanish and Portuguese, it is called tamarindo; in French, tamarinier, tamarinde; in Dutch and German, tamarinde; in Italian, tamarindizio; in Hindi, it is known as tamarind, tamrulhindi and it has other local names as well (e.g. ambli, imli, chinch, etc.). In the eighteenth century, Linnaeus gave it the name Tamarindus indica, inspired by the Arabic name tamar-ul-Hind, meaning date of India. Tamarind is widespread throughout the tropics and subtropics and grows in more than 50 countries in Africa, Asia and Central America. It most probably


Tamarind (Tamarindus indica L.)

443

originated in tropical Africa (Coates-Palgrave, 1988), although there is a common belief that tamarind is native to India (Morton, 1987) where it is believed to have been introduced thousands of years ago (Hort, 1916), and to have reached Central America in the seventeenth century with the Spanish and Portuguese (Patino, 1969). According to Salim et al. (1998) in Africa tamarind is native to Burkina Faso, the Central African Republic, Chad, Eritrea, Ethiopia, Gambia, Guinea, Guinea-Bissau, Kenya, Madagascar, Mali, Mozambique, Niger, Nigeria, Senegal, Sudan, Tanzania, Uganda and Zimbabwe and exotic to Mauritania, Togo, Cote d’Ivoire, Egypt, Libya, Ghana, Zambia and Liberia. Also, tamarind is exotic to Australia, Asia (Afghanistan, China, Bangladesh, India, Indonesia, Iran, Laos, Malaysia, Nepal, Pakistan, Philippines, Myanmar, Sri Lanka, Thailand, Papua New Guinea, Cambodia, Vietnam and Brunei) and the Americas (Brazil, Colombia, Cuba, Dominican Republic, Guatemala, Haiti, Honduras, Jamaica, Mexico, Nicaragua, Panama, Puerto Rico and southern United States of America). It is widely used in Mexico (see Plate XXXVIII in the colour section between pages 238 and 239), especially in the preparation of drinks (tamarind water, tamarind juices) and desserts. Tamarind is an evergreen or semi-evergreen bushy tree that has a dense foliage crown. It is a slow growing tree; the annual growth rate of seedlings is about 60 cm and the juvenile stage takes between four and five years, but trees can reach up to 200 years of age. The tamarind tree can reach a maximum height of up to 20–30 m, with bole 1–2 m and trunk diameter 1.5–2 m (Jambulingam and Fernandes, 1986; Stross, 1995). Leaves are bright green in color, alternate and compound with 10–18 pairs of leaflets (see Plate XXXIXA in the colour section). Leaflets are 1.2–3.2 × 0.3–1.1 cm in size, petiolate, and rounded at the apex. Flowers are bisexual, 2.5 cm wide, five-petalled, borne in small racemes, and yellow with orange or red streaks. Buds are pink with 4 sepals and 5 petals. The fruit is a curved or straight pod with rounded ends, 12 to 15 cm in length, covered with a hard brown exterior shell. Fruit pulp is brown or reddish-brown when mature and the fruit pod contains between 1 and 12 flat and glossy brown seeds. Tamarind pulp, seeds and shell are about 55%, 34%, and 11%, respectively, of the tamarind fruit (Rao and Srivastava, 1974). The seed is made up of the seed coat or testa (20–30%) and the kernel or endosperm (70–80%). The shell is light greenish or scruffy brown in color (see Plate XXXIXB in the colour section). The shell is scaly and irregularly constricted between seeds; it is also brittle and easily broken when pressed. The pulp is soft and thick (Coronel, 1991; Purseglove, 1987). The seeds are 1.6 cm long, very hard, shiny, smooth and reddish or purplish brown in color with irregular shape and are joined to each other with tough fibers (Purseglove, 1987). Tamarind pods usually contain 1–12 seeds but the Indian pods contain 6–12 seeds, and are usually longer than the African and South American pods. There are two main types of tamarind: sour (the most common) and sweet (which mostly comes from Thailand). The tamarind tree has the capability to withstand long periods of drought because of its deep tap rooting and extensive lateral rooting system, and also the ability to grow in poor soils because of their nitrogen fixing property (Felker, 1981; Felker and Clark, 1980).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

444 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


22.1.2 Worldwide importance and economic value Tamarind is economically valuable and multi-purpose insofar as almost every part of the tree has a use, but the tree is best known for its fruit and the marketability of tamarind fruit has increased consistently over the years. The tamarind major production area is in Asia, where India is considered the major producer with a production of 300 thousand tons annually (El-Siddig et al., 2006) (Tables 22.1 and 22.2). According to the spices board of India, the production area was 58 624 ha in 2006–2007 and the export was 10 200 tons. The potential for Indian export in the past 5 years shows a good market for tamarind, especially in the Gulf Countries and Europe (Kumar and Bhattacharya, 2008). Thailand is the second major producer of tamarind, with 140 thousand tons produced in 1995 (Yaacob and Subhadrabandhu, 1995), and the export amounted to about 7000 tons in 1999. Sri Lanka exported 6903 tons of tamarind in 1997. Other Asian countries produce and export tamarind but on a much smaller scale compared to India and Thailand. In the Americas, Costa Rica produces about 220 tons of tamarind annually and is considered quite a large producer. The annual production of tamarind amounts to 37 tons in Mexico and 23 tons in Puerto Rico (Bueso, 1980). The Asian tamarind is mainly exported to Asian countries, Europe and North America, while the Table 22.1 Area (hectares), production and export (tons) and values (Rs. millions) of tamarind from India Year

Area

Production

Export

Values

2002–03 2003–04 2004–05 2005–06 2006–07 2007–08 2008–09

61 958 60 629 61 624 61 084 58 624 – –

178 974 183 871 194 032 192 186 190 073 – –

– –

– – 1833.98 3078.20 3000.00 3100.00 4105.00

5 944 14 101 10 200 11 250 11 500

Source: Spices Board India, Ministry of Commerce and Industry, Gov. of India. http://www.indianspices.com/

Table 22.2 Quantities (tons) and values (RS. millions) of different commodities of tamarind exported from India Commodity

Dried Fresh Flour meal Seeds

Quantity

Value

2000–01

2001–02

2000–01

2001–02

7071.14 2278.59 572.08 2997.39

4594.58 1434.15 817.97 887.38

151.782 33.932 11.348 47.131

109.667 23.988 15.528 19.322

Source: Spices Board India, Ministry of Commerce and Industry, Gov. of India. http://www.indianspices.com/



445

American tamarind is mainly exported to North America and Europe. In most of the producing countries, tamarind does not grow on a commercial scale, and fruits are collected from the wild and home gardens. Although widespread in Africa, no African country cultivates tamarind on a commercial scale and almost all of the produce is consumed locally. Similarly, most of the tamarind produced in India and Thailand is also consumed locally. The sour tamarind is the most widespread; it comprises 95% of the total world production. Thailand is the largest producer of sweet tamarind, being 30% of its crop. 22.1.3 Culinary uses, nutritional value and health benefits Tamarind fruit pulp has many uses in domestic and industrial food and medicine and is considered the most valuable part of the tree. In most tamarind-producing countries, rural households dry tamarind pods in the sun, separate pulp from the fibers, seeds and shells, and compress and pack pulp in palm leaf mats, baskets, corn husks, jute bags, earthenware pots or plastic bags. The fruit pulp is a common ingredient in curries, sauces, and certain beverages. Ripe tamarind pulp, especially the sweet tamarind, is often eaten fresh. Both sour and sweet ripe tamarind pulps are also consumed processed in desserts, pickles, jams, candy, juice, porridge and drinks. Tamarind, especially the unripe pulp, is used as a spice and sauce in many Asian cuisines. In India a pickle made from tamarind pulp is used as seasoning to prepare fish. Also, unripe fruit dipped in salt or wood ash is eaten as a snack. Tamarind juice is very popular in many countries; a refreshing drink is prepared from the pulp water extract mixed with wood ash or sugar. In Eastern Africa, porridge is prepared from pulp juice cooked with sorghum or maize. Sometimes the pulp juice is fermented into an alcoholic beverage. In Burkina Faso, tamarind pulp extract is used to purify drinking water (Bleach et al., 1991). In many Asian countries tamarind balls are made from the pulp mixed with sugar. In Thailand, the pulp is mixed with salt, compressed and packed in plastic bags. In East India, the pulp is covered with salt, rolled into balls, exposed to dew and stored in earthenware jars (Chapman, 1984; Morton, 1987), whereas in Java, the salted pulp is rolled into balls, steamed and sun-dried, then exposed to dew for a week before packing in stone jars. In Sri Lanka, the dried pulp is mixed with salt, packed in clay pots and kept in a dry place; seedless pulp is stored in plastic bags in retail shops (Gunasena, 1997). Tamarind seeds are eaten, roasted or boiled, during off-seasons and food shortages. Roasting the seeds is usually followed by decorticating the testa from the edible kernel. Roasted tamarind seeds can also be used as a substitute for coffee. The seed oil is edible and has many culinary uses. Of the tamarind seed kernel, 46 to 48% consists of a gel-forming substance, known as jellose or polyose, which has many applications in the food industry. Jellose is mainly a polysaccharide and can be used for the preservation, thickening, stabilizing and gelling of food (Gliksman, 1986; Chen et al., 1988; Kawaguchi et al., 1989). Unlike fruit pectin, tamarind seed polysaccharide is characterized by its ability to form gels over a


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

446 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


wide range of pHs and gelatinizes with sugar concentrates in cold neutral aqueous solutions (Savur, 1948). Also, tamarind polysaccharides are heat resistant and are not affected by long boiling periods, while fruit pectin degrades to one-third of its original value after one hour of boiling. Tamarind kernel powder (TKP) is a more effective gelling agent when combined with other gums (Yin and Lewis, 1981). Protein concentrates have also been made from tamarind kernel powder (Rao and Subramanian, 1984) and can be used to prepare jelly, and fortified bread and biscuits (Bhattacharya, 1990; Bhattacharya et al., 1994). The shelf life of fish can be extended by using TKP as a film forming gum (Shetty et al., 1996). Tamarind fruit pulp is a good source of minerals and a rich source of riboflavin, thiamin, and niacin, but it is poor in vitamins A and C (Table 22.3). Shankaracharya (1998) found that the whole tamarind seed contains 13% crude protein, 6.7% crude fiber, 4.8% crude fat and 5.62% tannins. Also, the seed contains good phytic acid, pentose, mannose, and glucose as principal soluble sugars (Ishola et al., 1990) as well as valuable amino acids (Shankaracharya, 1998; Bhattacharya et al., 1994). Bhattacharya et al. (1994) showed that tamarind seed is rich in glutamic acid, aspartic acid, glycine, and leucine, but deficient in sulphur-containing amino acids. The edible seed kernel was reported to be rich in phosphorus, potassium, and magnesium, but has a calcium content comparable with other cultivated

Table 22.3

Nutrition constituents of tamarind pulp per 100 g

Constituent

Amount per 100 g

Energy Moisture Protein Fat Fiber Carbohydrates Invert sugars (70% glucose; 30% fructose) Ash Calcium Phosphorus Iron Sodium Potassium Vitamin A Thiamine Riboflavin Niacin Ascorbic acid Tartaric acid

115–216 calories 28.2–52 g 2.40–3.10 g 0.1 g 5.6 g 51.5–67.4 g 30–41 g 2.9–3.3 g 35–170 mg 54–160 mg 1.3–10.9 mg 24 mg 116–375 mg 15 I.U. 0.16 mg 0.07 mg 0.6–0.7 mg 0.7–3.0 mg 8–23.8 mg

Data derived from: Morton (1987); Khairunnuur et al. (2009); Khanzada et al. (2008)


Tamarind (Tamarindus indica L.) Table 22.4

447

Mineral content of tamarind pulp, seed, kernel, and testa

Mineral mg100 g−1

Pulp

Seed

Kernel

Testa

Calcium Phosphorus Magnesium Potassium Sodium Copper Iron Zinc Nickel Manganese

81.0–466.0 86.0–190.0 72.0 62.0–570.0 3.0–76.7 21.8 1.3–10.9 1.1 0.5 –

9.3–786.0 68.4–165.0 17.5–118.3 272.8–610.0 19.2–28.8 1.6–19.0 6.5 2.8 – 0.90

1200.0 – 180.0 1020.0 210.0 – 80.0 100.0 – –

100.0 – 120.0 240.0 240.0 – 80.0 120.0 – –

Data derived and adapted from: Gunasena and Hughes (2000), Khanzada et al. (2008); Khairunnuur et al. (2009)

legumes (Table 22.4) (Bhattacharya et al., 1994; Khairunnuur et al., 2009). The seed is also rich in palmitic (14–20%), oleic (15–27%) and linoleic (36–49%) fatty acids (Andriamanantena et al., 1983; Khairunnuur et al., 2009). Tamarind fruits are known for their medicinal properties and have been used as herbal medicine in tamarind-producing countries (Jayaweera, 1981). Tamarind pulp is used to treat conditions such as intestinal ailments and skin infections which the pulp juice is used as a gargle to treat sore throats. Tamarind pulp also has uses as an anti-inflammatory (Rimbau et al., 1999) and has anti-bacterial, anti-fungal and molluscicidal properties as well (Imbabi et al., 1992). Tamarind pulp extract is used to cure malaria fever, alleviate sunstroke and as a digestive agent, and in the pharmaceutical industry, tamarind pulp is a common ingredient in cardiac and blood sugar reducing medicines. Tamarind seeds are considered a famine food, rich in protein. After removing the testa, which contains tannin and other anti-nutritional factors, they are consumed to prevent undesirable effects such as depression, constipation, and diarrhea (Rao and Srivastava, 1974; Khairunnuur et al., 2009). The seed was reported to have anti-diabetic effects (Rama Rao, 1975; Maiti et al., 2004) and to treat dysentery, ulcers and bladder stones (Rama Rao, 1975). Seeds have also shown anti-oxidant activity (Osawa et al., 1994; Luengthanaphol et al., 2004; Khairunnuur et al., 2009). Shimohiro (1995) reported that the quality of food was improved by adding the polysaccharide hydroxylates or xyloglucan oligosaccharides of tamarind seeds, which are known to have hypolipidemic effects. The tamarind seed coat was reported to be rich in procyanidin, which is known to have an anti-obesity effect (Koichi et al., 1997; Osumu et al., 1997), while a reduced-calorie food can be prepared using the cellulase hydrolysate of a tamarind polysaccharide (Whistler, 1991; Singer, 1994). Patil and Nadagoudar (1997) reported that polysaccharides derived from tamarind kernel powder were found to be suitable substitutes for corn steep liquor in the production of penicillin. The glucosyl transferase inhibitor, extracted from tamarind husks, was found to


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

448 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


have an anti-dental caries effect (Tamura et al., 1996) and tamarind kernel powder is an ingredient of several cosmetic preparations.

22.2

Fruit growth and ripening

22.2.1 Fruit growth, development and maturation Tamarind fruit goes through growth, maturation and ripening stages before being ready for harvesting. Tamarind pulp shows a change in color during the different developmental stages; in the case of sweet tamarind, the pulp color changes from yellowish green at the half-ripe stage, and to reddish brown at the fully-ripe stage. Also, the pulp shrinks due to loss of moisture and becomes sticky, the immature pods have green and tender shells and the seeds are soft and whitish. As the pods mature, the shell develops into a brown color, the pulp turns sticky and brown or reddish-brown, and the seeds become harder and darker. When fully ripe, the shells become brittle and easily broken. Fruit ripening is characterized by an increase in the total acidity, sugars and alcohol insoluble materials of the pulp (Hernandez-Unzon and Lakshminarayana, 1982b). Total ash, phenolics and pectins increase in the peel but decrease in the pulp. 22.2.2 Respiration, ethylene production and ripening Tamarind fruit is non-climacteric (Yahia, 2004); it produces little or no ethylene and there is no large increase in CO2 production. The maximum CO2 production occurs four weeks after fruit set and gradually declines thereafter (HernandezUnzon and Lakshminarayana, 1982b). The pods reach the ripening stage in 8–10 months after flowering while the fruit is fully ripe when up to half of its original water content is dehydrated. Dehydration begins 203 days after fruit set and may continue to the 245th day (Chaturvedi, 1985). Fruit pods are harvested green for flavoring, and ripe for processing. The fruits of the sweet type are also harvested at two stages, half-ripe and fully-ripe.

22.3


A tamarind tree takes more than seven years to start fruiting and 10–12 years to produce economically appreciable amounts of fruits. Tamarind fruit growth is a typical sigmoid type (Hernandez-Unzon and Lakshminarayana, 1982a). The fully ripened fruits can remain on the tree until the next flowering period without showing any significant deterioration in quality (Rama Rao, 1975); however, they can be subjected to bird and insect attack. The physical separation of the peel from the pulp results from the loss in water content. It is recommended that fruit be harvested when the moisture content is less than 20% to facilitate the separation of the shell from the pulp. Pods from the same tree do not reach maturity at the same time, which makes selective harvesting a necessity.



22.4

449


22.4.1 Rainfall The tamarind tree is well adapted to semiarid tropical conditions and grows well with an evenly distributed mean annual rainfall of 500–1500 mm (FAO, 1988; Jama et al., 1989; Hocking, 1993). In areas where annual rainfall is less than 500 mm, the trees are usually located near the water table or along water courses. The minimum annual rainfall which tamarind can tolerate is 250 mm and the maximum is up to 4000 mm in well-drained soil (Duke and Terrell, 1974). Tamarind grows well under wet conditions but does not flower (Allen and Allen, 1981; Morton, 1987) as dry weather is important for flowering and fruiting. It produces more fruit when subjected to a fairly long annual dry period (Allen and Allen, 1981; von Maydell, 1986) as a deep and extensive root system helps the tree to grow in very dry areas and withstand up to six months of drought (Coronel, 1991). This can be observed in the north and south dry zones of Sri Lanka, where there is a prolonged dry season of over 4–6 months. In dry zones the bearing ability of tamarind is comparatively less than those grown in intermediate rainfall areas as a sharp drop in rainfall and air temperature increases the curving of tamarind pods due to the low moisture content. Tamarind is usually evergreen but may shed its leaves in very dry conditions during the hot/dry season (Morton, 1987).

22.4.2 Temperature Tamarind grows within an annual temperature range of 33–37 °C and at a minimum temperature of 9.5–20 °C. Older trees can withstand temperatures as high as 47 °C and as low as −3 °C without serious injury (Verheij and Coronel, 1991). Tamarind may not survive in an altitude higher than 2000 m (Roti-Michelozzi, 1957; Dale and Greenway, 1961; Brenan, 1967; FAO, 1988; Jama et al., 1989), probably because of the low temperature rather than the altitude itself. It is very sensitive to fire and frost and requires protection when small (Troup, 1921; NAS, 1979) and is a light-demanding tree. The strong and pliant branches and deep and extensive root system make the tree wind-resistant (Coronel, 1986) and it is therefore known as the hurricane-resistant tree (NAS, 1979; von Maydell, 1986; von Carlowitz, 1986).

22.4.3 Soil The tamarind tree can grow in a wide range of soils and has no specific soil requirement (Chaturvedi, 1985; Sozolnoki, 1985; Galang, 1955). The tamarind tree has the ability to grow in poor soils because of its nitrogen fixing capability (Felker, 1981; Felker and Clark, 1980) and it can grow on rocky soil too. In India and Thailand, tamarind has been reported to grow on sodic and saline soils and on degraded land as well (Anon, 1991; Nemoto et al., 1987). Old tamarind trees have been found growing close to the sea (NAS, 1979; Pongskul et al., 1988;


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

450 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Anon, 1991). Pot experiment results showed that tamarind can grow in soil containing up to 45% exchangeable sodium (Dwivedi et al., 1996). El-Siddig et al. (2004a, 2004b) found a slight delay in emergence, but no effect on seedling growth, with up to 30 mM NaC1 salinity, while Gebauer et al. (2001) reported that tamarind seedlings can tolerate salinity up to 80 mM NaCl. It prefers soils that favor the development of a long tap root (Galang, 1955; Kelly and Cuny, 2000; Rao et al., 2000). Tamarind does not withstand low water-drainage soil (Relwani, 1993; Vogt 1995). The optimum pH is slightly acidic, 5.5–6.8 (FAO, 1988), though it also grows well in alkaline soils (Singh et al., 1997, quoted from Rao et al., 1999). It has been suggested that the association of tamarind with anthills and termite mounds may be due to a preference for slight lime content (Jansen, 1981) and aerated soil (Dalziel, 1937; Eggeling and Dale, 1951; Irvine, 1961; Allen and Allen, 1981).

22.5

Diseases and pests and their control

Tamarind fruits are subject to pests and diseases but are usually very tolerant to pathogens and insects, except in large plantations, because of their low moisture content and high content of acids and sugars. Also, the high phenolic content in the peel makes the fruit highly resistant to attacks from pathogens. Pulp separated from peel has good keeping quality but is subject to various molds in refrigerated storage. There are more than fifty insect pests that have been reported to attack tamarind in India (Joseph and Oommen, 1960; Senguttavan, 2000). These pests attack the tamarind tree at different growth stages; in the nursery as seedlings, and in the field once mature. They also attack different parts of the tree including stem, bark, branches, leaves, flowers and fruits. Fruits are attacked at different stages of ripening before and after harvesting. All these pests and diseases are of different economic importance, causing reduction in fruit production to different extents. In humid climates, fruit are readily attacked by beetles and fungi, and should therefore be harvested before they are fully ripe. The most serious pests of the tamarind are hard scale insects that suck the sap of the buds and flowers and accordingly reduce fruit production (Butani, 1978). The most important of these is the oriental yellow scale insect (Aonidiella orientalis). These scale insects can be controlled by removing the affected parts of the tree at an early stage while serious infestation can be controlled effectively using pesticides such as Diazinon or Carbosulphan at 0.1% solution (Butani, 1979). The mealy-bugs Nipaecoccus viridis and Planococcus lilacinus suck the sap of leaflets, causing defoliation, and may feed on young fruits; Chionaspis acuminata-atricolor and Aspidiotus spp suck the sap of twigs and branches. Mechanical control of mealy bugs can be achieved by removing the infected parts, but when serious infestations take place, chemicals such as Diazinon or Carbosulphan at 1% solution can be sprayed (Butani, 1979). Caterpillars, Thosea aperiens, Thalarsodes quadraria, Stauropus alternus, and Laspeyresia palamedes;



451

the black citrus aphid, Toxoptera aurantii; the white fly, Acaudaleyrodes rachispora; thrips, Ramaswamia hiella subnudula, Scirtothrips dorsalis, and Haplothrips ceylonicus; and cow bugs, Oxyrhachis tarandus, Otinotus onerotus, and Laptoentrus obliquis, and other predators attack tamarind leaves or flowers. Other important pests that attack tamarind include fruit borers such as larvae of the cigarette beetle, Lasioderma serricorne, also of Virachola isocrates, Dichocrocis punctiferalis, Tribolium castaneum, Phycita orthoclina, Cryptophlebia (Argyroploca) illepide, Oecadarchis sp., Holocera pulverea, Assara albicostalis, Araecerus suturalis and Aephitobius laevigiatus. The fruit borer Aphomia gularis, the tamarind beetle Pachymerus (Coryoborus) gonogra and the tamarind seed borer Calandra (Sitophilus) linearis attack ripening pods before and after harvest. The rice weevil Sitophilus oryzae, rice moth Corcyra cepholonica, and the fig moth Ephestia cautella infest the fruits during storage. The borer Rhyzopertha dominica infests tamarind seeds during storage. Larvae of the groundnut bruchid beetle are serious pests that attack the fruit and seed in India while Bacterial leaf-spot is caused by Meliola tamarindi. Rots attacking the tree include saprot (Xylaria euglossa) brownish saprot (Polyporus calcuttensis), and white rot (Trametes floccosa). The tamarind tree is also susceptible to nematodes (e.g. Xiphinema citri and Longidorus elongates) that attack the roots of older trees. Other minor pests in India include lac insect and bagworms.

22.6


22.6.1 Temperature management Storage for long periods under poor conditions, such as exposure to extremes of temperature and humidity, causes gradual changes in color from brown or yellowish-brown to black colors (FAO, 1989). Also, high temperatures cause pulp to lose moisture and become sticky and curved. 22.6.2 Water loss Drying the fruits in the sun for 3–4 days is used to remove excess moisture and prevent the growth of molds. However, severe dehydration associated with sharp water loss causes curving of the fruits which are considered of lower quality compared to straight pods (Yahia, 2004). 22.6.3 Physical damage The main problem with fresh sweet tamarind is the damage caused by packaging, which deteriorates the fruit quality and reduces the amount of consumable fruit. Also harvesting the fruits, which is usually done by shaking the branches, might result in fruit damage. A better quality of fruit could be obtained by using scissors to harvest the fruits, especially in the case of the sweet tamarind type.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

452 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

22.7



22.7.1 Harvest operations Pod yield stabilizes at about 15 years and continues for up to 50 or 60 years. Tamarind fruits are mature and ready for harvesting when a hollow and loose sound is produced by finger pressing, as the pulp shrinks with maturity and the shell becomes brittle. Also, the change in testa color might indicate the maturity of the fruit. However, it is not always easy to determine whether the fruits are ready for harvesting, as the testa color only changes slowly as the pods mature. Individual fruits on the same tree also mature at different times, making selective harvesting necessary. Pods are harvested at different stages of ripeness, according to how they are going to be used. Immature green fruits are usually harvested earlier for flavoring. In most countries, the sour tamarind ripe fruits are usually gathered by shaking the branches and collecting the fruits that have fallen; the remainder of the fruit is left to fall naturally when ripe. Sweet tamarind fruits tend to gain higher market prices, and therefore are carefully picked by hand. To avoid damaging the pods and to increase the marketability of both sweet and sour types, harvesting by clipping should be practiced (Coronel, 1991). Pickers should not knock the fruits off the tree with poles, as this will damage developing flowers and leaves. Generally, the fruits are left to ripen on the tree before harvesting, so that the moisture content is reduced to about 20%. If unharvested, the pods may remain hanging on the tree for almost one year after flowering and sometimes until the next flowering period (Chaturvedi, 1985), and eventually will fall naturally. Fruits for immediate processing are often harvested by pulling the pod away from the stalk, which is left with the long, longitudinal fibers attached. Beetles and fungi readily attack ripe fruit in humid climates, and therefore they should be harvested before they are fully ripe.

22.7.2 Packinghouse practices One of the most important operations in a packing line is sorting for maturity, color, shape, size, and defects. The efficiency and effectiveness of sorting govern the quality standard of the packing lines and product (Office of Thai Agricultural Commodity and Food Standard, 2003), which in turn determines the marketability of the product. Manual sorting continues to be the most prevalent method used, although it is costly in terms of labor and time. Also, the lack of trained labor is one of the reasons that manual sorting may become inefficient and cause damage. One of the most practical and successful techniques for nondestructive quality evaluation and sorting of agricultural products is the electro-optical technique, which judges the optical properties of the product (Chen, 1996). This technique, which can be used to detect color uniformity, shape, size, external defects, foreign materials, and disease, has been used for postharvest grading for a wide variety of agricultural products including tamarind. Jarimopas et al. (2008) proposed packaging in a sleeve design, 15 cm in diameter by 20 cm in height, containing a mixture of 5 mm foam balls and sweet tamarind inserted vertically. This packaging



453

imparts 15 to 16% of the damage of conventional packaging and costs half the price. 22.7.3 Control of ripening and senescence Tamarind fruit, as a non-climacteric (Yahia, 2004), will not ripen any further after harvest. The flavor, juice, sugars and some other contents remain unchanged. No information is readily available on techniques for controlling tamarind ripening. 22.7.4 Recommended storage and shipping conditions The high soluble solids content to titratable acidity (SSC : TA) and the low water content of tamarind fruit contributes to its long storage-life. Tamarind can be stored with the shell, or as a separated dry pulp, and tightly packaged pods can be stored at 20 °C for several weeks. The pulp of mature tamarind is commonly compressed and packed in palm leaf mats or plastic bags and stored at 20 °C for a significant period when processed into paste. It can be frozen and stored for one year, or refrigerated for up to six months. Under dry conditions the pulp remains good for about one year, after which it becomes almost black. In humid weather, especially, the pulp becomes soft and sticky as pectolytic degradation takes place and moisture is absorbed (Lewis and Neelakantan, 1964a; Anon, 1976). During storage, the dry, dark-brown pulp becomes soft, sticky, and almost black. The pulp can be stored for a longer period after drying or steaming. According to the research findings of CFTRI (Central Food Technological Research Institute, Mysore, India), the pulp could be preserved well for 6–8 months, without any treatment, if it is packed in airtight containers and stored in a cool dry place (Shankaracharya, 1997). The tamarind kernel powder is liable to deterioration during long storage, particularly in a moist environment; thus a dry place in moisture proof containers is preferred, after suitable fumigation. The powder may be mixed with 0.5% of sodium bisulphite before packing to prevent enzymic deterioration (Anon, 1976).

22.8

Processing

22.8.1 Processing of tamarind pulp Fresh-cut processing is not an industrial practice: it is usually carried out on a smaller scale when the fruits are intended to be eaten immediately. Fresh-cut tamarind is processed to make tamarind balls mixed with sugar after removing the shells, seeds and fibers. In Asia, the immature green pods are often eaten dipped in salt as a snack. In the Bahamas the unripe pods are roasted in coal, peeled back and the sizzling pulp is dipped in wood ash and eaten. In processing factories, tamarind pulp is separated from the fiber and seed, then mashed with salt before being packed into bags and if tamarind is intended to be stored for a long period, drying or freezing is required. To preserve tamarind,


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

454 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


the fruit are shelled, layered with sugar in boxes or pressed into tight balls and covered with cloth and kept in a cool and dry place. For shipment, tamarinds may be shelled, layered with sugar in barrels and covered with boiling syrup. East Indians shell the fruit and sprinkle them lightly with salt as a preservative. In Java, the salted pulp is rolled into balls, steamed and sun-dried, then exposed to dew for a week before being packed in stone jars. In India, the pulp, with or without seeds and fibers, may be mixed with salt (10%), pounded into blocks, wrapped in palm-leaf matting, and packed in burlap sacks for marketing. To store for long periods, the blocks of pulp may be first steamed or sun-dried for several days. During pre-processing, fresh tamarind fruit is subjected to sun-drying or small scale dehydrators are sometimes used. The dry fruit is cracked, the pulp and fibers are separated and the seeds are removed. Pods can be store for several weeks at 20 °C. Also, pulps can be stored for 4–6 months at 10 °C by packing in high density polythene. Mixing with salt can extend the storage period to one year. Tamarind juice is usually prepared by boiling tamarind pulp in water and filtering the juice to remove the pulp before pouring into bottles and sealing. Tamarind concentrate is easily dispersible in water, and can be used for many purposes, such as in ketchups, sauces, soft drinks, dairy products and as a souring agent. It is prepared by soaking the tamarind pulp in water and boiling, separating fine and pulpy matter using a filter, then pressing the residue and mixing this with the extract. The filtered extract is concentrated by evaporating it in a vaccum, filling containers, cooling and sealing, and storing in airtight plastic or glass bottles or cans, in the dark, for over a year. Tamarind is often further processed into drinks and sweets or packaged into more convenient forms for export. In some parts of India, it is made into a jelly by mixing with water and sieving. It is then compressed into moulds and can be cut like cheese when required. 22.8.2 Processing of tamarind seed The hard, brown outer testa has to be completely removed from the kernel to prevent it from causing undesirable effects such as depression, constipation, and gastrointestinal inflammation, so the testa is separated from the kernels by either roasting or soaking the seed in water. Washing the seeds helps to remove the adhering pulp and to float away partially hollow infected seeds. When roasting, the temperature and duration of heating should be controlled to avoid the development of any undesirable characteristics in the isolated gum (Anon, 1976). The parched seed is then fed into a grain cleaner to remove the testa and dirt (Whistler and Barkalow, 1993). Very white tamarind kernel powder can be obtained by hydrating the seeds at room temperature for 24 hours, drying in the shade for 24 hours and then sand roasting at 125–175 °C for 3–8 minutes. Different processing methods to remove the testa were reported by Kumar and Bhattacharya (2008).



22.9

455

Conclusions

The intrinsic value of raw tamarind can be further enhanced through value addition activities and there is a good market for these processed products both in the domestic as well as in international markets.

22.10

References

Allen ON and Allen EK (1981), The Leguminosae: A Source Book of Characteristics, Uses and Nodulation, Madison, WS, University of Wisconsin Press. Anon (1955), Tamarind seed has many uses. Forest Research Institute. Dehra Dun, India. Indian Farming, 5, 21–24. Anon (1976), Tamarindus. In The Wealth of India (Raw materials series), Vol X: 114–120. Council of Scientific and Industrial Research, New Delhi, India. Bhattacharya S (1990), ‘A study on the processing and utilization of tamarind (Tamarindus indica) kernel for food uses’, PhD thesis, Post Harvest Technology Centre, Indian Institute of Technology, Kharagpur, India. Bhattacharya, S. (1997). ‘Utilisation of tamarind seed kernel in food industry’. In: Proceedings of National Symposium on Tamarindus indica L., Tirupathi, India, pp 162–168. Bhattacharya S, Bal S, Mukherjee RK, and Bhattacharya S (1994), Functional and nutritional properties of tamarind (Tamarindus indica) kernel protein, Food Chemistry, 49, 1–9. Bleach MF, Guillemin F, Baure L and Hartemann P (1991), Preliminary study of antimicrobial activity of traditional plants against E. coli. Zentralblatt hygiene und umweltmedizin, 192(1), 45–56 (English summary). Bueso CE (1980), ‘Soursop, tamarind and chironja’. In: Nagy S and Shaw PE (eds) Tropical and Subtropical Fruits, AVI Pub, Westport CT, pp. 375–406. Butani DK (1978), Insect pests of tamarind and their control, Pesticides, 12(11), 34–41. Butani DK (1979), Insects of Fruits, Periodical Export Agency, Vivek Vihar, Delhi, p. 415. Chaturvedi AN (1985), Firewood farming on the degraded lands of the Gangeticplain, U. P. Forest Bulletin, No.50. Lucknow, India Government of India Press 1, 286. Chen J, Ji YZ and Shujuan HX (1988), Effect of tamarind seed polysaccharide on the storage of pineapple fruits, Zhiwu Shenglixre Tongxun, 4, 30–32. Coates-Palgrave K (1988), Trees of Southern Africa, 10. Tamarindus indica L. C. S. Striuk Publishers, Cape Town, pp. 278–279. El-Siddig K, Gunasena HPM, Prasad BA, Pushpakumara DKNG, Ramana KVR, et al. (2006), Tamarind (Tamarindus indica L.), Southampton Centre for Underutilised Crops, W. Sussex, England. FAO (1988). Fruit Bearing Trees. Technical notes. FAO-SIDA Forestry Paper, 34, 165–167. FAO (1989), Prevention of Post-harvest Losses: Fruits, Vegetables and Root Crops, FAO Training Series No 17/2, Rome. Hasan SK and Ijaz S (1972), Tamarind – A review, Sci Indus Pakistan, 9, 131–137. Hernadez-Unzon HY and Laksminarayana S (1982a), Developmental physiology of tamarind fruit (Tamarindus indica L.), HortScience, 17, 938–940. Hernadez-Unzon HY and Laksminarayana S (1982b), Biochemical changes during development and ripening of tamarind fruit (Tamarindus indica L.), HortScience, 17, 940–942. Hort A (1916), Theophrastus; Enquiry into Plants, Heinemann, London. Imbabi ES and Abu-Al-Futuh IM (1992), Investigation of the molluscicidal activity of Tamarindus indica L., International Journal of Pharmacology, 30(2), 157–160.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

456 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Ishola M, Agbaji B and Agbaji AS (1990), A chemical study of Tamarindus indica (Tsamiya) fruits grown in Nigeria, J Sci Food Agric, 51, 141–143. Jambulingam R and Fernandes ECM (1986), Multipurpose trees and shrubs in Tamilnadu state (India), Agroforestry Systems, 4, 17–32. Jarimopas B, Sirisomboon P, Sothornvit R and Terdwongworakul A (2008), ‘The development of engineering technology to improve the production of tropical fresh produce in the developing countries’. In: Pletney, Vivian N. (ed.), Focus on Food Engineering Research and Development, Nova Science Publishers, Inc., New York. Jayaweera DMA (1981), ‘Medicinal plants (indigenous and exotic) used in Ceylon’, Part 111. Flacourtiaceae-Lytharaceae. A publication of the National Science Council of Sri Lanka, pp. 244–246. Joseph KV and Oommen P (1960), Notes on some insect pests infesting dry tamarind fruits in Kerala State, Indian Journal of Entomology, 22(3), 172–180. Khairunnuur FA, Zulkhairi A, Azrina A, Moklas MAM, Khairullizam S, et al. (2009), Nutritional composition, in vitro antioxidant activity and Artemia salina L. lethality of pulp and seed of Tamarindus indica L. extracts, Mal J Nutr, 15(1), 65–75. Khanzada SK, Shaikh W, Sofia S, Kazi TG, Usmanghani K, et al. (2008), Chemical constituents of Tamarindus indica L. medicinal plant in Sindh, Pak J Bot, 40(6), 2553–2559. Koichi N, Masaaki T and Yukiyoshi T (1997), Antiobesity agent containing procyanidin as the active agent, Chemical Abstract, 127, 126638. Kuwano K, Suzuki J, Oowadani K, Shiratawa M (1995), Xyloglucan for inhibition of fat increase, Japanese Patent, 07, 147, 934. Lefebvre JC (1971), Tamarind – A Review, Fruits, 26, 687–695. Lewis YS and Neelakantan S (1964), The real nature of tamarind anthoxanthin, Curr Sci, 15, 460. Luengthanaphol S, Mongkholkhajornsilp D, Douglas S, Douglas PL, Pengsopa L and Pongamphai S (2004), Extraction of antioxidants from sweet Thai tamarind seed coatpreliminary experiments, J Food Engineering 63, 247–252. Maiti R, Jana D, Das UK and Ghosh D (2004), Antidiabetic effect of aqueous extract of seed of Tamarindus indica in streptozotocin-induced diabetic rats, J Ethnopharmacol, 92(1), 85–91. Marangoni A, Ali I, Kermasha S (1988), Composition and properties of seeds of the true legume Tamarindus indica, J Food Sci, 53, 1452–1455. Morton J (1987), Fruits of Warm Climates, Miami, FL, pp. 115–121. Morton JF (1958), The tamarind, its food, medicinal and industrial uses, Proc Fla State Hort Soc, 79, 355–366. Office of Thai Agricultural Commodity and Food Standard (2003), Thai Agricultural Commodity and Food Standard, No. TACFS 5-2003, Mango. Ministry of Agriculture, pp. 6. Osawa T, Tsuda T, Watanabe M, Ohshima K and Yamamoto A (1994), Antioxidative components isolated from the seeds of tamarind (Tamarindus indica L.), J Agric Food Chem, 42, 2671–2674. Osumu B, Junko S, Mayumi S and Kazuhiko Y (1997), Lipid increase inhibitors containing xyloglucan, Chemical Abstract, 127, 247372. Patino VM (1969), ‘Plantes cultivadas y animales domesticos en America equinoccial. Tomo IV. Plantes introducidas Imprenta Departamental’, Cali, Colombia, 233–235. Rama Rao (1975), Flowering Plants of Travencore, Dehra Dun, India: Bishen Singh Mahendrapal Singh, 484 p. Rao PS (1948), Tamarind seed (jellose pectin) and its jellying properties, J Sci Ind Res, 68, 89–90. Reddy SG, Rao JMS, Achyutaramayya D, Azeemoddin G and Rao TSD (1979), Extraction, characteristics and fatty acid composition of tamarind kernel oil, J Oil Technol Assoc India, 11, 91–93.



457

Rimbau V, Cerdan C, Vila R and Iglesias J (1999), Antiinflammatory activity of some extracts from plants used in the traditional medicine of North-African countries, Phytotherapy Research, 13(2), 128–132. Senguttuvan T (2000), Insect pest associated with three semi arid fruits under agroforestry, Insect Environment, 6(2), 78. Shankaracharya NB (1998), ‘Chemical and Technological Aspects of Tamarindus Indica Fruit.’, Proc. Nat. Sym. on Tamarindus indica L, Tirupathi (A.P.), organized by Forest Dept. of A.P., India, 27–28 June, 1997, pp. 226–30. Tsuda T, Fukaya Y, Ohshimo K, Yamamoto A, Kawakishi S and Osawa T (1995a), Antioxidative activity of tamarind extract prepared from the seed coat (Japanese), J Japanese Food Sci Technol (Nippon-Shokuhin-Kogyo- Gakkaishi), 42, 430–435. Tsuda T, Watanabe M, Ohshima K, Yamamoto A, Kawakishi S and Osawa T (1994), Antioxidative components isolated from the seeds of tamarind (Tamarindus indica L.), J Agric Food Chem, 42, 2671–2674. von Maydell HJ (1986), Trees and Shrubs of Sahel. Their Characteristics and Uses, Deutsche Gesellschaft für Technische Zusammenarbeit, Eschborn, Germany. Yaacob O and Subhadrabhandu S (1995), The Production of Economic Fruits in South East Asia, Oxford University Press, 133–142. Yahia EM (2004), ‘Date’, in: U.S. Dept. Agric. Agric. Handbook #66: (http://www.ba.ars. usda.gov/hb66/index.html).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

(a)

(b)

Plate XXXVIII

(Chapter 22) (a) Packaged Tamarind from Mexico; (b) Tamarind in a local market in Mexico.

(a)

(b)

Plate XXXIX

(Chapter 22) (a) Tamarind tree; (b) Tamarind pods.


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

23 Wax apple (Syzygium samarangense (Blume) Merr. and L.M. Perry) and related species Z.-H Shü, Meiho University, Taiwan, C.-C. Shiesh and H.-L. Lin, National Chung-hsing University, Taiwan

Abstract: The wax apple (Syzygium samarangense (Blume) Merr. and L.M. Perry), belongs to Myrtaceae and has been commercially planted in many countries, such as Taiwan, Thailand, Indonesia and Malaysia. There are two major parts in this chapter: the first part introduces the origin, biology and preharvest cultural practices; the second part deals with postharvest handling and storage. The fruit of the wax apple is fragile, non-climacteric with a short shelf life. Water loss is a big problem for wax apple storage so to keep the moisture and decrease the perishing process, modified atmosphere packaging with temperatures between 10 to 12 °C is recommended for the storage of wax apple fruits. Key words: Syzygium samarangense, wax apple, postharvest, handling, storage.

23.1

Introduction

23.1.1

Origin, botany, morphology and structure

Origin and worldwide importance The wax apple (Syzygium samarangense (Blume) Merr. and L.M. Perry; other names are Java apple, wax jambu and water apple), which belongs to the Myrtaceae, is native to the Malaysian Archipelago and to the Andaman and Nicobar islands where the trees grow in coastal rainforests (Morton, 1987). Other species with similar fruits for fresh consumption that are commercially important are the water apple Syzygium aqueum, the rose apple Syzygium jambos, and the Malay apple Syzygium malaccense (Nakasone and Pall, 1988). All these species have spread throughout the tropical areas of the world. The fruit of Syzygium jambos, the rose apple, is relatively round to oval shaped and has the scent of a rose (Morton, 1987).


Wax apple (Syzygium samarangense (Blume) Merr. and L.M. Perry)

459

The flower and fruit of Syzygium malaccense, the Malay apple, are the most beautiful of those of the four species. The fruit of the water apple (Syzygium aqueum) is very similar to that of the wax apple (Syzygium samarangense), but it is smaller and insipid. The fruit of the wax apple is larger and sweeter (Shü and Paull, 2008; see Plate XL in the colour section between pages 238 and 239) and since it is the most delicious, it has been commercially planted in many countries, such as Taiwan, Thailand, Indonesia and Malaysia (Shü et al., 2008, 2009). Most research focuses on Syzygium samarangense since it is the only species commercially planted on a large scale among the four important freshly consumed species. The introduction of the biology, production and postharvest technology of the present article are thus based primarily on Syzygium samarangense. Biology The tree of the wax apple can grow to a height of 5–15 m depending on environmental conditions (Young, 1951), with flowers appearing in March in south Taiwan and fruits ripening in May under natural conditions. Fruits vary greatly in size, shape and skin color. The fruit size can be as small as about 4.3 cm long and 4.7 cm wide to more than 5.2 cm long and 5 cm wide (bell-shaped) or 7 cm long and 4 cm wide (elongated). Fruit mass ranges from 28 g to 100 g to the jumbo sized of more than 200 g per fruit. Fruit shape ranges from round to bell-shaped, oval or elongated and skin color diverges from white to pale green to dark green, pink to red to deep red. The fruit of wax apple are sweet when eaten fresh or cooked. Therefore they are better for eating than the Malay apple and other species in the same genus. A small percentage of the fruit is used for sauces, jams and jellies. Wax apple trees are tropical and cannot tolerate temperatures below 7 °C, preferring temperatures above 18 °C (Kuo, 1995; Huang et al., 2005). Fruits of wax apples prefer warm temperatures for normal growth and development as low temperatures impede fruit growth and red color development, while high temperatures accelerate fruit growth and ripening but inhibit red color development. The flesh is juicy, fragrant, crisp and sweet. Water content of the fruit is 92.9%, protein 0.35%, carbohydrate 6%, crude fiber 0.46% and ash (minerals) 0.21% (Shü and Paull, 2008). Flowering and fruiting ‘Pink’ is the leading cultivar, representing 85% of the planted areas in Taiwan (Shü et al., 2007; Wang, 2006). Flowers appear in March in south Taiwan and fruits ripen in May under natural conditions (Young, 1951). However, ‘Pink’ blooms and sets fruit almost year-round after flower forcing (Shü et al., 1996; Wang, 1991). As a result, fruits at different growing stages could be found in different orchards, on different trees and even on the same tree. The wax apple is a heavy producer on well-fertilized good soils and can produce more than 200 clusters per tree, with 4–5 fruits in each cluster when mature (see Plate XLI in the colour section). Average fruit weight of the ‘Pink’ variety is about 100 g, however a single fruit of ‘Big Fruit’, mutants of ‘Pink’, weighs from 150 g to more than 200 g (Chiu, 2003).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

460 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Climates and soils Wax apples prefer full sunlight for normal growing and fruiting, although they tolerate shade (Wang, 1991), and the best growing temperature for wax apple is around 25 °C. Temperatures under 8 °C may cause severe damage, both on the fruits and leaves. The wax apple can be grown on very wide range of soils from sandy to clayey and from acid to alkaline. However, for best fruit quality, fertile, wet and slight alkaline soils are preferred. Cultivars The wax apple, being planted commercially, has many cultivars. ‘Pink’ has been the leading cultivar in Taiwan, but other important cultivars in Taiwan are ‘Black King Kong’, ‘Light Red’, ‘Dark Red’, ‘Green’, ‘White’, and ‘Malacca’ (Shü et al., 2007). The major wax apple cultivars in Thailand are ‘Ma Mieaw’, ‘Nam Dokmai’, ‘Gam Hmam’, ‘Kaeg Dam’ and ‘Thub Thim Chan’. There are four cultivars grown in Malaysia, namely, ‘Pale Green’, ‘Dark Red’, ‘Light Red’ and ‘Green’ (Shü et al., 2008). Indonesia has the most abundant varieties, where wax apples are mostly grown as backyard trees covering an area of a couple of villages in a district, also known as ‘centers of production’. The largest centers of production are in Java and Madura Island. The most popular local cultivars are ‘Citra’, ‘Cincalo’, ‘Lilin Merah’, ‘Camplong’, ‘Kaget’, and ‘Semarang Prada’ (Shü et al., 2008). Propagation The wax apple can be propagated using seeding, cutting, grafting or air-layering (the most commonly used method). Most often air-layering is practiced during warm and wet seasons when wax apple trees grow rapidly. The bark, together with the vascular cambium, on two- to three-year-old healthy branches are removed (girdled) first for air-layering practice. The remaining wood (secondary xylem) are covered with wetted sphagnum moss and then covered with a plastic film to keep the moisture. It takes about one month to initiate new roots from the abaxial sides of the barks where girdles were taken. The rooted branches are removed from the mother plants when roots are well developed and brown in color (Wang, 2006). Planting The wax apple trees can be planted from 5 m × 5 m to 7 m × 8 m depending on different management systems. Avoid overcrowding of the trees and branches since this may cause self-shading, extra pest control practices, and branch die-back which reduces yield and produces low-quality fruits (Wang, 2006). Training and pruning Canopy size is important for wax apple tree management and fruit quality. Usually good quality wax apple fruits are located at the lower parts of the canopy, either



461

on the big branches or on the truck. Adequate canopy size control is extremely important for keeping fruit quality high since commercial wax apple trees bear fruits two to three times per year (Wang, 2006). Suitable training to keep the tree at medium size (averaging about 3 m high) is important since it saves labor on pruning, bagging, spraying, thinning fruits or harvesting. Besides, shorter trees are more resistant to strong wind damage. For wax apple tree production there are mainly three training systems, namely bald-cut, semi-bald cut and evergreen, with heavy, medium and light pruning practices, respectively, used in Taiwan (Fig. 23.1a, b; Shü et al. 2007; Wang, 2006).

Fig. 23.1

Evergreen (a) and bald-cut (b) training systems (courtesy of Chi-cho Huang).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

462 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X


Fertilization Adequate fertilization is very important for high yield and quality fruits. The amount of fertilizer to apply varies depending on tree age, size, vigor, yield, soil property and growing stages. Although experience is important, soil and leaf diagnosis are recommended for adequate fertilization (Wang, 2006). Off-season production 1. Advantages Normal flowering and harvesting periods for wax apples are from March to July and from May to September in Taiwan. Both the quality and price of the fruits produced during the normal harvesting periods are not acceptable to many consumers and farmers. Off-season production for wax apples means shifting the harvesting from summer to winter. Fruit quality and price are much more favorable for fruits produced in winter than in summer because winter fruits, due to a longer growing season and fewer pests, are bigger, crispier, sweeter, juicier, seedless and thicker in flesh (Wang, 2006). Nitrogen control, water logging, root pruning, trunk injury and canopy shading are commonly used methods of off-season production. Fruit quality improvement The quality of the wax apple fruit is closely related to the season and growing region. For example, the fruit produced in summer has greater weight and volume, while the fruit produced in winter has more total soluble solids concentration and hardiness (Chen, 2006; Lo, 2008). Wax apple fruits from Linbian have the darkest red color in summer, while fruits from the Liugui and Chaozhou areas in Taiwan have the darkest red color in winter (Chen, 2006). Position on the tree also influences quality of wax apple fruits, with the fruit on the lower trunk being heaver while the upper inner fruits have the reddest color (Shü, 1999). Anthocyanin and total soluble solids concentrations (SSC) were greater in the 20 °C treated discs when a skin disc in vitro culture system was used to study the effects of temperatures on fruit quality of wax apple (Pan and Shü, 2007). Among the 18 combinations, light/20 °C/6% sucrose gave the highest SSC and anthocyanin content, while dark/20 °C/6% sucrose produced the largest diameter (Shü et al., 2001). Sucrose at various concentrations enhanced the red color of the cultured fruit discs (Liaw et al., 1999). Fruit discs from the rapid growth stage to the red stage, i.e. from 4 to 8 weeks after anthesis, had greater anthocyanin induction potential than the other stages when cultured with 6% sucrose (Chang et al., 2003). Wax apple fruits treated with N-(2-chloro-4-pyridyl)-N′-phenylurea (CPPU, a synthetic cytokinin) had greater fruit volume, weight and flesh thickness than that of the control (Shü and Yeh, 1998). Manganese sulfate sprays at 1.5% or 2.0% four times at an interval of 14 days for three weeks after petal fall increased anthocyanin concentration (Lee, 2003).



463

23.1.2 Worldwide importance The wax apple has been planted as a backyard tree or only consumed either locally or domestically in some areas, but planted on a commercial scale for decades in others. In recent years wax apple fruits have been treated as an international trading commodity, and have been shipped to China, Hong Kong, Singapore, Canada and other foreign markets from Taiwan. Thailand has been sending wax apple fruits to China as well. However, before the perishable problems are solved, there is little potential for wax apple fruits to become a large international trading commodity. 23.1.3 Culinary uses, nutritional value and health benefits Wax apple fruits are primarily consumed fresh. The nutritional value of the fruit is as follows (for every 100 g): calorie 34 Kcal, water 90.6 g, crude protein 0.5 g, crude fat 0.2 g, carbohydrate 8.6 g, crude fiber 0.6 g, dietary fiber 1.0 g, ash 0.2 g, vitamin B1 0.02 mg, vitamin B2 0.03 mg, vitamin B6 0.03 mg, niacin 0.03 mg, vitamin C 6.0 mg, sodium 25 mg, potassium 340 mg, calcium 28 mg, magnesium 13 mg, phosphorus 35 mg, iron 1.5 mg, zinc 0.2 mg (http://www.doh.gov.tw/Food Analysis/). The genus of Syzygium comprises more than 500 species occurring in the tropics and subtropics. Some of the species, such as S. aromaticum, S. cordatum, S. cumini, S. jambolanum, S. jambos and S. samarangense, have been reported to have medical usage, such as diabetes or glucose tolerance impairment (Kelkar and Kaklij, 1996; Nagaraju and Rao, 1989, 1997; Prince et al., 1998; Rao and Rao, 2001; Stanely Mainzen et al., 1998; Teixeira et al., 1997; Thammanna et al., 1994; Toda et al., 2000), as well as inflammation (Chaudhuri et al., 1990; Kim et al., 1998; Muruganandan et al., 2001). They have also been used as anticonvulsant and sedative (De Lima et al., 1998), as antihypertensive (Bhargava et al., 1968), antimicrobial (Djadjo Djipa et al., 2000), against herpes virus (Kurokawa et al., 1998) and as an inhibitor of histamine release (Kim et al., 1998). An anti-inflammatory activity from Syzygium jambos leaf extracts was reported by Slowing et al. (1994a, b). The bark, leaves and roots of Syzygium cordatum are used for tuberculosis, diarrhea, stomach and respiratory complaints management in South Africa (Van Wyk et al., 1997). Syzygium alternifolium seed powder can be used for fevers and skin diseases (Thammanna et al., 1990). The antioxidant property of Syzygium cumini is well known (Prince et al., 1998) and juices of the fruits are stomachic, astringent and diuretic (Nadkarni and Nadkarni, 1976). Syzygium jambos extract has remarkable analgesic effects (Ávila-Peńa, 2007). Four cytotoxic and eight antioxidant compounds identified in the fruits (Simirgiotis et al., 2008) and four flavonoids, showing inhibitory potency on peripheral blood mononuclear cells (PBMC), were isolated from the leaves of Syzygium samarangense (Kuo et al., 2004).


1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

464 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 20 1 2 3 4 5 6 7 8 9 30 1 2 3 4 5 6 7 8 9 40 1 2 43 44 45X

23.2



23.2.1 Fruit growth, development and maturation The kinetics of fruit growth of the wax apple indicates single sigmoid curves. The firmness of the fruit decreases at late stages of fruit development while fruit color turns red gradually as the anthocyanin content increases. The chlorophyll concentration increases during early fruit development, then decreases and maintains a constant level until harvest, while total soluble solids of the fruit increase with fruit development. The concentrations of free amino acids and soluble protein of wax apple fruits are at their highest 20 days after full bloom, then diminished abruptly (Shü et al., 1998). 23.2.2 Respiration, ethylene production and ripening Both the fruits of wax apple (Akamine and Gao, 1979; Chiang, 2005; Hwang, 1998) and Malay apple (Basanta, 1998) are non-climacteric fruits. The respiration rate for the wax apple is steady at 65–75 ml CO2.kg−1.hr−1 and without a respiration peak at 25 °C (Liao et al., 1983). The rate reduces or increases when temperatures are reduced or increased, respectively; for example, respiration rate reduces to 15–25 ml CO2 kg−1.hr−1 at 5 °C and in summer increases to 1.5 times that of the respiration rate in winter (Horng, 1988). Wax apple fruits produce low concentration of ethylene (

Postharvest biology and technology of tropical and subtropical fruits: Volume 4: Mangosteen to white sapote

Postharvest Biology and Technology of Fruits, Vegetables, and Flowers

Underutilized Fruits and Nuts Vol.2: Fruits of tropical region

Postharvest Diseases of Fruits and Vegetables: Development and Control

Color Atlas of Postharvest Quality of Fruits and Vegetables

Color atlas of postharvest quality of fruits and vegetables

Diseases of Tropical and Subtropical Fruit Crops (Cabi Publishing)

HYPERSPECTRAL REMOTE SENSING OF TROPICAL AND SUBTROPICAL FORESTS

Processing fruits: science and technology

Plant Parasitic Nematodes in Subtropical and Tropical Agriculture

Communication Systems and Information Technology, Volume 4

Tropical Fruits and Frugivores: The Search for Strong Interactors

Volume 3, Fruits

Volume 3, Fruits

Diseases of Fruits and Vegetables: Volume II: Diagnosis and Management

Wiley Encyclopedia of Food Science and Technology, 4 Volume Set

Volume 2, Fruits

Microbiology of Fruits and Vegetables

Fruits and Nuts

Fruits and Nuts

Postharvest Pathogens and Disease Management

Research Priorities in Tropical Biology

White House Studies Compendium ~ Volume 4

Advances in Molecular and Cell Biology Volume 15b BIochemical Technology

Potatoes Postharvest

Comprehensive Natural Products II: Chemistry and Biology: Volume 4

Carbohydrates in Chemistry and Biology 4 Volume Set

Tropical Fruits, 2nd Edition, Volume 1 (Crop Production Science in Horticulture, Volume 20)

Tropical Fruits, Volume 1 (Crop Production Science in Horticulture, Volume 20)

MEMS and Nanotechnology, Volume 4

Tropical environments: the functioning and management of tropical ecosystems

Postharvest biology and technology of tropical and subtropical fruits: Volume 4: Mangosteen to white sapote

Postharvest Biology and Technology of Fruits, Vegetables, and Flowers

Underutilized Fruits and Nuts Vol.2: Fruits of tropical region

Postharvest Diseases of Fruits and Vegetables: Development and Control

Color Atlas of Postharvest Quality of Fruits and Vegetables

Color atlas of postharvest quality of fruits and vegetables

Diseases of Tropical and Subtropical Fruit Crops (Cabi Publishing)

HYPERSPECTRAL REMOTE SENSING OF TROPICAL AND SUBTROPICAL FORESTS

Processing fruits: science and technology

Plant Parasitic Nematodes in Subtropical and Tropical Agriculture

Communication Systems and Information Technology, Volume 4

Tropical Fruits and Frugivores: The Search for Strong Interactors

Volume 3, Fruits

Volume 3, Fruits

Diseases of Fruits and Vegetables: Volume II: Diagnosis and Management

Wiley Encyclopedia of Food Science and Technology, 4 Volume Set

Volume 2, Fruits

Microbiology of Fruits and Vegetables

Fruits and Nuts

Fruits and Nuts

Postharvest Pathogens and Disease Management

Research Priorities in Tropical Biology

White House Studies Compendium ~ Volume 4

Advances in Molecular and Cell Biology Volume 15b BIochemical Technology

Potatoes Postharvest

Comprehensive Natural Products II: Chemistry and Biology: Volume 4

Carbohydrates in Chemistry and Biology 4 Volume Set

Tropical Fruits, 2nd Edition, Volume 1 (Crop Production Science in Horticulture, Volume 20)

Tropical Fruits, Volume 1 (Crop Production Science in Horticulture, Volume 20)

MEMS and Nanotechnology, Volume 4

Tropical environments: the functioning and management of tropical ecosystems

Recommend Documents