Printed in Austria V.05-91153—March 2006—300
Herbs, spices and essential oils Post-harvest operations in developing countries
UNITED NATIONS INDUSTRIAL DEVELOPMENT ORGANIZATION Vienna International Centre, P.O. Box 300, 1400 Vienna, Austria Telephone: (+43-1) 26026-0, Fax: (+43-1) 26926-69 E-mail:
[email protected], Internet: http://www.unido.org
UNITED NATIONS INDUSTRIAL DEVELOPMENT ORGANIZATION
FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS
© UNIDO and FAO 2005 — First published 2005 All rights reserved. Reproduction and dissemination of material in this information product for educational or other non-commercial purposes are authorized without any prior written permission from the copyright holders provided the source is fully acknowledged. Reproduction of material in this information product for resale or other commercial purposes is prohibited without written permission of the copyright holders. Applications for such permission should be addressed to: -
the Director, Agro-Industries and Sectoral Support Branch, UNIDO, Vienna International Centre, P.O. Box 300, 1400 Vienna, Austria or by e-mail to
[email protected] -
the Chief, Publishing Management Service, Information Division, FAO, Viale delle Terme di Caracalla, 00100 Rome, Italy or by e-mail to
[email protected] The designations employed and the presentation of material in this information product do not imply the expression of any opinion whatsoever on the part of the United Nations Industrial Development Organization or of the Food and Agriculture Organization of the United Nations concerning the legal or development status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. The views expressed in this publication are those of the authors and do not necessarily reflect the views of the United Nations Industrial Development Organization and of the Food and Agriculture Organization of the United Nations. The mention or omission of specific companies, their products, or brand names does not imply any endorsement or judgement by the United Nations Industrial Development Organization or by the Food and Agriculture Organization of the United Nations. This publication has not been formally edited. Thumbnail images of spices were taken from http://www.indianspices.com/html/s2100lst.htm, for which permission has been sought by the authors.
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PREFACE There is a continuing and expanding international demand for herbs, spices and essential oils. Social changes, including food diversification, the desire for new flavours, increasing importance of “ethnic” food and the increased importance of processed food, which requires condiments and aromatic herbs for its preparation, are driving an increase in this demand. Developing countries have a significant opportunity to benefit from this increasing demand. Many of the products can be sold in a dried form or as extracts (e.g. essential oils), which gives them a high value per unit weight. These products could be a profitable source of diversification for small farmers in developing countries. It is in this connection that FAO and UNIDO decided to support this publication to give extension services and small-scale producers basic information on processing herbs and spices in view of increasing the awareness on this area of industry and improving the quality and marketability of these products. Spices and condiments are defined as “Vegetable products or mixtures, free from extraneous matter, used for flavouring, seasoning or imparting aroma in foods.” Herbs are a subset of spices, generally derived from fresh or dried leaves, but in this guide no distinction is made between spices and herbs, in keeping with the International Standards Organization (ISO) definition. Essential oils or extracts are also derived from these plant sources either as a primary processing or a secondary opportunity. This guide is a broad introduction to generic post-harvest operations, which are often the limiting factors in the establishment of a profitable production enterprise based around herbs, spices and essential oils in developing countries. It is not intended to replace specialist and specific crop advice in production and post harvest processing which is available in publications and from experts. This guide was prepared by M. Douglas, J. Heyes and B. Smallfield of the New Zealand Institute for Crop and Food Research Inc. assisted with revisions by F. Mazaud (FAO) and C. Jenane (UNIDO). Special thanks to Ms. E. Jaklitsch, Ms. G. Garcia Nieto and Ms. V. Durand-Vuaille for the final editing and lay out of the guide.
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Preface
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1
Introduction
1
2
Major spice crops in world trade
1
3
Economic Impact and Trade
5
4
Products
8
4.1
Primary products........................................................................................ 8
4.2
Secondary and Derived Products .............................................................. 9
4.3
Requirements for Export and Quality Assurance ....................................... 9
4.4
Consumer Preferences ............................................................................ 11
5
Post-Production Operations 5.1
11
Pre-harvest Operations ............................................................................ 12
5.2 Harvesting................................................................................................ 13 5.2.1 Harvesting Seeds and Fruits ................................................................ 13 5.2.2 Harvesting Leaves and Stems.............................................................. 15 5.2.3 Harvesting Flowers and Buds............................................................... 15 5.2.4 Harvesting Roots and Rhizomes .......................................................... 16 5.2.5 Harvesting Bark, Wood, and Resins..................................................... 16 5.3
Transport.................................................................................................. 16
5.4
Threshing ................................................................................................. 17
5.5 Drying ...................................................................................................... 17 5.5.1 Drying Seeds and Fruits ....................................................................... 19 5.5.2 Drying Leaves and Stems .................................................................... 21 5.5.3 Drying Flowers and Buds ..................................................................... 21 5.5.4 Drying Roots and Rhizomes................................................................. 22 5.6
Cleaning................................................................................................... 22
5.7 Packaging ................................................................................................ 23 5.7.1 Packaging for Seeds and fruits............................................................. 23 5.7.2 Packaging for Leaves and stems ......................................................... 24 5.7.3 Packaging for Flowers and buds .......................................................... 24 5.7.4 Packaging for Roots and Rhizomes ..................................................... 24 5.7.5 Packaging for Bark, Wood, and resins ................................................. 24 5.8
Storage .................................................................................................... 24
5.9 Processing ............................................................................................... 25 5.9.1 Grinding and separating ....................................................................... 25 5.9.2 Extraction of essential oils .................................................................... 26
6
Overall Losses
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7
Pest control 7.1
Pest species ............................................................................................ 33
7.2
Relative status of major pest species ...................................................... 34
7.3
Pest control methods ............................................................................... 34
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9
33
Economic and Social Considerations
35
8.1
Overview of costs and losses .................................................................. 35
8.2
Majors problems: Maintenance of Quality Standards .............................. 35
8.3
Proposed improvements .......................................................................... 35
8.4
Gender aspects ....................................................................................... 36
References
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Appendix I: Spice and Essential Oil Products and their Growing Regions 38 Appendix II: Trade in Spices and Essential Oils
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Appendix III: Quality Assurance and Standards
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1
Introduction
Spices are used for flavour, colour, aroma and preservation of food or beverages. Spices may be derived from many parts of the plant: bark, buds, flowers, fruits, leaves, rhizomes, roots, seeds, stigmas and styles or the entire plant tops. The term ‘herb’ is used as a subset of spice and refers to plants with aromatic leaves. Spices are often dried and used in a processed but complete state. Another option is to prepare extracts such as essential oils by distilling the raw spice material (wet or dry), or to use solvents to extract oleoresins and other standardized products. There are many texts which provide an overview of the industry in general [1], [2], [3], [4] or for specific crops, [5-7]. Essential oils are liquid products of steam or water distillation of plant parts (leaves, stems, bark, seeds, fruits, roots and plant exudates). Expression is used exclusively for the extraction of citrus oil from the fruit peel, because the chemical components of the oil are easily damaged by heat. Citrus oil production is now a major by-product process of the juice industry. An essential oil may contain up to several hundred chemical compounds and this complex mixture of compounds gives the oil its characteristic fragrance and flavour. An essential oil may also be fractioned and sold as individual natural components. Other processing options can also produce further products that can be sold alongside essential oils. The plant parts can be extracted with organic solvents to produce oleoresins, concretes and absolutes or extracted with a near or supercritical solvent such as carbon dioxide to produce very high quality extracts. These oleoresins and extracts contain not only the volatile essential oil but also the concentrated non-volatile flavour components and these have wide application in the food and pharmaceutical industries. The solvent extraction processes are more difficult and complex than steam distillation and will normally be beyond the financial resources of most small scale processors, but supplying the raw materials to these extraction plants can be a market option. The most important spices traditionally traded throughout the world are products of tropical environments. The major exceptions to this group are the capsicums (chilli peppers, paprika), and coriander which are grown over a much wider range of tropical and nontropical environments. Production of spices and essential oils in these wet and humid environments brings special difficulties for crop and product management. Drying the crop to ensure a stable stored product is of particular importance, and in wet humid environments this creates the need for efficient and effective drying systems.
2 Major spice crops in world trade In terms of world trade value, the most important spice crops from the tropical regions are pepper, capsicums, nutmeg/mace, cardamom, allspice/pimento, vanilla, cloves, ginger, cinnamon and cassia, and turmeric. Coriander, cumin, mustard, and sesame seeds and the herbs sage, oregano, thyme, bay and the mints are the most important spice crops from non-tropical environments. The characteristics and environmental needs of the crops dominating the global spice trade are described below. Pepper Pepper (Piper nigrum) is a perennial vine, which produces a small berry fruit, which is dried to become pepper. Pepper is a plant of the humid tropics requiring adequate rainfall and warmth for its growth. It is grown successfully between latitudes of 20° North and 20° South and from sea level up to an altitude of 2400m. The crop can tolerate a temperature range between 10° and 40°C but the optimum is between 25°C-40°C. A well-distributed rainfall in the range of 1250mm2000mm is considered necessary for pepper production. 1
Capsicums, Chilli peppers and Paprika Capsicums (Capsicum annuum var. annuum; C. chinense; C. frutescens) are the dried and processed fruit of these annual peppers. A rainfall of 600-1250mm is desirable. Rainfall is needed over the growing season but is not needed as the fruits ripen. Heavy rain during flowering adversely affects pollination and wetness at ripening encourages fungal spoilage. Capsicums flourish in warm sunny conditions, require 3-5 months with a temperature range of 18°C-30°C; below 5°C growth is retarded, and frost kills plants at any growth stage. A seedbed temperature of 20-28°C is the optimum for germination.
Nutmeg, Mace and By-products The perennial nutmeg tree (Myristica fragrans) grows to a height of 20m. Nutmeg is the kernel of the seed, while mace is the net like crimson coloured leathery outer growth (aril) covering the shell of the seed. The tree requires an optimal growing temperature between 20-30°C and the annual rainfall should be between 1500-2500mm.
Cardamom Cardamom (Elettaria cardamomum; E. major; E. speciosa) is a tall growing (
