Hydrocolloids in Food Processing

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Hydrocolloids in Food Processing

Hydrocolloids in Food Processing Edited by Thomas R. Laaman © 2011 Blackwell Publishing Ltd. and Institute of Food Technologists ISBN: 978-0-813-82076-7

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The IFT Press series reflects the mission of the Institute of Food Technologists – to advance the science of food contributing to healthier people everywhere. Developed in partnership with Wiley-Blackwell, IFT Press books serve as leading-edge handbooks for industrial application and reference and as essential texts for academic programs. Crafted through rigorous peer review and meticulous research, IFT Press publications represent the latest, most significant resources available to food

scientists and related agriculture professionals worldwide. Founded in 1939, the Institute of Food Technologists is a nonprofit scientific society with 22,000 individual members working in food science, food technology, and related professions in industry, academia, and government. IFT serves as a conduit for multidisciplinary science thought leadership, championing the use of sound science across the food value chain through knowledge sharing, education, and advocacy.

IFT Book Communications Committee Dennis R. Heldman Joseph H. Hotchkiss Ruth M. Patrick Terri D. Boylston Marianne H. Gillette William C. Haines Mark Barrett Jasmine Kuan Karen Nachay

IFT Press Editorial Advisory Board Malcolm C. Bourne Dietrich Knorr Theodore P. Labuza Thomas J. Montville S. Suzanne Nielsen Martin R. Okos Michael W. Pariza Barbara J. Petersen David S. Reid Sam Saguy Herbert Stone Kenneth R. Swartzel

A John Wiley & Sons, Ltd., Publication

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Editor

Thomas R. Laaman

A John Wiley & Sons, Ltd., Publication

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Edition first published 2011 C 2011 Blackwell Publishing, Ltd. and Institute of Food Technologists Blackwell Publishing was acquired by John Wiley & Sons in February 2007. Blackwell’s publishing program has been merged with Wiley’s global Scientific, Technical, and Medical business to form Wiley-Blackwell. Editorial Office 2121 State Avenue, Ames, Iowa 50014-8300, USA For details of our global editorial offices, for customer services, and for information about how to apply for permission to reuse the copyright material in this book, please see our Website at www.wiley.com/wiley-blackwell. Authorization to photocopy items for internal or personal use, or the internal or personal use of specific clients, is granted by Blackwell Publishing, provided that the base fee is paid directly to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923. For those organizations that have been granted a photocopy license by CCC, a separate system of payments has been arranged. The fee code for users of the Transactional Reporting Service is ISBN-13: 978-0-8138-2076-7/2011. Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought. Library of Congress Cataloging-in-Publication Data Hydrocolloids in food processing / edited by Thomas R. Laaman. p. cm. – (IFT Press series) Includes bibliographical references and index. ISBN 978-0-8138-2076-7 (hardback : alk. paper) 1. Hydrocolloids. I. Laaman, Thomas. TP456.H93H93 2010 664–dc22 2010011387 A catalog record for this book is available from the U.S. Library of Congress. Set in 11.5/13.5 Times NR PS by AptaraR Inc., New Delhi, India Printed in Singapore Disclaimer The publisher and the author make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation warranties of fitness for a particular purpose. No warranty may be created or extended by sales or promotional materials. The advice and strategies contained herein may not be suitable for every situation. This work is sold with the understanding that the publisher is not engaged in rendering legal, accounting, or other professional services. If professional assistance is required, the services of a competent professional person should be sought. Neither the publisher nor the author shall be liable for damages arising herefrom. The fact that an organization or Website is referred to in this work as a citation and/or a potential source of further information does not mean that the author or the publisher endorses the information the organization or Website may provide or recommendations it may make. Further, readers should be aware that Internet Websites listed in this work may have changed or disappeared between when this work was written and when it is read. 1

2011

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Titles in the IFT Press series r Accelerating New Food Product Design and Development (Jacqueline H. Beckley, Elizabeth J. Topp, M. Michele Foley, J.C. Huang and Witoon Prinyawiwatkul)

r Advances in Dairy Ingredients (Geoffrey W. Smithers and Mary Ann Augustin) r Bioactive Proteins and Peptides as Functional Foods and Nutraceuticals (Yoshinori Mine, Eunice r r r r r r r r r r r r r r r r r r r r r r r r r r r r r r

Li-Chan and Bo Jiang) Biofilms in the Food Environment (Hans P. Blaschek, Hua H. Wang, and Meredith E. Agle) Calorimetry and Food Process Design (Gönül Kaletunç) Food Ingredients for the Global Market (Yao-Wen Huang and Claire L. Kruger) Food Irradiation Research and Technology (Christopher H. Sommers and Xuetong Fan) Foodborne Pathogens in the Food Processing Environment: Sources, Detection and Control (Sadhana Ravishankar, Vijay K. Juneja and Divya Jaroni) High Pressure Processing of Foods (Christopher J. Doona and Florence E. Feeherry) Improving Import Food Safety (Wayne C. Ellefson, Lorna Zach and Darryl Sullivan) Microbial Safety of Fresh Produce: Challenges, Perspectives and Strategies (Xuetong Fan, Brendan A. Niemira, Christopher J. Doona, Florence E. Feeherry and Robert B. Gravani) Microbiology and Technology of Fermented Foods (Robert W. Hutkins) Multiphysics Simulation of Emerging Food Processing Technologies (Kai Knoerzer, Pablo Juliano, Peter Roupas and Cornelis Versteeg) Multivariate and Probabilistic Analyses of Sensory Science Problems (Jean-François Meullenet, Rui Xiong, and Christopher J. Findlay Nanoscience and Nanotechnology in Food Systems (Hongda Chen) Natural Food Flavors and Colorants (Mathew Attokaran) Nondestructive Testing of Food Quality (Joseph Irudayaraj and Christoph Reh) Nondigestible Carbohydrates and Digestive Health (Teresa M. Paeschke and William R. Aimutis) Nonthermal Processing Technologies for Food (Howard Q. Zhang, Gustavo V. Barbosa-Cànovas, V.M. Balasubramaniam, Editors; C. Patrick Dunne, Daniel F. Farkas, James T.C. Yuan, Associate Editors) Nutraceuticals, Glycemic Health and Type 2 Diabetes (Vijai K. Pasupuleti and James W. Anderson) Organic Meat Production and Processing (Steven C. Ricke, Michael G. Johnson and Corliss A. O’Bryan) Packaging for Nonthermal Processing of Food (J. H. Han) Preharvest and Postharvest Food Safety: Contemporary Issues and Future Directions (Ross C. Beier, Suresh D. Pillai, and Timothy D. Phillips, Editors; Richard L. Ziprin, Associate Editor) Processing and Nutrition of Fats and Oils (Ernesto M. Hernandez, and Afaf Kamal-Eldin) Processing Organic Foods for the Global Market (Gwendolyn V. Wyard, Anne Plotto, Jessica Walden and Kathryn Schuett) Regulation of Functional Foods and Nutraceuticals: A Global Perspective (Clare M. Hasler) Resistant Starch: Sources, Applications and Health Benefits (Yong-Cheng Shi and Clodualdo Maningat) Sensory and Consumer Research in Food Product Design and Development (Howard R. Moskowitz, Jacqueline H. Beckley, and Anna V.A. Resurreccion) Sustainability in the Food Industry (Cheryl J. Baldwin) Thermal Processing of Foods: Control and Automation (K. P. Sandeep) Trait-Modified Oils in Foods (Frank T. Orthoefer and Gary R. List) Water Activity in Foods: Fundamentals and Applications (Gustavo V. Barbosa-Cànovas, Anthony J. Fontana Jr., Shelly J. Schmidt, and Theodore P. Labuza) Whey Processing, Functionality and Health Benefits (Charles I. Onwulata and Peter J. Huth)

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Table of Contents

Preface Contributor List

ix xiii

Chapter 1

Hydrocolloids: Fifteen Practical Tips Thomas R. Laaman

Chapter 2

Hydrocolloids in Salad Dressings Alan H. King

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Chapter 3

Hydrocolloids in Muscle Foods James W. Lamkey

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Chapter 4

Hydrocolloids in Bakery Products William Santa Cruz

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Chapter 5

Hydrocolloids in Bakery Fillings Marceliano B. Nieto and Maureen Akins

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Chapter 6

Hydrocolloids in Frozen Dairy Desserts Philip A. Rakes and Thomas R. Laaman

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Chapter 7

Hydrocolloids in Cultured Dairy Products Joseph Klemaszewski

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Chapter 8

Hydrocolloids in Restructured Foods Ian Challen and Ralph Moorhouse

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Chapter 9

Hydrocolloids in Flavor Stabilization Milda E. Embuscado

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Table of Contents

Chapter 10 Hydrocolloid Purchasing I: History and Product Grades Thomas R. Laaman

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Chapter 11 Hydrocolloid Purchasing II: Pricing and Supplier Evaluation Thomas R. Laaman

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Index

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Preface

This is a highly practical book written primarily for three groups who make their living in the food industry: product development scientists, quality assurance scientists, and purchasing directors and managers. University professors who want to impart industry-based practical knowledge to their students and food science students, especially those in product development courses can also richly benefit from this work. For students, the chapters of this book can provide valuable insights into the results of decades long practical research in developing food products utilizing hydrocolloids as key components. Although most of the writers of this book have Ph.D. degrees, and nearly all of the rest have M.S. degrees, these writers also have decades of lab, pilot plant, and plant experience in this field. They have combined a thorough scientific education with the practical hands on experience required to master this difficult area of practical hydrocolloid applications. These writers were all chosen because they are the practical masters in hydrocolloid knowledge in their specific food areas. How should this book be read? Carefully, thoughtfully, and repetitively. Practical hydrocolloid applications can be mastered and once mastered, provide one of the most valuable job skills in this business. So many foods depend on thorough mastery of the hydrocolloid component and once that is accomplished, the rest of the food product usually just falls together, literally. Of course there are other specialized knowledge areas that are important to many foods, such as flavor chemistry, but hydrocolloids even impact flavor quite noticeably. In any case, mastery in this field usually requires many reviews of the same information, until it becomes second nature. ix



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Preface

Thus, it is recommended that this book be kept in the lab or office, and read over and over again until it becomes thoroughly familiar. Also, regardless of the food area that one is employed in, reading all the chapters in the book will pay good dividends. Each chapter provides valuable insights into various hydrocolloids and these insights extend well beyond the specific food applications being discussed. Also, much of the innovativeness in our food industry results from applying concepts used in one branch of the food industry to another branch of industry. Finally, it is good to become familiar with other branches of the food industry because one may be employed there in the future; few jobs are all that stable in this industry. Some authors of chapters in this book have referenced many other sources, some only a few or none. Why is that? The truth of the matter is much of the key practical knowledge in the hydrocolloid area is proprietary. Those authors who are employed by various hydrocolloid suppliers have the approval of their individual company to publish the material in their chapters that may belong to that company. But even in those cases some or much of the material in their chapters may be knowledge they may have picked up in various research assignments they have had over the course of their careers, in many companies, or as consultants. It would be difficult in most cases to reference manuals published by companies in the hydrocolloid field since the material is so totally hackneyed. Six different companies that sell a certain hydrocolloid have almost the identical information in their brochures and that same material was already found in publications from 30 years ago of companies that no longer exist. In any case, much material in this book is new and has never appeared in print before in any company brochure. There can be several hydrocolloid combinations that will make quality, stable food products. Most of the chapter authors try to provide some of these alternate approaches. In cases where one combination is suggested there may be other combinations that will also work. In those cases gaining expertise in how and why one hydrocolloid combination is particularly effective can stimulate the reader to consider other approaches as well. That is all part of hydrocolloid learning and mastery. I would expect that some of the more creative readers of this book will find new approaches to their specific product development challenges based on the foundations laid in this volume.



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Preface

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This book is divided into three sections. The first chapter provides important general practical concepts in the use of hydrocolloids that are applicable to many food products. Chapters 2–9 provide food-by-food specific details in the utilization of hydrocolloids in these various categories. In most cases, the chapters explain not only how to successfully use hydrocolloids but most of the keys toward making those food categories themselves. Thus, the chapters are actually practical guides to making specific foods. Chapters 10 and 11 provide a thorough guide to purchasing hydrocolloids, and contain valuable information for purchasing directors, QA scientists, and product development specialists. It is hoped that this book not only helps significantly in practical ways in your current and future jobs, but that you begin to glimpse the love and fascination the complex world of hydrocolloids brings to us who have labored for so long in this viscous realm. Thomas R. Laaman Guaranteed Gums



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Contributor List

Maureen Akins (Chapter 5) TIC Gums Inc. White Marsh, MD, USA Ian Challen (Chapter 8) Hydrocolloid Solutions Houston, TX, USA William Santa Cruz (Chapter 4) Gums Per Tucson, AZ, USA Milda E. Embuscado (Chapter 9) McCormick & Co. Inc. Hunt Valley, MD, USA Alan H. King (Chapter 2) Rutgers, The State University of New Jersey Westfield, NJ, USA Joseph Klemaszewski (Chapter 7) Cargill Inc. Atlanta, GA, USA

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Contributor List

Thomas R. Laaman (Chapters 1, 6, 10, 11) Guaranteed Gums Madbury, NH, USA James W. Lamkey (Chapter 3) Symrise Teterboro, NJ, USA Ralph Moorhouse (Chapter 8) Hydrocolloid Solutions Houston, TX, USA Marceliano B. Nieto (Chapter 5) TIC Gums Inc. Abingdon, MD, USA Philip A. Rakes (Chapter 6) Main Street Ingredients La Crosse, WI, USA

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Chapter 1 Hydrocolloids: Fifteen Practical Tips Thomas R. Laaman

Tip One: Dissolving Hydrocolloids—The Influence of Mesh Size Achieving maximum hydrocolloid functionality in most food products begins with fully dissolving the hydrocolloid. Particle size or mesh size is a fundamental issue influencing solubility. The basic principle is that larger particles, corresponding to a coarser mesh size, such as 40–80 mesh, take longer to dissolve because the water takes longer to penetrate the dry hydrocolloid particle. A finer mesh particle, such as those that pass through 120, 150, or 200 mesh screens, takes less time for water to penetrate and become fully soluble. However, the converse of this situation is that a coarser size particle is less subject to lumping, while a finer mesh particle lumps more easily. Once lumps are formed, achieving full solubility becomes more difficult and also takes much more mixing to do so. There are two ways to overcome the potential for lumping for small particle size hydrocolloids. One is to use high agitation mixing. The other is to preblend the hydrocolloid with another dry ingredient such as sugar. By preblending, the hydrocolloid particles are separated from each other before entering the liquid, thereby minimizing lumping. In summary, if high agitation is used in dispersing the hydrocolloid or if it can be preblended with a dry ingredient then fine mesh grades will allow the most rapid solubility. If mixing is not as vigorous and Hydrocolloids in Food Processing Edited by Thomas R. Laaman © 2011 Blackwell Publishing Ltd. and Institute of Food Technologists ISBN: 978-0-813-82076-7

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the hydrocolloid is not preblended then it is safer to use a coarser mesh product to avoid lumping, even though this will require more mixing time to achieve full solubility. Tip Two: Dissolving Hydrocolloids—The Influence of Temperature Some hydrocolloids require heat to dissolve. In these cases, it is important to know exactly how much temperature is required for the exact grade being used. There can be a substantial difference in the required temperature based on other ingredients, especially ions. Thus, it is important to heat the food product to different temperatures and determine the minimum temperature to achieve full functionality, in terms of maximum viscosity, gel strength, or stability of the food product. Temperature should be measured carefully. First, the thermometer or thermal probe being used must be precise and accurate. Mechanical thermometers are especially notorious for requiring frequent calibration to ensure accuracy. Another issue can be that the product mixing is not sufficiently vigorous during heating, allowing pockets of higher or lower temperature. This must be ascertained by moving the thermometer or thermal probe around to different locations in the mix to determine if temperature gradients exist. The minimum temperature achieved in any part of the mix should be the benchmark used to determine if the temperature is adequate. One contrary thought is important to add. Although it is important to achieve full functionality of a hydrocolloid, it is also true that some hydrocolloids can be partially degraded by excessive heat, for example, guar gum. Some other hydrocolloids may be degraded if there is a combination of heat and acid, for example, carrageenan. Therefore, the heating should be adequate to fully dissolve all the hydrocolloids and thus gain full viscosity, but not high enough that the viscosity is decreased due to partial hydrolysis of the hydrocolloid. Tip Three: Dissolving Hydrocolloids—The Influence of Cations Some hydrocolloids are not highly influenced by ions (except at very high ion concentrations), for example, agar, xanthan gum, guar gum, and locust bean gum. Several others are influenced in their solubilization by



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Hydrocolloids: Fifteen Practical Tips

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ions. These include sodium alginate, carrageenan, pectin, gellan gum, and sodium carboxymethyl cellulose (CMC). In these cases divalent cations and in some cases monovalent cations can influence the ability of the hydrocolloid to dissolve. Calcium is the major issue for sodium alginate, ␫-carrageenan, lowmethoxy pectin, and gellan gum. Potassium is the major issue for ␬-carrageenan, and sodium chloride can inhibit full viscosity development for CMC for certain grades. Options to circumvent reduced solubility include the following procedures. First, the ions can be added to the food product after the hydrocolloid has been dissolved. Second, for gums such as carrageenan, where the ions are present with the gum powder, solubility can be achieved by heating to a higher temperature. Third, for calcium, sequestrants can be added to bind these ions, at least temporarily, to allow the gum to dissolve. If water used in the processing plants is naturally quite high in calcium, this approach may be necessary if the water is not pretreated to remove these ions. Sequestrants include phosphate compounds such as sodium hexametaphosphate, tetrasodium pyrophosphate, and dipotassium phosphate and also citrates. Fourth, also for calcium, it is possible to add in very low solubility forms, thus largely delaying the calcium going into solution until after the gum has dissolved. Tricalcium phosphate is a very slow-dissolving calcium source, and dicalcium phosphate is also quite slow, the anhydrous form being slower than the dihydrate form.

Tip Four: Gelling Hydrocolloids—The Effect of Temperature Some hydrocolloids gel by simply cooling a hot solution. Agar and gelatin are the prime examples. Others gel after cooling, but also require ions to be present. These include ␬- and ␫-carrageenan, low-methoxy pectin, and gellan gum. High-methoxy pectin gels after cooling in a lowpH or high-sugar environment. Methyl cellulose forms and maintains a gel only while it is being heated. The first significant aspect is to make sure the gum has been given enough heat to fully dissolve, as discussed in Tip two. Whatever amount of gum is left undissolved will not contribute to the final gel properties. Only fully dissolved gum will gel when cooled. The exact gelling


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temperature will vary by the product and grade in a similar fashion as the solubility temperature varies. But this is generally less significant since eventually the product will generally be cooled to at least room temperature and fully gel. The key item to remember when gel formation is occurring during cooling is whether the gel will be broken apart during gel formation or left intact. ␫-Carrageenan has some gel “healing” properties, but most gums will not reform a gel well when the gel is broken up by agitation or motion during gelling. For most products, it is imperative that the gelled product is placed into a quiescent situation when the critical gelling temperature is near to being reached. For products where a disrupted gel is sought, it is still important to make sure that disruption occurs in a way to facilitate the exact product texture desired. This may require some experimentation. There are cases where a semi-gelled structure is sought and in those cases mixing during cooling is often acceptable. One interesting example is the use of ␬-carrageenan to suspend cocoa powder and also provide some mouthfeel in chocolate milk. If there is no mixing during the gel formation stage, the cocoa powder will completely settle out. If the product is mixed during cooling, the ␬-carrageenan will be able to begin to suspend the cocoa as its weak gel begins to form. In this case the disruption of the gel by mixing is not a negative since the texture and stabilizing functionality that is desired is achieved.

Tip Five: Gelling Hydrocolloids—The Influence of Cations Cations are needed for gelation of many hydrocolloids. Those requiring heating and cooling simply need adequate amounts of the appropriate cation to fully gel. Some cations may be present in the hydrocolloid powder, some in the other ingredients used to make the food, and some may be added to ensure that an adequate amount is present. Generally, enough should be added to get maximum gel strength, especially if it is a gelled product. If the gel is too strong then it is more economical to reduce the amount of the hydrocolloid used than to have the hydrocolloid starved for gelling ions. An exception to this principle is when a semi-gelled-type product is sought. This type of product would generally be not seen as a fully gelled product but as something pourable, such as a sauce. However, some



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linkages used in gelling are allowed to occur to take advantage of the thickening and stabilizing properties of the semi-gelled hydrocolloid. In the case of sodium alginate, calcium is needed, but no heat, to form a gel. However, calcium also inhibits solubility, and therefore either the calcium must be added after the alginate has solubilized or the calcium must be bound using a sequesterant to allow the alginate to first dissolve, or the calcium can be added in a low solubility form where it slowly releases, mostly after the alginate is dissolved. Once the alginate is dissolved, the calcium may be added in a quickly available form or a slowly available form. The former includes calcium chloride and calcium acetate. The latter includes tri- and dicalcium phosphates. Intermediate is monocalcium phosphate and calcium lactate. If a quick reaction is desired then the product must already be in some mold (such as onion rings) or there must be no worry about a broken gel (such as imitation fruit pieces). If enough time is needed for the food product to be mixed and pumped then a slow-release calcium is used, such as for fruit fillings.

Tip Six: Hydrocolloid Functionality—Texture Hydrocolloids have an impact, whether desirable or undesirable, on stability, texture, color or appearance, and flavor of the foods in which they are utilized. Hydrocolloids are generally added to a food to have a decisive role in one or both of the first two parameters. The goal should be to have a positive or neutral impact on all four parameters. In terms of the range of texture, hydrocolloids may be used to impart the characteristic texture of the food or be added for stability with the desire to have no noticeable impact on texture. If the goal is to impart a specific texture then this texture should first be defined, and second measured in some way. Now, of course, food comes in a wide range of textures from thin liquids, to thicker but pourable liquids, to solid foods of many different types. Hydrocolloids are often used to make liquids thicker and even to give fairly thin liquids, such as chocolate milk or eggnog, a noticeable mouthfeel. Solid gelled foods are also frequently given their characteristic texture using hydrocolloids. A characteristic texture may be the texture of a good prototype or a competitor’s product that is being matched. The first step is to establish what will be the “gold standard” to be matched. The second step requires


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that by taste testing and/or instrumental testing this gold standard’s texture must be measured in ways that are reproducible. This allows newly developed sample prototypes to be accurately compared to the gold standard. The third step is to figure out what hydrocolloid or blend of gums will allow this texture to be achieved.

Tip Seven: Hydrocolloid Functionality—Stabilization Stabilization, with or without contributing to important textural parameters, is a prime reason why hydrocolloids are used in foods. Stability can often be defined best by a lack of negative effect: the food product does not fall apart. Loss of stability can be seen in a number of common dilemmas. These include separation of the product into phases, including something dropping to the bottom or separating to the top of the food. Separating components can be gaseous (foams), liquid (oil or aqueous layers), or solid (particulates or even a solid lump). Sometimes there is one main source of separation, and other cases involve multiple problems. To best understand stability, it is necessary to fully understand instability. The food scientist will comprehend what makes the product stable by pushing at the edges of stability to see when and how an unstable product could occur. The advantage of this is that if problems should occur in the future in plant production, the scientist will have a list of common unstable prototypes and how these were made using deviations of the hydrocolloid levels. It is always good, for example, when 0.5% of a gum is used in a food to know how the product would look at 0.4%, 0.3%, etc., especially testing to see when the product would not hold together, and how it would separate. It could even be the source of new product ideas. What about a drinkable pudding? Another potential problem with hydrocolloids being used to stabilize foods is overstabilization. This condition is caused by using too high a level of gums in a product, causing it to become too gummy, too firm, or in some other way too strong in texture. There are two approaches that can be taken to gain a more equitable texture while retaining full stability. The first is to lower the gum level or levels until the texture is appropriate and determine if the stability is still adequate. In many cases much of the gum used is not even necessary to achieve stability.



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If this does not work then the use of a new stabilizer system may work to bring about full stability while not causing an overstabilized texture. Too high a gum level can also cause the product to fall apart and separate because some bonds become too strong and therefore disrupt the overall equilibrium of forces holding the product together. A typical example of this concept is an increase of aqueous syneresis, where water is squeezed out of a gelled matrix. Again, when this type of instability is present, it is useful to consider lowering the level of the stabilizer system to determine if improvement is possible while also avoiding introduction of new stability concerns. It can be a balancing act but is often not that difficult once the overall philosophy is adopted that both too little and too much of these powerful hydrocolloids can cause problems in the food, and therefore the optimum middle level should be sought.

Tip Eight: Hydrocolloid Functionality—Color or Appearance Hydrocolloids are most often used to provide intentional effects on texture and stability. But hydrocolloids can have noticeable effects on the color and appearance of foods, either intentionally or nonintentionally. These effects can be perceived as both positive and negative depending on the desired food parameters and which hydrocolloids are utilized. Let us review some major color or appearance effects caused by gums. One major effect is the increase in opacity in foods that can be caused by hydrocolloids. In some cases this is due to insoluble particles found in the gum powder. Microcrystalline cellulose is completely insoluble and has the greatest effect in increasing opacity. If the desired product is a clear beverage, the opacity will be a negative, but in many products opacity is sought, especially if the product is a low-fat version of an established product. Removal of fat can reduce the opacity of foods, for example, in coffee whitener. If the food product is considered of best quality when it is transparent, then transparent versions of several gums are available, including sodium alginate, xanthan gum, and carrageenan. For these gums the insoluble components are removed during processing. If a gum is not fully dissolved then this can be an additional source of insoluble particulates in the food product and therefore achieving full solubility is important from an appearance as well as textural point of view.


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Opacity can also be caused by increased air incorporation, which gums can also contribute to. This can be either desirable or undesirable. If the latter, then the mixing procedure can be altered to minimize air incorporation. Gums can contribute glossiness and sheen to foods, which can be a strong benefit. The natural brightness of the foods can be accentuated this way. This is true of various sauces, fruit fillings and glazes, and many gelled products. Gums can provide an inherently positive benefit, and when compared to alternative texture providers such as modified starches, the contrast in quality can be staggering. The hydrocolloid-stabilized products are often seen to be much more bright, glossy, and full of rich, natural color than pure starch alternatives.

Tip Nine: Hydrocolloid Functionality—Effects on Flavor Flavor effects are somewhat parallel to effects on color and appearance. Most of the time, the gums are added for reasons other than flavor, but flavor can be impacted. In most cases, flavor will be somewhat suppressed by the use of gums. This can be a negative effect when flavors are added or are naturally present in a food. Some of that flavor will be suppressed, requiring the use of additional flavor. It can be a positive effect when flavors are desired to have less impact, such as acid flavor in salad dressings. In this case, flavor suppression is helpful to allow the product to be less harsh. Since a thick product requires something to make it thick, the question is not whether flavor suppression occurs but how much is acceptable and to use appropriate choices among hydrocolloids to achieve the best product. As with color, starch tends to have the most flavor-suppressing effect, and therefore substitution by the much lower levels of gums needed tends to cause a large increase in flavor perception. In many cases this is a big positive effect, but in some cases the starch suppresses undesirable flavors. Also, among hydrocolloids there is a wide range of flavor suppression. These are best explored experimentally since it is not simply a matter of more or less flavor, but flavor nuances as well. Certain components of a flavor profile may be suppressed more or less than other components. A comparison of four or five gums in a food system will quickly indicate the differences in flavor release caused by the various gums.



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Tip Ten: Using Hydrocolloids—Basic Tests Hydrocolloids can be complicated to completely understand and use most effectively. One danger is that one or two gums, the easiest to use, will be used again and again in all applications. Product quality and cost savings may both be sacrificed by this approach. It is prudent to take steps to learn about all the major hydrocolloids, at least those that are used in the specific food where product development efforts are focused. Learning about hydrocolloids can occur on many levels including observing the effects on functional properties and stabilities of foods with various hydrocolloid types and levels. But it is a simple process and well worth the investment of research time to make up pure solutions and/or gels of various hydrocolloids. Simply making up 1% solutions or gels of a number of hydrocolloids in water, or in some cases milk, can be very instructive. Observe the appearance and color of the solutions or gels. Then compare the textures and flavors of the hydrocolloids. Is the texture long or short; that is, is it like jam (long textured) or does the liquid break from itself quickly and cleanly (short)? What kind of mouthfeel does each of the gums provide? Is this the texture desired in the food product itself? It is also interesting to check stability properties such as suspending ability by adding some spices or other particulates and determining the ability of the gums to stabilize emulsions by adding oil and mixing the oil into the aqueous phase to generate an emulsion. A day spent in the laboratory with the above-mentioned assignment would add immensely to the practical understanding of the world of hydrocolloids. It is true that within a food system there are a myriad of sometimes complex interactions. At the root of it all, however, are the hydrocolloids and their immense effect on the water within the food.

Tip Eleven: Using Hydrocolloids—Single Gum versus Multiple Gums Although it may be a challenge to fully understand one hydrocolloid in a food system, it is often desirable to use a combination of gums in a food product. Before discussing how to approach research and


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product development with two or more gums in a food product, let us quickly review some of the primary reasons for using multiple gums in a formulation. Four of the most common reasons are cost, synergy, serendipity, and quality. For cost a common rationale involves using a highly effective gum at a low use level to give some needed stabilization to a food and then adding onto that a less expensive gum to fill out the requirement for viscosity and texture. Several gums are synergistic with other gums, meaning that the net viscosity or gel strength, when the two gums are used together, is greater than would be expected from the additive combinations of each gum. The gums form an interaction that creates a more effective three-dimensional network to structure water. Xanthan gum is synergistic with guar gum and locust bean gum. Konjac is synergistic with carrageenan, xanthan gum, and putatively alginate. These are some of the most common examples. Often synergistic gums are most synergistic at a one-to-one ratio with each other. Serendipity is used to explain that in the real world many prototype formulations are tested with various combinations of gums and one seems to work better than all the others. So this combination is used in the final product. In one case a product development manager tried two complex, but totally disparate, approaches to develop a specialized type of frozen pancake batter and neither was totally acceptable. Finally, he mixed the two different batters together and found that to be a good final product. This blended formulation had 30 different ingredients including several hydrocolloids. It was probably not an optimized formulation, but it worked, and time constraints dictated that the research and development time was ended and this became the final formulation. Quality approaches with multiple gums are generally more sophisticated and are practiced by those who understand the nuances of gums more proficiently. Costs, synergies, desired textures, and stabilities are all considered during product development to come up with what is hoped to approach an ideal formulation. Costs are minimized, synergies are maximized, and stability is very good but not at the expense of desirable texture being sacrificed. A common theme in many of these sophisticated formulations is that a gum, which might be an excellent stabilizer, but not ideal for textural parameters, such as xanthan gum, is kept at a set low level where stability is assured but texture is not compromised.



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To begin to approach this area of research, the following ideas may be helpful. To understand synergies, and indeed any gum combination, make up simple model systems in water to better observe the differences in viscosities, textures, gels, and stabilities. From a cost point of view, get current and accurate pricing of all the major hydrocolloids and make cost in use comparisons. Molecular weight and viscosity are often correlated for a specific hydrocolloid. Very low-viscosity grades may be more expensive to buy due to extra processing costs to degrade the hydrocolloid to a much lower molecular weight. Very high-viscosity grades may be more expensive because only a portion of the raw material used for that gum may yield a very high viscosity and also it is more difficult to gently process it in such a way as to maintain absolute maximum molecular weight. The low- to middle or high-viscosity grades for a specific hydrocolloid are often priced about the same since the raw material costs and processing costs are similar for these grade ranges. The issue is not cost per kilogram however, but cost to make a say 300 cP viscosity solution. Since the middle or high grade requires a lower amount to make a 300 cP solution than the lower viscosity grade, it tends to be more cost-effective to use in the actual food product than the lower viscosity grades. Rather than using pure serendipity to find the best prototype, it is best to use a systematic approach in product development. If it is decided to use two or three gums in a series of prototypes, vary the ratios of the gums in a systematic way to determine the whole panorama of textures and stabilities that are possible. This is better than a typical approach often used where some guess is made of what good use levels may be for the gums in a formulation and then these are tweaked up or down as prototypes are made and found defective in various ways. The quality approach can also be done in a systematic way. For example, the minimum level of a good stabilizing but poor texturizing gum can be ascertained in tests. Once the minimum level needed for stability is determined then that gum is set at that level and the other gums are altered to get the best texture. Of course, for this minimumlevel test to be accurate, the other gums must be present in sufficient quantity to give a texture or viscosity similar to the final desired product. Similarly, the maximum level of a low-cost gum can be determined before textural and other product quality considerations dictate that its level has gone too high.


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Tip Twelve: Using Hydrocolloids—Substitution of Gums for Starch Modified starch is generally of low cost on a cost per kilogram of product basis, but the use levels of starch are much higher than of gums. In addition, starch will generally cause a gummy mouthfeel, be found to be flavor suppressing, and often affect the color or appearance in a negative way. Often it is best to think of starch as a low-cost hydrocolloid, which it is, that can be useful to provide some base viscosity or gel strength but whose use level must not be allowed to go too high to avoid adversely affecting product quality. Fortunately, although gums are more expensive on a per kilogram basis, the cost in use is much more comparable to starch and sometimes lower. This is because gums can often substitute for starch on a onefor-ten weight basis. For example, in the fruit pie filling formulations in Table 1.1, it is seen that the pure starch formulation uses 5–6% starch to provide adequate gel strength and some boil-out stability during baking. But the sodium alginate-containing formulation drops the starch content Table 1.1. Alginate versus starch in pie fillings. Fruit Pie Filling: Starch

Weight (%)

IQF fruit Corn syrup Sucrose Cornstarch Total

65.0 19.0–20.0 10.0 5.0–6.0 100.0

Fruit Pie Filling: Alginate and Starch

Weight (%)

IQF fruit Corn syrup Sucrose Cornstarch Sodium alginate (800 cP) Tetrasodium pyrophosphate Dicalcium phosphate, anhydrous Total

65.0 22.4–22.5 10.0 2.0 0.3–0.4 0.1 0.1 100.0

Source: Guaranteed Gums (2007). IQF, individually quick frozen.



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down to 2% while only using 0.3–0.4% sodium alginate to produce the same gel strength and far superior boil-out protection. Also, the alginate product has much better flavor release (due to its lower use level), is not gummy, is clearer, and has excellent sheen. Briefly, we can therefore summarize the major concepts when substituting gums for starches. First, there is an order of magnitude difference in use level. Second, costs therefore tend to be similar on a use level basis and perhaps somewhat less for the gum. Third, stability is often better for the same texture or gel strength. Fourth, the overall appearance and desirability of the product is often improved due to better texture, less pastiness, combined with greater clarity, sheen, and improved flavor release. This can allow the use of more cost savings by some reduction in added flavors and flavor-providing ingredients.

Tip Thirteen: Using Hydrocolloids—Benchtop Product Development Although benchtop product development is not usually done in the way that is recommended here, this method ensures that the full functionality of hydrocolloids will be understood and appropriated in the food system where the gums are being utilized. The first step is to guarantee the gums can be fully functional by making sure they are fully dissolved and have all the other key conditions such as sufficient heat and/or specific cations for maximum functionality. The goal should be to guarantee the gums are fully functional and not worry about making the food product in the most efficient manner. That will come later. Mixing, heating or cooling, and cations are the three areas that must be focused on. Mixing may require premixing the gum by itself to ensure that the gum is completely dissolved. Also, it may require using much higher shear that is normally used, but be sure not to allow air to be whipped in unless this is desired for the food product being made. In addition, it may be a good idea to allow a much longer mixing time to ensure full dissolution. Care should be taken to evaluate the mix after mixing to see if there are any signs of incomplete solubilization. That is one advantage to predissolving the gum in only water—it is easier to detect any lumping. For heating and cooling, be sure the temperature probe or thermometer is completely accurate. This has often not been the case with


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laboratory instruments that have been in use for a long time and not calibrated recently. Especially this is true for older or cheaper instruments. Next, be certain all the mass of product reaches the desired temperature and if possible goes a little above that temperature or holds for a slightly longer period at the temperature if that can be done without sacrificing product quality. Cations use and control is the final key area to ensure complete gum functionality. The first issue is to control cations that may inhibit full solubility of a gum. It is often a good idea to use distilled water to make sure there is no chance of interfering ions in these idealized first tests. After the gum is fully dissolved, for a number of gums, cations are added to allow full gel strength or viscosity. It is important to be sure these added cations are dissolved enough to be available for the hydrocolloid to utilize. In these preliminary tests, it is a good idea to add more than the theoretically required amount of cation to ensure a sufficient amount. Once this idealized prototype is made where the gum’s functionality is fully maximized, it is necessary to thoroughly evaluate the prototype, especially for textural parameters, both by instrumental methods and by taste testing. If more or less gum is indicated by these testing methods then the next prototypes can be made in the same careful way. Once the prototype is close to what may be required from a textural and stability point of view, the next steps of finding the most efficient formulation and processing procedure can be undertaken. At this point it is useful to consider the plant processing procedures and think about limitations in the plant operations, especially in the area of mixing. Then it is useful to plan a benchtop procedure that will best mimic the plant operations. The good thing is that it is known what the product will look like if the gum is allowed to become fully functional. The rest of the product development is to take the idealized procedure developed to allow maximum gum functionality and gradually adjust it to allow a simpler operation for the plant while maintaining full functionality. This should be done step by step. For example, cations can be reduced to the point where the gum starts to lose some functionality. At this point add back enough ions to allow full functionality. The mixing time and intensity can be reduced, and each time the product made can be compared to the gold standard to determine the minimum mixing time and intensity required.



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Tip Fourteen: Using Hydrocolloids—Scale-Up to Plant Production Scale-up to pilot plant and then to plant production can be tricky for any food product, and where hydrocolloids are used as ingredients, it should be done carefully. There do not have to be any difficulties, but certain precautions are important. It is best to plan and proceed systematically. Among the steps that may be critical involving hydrocolloids include incorporation of the gums, mixing, any ion addition step, heating, cooling, holding, and packaging. The thing to remember is that at the benchtop scale several of these steps are easily controlled and some are hardly even thought about. One benefit of the benchtop is that often everything that is happening is easy to monitor and adjust, but not so in the plant. For example, unwanted air incorporation can be easy to see and adjust on the bench but may not even be observed in the mixing tanks used in the plant. Incorporation of the gum is what first should be considered. When and how to do this is important as well as what should be done before and what should be done after concerning other ingredients. Avoiding lumping by premixing with another dry ingredient or high shear is important. Also, sufficient time must be allowed for the gum to fully dissolve. In some cases the mixing time must be increased in the plant compared to benchtop tests because the mixing may not be as intense or efficient. If sequestrants, such as phosphates, are added to help the gum dissolve, these should be added before the gum or at least with the gum. For the heating and cooling steps, it is important to ensure that the entire mass of product reaches the maximum heating temperature and also the final cooling temperature. The holding and packaging steps are very critical to plan for and monitor during plant production. During benchtop tests, these steps are often done with no delay, but in the plant, emptying out a large mixing tank and packaging the product may take many minutes. If the product begins to gel or set up during or shortly after cooling, or after adding some cations, then it must be ensured that the entire product is packaged before this occurs. Otherwise, the gelling product will be chopped up and may permanently ruin the texture and stability. If the product gels with calcium, such as with sodium alginate, then adding a less soluble calcium salt will allow the extra time needed for


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the product to be fully packed before gelation becomes an issue. If the product gels by cooling, then packaging the product before fully cooled may alleviate premature gelation.

Tip Fifteen: Using Hydrocolloids—Plant Troubleshooting This tip deals with the situation where everything has been going well in plant production for quite some time and suddenly a problem or problems appear. What is to be done in these cases? The most important step is to collect all relevant information for both the ingredients used in the problem batch and all the data recorded and information available from each unit processing step. From the processing point of view, it should be determined if any new employees operated any equipment, if processing times and temperatures were altered for that lot, and if any equipment showed any signs of malfunction. Instruments that record temperatures and other parameters should be carefully checked to determine if any anomalies occurred. On the ingredient side, even though texture or stability may be affected, it should not be automatic to assume that the prime textural and stability components, hydrocolloids, are always the culprit. Still, the first step when texture or stability problems occur is to check all the ingredients, including the hydrocolloids, and determine if any of them had a new lot that was first used in the problem production run. If the problem in the plant coincides exactly with a new lot of hydrocolloid being used in that batch, the hydrocolloid should be investigated. The first step is to look at the quality assurance (QA) data for that lot, both that provided by the manufacturer and any that was generated by the customer’s QA department. At the same time when this sheet of data is evaluated, also pull out the data from several of the previous lots for comparison. It is unusual for a manufacturer of gums to ship out a lot that is out of spec. Therefore, it is helpful to determine first of all if anything is atypical about the lot, even if it is still within specifications. For example, one of the oldest and largest alginate manufacturers sent a lot of sodium alginate to their largest customer a few years ago. The sauce being made was too thin even though the viscosity of the alginate was in spec. But someone noted that the moisture content was extremely low, about 6%. The specification specified less than 15% moisture, and most previous lots had 12–15% moisture. It turns out



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that the viscosity of the lot was low, and the production people in the alginate plant decided to overdry the product to squeeze it into the right viscosity. But this caused extreme dusting problems and damaged the hydration ability of the alginate when used in the sauce. The main point is to look for unusual data, even data that look too low, as in this case. Incidentally, one-way specifications should be avoided, as this case typifies. Instead of less than 15% moisture, it is better to specify between 10 and 15% moisture, for example. What if the hydrocolloids were all used in previously acceptable production batches? In that case, look at any other ingredient that may have been from a new lot. Also, check the water source and water purification system for potential problems. It is not uncommon for carbon filtration systems to become overloaded at times in water purification systems, and thus improperly treated water may have been used in the production batch. The water may have then been the source of higher ion contents being added to the mix, which could have inhibited some hydrocolloids from hydrating. Was the clean in place (CIP) system not used correctly allowing some iodine or chlorine to enter the batch? These types of strong oxidizing agents can damage macromolecules in the food system and cause unstable final products. Good troubleshooting will almost always determine where the problem occurred so that the situation can be remedied to avoid future problems.

Reference Guaranteed Gums. 2007. Newsletter, August 2007 Issue, p. 2.



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Chapter 2 Hydrocolloids in Salad Dressings Alan H. King

This chapter covers the various types of salad dressings used in the United States and Canada, including typical ingredients, manufacturing equipment, and how to assemble the different products. The common functions of dressing stabilizers are addressed, along with a discussion of the major stabilizers used, usage levels, and benefits versus liabilities for each stabilizer. Tips are presented on determining the proper hydrocolloid level, how to achieve the desired shelf life, and rheological properties for dressings, as well as some pitfalls to avoid. To begin with, let us consider the various types of salad dressings that are marketed in the United States and Canada. They include spoonable dressings such as mayonnaise and salad dressing, pourable dressings with shelf-stable emulsions and also temporarily stable emulsions or separating dressings, and dry mix dressings for home or restaurant preparation. There are two types of pourable, shelf-stable dressings, “fine” and “coarse” emulsions. Examples of “fine” emulsions are regular French dressing and ranch dressing. Examples of “coarse” emulsions are Catalina French and Golden Italian. Italian dressings are made in four different forms: creamy (a “fine” emulsion), golden (“coarse” emulsion), separating, and dry mix, which may be either of the separating or stable emulsion type. Obviously there is a plethora of dressings available, and to add another order of complexity, all of these dressings are made in low-oil or no-oil forms as well. Hydrocolloids in Food Processing Edited by Thomas R. Laaman © 2011 Blackwell Publishing Ltd. and Institute of Food Technologists ISBN: 978-0-813-82076-7

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Real mayonnaise is a standardized product that requires at least 65% oil and does not allow any hydrocolloid stabilizers. (See the following web site: http://www.accessdata.fda.gov/scripts/cdrh/cfdocs/ cfcfr/CFRSearch.cfm?fr=169.140.) However, lower oil dressings of this type (i.e., spoonable), including “salad dressing,” will contain hydrocolloid stabilizers and oil levels from 0–55%. The only hydrocolloid allowed in “standardized salad dressing” is starch, and it must have at least 30% oil. (See the following web site: http://www.accessdata. fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=169.150.) French dressing is another standardized product (i.e., pourable dressing) which must contain at least 35% oil and may contain various hydrocolloids. (See the following web site: http://www.accessdata.fda.gov/ scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=169.115.) Of the regular (i.e., full oil) pourable salad dressings, the top 12 most popular flavors are listed below. Top 12 Popular Flavors (Regular Varieties) 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12.

Ranch Blue cheese Italian (separating) French Thousand Island Caesar Honey Dijon Poppy seed Balsamic vinaigrette Olive oil vinaigrette Red wine vinaigrette Italian (creamy)

Flavor Trends—Association for Dressings and Sauces, November 2004.

Typical Salad Dressing Ingredients Water, oil, and vinegar are the major ingredients of “regular” salad dressings. Additional important ingredients include salt, spices, hydrocolloid stabilizers, emulsifiers, chelators, flavorings, and colors. The oil component is normally a vegetable oil, such as corn, soy, or canola.



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Vinegars may be of various types like white (essentially acetic acid), wine, cider, etc. Often vinegar used in commercial production will be of 100 grain strength (i.e., 10% acetic acid). Emulsifiers may be “natural” or “chemical.” Examples of “natural” emulsifiers would be lecithin and cholesterol (in egg yolks) and mustard powder (dressing grade). Examples of “chemical” emulsifiers would be polysorbates 60 and 80—usually of hydrophilic/lipophilic balance (HLB) 12 or higher for pourable dressings. Chelators such as ethylenediaminetetraacetic acid (EDTA) are used to extend the oil shelf life by chelating heavy metal ions, which promote oil rancidity.

Typical Equipment for Making Salad Dressings While assembling pourable dressings, one should guard against forming vortices in mixing tanks since they tend to incorporate air, which is anathema to dressings. Air incorporation leads to many negative consequences including emulsion separation, unsightly striations, slack fills, and oil rancidity. A horizontal, variable speed, squirrel cage-type mixer in the bottom of the mixing (premix) tank provides a rolling action with no vortex and little if any air incorporation. Dixie agitated premix tank, 100 gallon, 29 dia × 41 deep w/6 deep cone bottom. 316 SS triple squirrel cage agitation. Another important point is the need for all stainless steel equipment. The use of any brass surfaces that contact the dressing will result in copper ion introduction and very rapid development of oil rancidity. Most stable emulsion, pourable dressings, as well as spoonable dressings, are passed through colloid mills to make the oil droplets as small as possible and thus contribute to increased shelf life, viscosity, and homogeneity. Colloid mills allow for much faster throughput than homogenizers and thereby increase production rate and require much less space than comparable capacity homogenizers.

How to Assemble Dressings Stable, pourable emulsions will be considered first. The “minor” ingredients (i.e., low percentage ingredients such as emulsifiers, spices (except for salt), color, flavors, chelators) should be


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added to the water first. Then any stabilizers (e.g., a 3:1 oil to stabilizer slurry, or dry mixed with 5–10 parts of sugar) should be dispersed and the dispersion should be added to well-agitated water in order to hydrate the stabilizer. Mixing under high shear conditions should be continued (for 3–5 minutes) to hydrate the stabilizers before addition of remaining ingredients. It is very important to completely hydrate the hydrocolloid stabilizers before addition of water competitors like vinegar, salt, sugar, etc. since these competitors may prevent further hydration of incompletely hydrated hydrocolloids! An additional minute or 2 of high shear mixing at this initial stage will accomplish far more than 10–20 minutes of mixing in the presence of competitor ingredients! Add the ingredients that compete for water, such as vinegar, sugars, and salt, once the gum is completely hydrated. The oil is normally added last, under high shear mixing. It should be added slowly at first, then more rapidly as it becomes incorporated into the emulsion (but not so rapidly as to allow “pooling”) to form stable, “fine” emulsions. Note: “coarse” emulsion dressings require relatively low shear mixing under carefully controlled conditions and the absence of o/w emulsifiers. Once the formation of the emulsion in the premix tank is complete, it is normally passed through a colloid mill, with the exception of most low oil/fat-free and “coarse emulsion” products. The last step before packaging would be the addition of any particulates that should not go through the colloid mill (e.g., chunks of blue cheese, bell peppers), mixing just enough to insure uniform dispersion throughout the dressing. Separating dressings—The aqueous phase of separating dressings is assembled similarly to that of stable emulsion dressings, but the oil is held aside and added as the second stage of a two stage filling operation. In other words, the completed aqueous phase is filled into bottles first, followed by the oil phase that is filled on top of the aqueous phase in order to create minimal mixing between the two phases. Spoonable dressings differ from “fine emulsion,” pourable dressings, as in that most of the viscosity comes from starch. A modified starch, designed for salad dressings, should be used. The starch must be cooked (gelatinized) to form a starch paste, which must then be cooled before assembling the rest of the dressing. Any additional hydrocolloids (gums) may be added to the starch slurry before cooking, using typical



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dispersion techniques, or hydrated in a portion of the formula water and added as a solution to the starch paste after cooling. Remaining ingredients are added much the same as for the “fine emulsion,” pourable dressings, with oil again being the last ingredient, followed by milling. Pregelatinized (or instant) starches are also available that do not require cooking and are treated like other cold water soluble hydrocolloids (i.e., require proper dispersion methods to prevent lump formation). Dry mix dressings may be either of the separating type (standard Italian dressing) or stable emulsion type. In either case, the hydrocolloid particle size (mesh size) is very critical and particle size of other dry mix ingredients is also important. A fine mesh hydrocolloid (e.g., 200 mesh) is normally required to achieve rapid hydration of the gum under minimal shear conditions (such as handshaking in a cruette with vinegar and salt present). The mesh size of other ingredients, such as sugar and salt, are important to provide sufficient surface area to act as good dispersants for the hydrocolloid. This becomes especially important with fine mesh gums, because they tend to form lumps much easier than more coarse mesh gums, so efficient dispersion is required.

Typical Functions of Hydrocolloid Dressing Stabilizers Viscosity is one of the major functions of dressing stabilizers, which is related to suspension of particulates, emulsion stability, pourability, etc. Just about all hydrocolloids will provide significant initial viscosity, but long-term stability of viscosity is crucial. Often these dressings must maintain a stable viscosity for up to 1 year, or even longer, after manufacture. This means that only those hydrocolloids which have sufficient acid, and sometimes temperature, stability, can be used when such longterm shelf life is needed. The most acid stable of the gums are xanthan gum (XG), gum tragacanth, propylene glycol alginate (PGA) and microcrystalline cellulose (MCC). Generally speaking, neutral gums like guar and locust bean gum produce good viscosity initially but have relatively poor long-term acid stability. Of course, once viscosity drops due to acid degradation, then the dressing looses its ability to suspend, the emulsion may start to separate, the color can change, etc. The ability of the dressing to cling nicely to salad greens is another important function of the stabilizer. This not only depends on


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viscosity, but more importantly on rheology, or the specific flow properties of the hydrocolloid stabilizer and hence the dressing. If the dressing is Newtonian-like, it will pour nicely (smoothly), but will not cling as well to the greens as a dressing with a more pseudoplastic rheology. The pseudoplastic rheology is characterized by very high viscosity at rest, and much lower viscosity while being subjected to work (shear, like pouring, pumping). Consequently, dressings with pseudoplastic flow properties tend to cling to the salad very well, since the viscosity is very high while sitting on the lettuce. Rheology is also very important during filling operations, and clean cut off during filling (i.e., lack of “tailing”) is extremely important when filling portion packs and to prevent splashing during filling of larger containers. Again, a pseudoplastic rheology is best for these functions. Suspension of particulates and oil droplets is of course very important and related directly to viscosity and rheology. When hydrocolloid stabilizers are degraded, viscosity drops and suspension properties are also degraded. All of the hydrocolloids will suspend particles, but those with pseudoplastic rheology will be considerably more efficient than those with more Newtonian rheology because their effective or apparent viscosity will be much higher at rest than when being mixed, and therefore can be formulated at considerably lower viscosity values (as measured on a Brookfield RVT viscometer at 20 rpm, for example). Prevent/control separation: This function is also directly or indirectly related to viscosity and suspending power, which is related directly to gum concentration. Once the viscosity drops below some critical value, separation of oil and settling of particles will begin to occur. Of course this phenomenon will be exacerbated at elevated temperatures, and storage of emulsions in ovens (100◦ F, for example) is often used as an “accelerated emulsion stability” test. Maintain/impart color: This function relates to loss of viscosity because this can cause emulsions to degrade. The oil droplets then become larger through coalescence, and that usually means colors become darker. For example, a typical creamy French dressing with a light reddish orange color will change to a deeper color, typical of a Catalina-type dressing, due to the change from a fine, creamy emulsion to a coarser one. Limit calories: Since all hydrocolloid stabilizers, except for starch, are nondigestible, they do not contribute any significant calories,



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especially at typical use levels of under 1.0%. Even some starches (resistant starches) are now available which are minimally digestible. Mouthfeel: Each of the hydrocolloid stabilizers contributes different kinds of mouthfeel, and some are actually used for this purpose. For example, MCC is frequently used in low calorie dressings as a fat memetic, and other hydrocolloids are used to modify the mouthfeel characteristics of starch in spoonable dressings.

Major Dressing Stabilizers—Benefits/Liabilities The hydrocolloid stabilizers that we discuss here are XG, PGA, starches, MCC, and guar gum. Although other hydrocolloids may be used occasionally, these are the major players. XG: Few will disagree that XG is the most versatile of the hydrocolloid stabilizers for salad dressing, especially of the pourable variety. This benefit flows from its rheological and stability properties. Rheologically speaking, XG is best described as highly pseudoplastic, which gives it the superior suspension, cling, ease of pumping and mixing, and excellent filling characteristics, as mentioned earlier. In addition to rheology, XG’s stability toward acid, temperature, and enzymes help to explain why it is the favorite stabilizer for pourable salad dressings. One can prepare emulsions that are stable against separation for 3 years with XG. No other dressing stabilizers possess such long-term acid stability. It also tends to maintain a steady viscosity over a wide range of temperatures, unlike most other hydrocolloids that typically thin with increasing temperatures. The amount of XG needed depends on the type of dressing being produced. Regular oil dressings usually require about 0.25%, separating dressings generally require considerably less, and low- or no-oil dressings need around 0.5%. On the negative side, XG can produce dressings with “gloppy” or “chunky” flow characteristics if used at high concentrations (usually >0.5%). This becomes a problem mainly in low calorie dressings, which require considerably higher hydrocolloid levels due to the increased amount of water that must be stabilized. This brings us to the next hydrocolloid. PGA: Before food approval of XG, PGA was the hydrocolloid of choice for pourable salad dressings. It has the advantages of being quite acid stable (6–9 months in dressing environs), possessing secondary


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emulsifying properties, and a smooth, Newtonian-like rheology. Also, PGA is sensitive to high levels of calcium (a potential problem in dressings containing substantial levels of dairy ingredients), and its heat stability is rather poor. At current prices, it is also considerably more expensive than other choices. In today’s marketplace, PGA is used mainly to modify the rheology of XG (to make it more smooth), especially in low- or no-oil dressings, which require high hydrocolloid concentrations. There is a convenient relationship between XG and PGA viscosity/use level. Two parts of low viscosity, dressing grade PGA, are roughly equal in viscosity to one part of XG in salad dressing formulas. Generally speaking, PGAs should not be used in “coarse” type emulsions, due to their emulsifying properties, which favor “fine” emulsion formation. Modified starches are used mainly in spoonable dressings. These starches are modified to have improved acid and shear stability so that they may withstand high acid and shear conditions encountered during processing and storage. Starches have the advantages of giving the typical spoonable texture, not obtainable from other hydrocolloids, being “consumer friendly” (clean label), being permitted in standardized dressings, and possessing low cost per pound. They are usually digestible and used at concentrations approaching 5%, so contribute calories to the formulas. Many of the starches require cooking to gelatinize them before they can be used in the dressing and are susceptible to degradation under high heat and acid conditions. At the highest usage levels, starches can contribute a pasty mouthfeel and tend to mask delicate flavors. A major difference between mayonnaise and spoonable salad dressing is the “heavier” mouthfeel caused by the presence of starch in the salad dressing. MCC is used extensively as a fat mimetic in low- or no-oil dressings. It contributes opacity (very white) to dressings and can produce starchlike consistency or texture if the levels are high enough (>2%) and so, it is useful in spoonable as well as pourable dressings. MCC possesses good stability to acid, salts, and temperature, so it works well together with other hydrocolloids. MCC also acts as a good suspending agent, due to its thixotropic rheology. Although relatively high shear is needed to develop MCC’s full viscosity, this is normally not a problem when using dressing equipment. For coarse emulsion products, MCC could be problematic and its whiteness would likely change the color from the desired hue.



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Guar gum is the lowest cost hydrocolloid (on a usage level basis). It is rarely used alone in dressings, and is sometimes combined with XG as a means of lowering the total hydrocolloid cost. Under certain conditions, guar and XG combinations provide synergistic viscosity increases, but this effect is markedly reduced as the pH decreases below 5 and as the salt concentration increases, because the synergism is due to hydrogen bonding between the 2 gums, and that effect is significantly reduced as hydrogen and other ion concentrations increase. Additionally, guar has poor long-term acid stability. When used in combination with XG, after a few weeks the guar will start being hydrolyzed by the acid. When that occurs, not only is guar viscosity lost, but any viscosity from the synergism between XG and guar will also be lost. This may result in a significant viscosity loss and subsequent emulsion separation. Heat exacerbates degradation and will further reduce dressing shelf life. Therefore, manufacturers should be very cautious about using guar in salad dressings. Typical Dressing Formulae Typical Pourable French Dressing Ingredients Vegetable oil, soybean Water Sugar, granular Vinegar, white, 10% (100 grain) Tomato paste (26% T.S.) Spices, color, flavor, etc. Salt Mustard powder Xanthan gum

Grams (g)

Percent (%)

382.0 308.0 115.0 100.0 60.0 12.5 10.0 10.0 2.5

38.20 30.80 11.50 10.00 6.00 1.25 1.00 1.00 0.25

1000.0

100.00

Preparation 1. Blend all dry ingredients except for XG and salt, and add to wellagitated water. 2. Slurry XG in 3–5 times its weight of oil.


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3. Add oil/gum slurry to #1 aqueous solution, under vigorous agitation, and continue vigorous mixing for 3–5 minutes. 4. Continue mixing and add tomato paste, color (if liquid) and salt. Mix to homogeneity. 5. Add oil slowly, under continued vigorous agitation. 6. Continue mixing and add vinegar. Mix until homogeneous. 7. Pass dressing through a colloid mill set at 0.25 mm (0.01 ). 8. Fill containers. This dressing uses only one stabilizer (XG) and should possess a viscosity of about 3,500 cP (Brookfield LV viscometer, spindle #4, 60 rpm), pH of 3.6, and aqueous phase acidity of 2.26 (as acetic acid). Unless augmented by other preservatives, the aqueous phase of dressings should typically be >2% as acetic acid to inhibit bacterial growth. Typical Spoonable Salad Dressing Ingredients Vegetable oil Water Sugar, granular Vinegar, white, 10% (100 grain) Egg yolks, frozen Modified corn starch Salt Mustard flour Xanthan gum

Grams (g)

Percent (%)

350.00 319.00 120.00 100.00 55.00 35.00 15.00 5.00 1.00

3.5 31.90 12.00 10.00 5.50 3.50 1.50 0.50 0.10

1,000.00

100.00

Preparation (laboratory) 1. Preblend all dry ingredients and add to the water while mixing and heating to 180◦ F (82◦ C) in a double boiler. 2. Cool to room temperature, while stirring in an ice water bath. 3. Transfer to a Hobart-type mixer with a wire whip. 4. Add thawed egg yolks; mix with a wire whip. 5. Add oil slowly, while continuing mixing.



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6. Add vinegar slowly and continue mixing until smooth. 7. Pass through a colloid mill set at 0.01 (0.25 mm). This spoonable dressing’s main stabilizer is starch, but the level of starch is reduced by the addition of 0.1% XG, thereby improving the texture and stability of the dressing.

Typical Italian Dressing (Separating Type) Ingredients Vegetable oil, soybean Cider vinegar, 5% (50 grain) Water Lemon juice, single strength Salt Spices and flavorings to suit Xanthan gum

Grams (g)

Percent (%)

560.0 280.0 90.0 50.0 10.0 9.8 0.2

56.00 28.00 9.00 5.00 1.00 0.98 0.02

1,000.0

100.00

Preparation 1. Dry blend XG with all dry ingredients. 2. Hydrate dry blend in all available water under vigorous agitation for 10 minutes. 3. Add lemon juice and vinegar. 4. Fill aqueous and oil phases in a two-step process by weight or volume. This should produce a dressing with pH of 4, viscosity of 130 cP∗ (after shaking at room temperature), and aqueous phase acidity of 4%, as acetic acid. (∗ Brookfield LVT, spindle #2, 60 rpm). Note: This separating dressing will only hold together for a few minutes at this low concentration of XG. Higher levels of XG may produce dressings that are stable for considerably longer periods of time but may not separate as cleanly as the low concentrations.



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Hydrocolloids in Food Processing Typical Low-Calorie Italian Dressing Ingredients Water Vinegar, white, 10% (100 grain) Salt Spices, flavors, and sweeteners to suit Xanthan gum Propylene glycol alginate Sodium benzoate Potassium sorbate

Grams (g)

Percent (%)

820.30 150.00 10.00 8.20 4.50 3.00 0.50 0.50

82.03 15.00 1.00 0.82 0.45 0.30 0.05 0.05

1,000.00

100.00

Preparation 1. 2. 3. 4. 5. 6.

Thoroughly blend all dry ingredients, except salt. Add dry blend to available water under vigorous agitation. Mix for 5–7 minutes. Add vinegar and mix until homogeneous. Add salt and mix for 1–2 minutes. Bottle.

This formula should produce a dressing with pH 3.3, viscosity of 720 cP∗ (room temperature), and aqueous phase acidity of 1.6%, as acetic acid. (∗ Brookfield LV spindle #3, 60 rpm). Two gums, XG and PGA, are used. In order to achieve sufficient viscosity with only XG, a dressing with objectionably “chunky” rheology would result. PGA produces more Newtonian flow properties than XG and is used to give the added viscosity needed after the maximum XG level (from a rheological aspect—usually 0.5% or less) is used. Since the water phase makes up over 80% of this dressing, additional preservatives (benzoate and sorbate) are used to allow for lower vinegar levels and better flavor.



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31

Mayonnaise-Type (7% Oil) Spoonable Salad Dressing Ingredients

Grams (g)

Percent (%)

1163.00 300.00 140.00 112.00 108.00 60.00

58.15 15.00 7.00 5.60 5.40 3.00

Modified waxy maize starch (instant)

55.00

2.75

Salt Xanthan gum

34.00 13.00

1.70 0.65

Flavor, spices, color, etc. (to suit) Sodium benzoate Potassium sorbate, powdered

13.00 1.00 1.00

0.65 0.05 0.05

2,000.00

100.00

Water Egg whites, pasteurized Soybean oil Vinegar, distilled, 100 grain Sugar, granular Microcrystalline cellulose

Preparation (Use a 5 quart Hobart-type mixer, equipped with wire whip.) 1. Add emulsifiers and all dry ingredients (except for salt and sugar), to the water. 2. Dry blend hydrocolloids (MCC, starch, and XG) with the sugar. 3. Add hydrocolloid (HC) or sugar dry blend to the water under highspeed agitation and mix for 5 minutes. 4. Add liquid egg whites and mix until uniform (ca. 1 minute). 5. Add chilled oil slowly, and mix for 2 minutes at high speed. 6. Add the salt and continue to mix. 7. Add vinegar and any other liquid flavors or acids, and mix 3 minutes at medium speed. 8. Optional: Pass through colloid mill at 0.06 . Note: In order to achieve a mayonnaise-like flavor, acidity must be kept as low as possible. Therefore, using a considerably lower vinegar concentration than needed for proper preservation requires the use of


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additional preservatives (e.g., sorbate and benzoate). Since the preserving function of vinegar depends on the amount of undisassociated acetic acid present, other acids (citric or mineral acids, for example) may also be added to lower the pH and make the formula vinegar more efficient in its preserving role. MCC is used mainly as a fat mimetic and to provide spoonable texture similar to starch, but without calories. Both XG and MCC allow for the lowest possible starch level, which contributes to better flavor release and a texture more like real mayonnaise than typical spoonable salad dressing.

Determining the type and level of hydrocolloid (HC) needed 1. The particle size (or mesh size) of the HC needed depends on the type of dressing being produced. For dressings produced with high shear mixing equipment, a “regular” particle size (e.g., 80 mesh) is desirable. For dry mix dressings to be used in home settings, “fine” particle (e.g., 200 mesh) sized HCs are needed, since they are hydrated under very low shear, gentle mixing conditions (e.g., hand shaking in a cruette). This also requires careful choice of other dry ingredients to act as dispersing agents for the fine mesh gums which will have greater tendencies to form lumps. Fine mesh sugar may be required for such applications, for example. 2. To determine how much HC is needed for a particular function, prepare two identical dressings, except that one should contain a significantly higher HC concentration than needed and one should have a significantly lower concentration than needed. Mix the two dressings together in different proportions to create a spectrum of different HC concentrations, measure viscosity values and store them in 100 ml graduated cylinders to observe for particulate settling, oil separation, heat stability, etc. 3. To obtain a desired rheology, a similar method may be used, except this time two dressings are prepared with equal viscosity, but stabilized with different gums possessing differing rheological characteristics. Consider the typical French dressing formula above as an example. This formula calls for 0.25% XG. If a smoother flowing dressing is desired, prepare an equal viscosity dressing with PGA at 0.5% instead of XG. Subsequently, the two equal viscosity dressings



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33

may be mixed together in different proportions to determine which proportion gives the desired rheology for the dressing. This procedure becomes even more useful when dealing with low calorie/no oil dressings which must use high gum levels, due to the expanded aqueous phase. Rheology becomes an even greater factor in such cases.



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Chapter 3 Hydrocolloids in Muscle Foods James W. Lamkey

There are a number of reasons why meat formulas differ over time and across regions. Economic conditions play a major role in the composition of processed meat products. Economically underdeveloped countries make products that are affordable to the majority of the population, replacing meat proteins with less expensive nonmeat ingredients. Raw material availability is also a major reason for adjustments to formulations. Animal fat, for example, is less available in some countries, requiring formulations to make adjustments for the lack of fat. This is also true in some countries where consumers want the taste and texture of traditional products but do not want the fat. Food safety concerns have also caused processors to reformulate products to withstand treatments that promote a safer food product. Postpackaging pasteurization can cause a high level of moisture loss, requiring the addition of an ingredient that aids in the retention of moisture. Organic acid is being used as an added hurdle for food safety. When adding the sodium salts of these acids, sodium levels approach the upper limit of nutritional labels. When the potassium salt is substituted to adjust for this increase in sodium, there may be effects on other ingredients in the formula, requiring a substitution to recover the taste and texture desired. As the industry grows and markets reach beyond domestic borders, formulations will need to meet the requirements of the target regions.

Hydrocolloids in Food Processing Edited by Thomas R. Laaman © 2011 Blackwell Publishing Ltd. and Institute of Food Technologists ISBN: 978-0-813-82076-7

35


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Ingredients added to meat can either enhance meat protein functionality or be a supplement to meat protein functionality. Proteins are the primary component in meat that aid in the retention of moisture. However, in the area of processed meat, the proteins are asked to retain more moisture than normally contained within the protein. The proper use of ingredients, as well as optimal process conditions, will enhance the proteins ability to retain moisture. In many cases, however, this is not enough to meet the desires of the processor. Other ingredients are then added to aid in the retention of the excess moisture, but the selection is based on cost as much as the overall contribution to the end product. In the selection of an ingredient for a particular product, a processor must consider how these ingredients perform in the presence of other ingredients, as there becomes a competition for moisture. When one ingredient has a higher affinity for water, but cannot tightly hold the water during cooking or heating, there can be a noticeable reduction in the cook yield. Optimal use of the ingredients will give the best overall functionality at the best cost. In some cases, when the ingredients are not added properly, there will be a reduction in moisture retention. Ingredients react and perform differently in meat applications. Information in Table 3.1 allows us to differentiate between ingredients on the basis of degree of activity in the food system. Starches and some gums are considered highly active because these ingredients obtain their full functionality during thermal processing. Soy protein isolate, on the other hand, aggregates during the initial stages of processing which is set during thermal process. These matrices assist in the retention of moisture and contribute to texture. Salt and phosphate are the most common ingredients added to meat products, which act on proteins to enhance functionality. Prior to the advent of refrigeration, salt was used at levels that limited the growth of microorganisms and therefore extended the usable life of the product. Most of the proteins responsible for moisture retention are salt soluble. Salt, and specifically chloride ions, adapts the protein for greater moisture retention by masking some of the positive charges on the protein molecule. This in turn gives the protein a stronger negative charge, increasing repulsion within the molecule, opening up the structure for moisture retention. In the case of further processed meat products, salt soluble proteins are extracted and made available for water and protein interactions that enhance texture. Alkaline phosphates, as the name



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Hydrocolloids in Muscle Foods

37

Table 3.1. Characterization of biopolymers on the basis of degree of activity. Degree of Activity

Type of Biopolymer

Nature of Activity

Highly active

Starches, gums

Moderately active

SPI, wheat gluten, egg whites

Slightly active

Milk proteins, pregelatinized starches

Inactive

Cellulose (unmodified)

Inactive

Oil/fat

Thermally induced activation, formation of elastic globules No thermally induced activation, strong water binding, and formation of elastic mass upon hydration Moderate water binding, formation of nonelastic mass Water binding but no thermal activation No water binding or thermal activation

SPI, soy protein isolate. Adaptation from Lee 2002.

implies, increase the pH of the environment which in turn enhances the protein’s ability to hold water. In the presence of phosphates, actomyosin is dissociated into the primary components of actin and myosin through the action of pyrophosphate. In fact, salt and phosphates work synergistically to improve the moisture binding and texture enhancing characteristics of meat proteins through this action because myosin is higher in water binding capacity than is actomyosin and salt helps to extract the protein to further improve functionality. Although meat proteins are very functional, there are times when meat products can benefit from the addition of other ingredients. These additional ingredients do not enhance protein functionality but work with the proteins to help retain moisture and modify texture. Starch is the most widely used carbohydrate in the meat industry on a global basis. Both cost and functionality are primary reasons for its wide use. In the United States, starches are limited to 3.5% on the basis of their weight and can be used in combination with other hydrocolloids as long as the combined total does not exceed 3.5%. In some regions,


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such as Latin America, Asia, and Eastern Europe, it is not uncommon to see formulations with 5% or more starch. The type of starch used in meat products is primarily dependant on what is available in the region. Starches are obtained from a variety of sources with a wide variety of functionalities. Corn, potato, wheat, tapioca, and rice starch are the most common. The primary functionality of starch is to bind water, provide various degrees of freeze/thaw stability, and contribute to texture. Starch’s functionality is derived from its ability to swell and take on water, like many other hydrocolloids. The swelling of the starch occurs during the heating stage making it a highly active biopolymer. One of the differentiating features of starches is the amounts and ratios of amylose and amylopectin. Starches with high amounts of amylopectin, such as waxy maize, will not gel or synerese after gelatinization. High amylose starches will form very stiff gels. The modification of starches is done to enhance or quell inherent properties. In some cases it is modified to control texture, viscosity, heat tolerance, or freeze/thaw stability. Most of these modifications are based on performance in a water system without proteins. In meat applications, there are indications that starches do not become fully soluble under typical processing conditions and therefore the modification is not fully manifested in a meat application. Starches have been found to be synergistic with other hydrocolloids, one of which is carrageenan. Carrageenan is a hydrocolloid obtained from various species of red seaweed and can help processed meat products retain moisture. Carrageenan is available in many forms; however, the primary characteristics of which a processor should be aware of are type, composition, and concentration. There are three primary types of carrageenan: kappa, iota, and lambda. Very strong and brittle gels characterize ␬-carrageenans. Iota, on the other hand, is less strong and more elastic. ␭-carrageenans do not gel and are used primarily for suspension of particulates in sauces and dressings. Kappa and iota are the carrageenans showing the most benefit in meat applications, as water managers and texture modifiers. Lambda, like most cold soluble hydrocolloids, cannot manage the water in which they are soluble, and therefore shows little benefit in processed meat products. The composition of a carrageenan used in meat processing can widely vary. Of the components most often seen in a blend, the most common



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39

are carrageenan, potassium chloride (KCl), sodium chloride, sugars, and various other hydrocolloids to include like locust bean, guar, and xanthan. Some of these ingredients show an advantage, or synergy, when included in water gels, but may not show the same benefit in meat applications. The presence of ions and the insulating effect of the proteins subdue any synergies that may be possible. KCl is the most common ingredient in carrageenan as potassium is required for gelling of ␬-carrageenans. KCl is also used for the precipitation of carrageenan in gel press applications. Therefore, KCl is commonly a component of the carrageenan molecule and is necessary for proper functioning. Regulations specify that the ash content of carrageenan cannot exceed 35%. If KCl is the only added component in the blend, levels resulting in ash contents above regulatory limits require the labeling of KCl. In some cases, however, carrageenan is blended with additional KCl for improving water gel firmness. Up to 20% of the carrageenan weight can be added to KCl for water gel strength improvement. Adding KCl at concentrations above 20% of carrageenan reduces gel strength due to a dilution effect. An increase in gel strength with added potassium, however, is only seen in water gel applications and not necessarily in meat firmness. In fact the addition of KCl may interfere with the function of carrageenan. In the presence of potassium the temperature at which carrageenan becomes soluble increases, which in turn restricts the swelling of carrageenan and reduces its ability to manage water. This, in turn leads to loss of weight in the processed meat during cooking, referred to as cookout. Please see Table 3.2. Discussions about carrageenan always include gelling characteristics due to their ability to differentiate between carrageenan types. For the most part, gelling characteristics are very important, especially from a quality assurance standpoint. However, comparison between carrageenans should stop short of discussing gel strength as an indicator of functionality in meat applications. In a study designed to investigate the gelling mechanism of a simulated protein solution similar to the aqueous environment of turkey breasts, Bater et al. (1992) found that ␬-carrageenan swelling was initiated at higher temperatures as the salt level increased. The authors found that at 0% salt, ␬-carrageenan began swelling at 28◦ C while at 4.4% salt, swelling didn’t begin until 67◦ C. Proteins began gelling at 52◦ C. Bater et al. (1992) concluded that an increase in salt concentration could cause an increase in swelling temperature and a decrease in ␬-carrageenan in meat products. At that



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Table 3.2. Addition of potassium chloride and effect on carrageenan functionality (Lamkey 2006). Added KCl Treatment (% of F.P.)∗ Cookout (%) Comments 1

0.00

0.2

2 3

0.16 0.32

0.7 2.3

4

0.64

8.5

5

1.28

11.6

6

2.55

10.6

∗

Excellent protein adhesion to cooking film Acceptable. Minimal protein adhesion Unacceptable. Gelled cookout on meat surface Unacceptable. Excessive soft gel cooked out Cookout was watery. Carrageenan did not swell Same as treatment#5

Finished product weight

point in time, the authors believed that carrageenan functionality in meat requires that the carrageenan go into solution. Prahbu and Sebranek (1997) found that carrageenan particles were dispersed throughout the product without evidence of gel formation. The authors’ hypothesis was that protein gels before carrageenan becomes fully soluble and therefore gets trapped within the protein gel structure. Prahbu and Sebranek (1997) also observed that starch and carrageenan were found in localized regions separated from each other. From these data it is highly unlikely that the synergism known to exist in water gels is manifested within the meat product. Carrageenan improves water retention, consistency, sliceability, and texture of poultry products with high levels of added brine (Trudso 1985). In regions of the world where 10 and 15% starch is added to economical hams, carrageenan is added at quantities of 0.5–0.8% to improve syneresis control and sliceability. On a global basis, cured hams are commonly formulated with carrageenan. Mills (1995) showed that 1.5% in a 38% added ingredient (AI) cured pork ham exhibited the highest cook yield for cook-in-bag products. The closest ingredient to carrageenan for this characteristic was sodium caseinate, which had a cook yield of 8% below that of carrageenan. The U.S. Department of Agriculture (USDA) does allow up to 1.5% carrageenan in cured pork products but it should be noted that this level of use is often too much for that level of AIs.



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Figure 3.1. (a) Micrograph of carrageenan in cooked meat; (b) fully hydrated carrageenan in water.

The functionality of carrageenan comes from its ability to swell and absorb water (Figure 3.1). During the heating stage, carrageenans swell and absorb the water entrapping it through the heating and storage phase. This allows for an increase in cook yield and a reduction in purge (syneresis). Poor quality raw materials will have a detrimental effect on product quality. One of the more common conditions processors face is pale, soft, and exudative (PSE) raw material. This condition is most commonly found in pork and turkey. As the name implies, the characteristics of PSE raw materials include a pale appearance, soft texture, and loss of moisture. A rapid pH decline at high temperatures during harvest is considered the primary cause of this due to a reduction in functionality of the proteins. In an effort to find an ingredient that will reverse this challenge, Motzer et al. (1998) looked at starch, ␬-carrageenan, and isolated soy protein in the manufacture of hams with increasing levels of PSE. Results indicated that k-carrageenan gave the highest chill yield when used in a 100% PSE product. Use level of carrageenan will vary depending on quality of carrageenan, level of standardization, and extension level of product being made. For all carrageenans, the characteristic being measured will increase for each unit increase in carrageenan to an optimum use level. Beyond that optimum level, adding more carrageenan does not give



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Hydrocolloids in Food Processing 100 98

Cook yield (%)

96 94 92 90 88 86 84

0

0.2 0.4 Carrageenan concetration

0.6

Figure 3.2. Cook yield as affected by carrageenan concentration.

better results. That optimum level is unique for most processors, dependent on the product, raw materials, and processing condition. However, everything being equal, a rule of thumb for optimum carrageenan usage for cook yield, 0.1% carrageenan should be added for each 10% added brine (Lamkey 2006). Firmness requirements and purge control may need higher levels. The data in Figure 3.2 below depicts cook yield versus carrageenan concentration for turkey breast products that have been extended 50%. Optimum use for this application appears to be in the area of 0.5%. Although an interaction between milk proteins and carrageenan can be demonstrated, there is more of a symbiotic relationship with meat proteins. Meat proteins surround the carrageenan particle and act as an elastic netting to aid in the retention of water. In the event that the elastic netting is compromised, such as low quality raw materials or PSE, the retention of moisture will be reduced. Carrageenan does improve sliceabilty of meat products, especially for products destined for high-speed slicers. Firmness, however, is based more on the level of water added to the meat product. Figure 3.3 indicates the effect of added moisture on the firmness of turkey products. As the level of moisture increases, the firmness of the product decreases. With the addition of carrageenan, a trend exists where the carrageenan shows a different result at moisture to protein (M:P) ratios below 5.5 compared to those above 5.5. Figure 3.4 shows the effect on yield of using carrageenan versus a control without carrageenan. Figure 3.5



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43

Compression hardness

10000 9000 8000 7000 6000 5000 4000 3000 2000

4.00

4.50

5.00 5.50 6.00 Moisture to protein ratio Control

0.2

0.4

6.50

0.6

Figure 3.3. Hardness as affected by moisture protein ratio at four carrageenan concentrations.

shows the beneficial effect of carrageenan on water holding capacity in a warming tray over an extended period. Konjac Konjac is a hydrocolloid that is extracted from a tuber from the Asia Pacific region. The unique characteristic that sets konjac apart from other hydrocolloids is its ability to form heat stable gels. Konjac is able to achieve this characteristic through deacetylation, which is initiated 110.00 105.00

Yields (%)

100.00 95.00 90.00 85.00 80.00 75.00 70.00 Control

Carrageenan Treatments

Figure 3.4. Process yields as affected by carrageenan.



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Hydrocolloids in Food Processing Water holding capacity

Control vs. carrageenan

% Expressible moisuture

70.00 60.00 50.00 40.00 30.00 20.00 10.00 0.00

0

0.5

1 Warming Tray (Hrs) control

1.5

2

C

Figure 3.5. Moisture retention as affected by carrageenan.

by creating an environment that has a high pH. The higher the pH, the faster the reaction takes place. Unfortunately, in meat processing, proteins will be less functional at this pH and therefore the reaction must take place outside the system, creating an additional step. Synergies There are notable synergies between many hydrocolloids. Most notably, konjac/carrageenan, konjac/starch, carrageenan/starch, and konjac/ xanthan are a few of the synergies known. Synergism is defined as a measurable characteristic that shows a greater function in the presence of two or more ingredients that cannot be explained by a simple additive effect. For synergism to take an effect, the hydrocolloids have to be soluble and in intimate contact. In meat applications, heat soluble hydrocolloids show evidence of not being completely in solution. In addition, the protein matrix surrounding the hydrocolloid limits its movement and interaction with other ingredients in the product. Synergism among hydrocolloids is easily demonstrated in water gel systems, but may not manifest themselves in a meat application. Turkey Breast In the United States, turkey breast is the most common application for carrageenan. Products made with turkey breast can be whole muscle



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45

Table 3.3. Typical formulations for turkey breast.

Ingredients Water (

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