Understanding and measuring the shelf-life of food Related titles from Woodhead's food science, technology and nutrition list: The stability and shelf-life of food (ISBN 1 85573 500 8) The stability and shelf-life of a food product are critical to its success in the market place, yet companies experience considerable difficulties in defining and understanding the factors that influence stability over a desired storage period. This book is the most comprehensive guide to understanding and controlling the factors that determine the shelf-life of food products. Taints and off-flavours in foods (ISBN 1 85573 449 4) Taints and off-flavours are a major problem for the food industry. Part I of this important collection reviews the major causes of taints and off-flavours, from oxidative rancidity and microbiologically-derived off-flavours, to packaging materials as a source of taints. The second part of the book discusses the range of techniques for detecting taints and off-flavours, from sensory analysis to instrumental techniques, including the development of new rapid on-line sensors. Colour in food ± Improving quality (ISBN 1 85573 590 3) The colour of a food is central to consumer perceptions of quality. This important new collection reviews key issues in controlling colour quality in food, from the chemistry of colour in food to measurement issues, improving natural colour and the use of colourings to improve colour quality. Details of these books and a complete list of Woodhead's food science, technology and nutrition titles can be obtained by: · visiting our web site at www.woodhead-publishing.com · contacting Customer Services (email: [email protected]; fax: +44 (0) 1223 893694; tel.: +44 (0) 1223 891358 ext. 30; address: Woodhead Publishing Limited, Abington Hall, Abington, Cambridge CB1 6AH, UK) Selected food science and technology titles are also available in electronic form. Visit our web site (www.woodhead-publishing.com) to find out more. If you would like to receive information on forthcoming titles in this area, please send your address details to: Francis Dodds (address, tel. and fax as above; e-mail: [email protected]). Please confirm which subject areas you are interested in. Understanding and measuring the shelf-life of food Edited by R. Steele Published by Woodhead Publishing Limited Abington Hall, Abington Cambridge CB1 6AH England www.woodhead-publishing.com Published in North America by CRC Press LLC 2000 Corporate Blvd, NW Boca Raton FL 33431 USA First published 2004, Woodhead Publishing Limited and CRC Press LLC ß 2004, Woodhead Publishing Limited The authors have asserted their moral rights. This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. Reasonable efforts have been made to publish reliable data and information, but the authors and the publishers cannot assume responsibility for the validity of all materials. Neither the authors nor the publishers, nor anyone else associated with this publication, shall be liable for any loss, damage or liability directly or indirectly caused or alleged to be caused by this book. Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming and recording, or by any information storage or retrieval system, without permission in writing from the publishers. The consent of Woodhead Publishing Limited and CRC Press LLC does not extend to copying for general distribution, for promotion, for creating new works, or for resale. Specific permission must be obtained in writing from Woodhead Publishing Limited or CRC Press LLC for such copying. Trademark notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation, without intent to infringe. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library. Library of Congress Cataloging-in-Publication Data A catalog record for this book is available from the Library of Congress. Woodhead Publishing Limited ISBN 1 85573 732 9 (book); 1 85573 902 X (e-book) CRC Press ISBN 0-8493-2556-0 CRC Press order number: WP2556 The publisher's policy is to use permanent paper from mills that operate a sustainable forestry policy, and which have been manufactured from pulp which is processed using acid-free and elementary chlorine-free practices. Furthermore, the publisher ensures that the text paper and cover board used have met acceptable environmental accreditation standards. Project managed by Macfarlane Production Services, Markyate, Hertfordshire (e-mail: [email protected]) Typeset by MHL Typesetting Limited, Coventry, Warwickshire Printed by TJ International Limited, Padstow, Cornwall, England Contents Contributor contact details ............................................. xi Part I Factors affecting shelf-life and spoilage 1 The major types of food spoilage: an overview ................. 3 R. P. Singh and B. A. Anderson University of California, USA 1.1 Introduction . ................................................ 3 1.2 Physical instability . ...................................... 4 1.3 Chemical spoilage (degradation) . ........................ 9 1.4 Microbial spoilage . ...................................... 11 1.5 Future trends . ................................................ 17 1.6 Sources of further information ............................... 18 1.7 References . ................................................ 19 2 Shelf-life and moisture management . ........................ 24 R. Esse and A. Saari, Humidipak, Inc., USA 2.1 Introduction: moisture activity and shelf-life ................. 24 2.2 Water activity and moisture management . ................. 25 2.3 The effects of moisture on the storage stability of food . 29 2.4 How moisture management systems work: the case of meat jerky . ...................................... 32 2.5 Application of moisture management systems to food and other products ................................................ 37 2.6 Future trends . ................................................ 40 2.7 Bibliography . ................................................ 41 vi Contents 3 Temperature and food stability: analysis and control . 42 P. S. Taoukis and M. C. Giannakourou, National Technical University of Athens, Greece 3.1 Introduction: temperature and the shelf-life of food . 42 3.2 Quantifying the effect of temperature on food . 43 3.3 Shelf-life testing and indices . 52 3.4 Shelf-life prediction and management: time±temperature relationships . 53 3.5 Future trends . 61 3.6 References . 65 4 Genetic and physiological factors affecting colour and firmness . 69 R. E. Schouten and O. van Kooten, Wageningen University and H. Jalink, I. F. Kappers, J. F. H Snel and W. Jordi, Plant Research International, The Netherlands 4.1 Introduction . 69 4.2 Physiology of firmness: fruits and vegetables . 70 4.3 Methods of improving and maintaining firmness . 72 4.4 Physiology of colour: fruits and vegetables . 75 4.5 Methods of improving and maintaining colour . 78 4.6 Future trends . 82 4.7 Acknowledgements . 85 4.8 References . 85 5 Spoilage yeasts . 91 T. Deak, Budapest University of Economic Science, Hungary 5.1 Introduction . 91 5.2 Characteristics and classification of yeasts . 92 5.3 Factors affecting the growth and survival of spoilage yeasts . 97 5.4 Diversity and frequency of food spoilage yeasts . 100 5.5 Factors affecting the inactivation of spoilage yeasts . 103 5.6 Future trends: alternative technologies . 106 5.7 Sources of further information . 109 5.8 References . 109 6 Factors affecting the Maillard reaction . 111 A. Arnoldi, University of Milan, Italy 6.1 Introduction: the Maillard reaction (MR) . 111 6.2 Factors affecting the Maillard reaction . 114 6.3 The Maillard reaction and spoilage: flavour deterioration . 116 6.4 The Maillard reaction and spoilage: nutritional losses and browning . 119 6.5 Improving shelf-life: antioxidative Maillard reactions . 122 Contents vii 6.6 Improving shelf-life: the Maillard reaction and microbial spoilage . 124 6.7 Conclusion . 124 6.8 References . 124 7 Factors affecting lipid oxidation . 128 M. H. Gordon, University of Reading, UK 7.1 Introduction: mechanisms of autoxidation . 128 7.2 Factors influencing the rate of lipid oxidation . 131 7.3 Methods of measuring oxidation in an oil or food . 132 7.4 Monitoring changes in oxidation and the use of predictive methods . 137 7.5 Future trends . 140 7.6 Sources of further information and advice . 140 7.7 References . 140 8 Lipolysis in lipid oxidation . 142 C. Davies, Unilever R & D, Sharnbrook, UK 8.1 Introduction . 142 8.2 Lipolytic enzymes, lipids and food spoilage . 143 8.3 Lipolysis in particular foods: dairy, meat and fish products . 145 8.4 Lipolysis in particular foods: cereals and vegetables . 150 8.5 Controlling lipolysis to improve shelf-life . 153 8.6 Future trends . 154 8.7 Sources of further information and advice . 155 8.8 References . 156 Part II Measuring shelf-life and spoilage 9 Ways of measuring shelf-life and spoilage . 165 T. K. Singh and K. R. Cadwallader, University of Illinois, USA 9.1 Introduction: understanding and estimating the shelf-life of food . 165 9.2 Key factors influencing the shelf-life of food . 167 9.3 Quality indices for testing the shelf-life of food . 171 9.4 Conclusions and future trends . 178 9.5 Sources of further information