P1: SFK/UKS P2: SFK FM BLBK221-Taylor/Linforth November 25, 2009 15:44 Printer Name: Yet to Come P1: SFK/UKS P2: SFK FM BLBK221-Taylor/Linforth December 2, 2009 17:29 Printer Name: Yet to Come Food Flavour Technology Second Edition Edited by Andrew J. Taylor and Robert S.T. Linforth Division of Food Sciences, University of Nottingham, UK A John Wiley & Sons, Ltd., Publication P1: SFK/UKS P2: SFK FM BLBK221-Taylor/Linforth December 2, 2009 17:29 Printer Name: Yet to Come This edition first published 2010 C 2010 Blackwell Publishing Ltd Blackwell Publishing was acquired by John Wiley & Sons in February 2007. Blackwell’s publishing programme has been merged with Wiley’s global Scientific, Technical, and Medical business to form Wiley-Blackwell. 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Flavour. 2. Flavouring essences. 3. Flavour–Analysis. I. Taylor, A. J. (Andrew John), 1951- II. Linforth, Robert S. T. TP418.F65 2010 664.07–dc22 2009028000 A catalogue record for this book is available from the British Library. Set in 10/12 pt Times by Aptara R Inc., New Delhi, India Printed in Singapore 1 2010 P1: SFK/UKS P2: SFK FM BLBK221-Taylor/Linforth December 2, 2009 17:29 Printer Name: Yet to Come Contents List of contributors xi Preface xiii 1 Creating and formulating flavours 1 John Wright 1.1 Introduction 1 1.1.1 A little history 1 1.2 Interpreting analyses 2 1.3 Flavour characteristics 3 1.3.1 Primary characters 3 1.3.2 Secondary characteristics 4 1.3.3 Taste effects 5 1.3.4 Complexity 6 1.3.5 Flavour balance 6 1.3.6 Unfinished work 7 1.4 Applications 8 1.4.1 Ingredient factors 8 1.4.2 Processing factors 10 1.4.3 Storage factors 10 1.4.4 Consumption factors 11 1.5 Flavour forms 11 1.5.1 Water-soluble liquid flavours 11 1.5.2 Clear water-soluble liquid flavours 12 1.5.3 Oil-soluble liquid flavours 13 1.5.4 Emulsion-based flavours 13 1.5.5 Dispersed flavours 13 1.5.6 Spray-dried flavours 14 1.6 Production issues 15 1.7 Regulatory affairs 16 1.8 A typical flavour 16 1.9 Commercial considerations 19 1.9.1 International tastes 19 1.9.2 Abstract flavours 20 1.9.3 Matching 21 1.9.4 Customers 22 1.10 Summary 22 References 23 P1: SFK/UKS P2: SFK FM BLBK221-Taylor/Linforth December 2, 2009 17:29 Printer Name: Yet to Come iv Contents 2 Flavour legislation 24 Jack Knights 2.1 Introduction 24 2.2 Methods of legislation 24 2.3 Legislation in the United States 26 2.4 International situation: JECFA 27 2.5 Council of Europe 28 2.6 European community 30 2.6.1 Background – national to EU legislation 30 2.6.2 The 1988 Council Directive 31 2.6.3 Smoke flavourings 2003 Directive 40 2.6.4 Developments 2008 onwards 41 2.7 Current EU Situation and the future 47 References 48 3 Basic chemistry and process conditions for reaction flavours with particular focus on Maillard-type reactions 51 Josef Kerler, Chris Winkel, Tomas Davidek and Imre Blank 3.1 Introduction 51 3.2 General aspects of the Maillard reaction cascade 51 3.2.1 Intermediates as flavour precursors 54 3.2.2 Carbohydrate fragmentation 58 3.2.3 Strecker degradation 61 3.2.4 Interactions with lipids 62 3.3 Important aroma compounds derived from Maillard reaction in food and process flavours 65 3.3.1 Character-impact compounds of thermally treated foods 65 3.3.2 Character-impact compounds of process flavours 70 3.4 Preparation of process flavours 74 3.4.1 General aspects 74 3.4.2 Factors influencing flavour formation 74 3.4.3 Savoury process flavours 78 3.4.4 Sweet process flavours 80 3.5 Outlook 80 References 81 4 Biotechnological flavour generation 89 Ralf G. Berger, Ulrich Krings and Holger Zorn 4.1 Introduction 89 4.2 Natural flavours: market situation and driving forces 89 4.3 Advantages of biocatalysis 90 4.4 Micro-organisms 91 4.4.1 Biotransformation and bioconversion of monoterpenes 91 4.4.2 Bioconversion of C13-norisoprenoids and sesquiterpenes 95 4.4.3 Generation of oxygen heterocycles 96 P1: SFK/UKS P2: SFK FM BLBK221-Taylor/Linforth December 2, 2009 17:29 Printer Name: Yet to Come Contents v 4.4.4 Generation of vanillin, benzaldehyde and benzoic compounds 97 4.4.5 Generation of miscellaneous compounds 99 4.5 Enzyme technology 101 4.5.1 Liberation of volatiles from bound precursors 101 4.5.2 Biotransformations 101 4.5.3 Kinetic resolution of racemates 103 4.6 Plant catalysts 104 4.6.1 Plant cell, tissue and organ cultures 104 4.6.2 Callus and suspension cultures 105 4.6.3 Organ cultures 105 4.6.4 Plant cell biotransformations 107 4.7 Flavours through genetic engineering 107 4.7.1 Genetically modified micro-organisms 108 4.7.2 Isolated enzymes from genetically modified micro-organisms 109 4.7.3 Plant rDNA techniques 110 4.8 Advances in bioprocessing 112 4.8.1 Process developments in microbial and enzyme systems 112 4.8.2 Process developments of plant catalysts 114 4.9 Conclusion 114 References 115 5 Natural sources of flavours 127 Peter S.J. Cheetham 5.1 Introduction 127 5.2 Properties of flavour molecules 129 5.2.1 Flavour perception 129 5.2.2 Differences in sensory character and intensity between isomers 141 5.2.3 Extraction of flavours from plant materials 142 5.2.4 Commercial aspects 146 5.2.5 Economic aspects 147 5.2.6 Safety aspects 147 5.3 Dairy flavours 147 5.3.1 Background 147 5.3.2 Cream and butter 148 5.3.3 Cheese 149 5.4 Fermented products 151 5.4.1 Hydrolysed vegetable proteins 151 5.4.2 Chocolate 152 5.4.3 Tea 153 5.4.4 Coffee 154 5.4.5 Beer 154 5.4.6 Wine 156 5.4.7 Sweeteners 158 5.5 Cereal products 158 P1: SFK/UKS P2: SFK FM BLBK221-Taylor/Linforth December 2, 2009 17:29 Printer Name: Yet to Come vi Contents 5.6 Vegetable sources of flavour 159 5.6.1 Spice flavours 159 5.6.2 Mushroom 161 5.6.3 Garlic, onion and related flavours 161 5.6.4 Brassica flavours, including mustard and horseradish 163 5.6.5 ‘Fresh/green/grassy’ 164 5.6.6 Nuts 164 5.6.7 Other vegetables 165 5.6.8 Fermented vegetables 165 5.7 Fruit 165 5.7.1 Apples 166 5.7.2 Pears 167 5.7.3 Grapefruit 167 5.7.4 Blackcurrant 167 5.7.5 Raspberry 168 5.7.6 Strawberry 168 5.7.7 Apricot and peach 169 5.7.8 Tomato 169 5.7.9 Cherry 169 5.7.10 Tropical fruit flavours 170 5.7.11 Vanilla 170 5.7.12 Other fruits 171 5.7.13 Citrus 171 5.7.14 Citrus processing 172 5.8 Other flavour characteristics 174 5.9 Fragrance uses 174 5.10 Conclusion 175 References 175 6 Useful principles to predict the performance of polymeric flavour delivery systems 178 Daniel Benczedi´ 6.1 Overview 178 6.2 Introduction 178 6.3 Compatibility and cohesion 179 6.4 Sorption and swelling 182 6.5 Diffusion and release 184 References 187 7 Delivery of flavours from food matrices 190 Saskia M. van Ruth and Jacques P. Roozen 7.1 Introduction 190 7.2 Flavour properties 191 7.3 Thermodynamic aspects of flavour delivery 191 7.3.1 Definition of gas/product partition coefficients and activity coefficients 191 7.3.2 Types of binding 193 P1: SFK/UKS P2: SFK FM BLBK221-Taylor/Linforth December 2, 2009 17:29 Printer Name: Yet to Come Contents vii 7.3.3 Lipid–flavour interactions 194 7.3.4 Carbohydrate–flavour interactions 195 7.3.5 Protein–flavour interactions 196 7.4 Kinetic aspects of flavour delivery 197 7.4.1 Principles of interfacial mass transfer 198 7.4.2 Liquid food products 200 7.4.3 Semi-solid food products 200 7.4.4 Solid food products 201 7.5 Delivery systems: food technology applications 202 7.6 Conclusions 203 References 203 8 Modelling flavour release 207 Robert S.