Industrial Chocolate Manufacture and Use

INDUSTRIAL CHOCOLATE MANUFACTURE AND USE

SSBeckett_FM.inddBeckett_FM.indd i 110/1/20080/1/2008 10:00:4310:00:43 AMAM SSBeckett_FM.inddBeckett_FM.indd iiii 110/1/20080/1/2008 10:00:4410:00:44 AMAM INDUSTRIAL CHOCOLATE MANUFACTURE AND USE Fourth Edition

Edited by

Stephen T. Beckett Formerly Nestlé PTC York, UK

SSBeckett_FM.inddBeckett_FM.indd iiiiii 110/1/20080/1/2008 10:00:4410:00:44 AMAM This edition fi rst published 2009 Third edition published 1999 Second edition published 1994 by Chapman and Hall First edition published 1988 by Chapman and Hall © 1999, 2009 by 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 Scientifi c, Technical, and Medical business to form Wiley-Blackwell. Registered offi ce John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, United Kingdom Editorial offi ces 9600 Garsington Road, Oxford, OX4 2DQ, United Kingdom 2121 State Avenue, Ames, Iowa 50014-8300, USA For details of our global editorial offi ces, 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. The right of the author to be identifi ed as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher. Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. 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 Industrial chocolate manufacture and use / edited by Steve Beckett – 4th ed. p. cm. Includes bibliographical references and index. ISBN-13: 978-1-4051-3949-6 (hardback : alk. paper) ISBN-10: 1-4051-3949-8 (hardback : alk. paper) 1. Chocolate. 2. Cocoa. I. Beckett, S.T. TP640.I53 2008 664.5—dc22 2008006200 A catalogue record for this book is available from the British Library. Set in 10/12 pt Palatino by Newgen Imaging Systems Pvt. Ltd, Chennai, India Printed in Singapore by Fabulous Printers Pte Ltd 1 2009

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Preface xxii Contributors xxv

1 Traditional Chocolate Making 1 S.T. Beckett 1.1 History 1 1.2 Outline of process 2 1.2.1 Preparation of cocoa nib – ﬂ avour development 4 1.2.2 Grinding – particle size reduction 4 1.2.3 Conching – ﬂ avour and texture development 7 1.3 Concept of the book 8 References 9

2 Cocoa Beans: from Tree to Factory 10 M.S. Fowler 2.1 Introduction 10 2.2 Growing cocoa 10 2.2.1 Where cocoa is grown 10 2.2.2 Varieties of cocoa: Criollo, Forastero, Trinitario and Nacional 12 2.2.3 Climatic and environmental requirements 13 2.2.4 Propagation of the planting material 14 2.2.5 Establishment and development of the plants in the ﬁ eld 14 2.2.6 Major pests and diseases 15 2.2.7 Flowering and pod development 15 2.2.8 Harvesting, pod opening and yields 17 2.2.9 Environmental aspects of cocoa cultivation 19 2.2.10 Labour practices on farms 19 2.3 Fermentation and drying 20 2.3.1 Fermentation 20 2.3.2 Microbiological aspects of fermentation 21 2.3.3 Development of cocoa ﬂ avour precursors 21 2.3.4 Drying 23

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2.4 The cocoa supply chain 24 2.4.1 Internal market 25 2.4.2 International cocoa markets 25 2.4.3 Fairtrade 28 2.4.4 Shipment of cocoa 29 2.4.5 Moisture movement during shipment 29 2.4.6 Storage of cocoa 31 2.4.7 Infestation of cocoa 32 2.5 Quality assessment of cocoa 33 2.5.1 Composition of cocoa beans 33 2.5.2 Cocoa beans: quality aspects and contracts 33 2.5.3 Cocoa beans: sampling and the ‘cut test’ 37 2.5.4 Contaminants and residues 39 2.5.5 Cocoa butter hardness 39 2.5.6 Sensory evaluation 40 2.6 Types and origins of cocoa beans used in chocolate 40 2.6.1 Sources of bulk cocoas 40 2.6.2 Côte d’Ivoire (Ivory Coast) 41 2.6.3 Ghana 41 2.6.4 Indonesia 42 2.6.5 Nigeria 43 2.6.6 Cameroon 43 2.6.7 Brazil 43 2.6.8 Ecuador 43 2.6.9 Speciality, origin and ‘ﬁ ne’ or ‘ﬂ avour’ cocoas 44 Conclusions 45 References and Further reading 46 Abbreviations/Acronyms/Websites 47

3 Sugar and Bulk Sweeteners 48 Ch. Krüger 3.1 Introduction 48 3.2 The production of sugar 48 3.3 Sugar qualities 50 3.4 The storage of sugar 51 3.5 Sugar grinding and the prevention of sugar dust explosions 53 3.6 Amorphous sugar 56 3.7 Other sugars and bulk sweeteners 57 3.7.1 Invert sugar 57 3.7.2 Glucose 58 3.7.3 Fructose 58 3.7.4 Tagatose 59 3.7.5 Lactose 60

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3.7.6 Isomaltulose 60 3.7.7 Trehalose 60 3.7.8 Polydextrose 60 3.7.9 Inulin 61 3.7.10 Sorbitol 61 3.7.11 Mannitol 62 3.7.12 Xylitol 62 3.7.13 Erythritol 63 3.7.14 Maltitol 63 3.7.15 Maltitol syrup 64 3.7.16 Isomalt 64 3.7.17 Lactitol 64 3.8 Physiological characteristics of sugars and bulk sweeteners 65 3.9 The sweetening power of sugars and bulk sweeteners 67 3.10 Other sensory properties of sugars and bulk sweeteners 69 3.11 Solubilities and melting points of sugars and bulk sweeteners 70 3.12 Maximum conching temperatures of chocolate masses with different bulk sweeteners 71 Conclusions 72 References 73 Further reading 75

4 Ingredients from Milk 76 S.J. Haylock and T.M. Dodds 4.1 Introduction 76 4.2 Milk fat 79 4.2.1 Anhydrous milk fat 80 4.2.2 Flavour of milk fat 82 4.2.3 Interactions of milk fat and cocoa butter 83 4.2.4 Milk fat fractions 85 4.2.5 ‘Free’ and ‘bound’ milk fat 87 4.2.6 Bloom 89 4.3 Milk powder 90 4.3.1 Skim milk powder: non-fat dried milk 90 4.3.2 Whole milk powder 92 4.3.3 High-fat powders 94 4.3.4 Buttermilk powder 94 4.3.5 Formulated milk powders 95 4.3.6 Whey powders 96 4.4 Milk crumb 96 4.5 Lactose 97 4.6 New consumer requirements 98

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Summary 98 Acknowledgements 99 References 99

5 Chocolate Crumb 101 M.A. Wells 5.1 Introduction and history 101 5.2 Beneﬁ ts of milk crumb 102 5.3 Typical crumb recipes 103 5.4 Flavour development in chocolate crumb 103 5.5 Sugar crystallization during crumb manufacture 107 5.6 The structure of chocolate crumb 109 5.6.1 Crystallinity 109 5.6.2 Fat availability 110 5.6.3 Fat droplet size 110 5.6.4 Aeration 111 5.6.5 Overall particle size distribution 111 5.7 Typical crumb processes and equipment 112 5.7.1 Batch oven process 112 5.7.2 Continuous processes 113 5.8 Effect of the crumb process upon the crumb properties 117 5.9 Changes to crumb during storage 117 Conclusions 119 References 119

6 Production and Quality Standards of Cocoa Mass, Cocoa Butter and Cocoa Powder 121 H.J. Kamphuis 6.1 Introduction 121 6.2 Cleaning of cocoa beans 121 6.3 Removal of shell 122 6.4 Breaking and winnowing 124 6.5 Alkalization 126 6.6 Bean and nib roasting 127 6.7 Cocoa mass (cocoa liquor) 130 6.7.1 Grinding cocoa nibs 130 6.7.2 Quality of cocoa mass for the chocolate industry 131 6.7.3 Quality of cocoa mass for the production of cocoa powder and butter 132 6.8 Cocoa butter 133 6.9 Cocoa powder 135 6.9.1 Types of cocoa powder 136 6.9.2 Quality of cocoa powder 137 Summary 139

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Acknowledgements 139 References 139 Further reading 140

7 Particle Size Reduction 142 G.R. Ziegler and R. Hogg 7.1 Introduction 142 7.2 Principles of fi ne grinding 143 7.2.1 Breakage mechanisms 143 7.2.2 Grinding processes 144 7.3 Grinding equipment 146 7.3.1 Crushers 146 7.3.2 Media mills 146 7.3.3 Impact mills 147 7.3.4 Fluid energy mills 148 7.3.5 Guidelines for equipment selection 148 7.4 Cocoa nib grinding 149 7.5 Chocolate refi ning 152 7.5.1 The fi ve-roll refi ner 154 7.5.2 Crumb chocolate 158 7.5.3 Sugar substitutes 158 7.5.4 The refi ner-conche 159 7.5.5 Refi ning in the presence of water 159 7.5.6 Milling cocoa powder 160 7.6 Particle size reduction and chocolate fl ow properties 160 7.7 Particle size and sensory properties 165 Conclusions 166 References 166

8 Flavour Development in Cocoa and Chocolate 169 G. Ziegleder 8.1 Introduction 169 8.2 Fermentation 170 8.2.1 The fermentation process 170 8.2.2 Chemical changes and development of fl avour precursors 171 8.2.3 Over-fermentation 173 8.3 Drying 174 8.4 Roasting 176 8.4.1 Roasting process and the further development of fl avour precursors 176 8.4.2 Roast fl avour 179 8.5 Conching 184 8.5.1 Thin-fi lm-treatment of roasted cocoa liquor 184 8.5.2 Effect of conching on aroma development 184

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8.6 Plain chocolate and milk chocolate 187 Conclusions 188 References 188

9 Conching 192 S.T. Beckett 9.1 Introduction: The reason for conching 192 9.1.1 Flavour development 192 9.1.2 Flow property optimization 193 9.2 The principles of conching 193 9.2.1 Removal of volatiles and temperature control 193 9.2.2 Fat and emulsiﬁ er additions 195 9.2.3 The degree of mixing 196 9.3 The three phases of conching 198 9.3.1 Dry phase conching 199 9.3.2 Pasty phase conching 200 9.3.3 Liquid phase conching 201 9.4 Conching machines 202 9.4.1 History 202 9.4.2 Batch conches 204 9.4.3 Continuous conches 210 9.4.4 Cocoa mass (liquor) treatment devices 214 9.4.5 Liqueﬁ ers 217 9.4.6 Combined grinding/conching machines 219 Summary 221 References 222

10 Chocolate Flow Properties 224 S.T. Beckett 10.1 Introduction 224 10.2 Non-Newtonian ﬂ ow 225 10.3 Presentation of viscosity measurements 228 10.4 Single point ﬂ ow measurement 229 10.4.1 Flow-cup viscometer 230 10.4.2 Falling-ball viscometer 230 10.4.3 Gardner mobilometer 231 10.4.4 Torsion viscometer (Gallenkamp or Fison) 232 10.4.5 MacMichael viscometer 233 10.5 Rotational viscometers 233 10.6 Sample preparation and measurement procedures 235 10.6.1 Sample preparation 235 10.6.2 Checking the viscometer 236 10.6.3 Preconditioning 236 10.6.4 Shear rate range 237

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10.6.5 Holding time at the maximum shear rate 237 10.6.6 Hysteresis 237 10.6.7 Overall measurement time 237 10.7 Factors affecting the ﬂ ow properties of chocolate 238 10.7.1 Fat content 238 10.7.2 Particle size distribution 239 10.7.3 Surface-active agents (emulsiﬁ ers) 240 10.7.4 Conching 244 10.7.5 Moisture 244 10.7.6 Vibration 244 Conclusions 245 References 245

11 Bulk Chocolate Handling 247 J.H. Walker 11.1 Introduction 247 11.2 Viscosity and viscometry 247 11.2.1 What is viscosity? 247 11.2.2 Laminar and turbulent ﬂ ow 249 11.3 Pump sizes 250 11.3.1 Power 250 11.3.2 Speed 250 11.4 General criteria for choosing a pump 250 11.5 Types of pumps 251 11.5.1 Gear pumps 251 11.5.2 Sliding vane pumps 252 11.5.3 Lobe and rotary piston pumps 253 11.5.4 Screw pumps 253 11.5.5 Pawl pumps 254 11.5.6 Progressive cavity mono pumps 254 11.5.7 Positive displacement piston and diaphragm pumps 255 11.6 Pipeline pigging 256 11.7 Storage of liquid chocolate 257 11.8 Jacketed pipe work 258 11.9 Contamination removal 259 11.9.1 Magnets 259 11.9.2 Sieving 259 Conclusions 260

12 Chocolate Temper 261 G. Talbot 12.1 Introduction 261 12.2 Polymorphism of cocoa butter 261

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12.3 Relationship between polymorphism and chocolate tempering 266 12.4 Tempering 268 12.5 Measurement of temper 271 12.6 Tempering by seeding 273 Summary 274 References 275

13 Tempering 276 E.J. Windhab 13.1 Introduction 276 13.2 Physics of cocoa butter crystallization 277 13.3 Chocolate tempering technology 278 13.4 Measurement of temper and its related characteristics 280 13.4.1 Tempermeters 281 13.4.2 Differential scanning calorimetry (DSC) 283 13.4.3 Thermorheometry 284 13.4.4 Nuclear magnetic resonance (NMR) 285 13.5 Tempering processes 286 13.5.1 The principle of conventional continuous chocolate ‘stir/shear-tempering’ 286 13.5.2 Impact of temperature/temperature control 287 13.5.3 Impact of shear 288 13.5.4 Importance of residence time distribution (RTD) 292 13.5.5 ‘Recipe factors’ inﬂ uencing tempering quality 293 13.6 Types of tempering machine 294 13.6.1 Chocolate tempering kettles 294 13.6.2 Types of continuous industrial tempering machines 295 13.6.3 Continuous industrial seed-tempering 305 13.7 Properties of CBCS-tempered chocolate 312 13.7.1 Pre-crystallized liquid state 312 13.7.2 Semi-solid and solid state 313 13.8 Other methods of tempering 316 Conclusions 316 Acknowledgements 317 References 317 Further reading 319 Appendix 319

14 Moulding, Enrobing and Cooling Chocolate Products 320 M.P. Gray 14.1 Introduction 320 14.2 Moulding 320 14.2.1 Background 320 14.2.2 Loose and ﬁ xed mould plants 321

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14.2.3 Mould conditioning 324 14.2.4 Depositors 324 14.2.5 Adding inclusions 327 14.2.6 Removal of air bubbles 328 14.2.7 Shell forming 328 14.2.8 Centre ﬁ lling 329 14.2.9 Backing off 329 14.2.10 Cooling 331 14.2.11 Demoulding 334 14.2.12 Troubleshooting demoulding problems 335 14.2.13 In-line storage systems 336 14.2.14 Keeping moulds clean and changeovers 337 14.2.15 Other methods for shelling forming 337 14.2.16 Troubleshooting moulded product faults 339 14.2.17 Mould design, care and innovations 342 14.3 Enrobing 344 14.3.1 Background 344 14.3.2 Basic layout of an enrober 345 14.3.3 Enrobers with inbuilt temperers 346 14.3.4 Enrobers with external temperers 346 14.3.5 Chocolate recirculation 348 14.3.6 Temper 348 14.3.7 Enrober components 349 14.3.8 Changeovers 353 14.3.9 Avoidance of air bubbles 354 14.3.10 Avoidance of chocolate build-up inside an enrober 354 14.3.11 Down stream processes 354 14.3.12 Cooling 356 Conclusions 356 Acknowledgements 356 Further reading 357

15 Cold Forming Technologies 358 J.H. Walker and S.T. Beckett 15.1 Introduction 358 15.2 Background 358 15.3 Principle of operation of the cold forming technologies 359 15.4 Advantages of the cold forming technologies 361 15.5 Disadvantages of the cold forming method 362 15.6 Further developments 363 15.6.1 ‘Mouldless’ system 363 15.6.2 Multiple product with direct packing 363 15.6.3 Solidiﬁ cation on plunger 364 Conclusions 365 References 365

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16 Chocolate Panning 367 M. Aebi 16.1 Introduction 367 16.1.1 History 367 16.1.2 Deﬁ nitions 367 16.2 Panning methods 368 16.2.1 Chocolate panning 368 16.2.2 Soft coatings 368 16.2.3 Hard coating 369 16.2.4 Film and suspension coating 369 16.3 The process of chocolate panning 370 16.3.1 Centre selection 370 16.3.2 Centre preparation 371 16.3.3 Selection of chocolate and compound coatings 374 16.3.4 Chocolate and compound engrossing 375 16.3.5 Polishing and sealing 378 16.4 Packaging and storage 380 16.5 The panning department 381 16.5.1 Room conditions 381 16.5.2 Panning equipment 382 Summary 384 References 384

17 Non-Conventional Machines and Processes 385 S.T. Beckett 17.1 Introduction 385 17.2 Ultrasound 386 17.3 High shear/low-temperature crystallizer 388 17.4 High-pressure temperer 389 17.5 Extrusion 391 17.5.1 Types of extruders 391 17.5.2 The extruder as a ﬂ avour modiﬁ er 391 17.5.3 The extruder as a chocolate conche 393 17.5.4 The extrusion of tubular shapes, ropes and nets 396 17.6 ‘Single shot’ depositors 399 17.6.1 Background 399 17.6.2 Basic principles of ‘single-shot’ depositing 400 17.6.3 Limitations of ‘single-shot’ depositing 401 17.6.4 Key control parameters 403 17.7 Aeration of chocolate 404 17.7.1 Types of aeration 404 17.7.2 Vacuum aeration 405 17.7.3 High-pressure aeration systems 405 17.7.4 Water evaporation methods 406

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Conclusions 406 References 407

18 Chocolate Rework 409 E. Minson 18.1 Introduction 409 18.2 Rework 409 18.3 Constraints 410 18.4 Economics 412 Conclusions 414 References 414

19 Vegetable Fats 415 G. Talbot 19.1 Types of vegetable fat 415 19.2 Fat properties 416 19.3 Cocoa butter 418 19.4 Cocoa butter equivalents (CBEs) 420 19.4.1 Properties and production 420 19.4.2 Chocolate containing 5% CBE 424 19.4.3 Supercoating 425 19.5 Lauric cocoa butter substitutes 426 19.5.1 Quality control 428 19.6 Non-lauric cocoa butter replacers 429 19.7 New fats for chocolate and coatings 431 19.7.1 Fats to prevent chocolate bloom 431 19.7.2 Lower calorie fats 432 Summary 432 References 433 Further reading 433

20 Recipes 434 E.G. Wohlmuth 20.1 Chocolate tastes in different countries 434 20.1.1 History 434 20.1.2 Taste in different countries 434 20.2 The basic ingredients 436 20.2.1 Sugar 436 20.2.2 Milk 436 20.2.3 Cocoa beans and mass 436 20.3 Conching to develop ﬂ avours 437 20.4 Chocolate recipes 438 20.4.1 Chocolate bars/tablets 438 20.4.2 Chocolate confectionery 440

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