Table of Contents
Preface, xix
Acknowledgements, xxi
About the author, xxiii
1 History, origin and taxonomy of cocoa, 1
1.1 Introduction, 1
1.2 History of cocoa, 2
1.3 Taxonomy of cocoa, 5
1.4 Morphological and varietal characteristics of cocoa, 6
1.4.1 The cocoa plant, 6
1.5 Varietal effects on cocoa bean flavour, 10
1.6 The concept of this book, 15
2 World cocoa production, processing and chocolate consumption pattern, 17
2.1 Introduction, 17
2.2 World production of cocoa, 17
2.3 Major changes in world cocoa trade, 20
2.4 Cocoa yield in producing countries, 22
2.5 World cocoa grindings trends between 2005–2006 and 2014–2015, 23
2.6 World stocks of cocoa beans, 26
2.7 International cocoa price developments, 26
2.8 Cocoa processing trends, 31
2.9 Cocoa and chocolate consumption, 33
2.9.1 Apparent cocoa consumption, 33
2.9.2 World chocolate consumption, 34
2.9.3 World consumption of chocolate products, 35
2.9.4 World consumption of premium chocolate products, 38
2.10 Fairtrade cocoa and chocolate in the modern confectionery industry, 39
2.10.1 Sustainable fairtrade cocoa production, 39
2.10.2 Future of the fairtrade cocoa and confectionery industry, 41
2.11 The organic cocoa in chocolate confectionery industry, 42
2.11.1 The global organic food industry, 42
2.11.2 The organic cocoa industry, 43
2.11.3 Consumption patterns of organic cocoa, 44
2.11.4 Certification and market for organic cocoa, 45
2.12 The changing chocolate market, 48
3 Traditional and modern cocoa cultivation practices, 49
3.1 Introduction, 49
3.2 Environmental requirements for cocoa cultivation, 51
3.2.1 Temperature, 51
3.2.2 Rainfall, 52
3.2.3 Soils and nutrition, 52
3.3 Traditional cocoa cultivation practices, 53
3.3.1 Growth and propagation, 53
3.4 Modern cocoa cultivation practices using vegetative propagation, 54
3.5 Establishment and shade, 54
3.6 Flowering and pod development, 60
3.7 Harvesting of cocoa pods, 64
3.8 Pod breaking, 67
3.9 The cocoa pod, 68
3.10 Good agricultural practices in cocoa cultivation, 69
3.10.1 Quality improvement practices, 69
3.10.2 Weed control, 71
3.10.3 Pruning, 71
4 Cocoa diseases and pests and their effects on chocolate quality, 73
4.1 Introduction, 73
4.2 Major cocoa diseases, 73
4.2.1 Cocoa swollen shoot virus disease (CSSVD), 73
4.2.2 Black pod disease, 74
4.2.3 Witches broom disease, 76
4.3 Cocoa pests, 77
4.3.1 Pod borers (capsids, cocoa thrips and mealy bugs), 77
4.4 Cocoa crop protection, 79
5 Cocoa bean composition and chocolate flavour development, 80
5.1 Introduction, 80
5.2 Bean composition and flavour precursor formation, 81
5.2.1 Physical structure and chemical composition of the cocoa bean, 81
5.2.2 Cocoa pulp: the fermentation substrate, 83
5.2.3 Polyphenols and chocolate flavour quality, 85
5.2.4 Effects of proteins and sugars on flavour precursor formation, 85
5.3 Effects of genotype on cocoa bean flavour, 87
5.4 Flavour development during post-harvest treatments of cocoa, 87
5.4.1 Changes in biochemistry of the bean during flavour precursor formation in cocoa fermentation, 87
5.4.2 Microbial succession and enzymatic activities during flavour precursor generation in cocoa fermentation, 90
5.4.3 Drying, 94
5.5 Conclusion, 98
6 Cocoa processing technology, 102
6.1 Introduction, 102
6.2 Bean selection and quality criteria, 102
6.2.1 Free fatty acid, 103
6.3 Cocoa quality, grading and storage, 106
6.4 Selection of bean blends and chocolate flavour quality, 107
6.5 Steps in cocoa processing, 108
6.5.1 Cleaning, breaking and winnowing, 108
6.5.2 Sterilization, 109
6.5.3 Alkalization, 109
6.5.4 Roasting, 110
6.5.5 Nib grinding and liquor treatment, 111
6.5.6 Liquor pressing, 112
6.5.7 Cake grinding (kibbling), 112
6.5.8 Cocoa powder production, 112
6.5.9 Cocoa butter –chemistry, standards and quality characteristics, 112
7 Industrial chocolate manufacture – processes and factors influencing quality, 117
7.1 Introduction, 117
7.2 Chocolate manufacturing processes, 120
7.2.1 Mixing, 120
7.2.2 Refining, 121
7.2.3 Conching, 123
7.3 Tempering, lipid crystallization and continuous phase character during chocolate manufacture, 126
7.4 Casting and moulding, 130
7.5 Cooling, 130
7.6 Demoulding, 130
7.7 Wrapping/Packaging, 132
7.8 Factors influencing rheological and textural qualities in chocolate, 132
7.8.1 Particle size distribution, 132
7.8.2 The role of fats, 142
7.8.3 The role of sugar, 143
7.8.4 The role of milk and other dairy components, 144
7.8.5 The role of surfactants, 145
7.8.6 Moisture and chocolate flow behaviour, 146
7.9 Chocolate quality and defects, 146
7.9.1 Chocolate quality, 146
7.9.2 Chocolate defects, 150
7.10 Conclusion and further research, 152
8 The chemistry of flavour development during cocoa processing and chocolate manufacture, 154
8.1 Introduction, 154
8.2 Influence of bean selection on chocolate flavour quality, 154
8.3 Effect of roasting, 155
8.3.1 Maillard reactions – aldol condensation, polymerization and cyclization, 159
8.3.2 Effects of alkalization, 161
8.4 Flavour development during chocolate manufacture, 162
8.4.1 Conching, 162
8.5 Key flavour compounds in milk chocolate, 163
8.6 Key flavour compounds in dark chocolate, 163
8.7 Conclusion, 169
9 Alternative sweetening and bulking solutions in chocolate manufacture, 171
9.1 Introduction, 171
9.2 Types of sugar substitutes and their characteristics, 172
9.3 High-potency sweeteners, 173
9.3.1 Stevia rebaudioside A, 173
9.3.2 Thaumatin, 176
9.4 Bulk sweeteners, 178
9.4.1 Polyols (sugar alcohols), 178
9.4.2 Sucralose, 181
9.4.3 Tagatose, 183
9.4.4 Trehalose, 185
9.4.5 Isomultulose, 187
9.5 Low-digestible carbohydrate polymers, 188
9.5.1 Polydextrose, 189
9.5.2 Inulin and oligofructose, 191
9.5.3 Maltodextrin, 193
9.6 Laxation and low–digestible carbohydrate polymers, 193
9.7 Applicability and suitability of different sweeteners and carbohydrate polymers in chocolate processing, 194
9.8 Importance of blending different sugar substitutes, 200
10 Sensory character and flavour perception of chocolates, 202
10.1 Summary and industrial relevance, 202
10.2 Introduction, 203
10.3 Sensory perception of quality in chocolates, 204
10.3.1 Appearance, 208
10.3.2 Texture, 208
10.3.3 Taste, 209
10.3.4 Flavour and aroma, 210
10.4 Sensory assessment of chocolates, 211
10.5 Factor influencing chocolate flavour, 212
10.6 Flavour release and perception of sweetness in chocolate, 213
10.7 Dynamism of flavour perception in chocolate, 215
10.8 Retronasal flavour release and perception during chocolate consumption, 216
10.9 Measurement of flavour release and intensity in chocolates, 218
10.10 Electronic noses and tongues as online sensors for sensory assessment of chocolates, 221
10.11 Conclusion, 222
11 Nutritional and health benefits of cocoa and chocolate consumption, 223
11.1 Summary and significance, 223
11.2 Introduction, 223
11.3 Chemistry and composition of cocoa flavonoids, 225
11.4 Chocolate types and their major nutritional constituents, 226
11.5 Antioxidant properties and their mechanism of action, 229
11.6 Effects on endothelial function, blood pressure and the cardiovascular system, 231
11.7 Effects on insulin sensitivity and carcinogenic properties, 232
11.8 Cocoa, chocolate and aphrodisiac properties, 233
11.9 Conclusion, 234
12 Processing effects on the rheological, textural and melting properties during chocolate manufacture, 236
12.1 Summary and industrial relevance, 236
12.2 Introduction, 237
12.3 Materials and methods, 241
12.3.1 Materials, 241
12.3.2 Preparation of chocolate samples, 241
12.3.3 Determination of particle size distribution, 242
12.3.4 Rheological measurements, 242
12.3.5 Tempering procedure, 244
12.3.6 Texture measurements, 244
12.3.7 Colour measurements of solid dark chocolate, 246
12.3.8 Microstructure analysis, 247
12.3.9 Determination of melting properties of dark chocolates, 248
12.3.10 Experimental design and statistical analysis, 248
12.4 Results and discussion, 249
12.4.1 Particle size distribution of molten dark chocolate, 249
12.4.2 Rheological properties of molten dark chocolate, 249
12.5 Relationships between Casson model and ICA recommendations, 258
12.6 Textural properties, 262
12.6.1 Molten dark chocolate, 262
12.6.2 Hardness of tempered dark chocolate, 266
12.6.3 Colour measurements, 267
12.6.4 Relationships between textural properties and appearance of dark chocolate, 268
12.7 Microstructural properties of molten dark chocolate, 270
12.8 Melting properties of dark chocolate, 274
12.8.1 Effects of particle size distribution, 276
12.8.2 Effects of fat content, 281
12.8.3 Effects of lecithin, 282
12.9 Relationships between rheological, textural and melting properties of dark chocolate, 284
12.10 Conclusion, 294
13 Tempering behaviour during chocolate manufacture: Effects of varying product matrices, 297
13.1 Summary and industrial relevance, 297
13.2 Introduction, 298
13.3 Materials and methods, 300
13.3.1 Materials, 300
13.3.2 Tempering procedure, 300
13.3.3 Determination of particle size distribution, 301
13.3.4 Experimental design and statistical analysis, 301
13.4 Results and discussion, 304
13.4.1 Particle size distribution of dark chocolates, 304
13.4.2 Effect of particle size distribution on tempering behaviour, 308
13.4.3 Effect of fat content on tempering behaviour, 312
13.5 Conclusion, 316
14 Tempering and fat crystallization effects on chocolate quality, 317
14.1 Summary and industrial relevance, 317
14.2 Introduction, 318
14.3 Materials and methods, 319
14.3.1 Materials, 319
14.3.2 Determination of particle size distribution, 320
14.3.3 Tempering experiment, 320
14.3.4 Texture measurements, 320
14.3.5 Colour and gloss measurements, 321
14.3.6 Image acquisition and capture, 321
14.3.7 Determination of melting properties, 322
14.3.8 Microstructural determinations, 322
14.3.9 Scanning electron microscopy, 322
14.3.10 Experimental design and statistical analysis, 323
14.4 Results and discussion, 323
14.4.1 Particle size distribution of dark chocolates, 323
14.4.2 Fat crystallization behaviours during tempering of dark chocolate, 324
14.4.3 Effect of temper regime and PSD on mechanical properties, 325
14.4.4 Effect of temper regime and PSD on colour and gloss, 328
14.4.5 Effect of temper regime and PSD on melting properties, 330
14.4.6 Effect of temper regime on microstructure, 339
14.4.7 Effect of temper regime on scanning electron microstructure, 339
14.5 Conclusion, 343
15 Fat bloom formation and development in chocolates, 345
15.1 Summary and industrial relevance, 345
15.2 Introduction, 346
15.3 Materials and methods, 347
15.3.1 Materials, 347
15.3.2 Determination of particle size distribution, 348
15.3.3 Tempering experiment, 348
15.3.4 Texture measurements, 349
15.3.5 Surface colour and gloss measurements, 349
15.3.6 Determination of melting properties, 349
15.3.7 Microstructural determinations, 350
15.3.8 Experimental design and statistical analysis, 350
15.4 Results and discussion, 350
15.4.1 Particle size distribution of dark chocolates, 350
15.4.2 Changes in textural properties during blooming, 351
15.4.3 Changes in appearance (Surface Whiteness and Gloss) during blooming, 353
15.4.4 Changes in melting behaviour during blooming, 357
15.4.5 Changes in microstructure during blooming, 359
15.5 Conclusion, 364
16 Matrix effects on flavour volatiles character and release in chocolates, 365
16.1 Summary and industrial relevance, 365
16.2 Introduction, 365
16.3 Materials and methods, 367
16.3.1 Materials, 367
16.3.2 Tempering procedure, 368
16.3.3 Determination of particle size distribution, 368
16.3.4 Quantification of flavour volatiles by gas chromatography, 368
16.3.5 Gas chromatography–olfactometry analytical conditions, 369
16.3.6 Experimental design and statistical analysis, 369
16.4 Results and discussion, 369
16.4.1 Particle size distribution of dark chocolates, 369
16.4.2 Characterization of flavour compounds in dark chocolates, 370
16.4.3 Effects of particle size distribution on flavour volatile release, 374
16.4.4 Effects of fat content on flavour volatile release, 374
16.4.5 Relating flavour volatiles release to particle size distribution and fat content: product spaces, 379
16.5 Conclusion, 381
17 Process optimization and product quality characteristics during sugar-free chocolate manufacture, 382
17.1 Summary and industrial relevance, 382
17.2 Introduction, 382
17.3 Materials and methods, 384
17.3.1 Raw materials, 384
17.3.2 Experimental design and sample preparation, 384
17.3.3 Analytical methods, 385
17.4 Results and discussion, 387
17.4.1 Rheological properties, 390
17.4.2 Casson plastic viscosity, 390
17.4.3 Casson yield stress, 392
17.4.4 Microscopy, 393
17.4.5 Colour, 395
17.4.6 Hardness, 395
17.4.7 Moisture, 396
17.5 Optimization of chocolate formulation, 396
17.6 Conclusion, 397
18 Food safety management systems in chocolate processing, 399
18.1 Introduction, 399
18.2 The HACCP system, 400
18.2.1 HACCP principles, 401
18.2.2 HACCP plan, 402
18.2.3 Application of the HACCP system, 405
18.2.4 Advantages of HACCP, 405
18.2.5 Shortfalls of HACCP, 406
18.3 ISO 22000 approach, 406
18.3.1 Advantages of ISO 22000, 407
18.3.2 Comparison of ISO 22000 with HACCP, 408
18.4 Hazards associated with chocolate processing, 408
18.4.1 Physical hazards, 408
18.4.2 Chemical hazards, 409
18.4.3 Microbiological hazards, 411
18.5 Critical operations in cocoa processing and chocolate manufacture, 413
18.5.1 Cleaning, 413
18.5.2 Roasting, 413
18.5.3 Breaking and winnowing, 414
18.5.4 Refining, 414
18.5.5 Conching, 414
18.5.6 Tempering, 415
18.6 Conclusion, 415
19 Application of ISO 22000 and hazard analysis and critical control points (HACCP) in chocolate processing, 416
19.1 Summary and industrial relevance, 416
19.2 Introduction, 416
19.2.1 Hazard analysis and critical control points (HACCP), 417
19.2.2 HACCP principles, 418
19.2.3 ISO 22000, 419
19.3 Hazards associated with chocolate processing, 419
19.3.1 Physical hazards, 420
19.3.2 Chemical hazards, 421
19.3.3 Microbiological hazards, 421
19.4 Preprocessing operations, 421
19.5 Cocoa processing into semi-finished products, 422
19.5.1 Bean receipt and cleaning – CCP1, 422
19.5.2 Silos (Storage) – CCP2, 422
19.5.3 De-bacterizer – CCP3, 422
19.5.4 The roasting process – CCP4, 422
19.5.5 Breaking and winnowing, 424
19.5.6 Milling, 424
19.5.7 Storage and conditioning – CCP5, 424
19.5.8 Pressing – CCP6, 425
19.5.9 Centrifugation and filtration – CCP7, 425
19.5.10 Kibbling and pulverization, 425
19.6 Milk chocolate manufacturing operations, 425
19.6.1 Raw materials reception – CCP1, 425
19.6.2 Mixing – CCP2, 425
19.6.3 Refining, 426
19.6.4 Conching, 427
19.6.5 Tempering, 427
19.6.6 Casting and moulding – CCP3, 428
19.6.7 Cooling, 428
19.6.8 Demoulding, 428
19.6.9 Wrapping/Packaging – CCP4, 429
19.7 Hazard analysis, 429
19.7.1 Determination of critical control points, 435
19.7.2 Determination of prerequisite programmes, 435
19.8 Conclusion, 435
20 Conclusions and industrial applications, 441
20.1 Introduction, 441
20.2 Conclusions: Structure–properties relationships in chocolate manufacture, 441
20.3 Conclusions: Tempering behaviour from response surface methodology, 443
20.4 Conclusions: Effects of tempering and fat crystallization on microstructure and physical properties, 444
20.5 Conclusions: Fat bloom formation and development with under-tempering, 445
20.6 Conclusions: Flavour volatiles and matrix effects related to variations in PSD and fat content, 445
20.7 Conclusions: Process optimization and product quality characteristics of sugar-free chocolates, 446
20.8 Industrial relevance and applications of research findings in this book, 447
20.9 Recommendations for further research studies, 448
References, 450
Appendix 1 Abbreviations, 487
Appendix 2 Acronyms and websites of organizations related to the cocoa and chocolate industry, 490
Appendix 3 Glossary of cocoa and chocolate terminologies, 492
Index, 497
