Chocolate science and technology

k kContents Preface, xixAcknowledgements, xxiAbout the author, xxiii 1 History, origin and taxonomy of cocoa, 11.1 Introduction, 1 1.2 History of cocoa, 21.3 Taxonomy of cocoa, 51.4 Morp

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Chocolate Science and Technology

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Chocolate Science and Technology

Emmanuel Ohene Afoakwa

University of Ghana, Legon - Accra, Ghana Formerly of Nestlé Product Technology Centre, York, UK

SECOND EDITION

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This edition first published 2016 © 2016 John Wiley & Sons, Ltd.

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Library of Congress Cataloging-in-Publication Data

Afoakwa, Emmanuel Ohene.

Chocolate science and technology / Emmanuel Ohene Afoakwa.

p cm.

Includes bibliographical references and index.

ISBN 978-1-1189-1378-9 (hardback : alk paper) 1 Cocoa 2 Chocolate I Title.

TP640.A36 2010 664_.5–dc22

2009046211

A catalogue record for this book is available from the British Library.

Cover image credit: Getty/LarisaBozhikova Typeset in 9.5/13pt MeridienLTStd by SPi Global, Chennai, India

1 2016

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This book is dedicated to my dear wife, Ellen, and our three lovely children,Nana Afra, Maame Agyeiwaa and Kwabena Ohene-Afoakwa (Jr), whosewisdom, prayers and support have helped me achieve great success in mylife and professional career

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Contents

Preface, xixAcknowledgements, xxiAbout the author, xxiii

1 History, origin and taxonomy of cocoa, 11.1 Introduction, 1

1.2 History of cocoa, 21.3 Taxonomy of cocoa, 51.4 Morphological and varietal characteristics of cocoa, 61.4.1 The cocoa plant, 6

1.5 Varietal effects on cocoa bean flavour, 101.6 The concept of this book, 15

2 World cocoa production, processing and chocolate consumption pattern, 172.1 Introduction, 17

2.2 World production of cocoa, 172.3 Major changes in world cocoa trade, 202.4 Cocoa yield in producing countries, 222.5 World cocoa grindings trends between 2005–2006 and2014–2015, 23

2.6 World stocks of cocoa beans, 262.7 International cocoa price developments, 262.8 Cocoa processing trends, 31

2.9 Cocoa and chocolate consumption, 332.9.1 Apparent cocoa consumption, 332.9.2 World chocolate consumption, 342.9.3 World consumption of chocolate products, 352.9.4 World consumption of premium chocolate products, 382.10 Fairtrade cocoa and chocolate in the modern confectioneryindustry, 39

2.10.1 Sustainable fairtrade cocoa production, 392.10.2 Future of the fairtrade cocoa and confectionery industry, 412.11 The organic cocoa in chocolate confectionery industry, 42

2.11.1 The global organic food industry, 42

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2.11.2 The organic cocoa industry, 432.11.3 Consumption patterns of organic cocoa, 442.11.4 Certification and market for organic cocoa, 452.12 The changing chocolate market, 48

3 Traditional and modern cocoa cultivation practices, 493.1 Introduction, 49

3.2 Environmental requirements for cocoa cultivation, 513.2.1 Temperature, 51

3.2.2 Rainfall, 523.2.3 Soils and nutrition, 523.3 Traditional cocoa cultivation practices, 533.3.1 Growth and propagation, 533.4 Modern cocoa cultivation practices using vegetative propagation, 543.5 Establishment and shade, 54

3.6 Flowering and pod development, 603.7 Harvesting of cocoa pods, 643.8 Pod breaking, 67

3.9 The cocoa pod, 683.10 Good agricultural practices in cocoa cultivation, 693.10.1 Quality improvement practices, 69

3.10.2 Weed control, 713.10.3 Pruning, 71

4 Cocoa diseases and pests and their effects on chocolate quality, 734.1 Introduction, 73

4.2 Major cocoa diseases, 734.2.1 Cocoa swollen shoot virus disease (CSSVD), 734.2.2 Black pod disease, 74

4.2.3 Witches broom disease, 764.3 Cocoa pests, 77

4.3.1 Pod borers (capsids, cocoa thrips and mealy bugs), 774.4 Cocoa crop protection, 79

5 Cocoa bean composition and chocolate flavour development, 805.1 Introduction, 80

5.2 Bean composition and flavour precursor formation, 815.2.1 Physical structure and chemical composition of the

cocoa bean, 815.2.2 Cocoa pulp: the fermentation substrate, 835.2.3 Polyphenols and chocolate flavour quality, 85

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5.2.4 Effects of proteins and sugars on flavour precursor

formation, 855.3 Effects of genotype on cocoa bean flavour, 875.4 Flavour development during post-harvest treatments of cocoa, 875.4.1 Changes in biochemistry of the bean during flavour

precursor formation in cocoa fermentation, 875.4.2 Microbial succession and enzymatic activities during

flavour precursor generation in cocoa fermentation, 905.4.3 Drying, 94

6.5.1 Cleaning, breaking and winnowing, 1086.5.2 Sterilization, 109

6.5.3 Alkalization, 1096.5.4 Roasting, 1106.5.5 Nib grinding and liquor treatment, 1116.5.6 Liquor pressing, 112

6.5.7 Cake grinding (kibbling), 1126.5.8 Cocoa powder production, 1126.5.9 Cocoa butter –chemistry, standards and quality

characteristics, 112

7 Industrial chocolate manufacture – processes and factors influencingquality, 117

7.1 Introduction, 1177.2 Chocolate manufacturing processes, 1207.2.1 Mixing, 120

7.2.2 Refining, 1217.2.3 Conching, 1237.3 Tempering, lipid crystallization and continuous phase characterduring chocolate manufacture, 126

7.4 Casting and moulding, 1307.5 Cooling, 130

7.6 Demoulding, 1307.7 Wrapping/Packaging, 132

7.8.6 Moisture and chocolate flow behaviour, 1467.9 Chocolate quality and defects, 146

7.9.1 Chocolate quality, 1467.9.2 Chocolate defects, 1507.10 Conclusion and further research, 152

8 The chemistry of flavour development during cocoa processing andchocolate manufacture, 154

8.1 Introduction, 1548.2 Influence of bean selection on chocolate flavour quality, 1548.3 Effect of roasting, 155

8.3.1 Maillard reactions – aldol condensation, polymerization and

cyclization, 1598.3.2 Effects of alkalization, 1618.4 Flavour development during chocolate manufacture, 1628.4.1 Conching, 162

8.5 Key flavour compounds in milk chocolate, 1638.6 Key flavour compounds in dark chocolate, 1638.7 Conclusion, 169

9 Alternative sweetening and bulking solutions in chocolatemanufacture, 171

9.1 Introduction, 1719.2 Types of sugar substitutes and their characteristics, 1729.3 High-potency sweeteners, 173

9.3.1 Stevia rebaudioside A, 1739.3.2 Thaumatin, 176

9.4 Bulk sweeteners, 1789.4.1 Polyols (sugar alcohols), 1789.4.2 Sucralose, 181

9.4.3 Tagatose, 1839.4.4 Trehalose, 1859.4.5 Isomultulose, 1879.5 Low-digestible carbohydrate polymers, 1889.5.1 Polydextrose, 189

10 Sensory character and flavour perception of chocolates, 20210.1 Summary and industrial relevance, 202

10.2 Introduction, 20310.3 Sensory perception of quality in chocolates, 20410.3.1 Appearance, 208

10.3.2 Texture, 20810.3.3 Taste, 20910.3.4 Flavour and aroma, 21010.4 Sensory assessment of chocolates, 21110.5 Factor influencing chocolate flavour, 21210.6 Flavour release and perception of sweetness in chocolate, 21310.7 Dynamism of flavour perception in chocolate, 215

10.8 Retronasal flavour release and perception during chocolateconsumption, 216

10.9 Measurement of flavour release and intensity in chocolates, 21810.10 Electronic noses and tongues as online sensors for sensoryassessment of chocolates, 221

10.11 Conclusion, 222

11 Nutritional and health benefits of cocoa and chocolate consumption, 22311.1 Summary and significance, 223

11.2 Introduction, 22311.3 Chemistry and composition of cocoa flavonoids, 22511.4 Chocolate types and their major nutritional constituents, 22611.5 Antioxidant properties and their mechanism of action, 22911.6 Effects on endothelial function, blood pressure and thecardiovascular system, 231

11.7 Effects on insulin sensitivity and carcinogenic properties, 23211.8 Cocoa, chocolate and aphrodisiac properties, 233

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12.3 Materials and methods, 24112.3.1 Materials, 24112.3.2 Preparation of chocolate samples, 24112.3.3 Determination of particle size distribution, 24212.3.4 Rheological measurements, 242

12.3.5 Tempering procedure, 24412.3.6 Texture measurements, 24412.3.7 Colour measurements of solid dark chocolate, 24612.3.8 Microstructure analysis, 247

12.3.9 Determination of melting properties of dark chocolates, 24812.3.10 Experimental design and statistical analysis, 248

12.4 Results and discussion, 24912.4.1 Particle size distribution of molten dark chocolate, 24912.4.2 Rheological properties of molten dark chocolate, 24912.5 Relationships between Casson model and ICA recommendations, 25812.6 Textural properties, 262

12.6.1 Molten dark chocolate, 26212.6.2 Hardness of tempered dark chocolate, 26612.6.3 Colour measurements, 267

12.6.4 Relationships between textural properties and appearance of

dark chocolate, 26812.7 Microstructural properties of molten dark chocolate, 27012.8 Melting properties of dark chocolate, 274

12.8.1 Effects of particle size distribution, 27612.8.2 Effects of fat content, 281

12.8.3 Effects of lecithin, 28212.9 Relationships between rheological, textural and melting properties ofdark chocolate, 284

13.4.1 Particle size distribution of dark chocolates, 304

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13.4.2 Effect of particle size distribution on tempering

behaviour, 30813.4.3 Effect of fat content on tempering behaviour, 31213.5 Conclusion, 316

14 Tempering and fat crystallization effects on chocolate quality, 31714.1 Summary and industrial relevance, 317

14.2 Introduction, 31814.3 Materials and methods, 31914.3.1 Materials, 31914.3.2 Determination of particle size distribution, 32014.3.3 Tempering experiment, 320

14.3.4 Texture measurements, 32014.3.5 Colour and gloss measurements, 32114.3.6 Image acquisition and capture, 32114.3.7 Determination of melting properties, 32214.3.8 Microstructural determinations, 32214.3.9 Scanning electron microscopy, 32214.3.10 Experimental design and statistical analysis, 32314.4 Results and discussion, 323

14.4.1 Particle size distribution of dark chocolates, 32314.4.2 Fat crystallization behaviours during tempering of dark

chocolate, 32414.4.3 Effect of temper regime and PSD on mechanical

properties, 32514.4.4 Effect of temper regime and PSD on colour and gloss, 32814.4.5 Effect of temper regime and PSD on melting properties, 33014.4.6 Effect of temper regime on microstructure, 339

14.4.7 Effect of temper regime on scanning electron

microstructure, 33914.5 Conclusion, 343

15 Fat bloom formation and development in chocolates, 34515.1 Summary and industrial relevance, 345

15.2 Introduction, 34615.3 Materials and methods, 34715.3.1 Materials, 34715.3.2 Determination of particle size distribution, 34815.3.3 Tempering experiment, 348

15.3.4 Texture measurements, 34915.3.5 Surface colour and gloss measurements, 34915.3.6 Determination of melting properties, 349

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15.3.7 Microstructural determinations, 35015.3.8 Experimental design and statistical analysis, 35015.4 Results and discussion, 350

15.4.1 Particle size distribution of dark chocolates, 35015.4.2 Changes in textural properties during blooming, 35115.4.3 Changes in appearance (Surface Whiteness and Gloss)

during blooming, 35315.4.4 Changes in melting behaviour during blooming, 35715.4.5 Changes in microstructure during blooming, 35915.5 Conclusion, 364

16 Matrix effects on flavour volatiles character and release in chocolates, 36516.1 Summary and industrial relevance, 365

16.2 Introduction, 36516.3 Materials and methods, 36716.3.1 Materials, 36716.3.2 Tempering procedure, 36816.3.3 Determination of particle size distribution, 36816.3.4 Quantification of flavour volatiles by gas

chromatography, 36816.3.5 Gas chromatography–olfactometry analytical

conditions, 36916.3.6 Experimental design and statistical analysis, 36916.4 Results and discussion, 369

16.4.1 Particle size distribution of dark chocolates, 36916.4.2 Characterization of flavour compounds in dark

chocolates, 37016.4.3 Effects of particle size distribution on flavour volatile

release, 37416.4.4 Effects of fat content on flavour volatile release, 37416.4.5 Relating flavour volatiles release to particle size distribution

and fat content: product spaces, 37916.5 Conclusion, 381

17 Process optimization and product quality characteristics duringsugar-free chocolate manufacture, 382

17.1 Summary and industrial relevance, 38217.2 Introduction, 382

17.3 Materials and methods, 38417.3.1 Raw materials, 38417.3.2 Experimental design and sample preparation, 38417.3.3 Analytical methods, 385

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17.4 Results and discussion, 38717.4.1 Rheological properties, 39017.4.2 Casson plastic viscosity, 39017.4.3 Casson yield stress, 39217.4.4 Microscopy, 39317.4.5 Colour, 39517.4.6 Hardness, 39517.4.7 Moisture, 39617.5 Optimization of chocolate formulation, 39617.6 Conclusion, 397

18 Food safety management systems in chocolate processing, 39918.1 Introduction, 399

18.2 The HACCP system, 40018.2.1 HACCP principles, 40118.2.2 HACCP plan, 40218.2.3 Application of the HACCP system, 40518.2.4 Advantages of HACCP, 405

18.2.5 Shortfalls of HACCP, 40618.3 ISO 22000 approach, 40618.3.1 Advantages of ISO 22000, 40718.3.2 Comparison of ISO 22000 with HACCP, 40818.4 Hazards associated with chocolate processing, 40818.4.1 Physical hazards, 408

18.4.2 Chemical hazards, 40918.4.3 Microbiological hazards, 41118.5 Critical operations in cocoa processing and chocolatemanufacture, 413

18.5.1 Cleaning, 41318.5.2 Roasting, 41318.5.3 Breaking and winnowing, 41418.5.4 Refining, 414

18.5.5 Conching, 41418.5.6 Tempering, 41518.6 Conclusion, 415

19 Application of ISO 22000 and hazard analysis and critical controlpoints (HACCP) in chocolate processing, 416

19.1 Summary and industrial relevance, 41619.2 Introduction, 416

19.2.1 Hazard analysis and critical control points (HACCP), 41719.2.2 HACCP principles, 418

19.2.3 ISO 22000, 419

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19.3 Hazards associated with chocolate processing, 41919.3.1 Physical hazards, 420

19.3.2 Chemical hazards, 42119.3.3 Microbiological hazards, 42119.4 Preprocessing operations, 42119.5 Cocoa processing into semi-finished products, 42219.5.1 Bean receipt and cleaning – CCP1, 42219.5.2 Silos (Storage) – CCP2, 422

19.5.3 De-bacterizer – CCP3, 42219.5.4 The roasting process – CCP4, 42219.5.5 Breaking and winnowing, 42419.5.6 Milling, 424

19.5.7 Storage and conditioning – CCP5, 42419.5.8 Pressing – CCP6, 425

19.5.9 Centrifugation and filtration – CCP7, 42519.5.10 Kibbling and pulverization, 425

19.6 Milk chocolate manufacturing operations, 42519.6.1 Raw materials reception – CCP1, 42519.6.2 Mixing – CCP2, 425

19.6.3 Refining, 42619.6.4 Conching, 42719.6.5 Tempering, 42719.6.6 Casting and moulding – CCP3, 42819.6.7 Cooling, 428

19.6.8 Demoulding, 42819.6.9 Wrapping/Packaging – CCP4, 42919.7 Hazard analysis, 429

19.7.1 Determination of critical control points, 43519.7.2 Determination of prerequisite programmes, 43519.8 Conclusion, 435

20 Conclusions and industrial applications, 44120.1 Introduction, 441

20.2 Conclusions: Structure–properties relationships in chocolatemanufacture, 441

20.3 Conclusions: Tempering behaviour from response surfacemethodology, 443

20.4 Conclusions: Effects of tempering and fat crystallization onmicrostructure and physical properties, 444

20.5 Conclusions: Fat bloom formation and development withunder-tempering, 445

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20.6 Conclusions: Flavour volatiles and matrix effects related to variations

in PSD and fat content, 44520.7 Conclusions: Process optimization and product quality characteristics

of sugar-free chocolates, 44620.8 Industrial relevance and applications of research findings in thisbook, 447

20.9 Recommendations for further research studies, 448

References, 450Appendix 1 Abbreviations, 487Appendix 2 Acronyms and websites of organizations related to the cocoaand chocolate industry, 490

Appendix 3 Glossary of cocoa and chocolate terminologies, 492Index, 497

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Preface

Since the publication of the first edition of this book in 2010, the chocolateconfectionery industry has undergone dynamic changes due to the nature ofthe demand for chocolate The trends have transformed towards the increas-ing appeal of premium chocolate, including organic, Fairtrade, single-origin,reduced-sugar, sugar-free, dark and high cocoa content chocolates This hasengendered not only new challenges but also opportunities for all participants

in the sector Until recently, the general perception was that consumption ofchocolate in Europe and the United States was beginning to stagnate, as thesemajor chocolate markets were reaching saturation However, consumptionbehaviours across these mature markets have recently experienced majorchanges, also towards premium products Indeed, the confectionery markethas increasingly been characterized by consumer demand for quality, taste,convenience and health, and products addressing sustainability, traceability andethical and environmental concerns

New product developments and ‘functional foods’ with wholesome dients (foods that provide health benefits beyond basic nutrition) have played

ingre-an importingre-ant role in the upward trend of this emerging confectionery market

Many research activities have increasingly been conducted on the health andnutritional benefits of cocoa and chocolate The findings indicate that flavanoids

in cocoa may decrease low-density lipoprotein (LDL or ‘bad’ cholesterol) tion, helping to prevent cardiovascular diseases In addition, cocoa’s high content

oxida-of antioxidants has been proven to reduce the risk oxida-of cancer The demand for darkand high cocoa content chocolate in particular has surged in response to thesepositive findings

The chocolate industry has demonstrated a strong ability to meet thesechallenges and to benefit from the new opportunities brought about throughchanging consumer demand Companies traditionally known for milk chocolateproducts have been introducing new dark and high cocoa content varieties Theglobal market for dark chocolate is now estimated to represent about 13% ofthe total market for chocolate tablets (the others being plain milk, plain whiteand filled chocolate tablets), with a higher share in continental Europe than

in the United States and the United Kingdom Similarly, the certified organicand Fairtrade chocolate markets have been booming, increasing at double-digitpercentage rates

The advent of an increased demand for chocolates has impacted significantly

on the demand for cocoa beans in terms of both quantity and quality Although

mar-to meet the changing face of consumer demand through improved breeding andfarming techniques As a result of the increasing chocolate consumption trends,the cocoa processing and chocolate manufacturing industry faces an enormouschallenge in meeting the demand and quality criteria expected by the consum-ing populations This has to be matched vigorously by increasing productioncapacities of the chocolate manufacturing industry, which also requires a detailedunderstanding of the science and technology of chocolates.

As chocolate manufacturing is complex and requires numerous cal operations and the addition of a range of ingredients to achieve products ofsuitable physical and chemical attributes, appearance and taste parameters withpre-specified ranges, understanding the science of its manufacture and the tech-nological processes that can result in the expected product quality is paramount

technologi-Additionally, chocolate processing techniques differ as a result of historical opment within a producing company and the geographical locations in whichproducts are sold, and therefore require the necessary expertise to achieve thenecessary quality attributes, rheological characteristics, flavour development andthus sensory perception that are needed to satisfy a particular consuming pop-ulation Explanations of the scientific and technological processes employed bythe chocolate manufacturing industry today have been assisted by the scientificanswers to many of the frequently asked questions on process improvements,quality control, quality assurance, product quality and safety management sys-tems involved in the production of niche/premium products

devel-This second edition of Chocolate Science and Technology is therefore a

combina-tion of the convencombina-tional chocolate manufacturing processes and an overview ofthe innovative manufacturing processes being adopted by the industry for themanufacture of sugar-free, single-origin, reduced-sugar chocolates It providesdetailed information on the modern fundamental, scientific and technologicalknowledge and understanding of the processes involved in cocoa processing andchocolate manufacture to all who are engaged in the business of learning, mak-ing, consuming and using cocoa and chocolate products worldwide, especiallyconfectioners, industrialists, food scientists, students and consumers

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Acknowledgements

I wish to express my sincere gratitude and thanks to my parents – the late

Mr Joseph Ohene Afoakwa and Mrs Margaret Afoakwa – for ensuring that Iobtained the best education in spite of the numerous financial challenges thatthey faced in some periods of their lives Their profound love, prayers, supportand advice strengthened me from my childhood, giving birth to the manydreams and aspirations which have all become realities in my life today I amalso grateful to the Government of Ghana and to all cocoa farmers in Ghanawhose toils and sweats were used to fund my education through the GhanaCocoa Board Scholarship Scheme, which I earned throughout my secondaryeducation, and without which I could not have remained in school to make it

to University I am indeed grateful to you all

My gratitude and appreciation also go to the management of Nestlé ProductTechnology Centre (York, UK) for providing the funding and support for

my training in chocolate technology at their Centre, and also to Dr AlistairPaterson, Centre for Food Quality, University of Strathclyde, Glasgow, UK, MrMark Fowler, former Head of Applied Science Department of Nestlé ProductTechnology Centre (York, UK) and Dr Steve Beckett (former Director of Com-munications, Nestlé Product Technology Centre, York, UK) for their support,encouragement, patience and friendliness during the period of my doctoraltraining in York Many thanks also go to Dr Joselio Vieira, Dr Angela Ryan, DrJohn Rasburn, Peter Cooke, Dr Philip Gonus, Angel Manéz, Jan Kuendigar, DrRamana Sundara and Sylvia Coquerel of Nestlé Product Technology Centre,York, UK, and to Dr Jeremy Hargreaves of Nestlé Head Office, Vevey, Switzer-land, whose advice, guidance and support enhanced my understanding of thescience and technology of chocolate

My sincere thanks also go to the many friends and colleagues aroundthe world who have mentored, encouraged and inspired me in various waysthroughout my career, including Professor Samuel Sefa-Dedeh (formerlyDean, School of Engineering Sciences, University of Ghana), Professor GeorgeSodah Ayernor, Professor Anna Lartey (Director of Nutrition, FAO Head Office,Rome, Italy), Professor Ebenezer Owusu (Provost, College of Basic and AppliedSciences, [Vice Chancellor Elect], University of Ghana), Professor MatildaSteiner-Asiedu (Dean, School of Biological Sciences, University of Ghana),Professor Esther Sakyi-Dawson (Acting Director, Academic Quality AssuranceUnit, University of Ghana), Professor Kwaku Tano-Debrah, Professor AgnesSimpson Budu, Professor Firibu Kwesi Saalia, Dr William Bruce Owusu,

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Dr George Annor, Dr Maame Yaakwa Blay, Dr Angela Parry-Hanson Kunadu,

Dr Agartha Ohemeng, Dr Esi Colekraft, Dr Seth Adu-Afarwuah, Dr Gloria EthelOtoo and Dr Fred Vuvor, all of the Department of Nutrition and Food Science,University of Ghana, Legon, Accra, Ghana; Professor Demetre Labadarios,(formerly of Stellenbosch University) and Executive Director of KnowledgeSystems, Human Sciences Research Council in Cape Town, South Africa;

Professor Ruth Oniang’o, Founder and Editor-in-Chief of the African Journal of Food, Agriculture, Nutrition and Development (AJFAND), Nairobi, Kenya; Professor

Linley Chiwona-Karltun of the Swedish University of Agricultural Sciences,Uppsala, Sweden; Miss Priscilla Afram-Debrah (Maryland, USA), Mr GeorgeEkow Hayford, Quality Assurance and Regulatory Affairs Manager for NestléCentral West African Region; Dr Gene White, Dr Janey Thornton, Mrs BarbaraBelmont, Ms Penny McConnell, Mr Paul Alberghine and Mrs Mary Owens ofthe Global Child Nutrition Foundation, Washington, DC, USA

I am indebted to my research collaborators in Belgium, including ProfessorKoen Dewettinck (University of Ghent), Professor Pascal Boeckx (University

of Ghent), Professor Frédéric Dypepere (Barry Callebaut Company Limited,Belgium) and Dr Roger Philip Aidoo (Bayn Europe AB, Stockholm, Sweden),who contributed extensively to the writing and reviewing of the chaptersrelating to sugar-free chocolates during the doctoral studies of Dr Roger PhilipAidoo at Ghent University, Ghent, Belgium

My gratitude also goes to my master’s students, Farida Adam, Nana SerwaaBoateng, Albert Gattor, Gideon Dendzo, Lauretta, Esi, Doreen and LouisaOfosuah Obimpeh, and also to my doctoral students, John Edem Kongor,Michael Hinneh and Bobby Antan Caiquo, for their interest in cocoa processingand chocolate technology

Finally, my profound appreciation and love go to my siblings Sammy, Julianaand Regina for their prayers and support throughout my education, and again

to my dear wife, Ellen, and our lovely children Nana Afra, Maame Agyeiwaaand Kwabena Ohene-Afoakwa (Jr) for supporting me and most importantlyproviding the much needed love, encouragement and affection that havestrengthened me throughout my career We all have very good memories of thebeautiful cities of London, York and Glasgow, the Nestlé Rowntree factory andthe Nestlé Product Technology Centre in York, UK

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About the author

Emmanuel Ohene Afoakwa, PhD, is Professor of Food Science and

Technology and Head of the Department of Nutrition and Food Science,University of Ghana He holds a PhD degree in food science from the University

of Strathclyde, Glasgow, UK, and MPhil and BSc (Honours) degrees in foodscience from the University of Ghana, Legon, Accra, Ghana He also holdsCertificates in International Food Laws and Regulations from the Michigan StateUniversity, East Lansing, MI, USA, and Food Quality Management Systems fromthe International Agricultural Centre of Wageningen University, Wageningen,The Netherlands He is also a trained and a Licensed Food Auditor by the WorldFood Safety Organization, UK

Dr Afoakwa has vast relevant experience in food science and technology andinternational food laws and regulations He is a member of several professionalbodies, including the Institute of Food Technologists (IFT), the Food Scienceand Nutrition Network for Africa (FOSNNA), the Information Technology forthe Advancement of Nutrition in Africa (ITANA) society, the African Networkfor School Feeding Programmes (ANSFEP), the Ghana Institute of Food Scienceand Technology (GIFoST) and the Ghana Science Association (GSA) He hasauthored and co-authored 180 publications (including 86 peer-reviewed journalpublications, 4 books, 4 book chapters, 2 encyclopaedia chapters and 84 con-ference presentations with published abstracts) in food science and technology

In the pursuance of his duties as a food technologist, he has travelled to 38different countries around the world, where he has gained high internationalrecognition of his work

He is a Member of the International Expert Group and Head of the Ghanadelegation working with the European Commission and ISO in setting interna-tional standards for sustainable and traceable cocoa He is a Member of Board

of Directors of the Global Child Nutrition Foundation (GCNF) in Washington,

DC, USA, the Executive Secretary to the African Network for School FeedingProgrammes, the Secretary to the Ghana Institute of Food Science and Technol-ogy (GIFoST) and the Scientific Secretary to the Information Technology for theAdvancement of Nutrition in Africa (ITANA) society He is the Editor-in-Chief

of the Journal of Food Technology Research and also serves as a member of theEditorial Boards of several international journals and as a technical reviewer formore than 20 international peer-reviewed journals around the world Further,

he is a technical advisor to the International Foundation for Science (IFS) withinthe area of food science and nutrition, and also a trainer in scientific writing and

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grant proposal development for the African Women in Agricultural Researchand Development (AWARD) He has wide experience in food technology andnutrition, and translates his research findings through process and productdevelopment into industrial production towards the achievement of the UNMillennium Development Goals (MDGs), mainly on food and nutrition securityand sustainable agricultural development

Dr Afoakwa is a research scientist and international expert in cocoa tion and processing and chocolate technology He has contributed extensively

produc-to many international journals, books, book chapters and encyclopaedias in thearea of cocoa and chocolate technology, and has given numerous presentations

at both national and international conferences across the globe

Chocolate is derived from the cocoa bean, which is obtained from the fruit of

the cocoa tree, Theobroma cacao (Linnaeus) The term ‘Cocoa’ is a corruption of

the word ‘Cacao’ that is taken directly from Mayan and Aztec languages It isindigenous to Central and South America and believed to have originated from

the Amazon and Orinoco valleys Cocoa (Theobroma cacao L.) is one of the most

important agricultural export commodities in the world and forms the bone of the economies of some countries in West Africa, South America andSouth-East Asia It is the leading foreign exchange earner and a great source ofincome for many families in most of the world’s developing countries In Ghana,cocoa is the second highest foreign exchange earner and an estimated 1 millionfarmers and their families depend on it for their livelihood (Afoakwa, 2014)

back-Currently, in 2016, cocoa is cultivated on an estimated land size of 8 millionhectares in the tropics and secures the livelihoods of about 50 million peopleglobally More than 8 million of them are mainly smallholder farmers with anaverage farm size of just 3–4 hectares and an average family size of eight Of these,some 1.5 million are within West Africa, the most important cocoa-growingregion Such families frequently live exclusively on cocoa farming and processingand are thus dependent mainly on cocoa for their livelihoods Hence the eco-nomic importance of cocoa cannot be over-emphasized and the current globalmarket value of annual cocoa crop is over $8.1 billion (World Cocoa Foundation,2014)

Cocoa continues to be an important source of export earnings for manyproducing countries, particularly in Africa, Latin America and South-East Asia

Africa’s heavy dependence on cocoa and also on other primary commodities as asource of export earnings has been vulnerable to market developments, in par-ticular price volatility and weather conditions However, in some circumstances,real exchange rates, domestic marketing arrangements and government inter-vention have acted to buffer price movements for cocoa producers Cocoa wasthe second source of export earnings in Ghana in 2014, after gold, generatingUS$2.0 billion

Chocolate Science and Technology, Second Edition Emmanuel Ohene Afoakwa.

© 2016 John Wiley & Sons, Ltd Published 2016 by John Wiley & Sons, Ltd.

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The African region accounts for approximately 72.3% of net world exports

of cocoa and is by far the largest supplier of cocoa to world markets, followed

by the Americas (16.7%) and then Asia and Oceania (11.0%), and the cocoamarket remains highly concentrated, with the top five countries accounting for87% of world net exports, and over 98% originated from the top 10 countriesduring the 5-year period 2010–2015 Côte d’Ivoire (Ivory Coast) is the world’sleading exporter of cocoa, representing 40.6% of global net exports, followed

by Ghana (19.2%) and Indonesia (8.9%) (ICCO, 2015a) Interestingly, therehas been continuing repositioning of some countries, which in recent yearshave shown tremendous interest in advancing their cocoa production In 2014,Ecuador exported ∼230 000 tonnes of cocoa, which positioned it as the fifthlargest producer of cocoa in the world, displacing Cameroon and Brazil to sixthand seventh positions, respectively, and surpassed only by Nigeria, Indonesia,Ghana and Côte d’Ivoire This means that Ecuador has advanced its position inthe global market for the second consecutive year, having overtaken Brazil, one

of the leading producers in Latin America, in 2013 (Ricky and Moncayo, 2015)

With increased processing at origin, cocoa products now represent a slightlyhigher proportion of total cocoa exports in most cocoa-producing countries(ICCO, 2015a)

1.2 History of cocoa

Cocoa (Theobroma cacao L.) is a native species of tropical humid forests on the

lower eastern equatorial slopes of the Andes in South America Allen (1987)

reported the centre of genetic diversity of T cacao to be the Amazon Basin region

of South America and all 37 collecting expeditions listed by End et al (1990)

seeking germplasm of wild cacao were to the Amazon Basin region The wordcacao is derived from the Olmec and the subsequent Mayan languages (Kakaw)and the chocolate-related term cacahuatl is Nahuatl (Aztec language) derived

from Olmec/Mayan etymology (Dillinger et al., 2000) Cocoa was considered

divine in origin and, in 1737, the Swedish botanist Carolus Linnaeus (Carl von

Linné) named the cocoa tree Theobroma cacao, now its official botanical name,

from the Greek word ‘ambrosia’, which refers to the mythical background of thetree, literally meaning ‘cocoa, food of the gods’ (Alvim, 1984; Barry Callebaut,2008) Based on archaeological information, Purdy and Schmidt (1996) reportedthat the Mayans cultivated cocoa 2000–4000 years before Spanish contact It isrecorded that cocoa was domesticated and consumed for the first time by theMaya and Aztecs The Maya, Olmec, Toltec and Aztecs used the beans of cocoaboth as currency and as the base for a bitter drink (Purdy and Schmidt, 1996;

Nair, 2010; ICE Futures U.S., 2011)

The name ‘cocoa’ is a corruption of the word cacao, which originated from

the Amazons in South America Its cultivation and value spread in ancient times

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throughout central and eastern Amazonia and northwards to Central America(Afoakwa, 2010) Cocoa was first cultivated by the Aztecs in Mexico, SouthAmerica, and spread throughout the Caribbean islands Later, in the 1520s, Her-nandos Cortés, a Spaniard, took cocoa to Spain as a beverage and to SpanishGuinea as a crop The Spanish not only took cocoa to Europe, but also intro-duced the crop into Fernando Po in the seventeenth century and thus laid thefoundation of the future economies of many West African countries Currently,West Africa produces ∼73% of world cocoa (ICCO, 2015)

The use of cocoa beans dates back at least 1400 years (Rössner, 1997), whenAztecs and Incas used the beans as currency for trading or to produce the

so-called chocolatl, a drink made by roasting and grinding cocoa nibs, mashing

with water, often adding other ingredients such as vanilla, spices or honey Inthe 1520s, the drink was introduced to Spain (Minifie, 1989), although Coeand Coe (1996) emphasized that the Europeans arrivals in the New World,including Christopher Columbus and Herman Cortes, were unimpressed withthe Mayan beverage, sweetening it with honey Nevertheless, conquistadorsfamiliarized the chocolate beverage throughout Europe and, being expensive,

it was initially reserved for consumption by the highest social classes, andonly in the seventeenth century did consumption of chocolate spread throughEurope After the conquest of Central America in 1521, Hernan Cortez and hisconquistadors took a small cargo of cocoa beans to Spain in 1528, together withutensils for making the chocolate drink By 1580 the drink had been popularized

in the country and consignments of cocoa were regularly shipped to Spain Thepopularity of chocolate as a drink spread quickly throughout Europe, reachingItaly in 1606, France in 1615, Germany in 1641 and Great Britain in 1657(Fowler, 2009; Afoakwa, 2010)

Large-scale cultivation of cocoa was started by the Spanish in the sixteenthcentury in Central America It spread to the British, French and Dutch WestIndies (Jamaica, Martinique and Surinarn) in the seventeenth century and toBrazil in the eighteenth century From Brazil it was taken to Sao Tome and Fer-nando Po (now part of Equatorial Guinea) in 1840; and from there to other parts

of West Africa, notably the Gold Coast (now Ghana), Nigeria and Côte d’Ivoire

The cultivation of cocoa later spread to the Caribbean islands, Asia and Africa It

is currently grown in a number of Pacific islands, including Papua New Guinea,

Fiji, Solomon Islands, Samoa and Hawaii (Hebbar et al., 2011) In Ghana,

avail-able records indicate that the Dutch missionaries planted cocoa in the coastalareas of the then Gold Coast as early as 1815, and in 1857 Basel missionariesalso planted cocoa at Aburi (Jonfia-Essien, 2004) However, these did not result

in the spread of cocoa cultivation until Tetteh Quarshie, a native of Osu, Accra,who had travelled to Fernando Po and worked there as a blacksmith, returned

in 1879 with Amelonado cocoa pods and established a farm at Akwapim pong in the Eastern Region Farmers bought pods from his farm to plant andcultivation spread from the Akwapim area to other parts of the Eastern Region

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(Jonfia-Essien, 2004) In 1886, Sir William Bradford Griffith, the Governor, alsoarranged for cocoa pods to be brought in from Sao Tome, from which seedlingswere raised at Aburi Botanical Gardens and distributed to farmers In recognition

of the contribution of cocoa to the development of Ghana, the government in

1947 established the Ghana Cocoa Board (COCOBOD) as the main governmentagency responsible for the development of the industry Currently, there are sixcocoa-growing regions in Ghana, namely the Ashanti, Brong Ahafo, Eastern,Volta, Central and Western regions Ghana is the world’s second largest producer

of cocoa beans, producing approximately 17% of the world’s cocoa (ICCO, 2015)

As the consumption of chocolate became more and more widespread ing the eighteenth century, the Spanish monopoly on the production of cocoabecame untenable and plantations were soon established by the Italians, Dutchand Portuguese At this point, chocolate was still consumed in liquid form andwas mainly sold as pressed blocks of a grainy mass to be dissolved in water ormilk to form a foamy chocolate drink The mass production of these choco-late blocks also began in the eighteenth century when the British Fry familyfounded the first chocolate factory in 1728 using hydraulic equipment to grindthe cocoa beans The first US factory was built by Dr James Baker outside Boston

dur-a few decdur-ades ldur-ater, dur-and in 1778 the Frenchmdur-an Doret built the first dur-automdur-atedmachine for grinding cocoa beans The production of cocoa and chocolate wastruly revolutionized in 1828 by the invention by Coenraad Van Houten of a cocoapress that succeeded in separating cocoa solids from cocoa butter The resultingdefatted cocoa powder was much easier to dissolve in water and other liquidsand paved the way, in 1848, for the invention of the first real ‘eating chocolate’,produced from the addition of cocoa butter and sugar to cocoa liquor (Dhoedt,2008)

In the United Kingdom, Joseph Fry, in 1847, was the first to produce a plaineating chocolate bar, made possible by the introduction of cocoa butter as aningredient (Beckett, 2000) Demand for cocoa then sharply increased and choco-late processing became mechanized with the development of cocoa presses forthe production of cocoa butter and cocoa powder in 1828 by Van Houten andmilk chocolate in 1876 by Daniel Peters, who had the idea of adding milk pow-der – an invention of Henri Nestlé, a decade earlier This was followed by theinvention of the conching machine in 1880 by Rudolphe Lindt, from wherechocolate came to take on the fine taste and creamy texture that we now asso-ciate with good-quality chocolate It was still very much an exclusive product,however, and it was not until 1900 when the price of chocolate’s two main ingre-dients, cocoa and sugar, dropped considerably that chocolate became accessible tothe middle class By the 1930s and 1940s, new and cheaper supplies of raw mate-rials and more efficient production processes had emerged at the cutting edge

of innovation, with fast manufacturing technologies and new marketing niques through research and development by many companies in Europe and

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the United States, making chocolate affordable for the wider populace late confectionery is now ubiquitous, with consumption averaging around 8 kgper person per annum in many European countries

nomic importance The 22 species are sub-divided into six sections based on theirmorphological characters:

1 Andropetalum (T mammosum);

2 Glossopetalum (T angustifolium, T canumanense, T chocoense, T cirmolinae, T.

cirmolinae, T gradiflorum, T hylaeum, T nemorale, T obovatum, T simiarum, T.

sinuosum, T stipulatum, T subincanum);

3 Oreanthes (T bernouillii, T glaucum, T speciosum, T sylvestre, T velutinum);

4 Rhytidocarpus (T bicolor);

5 Telmatocarpus (T gileri, T microcarpum); and

6 Theobroma (T cacao)

(Figueira et al., 2002; Hebbar et al., 2011).

The 22 species are grown in Brazil except those of Andropetalum (T mammosum).

T grandiflorum, T obovatum, T speciosum, T sylvestre, T subincanum, T microcarpum,

T bicolor and T cacao are native to the Amazon basin of Brazil (Figueira et al.,

2002) All of these species have at least one fatty acid component similar to that

of T cacao (Figueira et al., 2002) The composition of the fatty acids in terms of palmitic acid for the Theobroma species differs from that of T cacao while at least one of the other fatty acids is similar to that of T cacao For example, species from the section Glossopetalum have stearic acid contents similar to that of T cacao whereas T sylvestre and T microcarpum have oleic acid contents similar to that of

T cacao (Figueira et al., 2002) The chemical compositions of the nibs of T sylvestre and T speciosum in terms of fatty acid composition are similar to that of T cacao (Carpenter et al., 1994; Figueira et al., 2002; Quast et al., 2011).

Cupuassu (Theobroma grandiflorum) is a fruit native to the Amazon region (Figueira et al., 2002; Quast et al., 2011) Among the Theobroma species, Theobroma grandiflorum has the largest fruit, with the unfermented seeds containing about 84% moisture and 60% fat on a dry weight basis (Quast et al., 2011) Theobroma

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grandiflorum has found applications in the food, pharmaceutical and chemical

industries The fat is found to be an alternative fat substitute for cocoa in

choco-late production (Figueira et al., 2002; Lannes et al., 2003; Medeiros et al., 2006).

Just like cocoa, Theobroma grandiflorum seeds are fermented, dried and deshelled

and the nibs are milled to obtain cupuassu liquor, which is used in a Brazilianproduct called ‘cupulate’, which has nutritional and sensorial characteristics thatare very close to those of chocolate (Awua, 2002)

Several other species are cultivated or wild-harvested on a relatively small

scale for human consumption These are T bicolor (mocambo, pataste), T florum (cupuaçu) and, to a lesser extent, T speciosum and T subincanum (Hebbar

grandi-et al., 2011) Nair (2010) reported that Theobroma bicolor Humb and Bonpl are

cultivated for the edible pulp around the beans and the beans are used like those

of cocoa The beans of Theobroma angustifolium Moc and Sesse are mixed with cocoa in Mexico and Costa Rica and the sweet pulp around the beans of Theo- broma grandiflorum (Wild ex Spreng.) Schumann are used for making a drink in

parts of Brazil and is also eaten

1.4 Morphological and varietal characteristics

of cocoa

1.4.1 The cocoa plant

The cocoa plant is usually a small tree, 4–8 m tall, although when shaded by largeforest trees it may reach up to 10 m in height The stem is straight, the wood islight and the bark is thin, somewhat smooth and brownish The fruit (pods) reach

up to 15–25 cm in length The mature fruit or pod consists of a comparativelythick husk containing between 30 and 50 seeds embedded in a thick mucilagi-nous pulp All cultivated cocoas show great variability and it is generally agreedthat they can be divided within the species The principal varieties of the cocoa

tree Theobroma cacao are as follows:

1 Forastero from the Amazonas region, and grown mainly in West Africa as bulk

cocoa;

2 Criollo, rarely grown because of susceptibility to disease;

3 Trinitario, a hybrid of Forastero and Criollo;

4 Nacional, with fine flavour, grown in Ecuador.

Forastero varieties form most of the ‘bulk’ or ‘basic’ cocoa market World

annual cocoa bean production is approximately 4.23 million tonnes and majorproducers are Côte d’Ivoire, Ghana, Indonesia, Nigeria, Ecuador, Cameroon,Brazil and Malaysia There are also a number of smaller producers, particularly

of ‘fine’ cocoa, which constitutes less than 5% of world trade In 2013, WestAfrica alone produced ∼75% of global production with Côte d’Ivoire and Ghanaproducing ∼38% and ∼22%, respectively, thus totalling ∼60%

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1.4.1.1 Forastero cocoa

Forastero means ‘foreigner’ in Spanish and refers to any cocoa trees that are not Criollo or a hybrid, and usually produces deep purple seeds (Hebbar et al., 2011).

Forastero is native to the Amazon region and largely grown in West Africa and

South-East Asia It represents 95% or ‘bulk’ of the world production of cocoa

(Delonga et al., 2009; Fowler, 2009; Afoakwa, 2010; Afoakwa et al., 2012) and is the most widely used as it has a higher yield than Criollo variety Forastero varieties

exhibit greater variability in both tree and fruit morphology The pods when ripeare hard, yellow and have a more rounded shape like a melon (Figures 1.1 and1.2), containing 30 or more pale to deep purple beans This variety is generallymore vigorous and less susceptible to diseases, such as swollen shoot, mottleleaf, yellow mosaic, cocoa necrosis, witches broom and black pod (Afoakwa,

2010; Dzahini-Obiatey et al., 2010), and also pests, such as capsids and cocoa pod borer (Conopomorpha cramerella) (Fowler, 2009; Afoakwa, 2010; ICCO, 2012) than the Criollo variety Forastero cocoa beans are characterized by darker brown

cotyledons which are slightly bitter but have the strongest flavour Chocolateproducts from these beans are rich in chocolate flavour but low in complex or

fruity flavour notes (deZaan Cocoa Manual, 2009; Hebbar et al., 2011).

Several cultivars of Forastero are grown in Ghana The main cultivars are

Amelonado (13.3%) and Amazonica (34.4%), including a new hybrid, the

Figure 1.1 Typical unripe Forastero cocoa pods (See plate section for color representation of this figure.)

k Figure 1.2 Typical ripe Forastero cocoa pod (See plate section for color representation of this figure.) k

mixed hybrid (52.3%) The farmers in Ghana locally call the mixed hybrid

variety akokora bedi, which literally means the aged will surely enjoy This is due

to the short duration needed to begin bearing fruits Amelonado is the Forastero variety widely grown in West Africa (Fowler, 2009; Hebbar et al., 2011) with

the varieties including Comum in Brazil, West African Amelonado in Africa,Cacao Nacional in Ecuador and Matina or Ceylan in Costa Rica and Mexico(ICCO, 2012)

The Forastero type of cocoa now forms the greater part of all cocoa grown

and is hardy and vigorous, producing beans with the strongest flavour It is amuch more plentiful variety of high-quality cocoa, representing most of thecocoa grown in the world Grown mainly in Brazil and Africa, it is hardier, higher

yielding and easier to cultivate than Criollo and is used in just about every blend

of chocolate that is made The pods are short, yellow and smooth without warts,with shallow furrows, and a pod has 30 or more pale to deep purple beans

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and hence is less cultivated (Afoakwa, 2010; Hebbar et al., 2011) This type is

now very rare and found only in old plantations in Venezuela, Central

Amer-ica, Madagascar, Sri Lanka and Samoa (Fowler, 2009) The Criollo bean has the

highest aromatic flavour quality on the international market It is less bitter andmore aromatic and therefore has a mild and nutty cocoa flavour (Fowler, 2009;

deZaan Cocoa Manual, 2009; Rusconi and Conti, 2010) than any other beans,

they are therefore highly priced The yield of a Criollo cocoa plantation is lower than that of a Forastero plantation of the same size The fruits of the Criollo variety

typically have a soft, thin husk or pod with a textured surface and usually havesome degree of red pigmentation with 20–30 white or faint purple beans When

Criollo pods are ripe, they are long, yellow or red, with deep furrows and large

warts (Figure 1.3)

1.4.1.3 Trinitario cocoa

Trinitario cocoa variety is a hybrid between the Criollo and Forastero varieties.

Trinitario developed in Trinidad (Willson, 1999; deZaan Cocoa Manual, 2009),

hence the name, but later spread to Venezuela, Ecuador, Cameroon, Samoa, Sri

Lanka, Java and Papua New Guinea (ICCO, 2012) Some Trinitario varieties

pro-duce cocoa beans with special flavours They have mostly hard pods and arevariable in colour, can be long or short, and they contain 30 or more beans ofvariable colour (Figure 1.4), but white beans are rare

1.4.1.4 Nacional cocoa

Nacional cocoa variety grows in Ecuador It is believed to have originated from

the Amazonian area of Ecuador (deZaan Cocoa Manual, 2009; Fowler, 2009;

Figure 1.3 Typical Criollo cocoa (See plate section for color representation of this figure.)

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Figure 1.4 Typical Trinitario cocoa pods.

Afoakwa, 2010) and has distinctive aroma and flavour characteristics (Afoakwa,

2010; Hebbar et al., 2011) but is less cultivated hence contributes about 5% of global cocoa production Currently, pure Nacional cocoa varieties are rare The one with Arriba flavour in Ecuador is a hybrid between Nacional and Trinitario (Fowler, 2009) Typical Nacional cocoa pods are shown in Figure 1.5 Research

conducted in 2008 in Latin America suggested a new classification of cacaogermplasm into 10 major groups: Marañon, Curaray, Criollo, Iquitos, Nanay,

Contamana, Amelonado, Purús, Nacional and Gulana (Motamayor et al., 2008;

deZaan Cocoa Manual, 2009;) This classification reflects much more accuratelythe genetic diversity of cacao Important characteristic differences between

typical Criollo, Forastero and Trinitario cocoas are presented in Table 1.1.

1.5 Varietal effects on cocoa bean flavour

The different cocoa bean genotypes or varieties discussed above influence bothflavour quality and intensity in chocolate during manufacturing (Taylor, 2002;

Luna et al., 2002; Counet et al., 2004) The differences are largely due to the

wide differences in the chemical compositions of the derived beans, likely mining the quantities of flavour precursors and activity of enzymes and thuscontributions to flavour formation Reineccius (2006) concluded that varietaldifferences were primarily due to quantitative (as opposed to qualitative) differ-ences in flavour precursor and polyphenol contents The contents of sugars and

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Figure 1.5 Typical Nacional cocoa pod.

Table 1.1 Characteristics of the different cocoa varieties

Characteristics Criollo Forastero Trinitario

pod

Colour of cotyledons

White, ivory or very pale purple

Pale to deep purple

Variable; white beans rarely

Pest and disease susceptibility

need

1–3 days maximum

mild and nutty

chocolate; full cocoa

Bean size (g/100 beans)

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enzymic breakdown of polysaccharides constitute an important source of cursors However, post-harvest processes (fermentation and drying) and roastinghave a strong influence on the final flavours (Kattenberg and Kemming, 1993;

pre-Clapperton et al., 1994; Luna et al., 2002; Counet and Collin, 2003) The three primary cocoa types, Forastero (bulk grade), Criollo (fine grade) and the hybrid Trinitario (fine grade) show wide variations in final flavour (Beckett, 2000; Awua, 2002; Amoye, 2006) Nacional cacao is viewed as a third fine variety, produc-

ing the well-known Arriba beans with distinctive floral and spicy flavour notes

(Despreaux, 1998; Luna et al., 2002; Counet et al., 2004) These differences in

flavour can be ascribed to variations in bean composition from botanical gin, location of growth and farming conditions Bulk varieties dominate blendswhereas fine grades, used in lesser quantities, are selected to make specific con-tributions to the overall flavour profile

ori-Each bean variety has a unique potential flavour character, but growing ditions such as climate, amount and time of sunshine and rainfall, soil conditions,ripening, time of harvesting and time between harvesting and bean fermenta-tion all contribute to variations in final flavour formation Table 1.2 summarizeshow differences in genetic origin, cocoa variety and duration of fermentationinfluence the flavour profile, but different conditions may lead to significant dif-ferences in flavour from a single cocoa variety A good example is the difference

con-in flavour profile between a scon-ingle Forastero variety produced origcon-inally con-in Ghana

Table 1.2 Effects of origin, cocoa variety and fermentation duration on flavourcharacter

Origin Cocoa type Duration (days) Special flavour character

Short

Medium

Long

Source: Afoakwa et al (2008a) Reproduced with permission of Taylor & Francis.

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and now grown in Malaysia (Clapperton, 1994), arising possibly through graphic and climatic conditions and duration and/or method of fermentation

geo-Bulk cocoas typically show strong flavour characters; fine cocoas are

per-ceived as aromatic or smoother (Kattenberg and Kemming, 1993; Jinap et al., 1995;

Luna et al., 2002) Clapperton et al (1994) noted consistent differences in flavour attributes, specifically overall cocoa flavour intensity, acidity, sourness, bitterness and astringency Bean origins include the West African Amelonado variety (AML),

four Upper Amazon clones [Iquitos Mixed Calabacillo 67 (IMC67), Nanay 33(NA33), Parinari 7 (PA7) and Scavina 12 (SCA12)] and Unidentified Trinatario(UIT1) grown in Sabah, Malaysia The flavour characters in UIT1 differed from

those in West African Amelonado, characterized by intense bitterness and gency associated with caffeine and polyphenol contents Fermented beans from South-East Asia and the South Pacific are characterized by a higher acidity (more lactic and acetic acids) than West African beans (Clapperton et al., 1994) due to

astrin-varietal differences, box fermentation and rapid artificial drying

Cocoa liquors differ in sensory character The West African group (Ghana,Côte d’Ivoire and Nigeria) are generally considered sources of standard (bench-mark) cocoa flavour with a balanced but pronounced cocoa character with sub-

tle to moderate nutty undertones Cameroon liquors are renowned for bitterness and those from Ecuador for floral–spicy notes American and West Indian vari- eties range from aromatic and winy notes from Trinidad cocoa to the floral or raisin–fruity notes of Ecuadorian stocks making unique contributions to blends.

Asian and Oceanian beans exhibit a range of flavour profiles ranging from subtle cocoa and nutty/sweet notes in Java beans to the intense acid and phenolic notes of Malaysian beans (De La Cruz et al., 1995).

Figure 1.6 shows an infograph prepared by Sean Seidell depicting the differentcocoa varieties grown in different cocoa-growing countries around the world

Counet et al (2004) reported that fine varieties with short fermentation cesses had high contents of procyanidins, while Trinatario from New Guinea and Forastero beans were specifically higher in total aroma Aroma compounds

pro-formed during roasting were found to vary quantitatively directly with tation time and inversely with the procyanidin content of cocoa liquors

fermen-High concentrations of phenol, guaiacol, 2-phenylbutenal and actone characterize Bahia beans known for typical smoked notes Also reported

𝛾-butyrol-are higher contents of 2-methylpropanal and 3-methylbutanal in Caracas(Venezuela) and Trinidad dried fermented beans (Dimick and Hoskin, 1999) OfMaillard products, Reineccius (2006) reported that roasting yields higher levels

of pyrazines in well-fermented beans (Ghana, Bahia) than in less-fermented(Arriba) or unfermented beans from Sanchez (Dominican Republic) or Tabasco

(Mexico) Lower in astringency and bitterness imparted by polyphenols, Criollo beans, in which anthocyanins are absent, are often less fermented than Forastero beans (Carr et al., 1979; Clapperton, 1994; Clapperton et al., 1994; Luna et al.,

2002)

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Figure 1.6 Infograph showing cocoas of different origins and their dynamic flavours Source:

courtesy of Sean Seidell (See plate section for color representation of this figure.)