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- Herausgeber: John Wiley & Sons
- Kategorie: Fachliteratur
- Sprache: Englisch
CHOCOLATE
SCIENCE AND TECHNOLOGY
This second edition provides information on recent advances in the science and technology of chocolate manufacture and the entire international cocoa industry. It provides detailed reviews of a wide range of topics, including cocoa production, cocoa and chocolate manufacturing operations, sensory perception of chocolate quality, flavour release and perception, sugar replacement and alternative sweetening solutions in chocolate production, industrial manufacture of sugar-free chocolates and the nutrition and health benefits of cocoa and chocolate consumption.
The topics cover modern cocoa cultivation and production practices with special attention to cocoa bean composition, genotypic variations in the bean, post-harvest pretreatments, fermentation and drying processes and the biochemical basis of these operations. The scientific principles behind industrial chocolate manufacture are outlined, with detailed explanations of the various stages of chocolate manufacturing, including mixing, refining, conching and tempering. Other topics covered include the chemistry of flavour formation and development during cocoa processing and chocolate manufacture; volatile flavour compounds and their characteristics and identification; sensory descriptions and character; and flavour release and perception in chocolate. The nutritional and health benefits of cocoa and chocolate consumption and the application of HACCP and other food safety management systems such as ISO 22000 in the chocolate processing industry are also addressed. Additionally, detailed research on the influence of different raw materials and processing operations on the flavour and other quality characteristics of chocolates have been provided, with scope for process optimization and improvement.
The book is intended to be a desk reference for all those engaged in the business of making and using chocolate worldwide; confectionery and chocolate scientists in industry and academia; students and practising food scientists and technologists; nutritionists and other health professionals; and libraries of institutions where agriculture, food science and nutrition are studied and researched.
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Table of Contents
Title Page
Copyright
Dedication
Preface
Acknowledgements
About the author
Chapter 1: History, origin and taxonomy of cocoa
1.1 Introduction
1.2 History of cocoa
1.3 Taxonomy of cocoa
1.4 Morphological and varietal characteristics of cocoa
1.5 Varietal effects on cocoa bean flavour
1.6 The concept of this book
Chapter 2: World cocoa production, processing and chocolate consumption pattern
2.1 Introduction
2.2 World production of cocoa
2.3 Major changes in world cocoa trade
2.4 Cocoa yield in producing countries
2.5 World cocoa grindings trends between 2005–2006 and 2014–2015
2.6 World stocks of cocoa beans
2.7 International cocoa price developments
2.8 Cocoa processing trends
2.9 Cocoa and chocolate consumption
2.10 Fairtrade cocoa and chocolate in the modern confectionery industry
2.11 The organic cocoa in chocolate confectionery industry
2.12 The changing chocolate market
Chapter 3: Traditional and modern cocoa cultivation practices
3.1 Introduction
3.2 Environmental requirements for cocoa cultivation
3.3 Traditional cocoa cultivation practices
3.4 Modern cocoa cultivation practices using vegetative propagation
3.5 Establishment and shade
3.6 Flowering and pod development
3.7 Harvesting of cocoa pods
3.8 Pod breaking
3.9 The cocoa pod
3.10 Good agricultural practices in cocoa cultivation
Chapter 4: Cocoa diseases and pests and their effects on chocolate quality
4.1 Introduction
4.2 Major cocoa diseases
4.3 Cocoa pests
4.4 Cocoa crop protection
Chapter 5: Cocoa bean composition and chocolate flavour development
5.1 Introduction
5.2 Bean composition and flavour precursor formation
5.3 Effects of genotype on cocoa bean flavour
5.4 Flavour development during post-harvest treatments of cocoa
5.5 Conclusion
Chapter 6: Cocoa processing technology
6.1 Introduction
6.2 Bean selection and quality criteria
6.3 Cocoa quality, grading and storage
6.4 Selection of bean blends and chocolate flavour quality
6.5 Steps in cocoa processing
Chapter 7: Industrial chocolate manufacture – processes and factors influencing quality
7.1 Introduction
7.2 Chocolate manufacturing processes
7.3 Tempering, lipid crystallization and continuous phase character during chocolate manufacture
7.4 Casting and moulding
7.5 Cooling
7.6 Demoulding
7.7 Wrapping/Packaging
7.8 Factors influencing rheological and textural qualities in chocolate
7.9 Chocolate quality and defects
7.11 Conclusion and further research
Chapter 8: The chemistry of flavour development during cocoa processing and chocolate manufacture
8.1 Introduction
8.2 Influence of bean selection on chocolate flavour quality
8.3 Effect of roasting
8.4 Flavour development during chocolate manufacture
8.5 Key flavour compounds in milk chocolate
8.6 Key flavour compounds in dark chocolate
8.7 Conclusion
Chapter 9: Alternative sweetening and bulking solutions in chocolate manufacture
9.1 Introduction
9.2 Types of sugar substitutes and their characteristics
9.3 High-potency sweeteners
9.4 Bulk sweeteners
9.5 Low-digestible carbohydrate polymers
9.6 Laxation and low–digestible carbohydrate polymers
9.7 Applicability and suitability of different sweeteners and carbohydrate polymers in chocolate processing
9.8 Importance of blending different sugar substitutes
Chapter 10: Sensory character and flavour perception of chocolates
10.1 Summary and industrial relevance
10.2 Introduction
10.3 Sensory perception of quality in chocolates
10.4 Sensory assessment of chocolates
10.5 Factor influencing chocolate flavour
10.6 Flavour release and perception of sweetness in chocolate
10.7 Dynamism of flavour perception in chocolate
10.8 Retronasal flavour release and perception during chocolate consumption
10.9 Measurement of flavour release and intensity in chocolates
10.10 Electronic noses and tongues as online sensors for sensory assessment of chocolates
10.11 Conclusion
Chapter 11: Nutritional and health benefits of cocoa and chocolate consumption
11.1 Summary and significance
11.2 Introduction
11.3 Chemistry and composition of cocoa flavonoids
11.4 Chocolate types and their major nutritional constituents
11.5 Antioxidant properties and their mechanism of action
11.6 Effects on endothelial function, blood pressure and the cardiovascular system
11.7 Effects on insulin sensitivity and carcinogenic properties
11.8 Cocoa, chocolate and aphrodisiac properties
11.9 Conclusion
Chapter 12: Processing effects on the rheological, textural and melting properties during chocolate manufacture
12.1 Summary and industrial relevance
12.2 Introduction
12.3 Materials and methods
12.4 Results and discussion
12.5 Relationships between Casson model and ICA recommendations
12.6 Textural properties
12.7 Microstructural properties of molten dark chocolate
12.8 Melting properties of dark chocolate
12.9 Relationships between rheological, textural and melting properties of dark chocolate
12.10 Conclusion
Chapter 13: Tempering behaviour during chocolate manufacture: Effects of varying product matrices
13.1 Summary and industrial relevance
13.2 Introduction
13.3 Materials and methods
13.4 Results and discussion
13.5 Conclusion
Chapter 14: Tempering and fat crystallization effects on chocolate quality
14.1 Summary and industrial relevance
14.2 Introduction
14.3 Materials and methods
14.4 Results and discussion
14.5 Conclusion
Chapter 15: Fat bloom formation and development in chocolates
15.1 Summary and industrial relevance
15.2 Introduction
15.3 Materials and methods
15.4 Results and discussion
15.5 Conclusion
Chapter 16: Matrix effects on flavour volatiles character and release in chocolates
16.1 Summary and industrial relevance
16.2 Introduction
16.3 Materials and methods
16.4 Results and discussion
16.5 Conclusion
Chapter 17: Process optimization and product quality characteristics during sugar-free chocolate manufacture
17.1 Summary and industrial relevance
17.2 Introduction
17.3 Materials and methods
17.4 Results and discussion
17.5 Optimization of chocolate formulation
17.6 Conclusion
Chapter 18: Food safety management systems in chocolate processing
18.1 Introduction
18.2 The HACCP system
18.3 ISO 22000 approach
18.4 Hazards associated with chocolate processing
18.5 Critical operations in cocoa processing and chocolate manufacture
18.6 Conclusion
Chapter 19: Application of ISO 22000 and hazard analysis and critical control points (HACCP) in chocolate processing
19.1 Summary and industrial relevance
19.2 Introduction
19.3 Hazards associated with chocolate processing
19.4 Preprocessing operations
19.5 Cocoa processing into semi-finished products
19.6 Milk chocolate manufacturing operations
19.7 Hazard analysis
19.8 Conclusion
Chapter 20: Conclusions and industrial applications
20.1 Introduction
20.2 Conclusions: Structure–properties relationships in chocolate manufacture
20.3 Conclusions: Tempering behaviour from response surface methodology
20.4 Conclusions: Effects of tempering and fat crystallization on microstructure and physical properties
20.5 Conclusions: Fat bloom formation and development with under-tempering
20.6 Conclusions: Flavour volatiles and matrix effects related to variations in PSD and fat content
20.7 Conclusions: Process optimization and product quality characteristics of sugar-free chocolates
20.8 Industrial relevance and applications of research findings in this book
20.9 Recommendations for further research studies
References
Abbreviations
Acronyms and websites of organizations related to the cocoa and chocolate industry
Glossary of cocoa and chocolate terminologies
Index
End User License Agreement
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Guide
Table of Contents
Preface
Begin Reading
List of Illustrations
Chapter 1: History, origin and taxonomy of cocoa
Figure 1.1 Typical unripe
Forastero
cocoa pods. (
See plate section for color representation of this figure
.)
Figure 1.2 Typical ripe
Forastero
cocoa pod. (
See plate section for color representation of this figure
.)
Figure 1.3 Typical
Criollo
cocoa. (
See plate section for color representation of this figure
.)
Figure 1.4 Typical
Trinitario
cocoa pods.
Figure 1.5 Typical
Nacional
cocoa pod.
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
.)
Chapter 2: World cocoa production, processing and chocolate consumption pattern
Figure 2.1 World leading cocoa-producing countries (ICCO, 2015a).
Figure 2.2 World cocoa production trends by continent from 2005–2006 to 2014–2015 (*estimates).
Figure 2.3 World cocoa yields in major producing countries in 2010–2011 and 2011–2012.
Figure 2.4 World cocoa grindings trends between 2004–2005 and 2014–2015.
Figure 2.5 World consumption of chocolate products by region.
Figure 2.6 Per capita consumption of chocolate products in selected countries worldwide in 2012.
Figure 2.7 Global manufacture/consumption pattern of the different chocolate types, 2011–2016 (forecast).
Figure 2.8 The Fairtrade Mark (ICCO, 2010b).
Figure 2.9 Different organic certification marks (ICCO, 2010b).
Figure 2.10 Marks used by certification bodies involved with cocoa traceability and good agricultural practices (ICCO, 2010b).
Chapter 3: Traditional and modern cocoa cultivation practices
Figure 3.1 Traditional nursery for raising cocoa seedlings for transplanting. (
See plate section for color representation of this figure
.)
Figure 3.2 Batch budding techniques used in multiplication of planting materials.
Figure 3.4 Side grafting techniques used in multiplication of planting materials.
Figure 3.5 Young cocoa plantation intercropped with plantain trees. (
See plate section for color representation of this figure
.)
Figure 3.9 Cocoa plantation interplanted with
Gliricidia
trees.
Figure 3.10 Budding and flowering of cocoa from bark of old tree.
Figure 3.11 Matured flower with opened sepals from bark of cocoa tree. (
See plate section for color representation of this figure
.)
Figure 3.12 Cocoa pod development. (
See plate section for color representation of this figure
.)
Figure 3.13 Matured unripe cocoa pods.
Figure 3.14 Matured and ripened cocoa pods.
Figure 3.15 Harvesting of cocoa pods by hand.
Figure 3.16 Harvesting of cocoa pods by a hook and pole tool. (
See plate section for color representation of this figure
.)
Figure 3.17 Heaping of harvested cocoa pods.
Figure 3.18 Opening of heaped cocoa pods with wooden clubs for fermentation. (
See plate section for color representation of this figure
.)
Figure 3.19 Typical ripe cocoa pod (the golden pod).
Figure 3.20 Longitudinal view of bean arrangement in matured cocoa pod. (
See plate section for color representation of this figure
.)
Figure 3.21 Cross-sectional view of bean arrangement in matured cocoa pod.
Figure 3.22 Pruned cocoa trees.
Chapter 4: Cocoa diseases and pests and their effects on chocolate quality
Figure 4.1 Swollen shoot virus disease (results in small pods).
Figure 4.2 Black pod disease: (a) on partially infested cocoa pods; (b) fully and partially infested cocoa pods; (c) mature fully infested cocoa pod; (d) immature fully infested cocoa pods.
Figure 4.3 Witches bloom disease.
Figure 4.4 Capsid.
Figure 4.5 Mealy bug.
Figure 4.6 Thrip.
Chapter 5: Cocoa bean composition and chocolate flavour development
Figure 5.1 Anatomy of the cocoa seed. Source: adapted from Lopez and Dimick (1995).
Figure 5.2 Fresh cocoa beans surrounded by white mucilaginous cocoa pulp.
Figure 5.3 Heap of fresh cocoa beans prior to fermentation. (
See plate section for color representation of this figure
.)
Figure 5.4 Heap of cocoa beans covered with banana leaves in fermentation. (
See plate section for color representation of this figure
.)
Figure 5.5 Changes in volatile acids, sugars and alcohol during fermentation of cocoa.
Figure 5.6 Changes in microbial activities during cocoa fermentation. Source: adapted from Schwan and Wheals (2004).
Figure 5.7 Drying of cocoa beans on raised platforms. (
See plate section for color representation of this figure
.)
Figure 5.8 Drying of cocoa beans on different types of raised platforms.
Figure 5.9 Drying of cocoa beans on mats on the ground and raised platforms.
Figure 5.10 Drying of cocoa beans using different drying systems (a) solar drier (b) mechanical drier system (c) mechanical drying platform.
Figure 5.11 Dried cocoa beans. (
See plate section for color representation of this figure
.)
Figure 5.12 Dried cocoa beans bagged in 64 kg packs.
Figure 5.13 Dried cocoa beans bagged in 1000 kg (1 tonne) packs.
Figure 5.14 Mechanism of cocoa flavour precursor formation and character from bean composition and post-harvest treatments.
Chapter 6: Cocoa processing technology
Figure 6.1 Fermented and dried cocoa beans.
Figure 6.2 Visual examination of bean quality from the bean cut tests.
Figure 6.3 Different colours of cocoa powder from the alkalization process. (
See plate section for color representation of this figure
.)
Figure 6.4 Flow diagram for the production of cocoa butter, cocoa cake and cocoa powder from fermented cocoa beans.
Figure 6.5 Flow diagram for the production of cocoa liquor, cocoa butter and cocoa powder showing detailed processes.
Chapter 7: Industrial chocolate manufacture – processes and factors influencing quality
Figure 7.1 The chocolate model.
Figure 7.2 Processing steps for chocolate manufacture.
a
Skimmed milk powder is only used in milk chocolate manufacture.
b
Panning means that the chocolate is used as coating for hard centres such as nuts. Source: adapted from Afoakwa
et al
. (2007).
Figure 7.3 Chocolate manufacturing process from cocoa to chocolate. (
See plate section for color representation of this figure
.)
Figure 7.4 Mixing of raw materials during chocolate manufacture.
Figure 7.5 Two- and five-roll refining processes.
Figure 7.6 Five-roll refiner.
Figure 7.7 Internal mechanics of Frisse conche.
Figure 7.8 The three different phases of the conching process. (
See plate section for color representation of this figure
.)
Figure 7.9 Molten chocolate. (
See plate section for color representation of this figure
.)
Figure 7.10 Polymorphic arrangements of crystalline fat. Source: adapted from Beckett (2008).
Figure 7.11 Tempering sequence during lipid crystallization of chocolates.
Figure 7.12 The Aasted temperer.
Figure 7.13 Depositing molten chocolate in a mould. (
See plate section for color representation of this figure
.)
Figure 7.14 Deposition and cooling plant in a chocolate manufacturing factory. (
See plate section for color representation of this figure
.)
Figure 7.15 Moulded chocolate. (
See plate section for color representation of this figure
.)
Figure 7.16 Chocolate pralines in different shapes and sizes.
Figure 7.17 Assorted brands of chocolates with different types of wrappers and packaging materials. (
See plate section for color representation of this figure
.)
Figure 7.18 Malvern particle size analyser. (
See plate section for color representation of this figure
.)
Figure 7.19 Illustration of the principle behind particle size distribution measurement by the laser diffraction technique.
Figure 7.20 Particle size distributions of different chocolate systems during manufacture depicting (a) 18, (b) 25, (c) 35 and (d) .
Figure 7.21 Molten chocolate for determination of rheological properties. (
See plate section for color representation of this figure
.)
Figure 7.22 Moulded chocolate balls. (
See plate section for color representation of this figure
.)
Figure 7.23 Fat bloom of (a) milk and (b) dark chocolates.
Chapter 8: The chemistry of flavour development during cocoa processing and chocolate manufacture
Figure 8.1 Model of Maillard reaction.
Figure 8.2 Mechanism of sugar–amine condensation to form a Schiff base.
Figure 8.3 Mechanism of the formation of a 1,2-enaminol from a Schiff base.
Figure 8.4 Formation of amino acid-specific aldehydes through the Strecker degradation reaction.
Figure 8.5 Mechanism of a Strecker degradation reaction.
Figure 8.6 Formation of pyrazines through the reaction of deoxy intermediates with amino acids.
Figure 8.7 Mechanism of chocolate flavour formation and development process.
Chapter 9: Alternative sweetening and bulking solutions in chocolate manufacture
Figure 9.1 Chemical structures of stevioside and related compounds.
Figure 9.2 Backbone structure of thaumatin I. The main body of the structure consists of two β sheets forming a flattened β barrel. The β strands in the top sheet are shaded light and those in the bottom sheet are darker. Open bars represent disulfide bonds and the regions with sequences homologous to monellin are indicated by the hatched marks. The viewing direction is along the crystallographic
c
-axis. Source: De Vos
et al.
(1985).
Figure 9.3 Chemical structure of maltitol.
Figure 9.4 Chemical structure of sucralose.
Figure 9.5 (a) acyclic
d
-tagatose and (b) β-
d
-tagatopyranose.
Figure 9.6 Chemical structure of trehalose.
Figure 9.7 Chemical structure of isomultulose.
Figure 9.8 Chemical structure of polydextrose. R = hydrogen, glucose, sorbitol, citric acid or polydextrose.
Figure 9.9 Chemical structure of inulin (
n
≈ 35).
Figure 9.10 Chemical structure of maltodextrin.
Chapter 10: Sensory character and flavour perception of chocolates
Figure 10.1 Main factors and influential processes affecting chocolate flavour.
Figure 10.2 Model of volatile flavour release and perception in chocolate.
Figure 10.3 Location of flavour receptors in the human head.
Figure 10.4 Typical time–intensity (TI) curve for sensory attributes.
Chapter 11: Nutritional and health benefits of cocoa and chocolate consumption
Figure 11.1 Chemical structures of the major cocoa flavanols (+)-catechin and (–)-epicatechin and procyanidins.
Figure 11.2 Packs of chocolates containing mixtures of the major types (dark, milk and white).
Figure 11.3 The role of cocoa polyphenols on the vascular system, with nitric oxide (NO) as target. eNOS = endothelial nitric oxide synthase.
Chapter 12: Processing effects on the rheological, textural and melting properties during chocolate manufacture
Figure 12.1 Typical rheology graphs illustrating measurement of (a) apparent viscosity and yield stress and (b) thixotropy from two dark chocolates containing (a) 50 µm particle size, 35% fat and 0.5% lecithin and (b) 50 µm particle size, 25% fat and 0.5% lecithin.
Figure 12.2 (a) Back-extrusion rig and (b) puncture test rig used for texture measurements of molten and solid chocolates, respectively.
Figure 12.3 Typical (a) back-extrusion curve and (b) penetration probe curve used for the measurement of molten and solid dark chocolates, respectively.
Figure 12.4 Particle size distribution of dark chocolate with
D
90
of (a) 18, (b) 25, (c) 35 µm, (d) 50 µm.
Figure 12.5 Effect of PSD and fat and lecithin contents on Casson plastic viscosity of dark chocolate.
Figure 12.6 Effect of PSD and fat and lecithin contents on Casson yield value of dark chocolate.
Figure 12.7 Effect of PSD and fat and lecithin contents on thixotropy of dark chocolate.
Figure 12.8 (a) Relationship between Casson plastic viscosity and apparent viscosity using bob-and-cup (reference) geometry. Data points (squares); linear regression (inner solid line); minimum and maximum tolerance intervals (outer two lines). Casson plastic viscosity = 0.477564 + 0.31802 × apparent viscosity. (b) Relationship between Casson yield value and yield stress using bob-and-cup (reference) geometry. Data points (squares); linear regression (inner solid line); minimum and maximum tolerance intervals (outer two lines). Casson yield value = –8.29934 + 0.458911 × yield stress. (c) Relationship between Casson yield value and Casson plastic viscosity using bob-and-cup (reference) geometry. Data points (squares); linear regression (inner solid line); minimum and maximum tolerance intervals (outer two lines). Casson yield value = –11.9953 + 18.4325 × Casson plastic viscosity. (d) Relationship between yield stress and apparent viscosity using bob-and-cup (reference) geometry. Data points (squares); linear regression (inner solid line minimum and maximum tolerance intervals (outer two lines). Yield stress = –14.4174 + 14.8302 × apparent viscosity. (e) Relationship between thixotropy from yield stress and thixotropy from apparent viscosity. Data points (squares); linear regression (inner solid line); minimum and maximum tolerance intervals (outer two lines). Thixotropy (YS) = 6.42097 + 1.1907 × thixotropy (AP). Source: Afoakwa
et al.
(2009a).
Figure 12.9 Principal component analysis showing the relationship between parameters within two rheological models (A) and their influencing factors (B). PC1 (74.2% variance) PC2 (13.7% variance). Source: Afoakwa
et al.
(2009a).
Figure 12.10 Effect of PSD and composition on firmness of molten dark chocolate.
Figure 12.11 Effect of PSD and composition on consistency of molten dark chocolate.
Figure 12.12 Effect of PSD and composition on cohesiveness of molten dark chocolate.
Figure 12.13 Effect of PSD and composition on index of viscosity of molten dark chocolate.
Figure 12.14 Effect of PSD and composition on hardness of tempered dark chocolate.
Figure 12.15 Principal component analysis of textural properties and appearance of dark chocolates (A) as affected by PSD (B) and composition (C).
Figure 12.16 Microstructure of dark chocolate containing 25% fat with particle size (
D
90
) of (a) 18, (b) 25, (c) 35 and (d) 50 µm. Source: Afoakwa
et al.
(2009a).
Figure 12.17 Microstructure of dark chocolate containing 35% fat with particle size (
D
90
) of (a) 18, (b) 25, (c) 35 and (d) 50 µm. Source: Afoakwa
et al.
(2009a).
Figure 12.18 Microstructure of dark chocolate containing 30% fat with particle size (
D
90
) of (a) 18, (b) 25, (c) 35 and (d) 50 µm. Source: Afoakwa
et al.
(2009a).
Figure 12.19 Illustration of DSC thermogram used to characterize the melting properties. Source: Afoakwa
et al.
(2009a).
Figure 12.20 Typical DSC thermograms for dark chocolate at constant fat and lecithin content and varying particle size: (a) 18, (b) 25, (c) 35 and (d) 50 µm. Source: Afoakwa
et al.
(2009a).
Figure 12.21 Typical DSC thermograms for dark chocolate at constant particle size and lecithin content with varying fat content: (a) 25, (b) 30 and (c) 35%. Source: Afoakwa
et al.
(2009a).
Figure 12.22 Typical DSC thermograms for dark chocolate at constant particle size and fat content with varying lecithin content: (a) 0.3 and (b) 0.5%. Source: Afoakwa
et al.
(2009a).
Figure 12.23 Relationship between yield stress and firmness in molten chocolate. Data points (squares); linear regression (inner solid line); 95% minimum and maximum tolerance intervals (outer two lines). Yield stress = 18.2498 + 0.683086 × firmness. Source: Afoakwa
et al.
(2008a).
Figure 12.24 Relationship between yield stress and index of viscosity in molten chocolate. Data points (squares); linear regression (inner solid line); 95% minimum and maximum tolerance intervals (outer two lines). Yield stress = 9.70711 + 0.13679 × index of viscosity. Source: Afoakwa
et al.
(2008a).
Figure 12.25 Relationship between yield stress and hardness in chocolate. Data points (squares); linear regression (inner solid line); 95% minimum and maximum tolerance intervals (outer two lines). Yield stress = –784.281 + 0.184538 × hardness. Source: Afoakwa
et al.
(2008a).
Figure 12.26 Relationship between apparent viscosity and firmness in molten chocolate. Data points (squares); linear regression (inner solid line); 95% minimum and maximum tolerance intervals (outer two lines). Apparent viscosity = 2.20313 + 0.0460588 × firmness. Source: Afoakwa
et al.
(2008a).
Figure 12.27 Relationship between apparent viscosity and index of viscosity in molten chocolate. Data points (squares); linear regression (inner solid line); 95% minimum and maximum tolerance intervals (outer two lines). Apparent viscosity = 1.5664 + 0.00927531 × index of viscosity. Source: Afoakwa
et al.
(2008a).
Figure 12.28 Relationship between apparent viscosity and hardness in chocolate. Data points (squares); linear regression (inner solid line); 95% minimum and maximum tolerance intervals (outer two lines). Apparent viscosity = –53.4812 + 0.0127469 × hardness. Source: Afoakwa
et al.
(2008a).
Figure 12.29 Relationship between yield stress and melting index in chocolate. Data points (squares); linear regression (inner solid line); 95% minimum and maximum tolerance intervals (outer two lines). Yield stress = –1620.41 + 246.64 × melting index. Source: Afoakwa
et al.
(2008a).
Figure 12.30 Relationship between apparent viscosity and melting index in chocolate. Data points (squares); linear regression (inner solid line); 95% minimum and maximum tolerance intervals (outer two lines). Apparent viscosity = –109.182 + 16.7535 × melting index. Source: Afoakwa
et al.
(2008a).
Figure 12.31 Relationship between firmness and melting index in chocolate. Data points (squares); linear regression (inner solid line); 95% minimum and maximum tolerance intervals (outer two lines). Firmness = –2371.11 + 357.237 × melting index. Source: Afoakwa
et al.
(2008a).
Figure 12.32 Relationship between index of viscosity and melting index in chocolate. Data points (squares); linear regression (inner solid line); 95% minimum and maximum tolerance intervals (outer two lines). Index of viscosity = –12263.5 + 1850.79 × melting index. Source: Afoakwa
et al.
(2008a).
Figure 12.33 Relationship between hardness and melting index in chocolate. Data points (squares); linear regression (inner solid line); 95% minimum and maximum tolerance intervals (outer two lines). Hardness = –4396.97 + 1318.07 × melting index. Source: Afoakwa
et al.
(2008a).
Figure 12.34 Principal component analysis of rheological, textural and melting properties of dark chocolates (A) as affected by PSD and fat and lecithin contents (B). Source: Afoakwa
et al.
(2008a).
Chapter 13: Tempering behaviour during chocolate manufacture: Effects of varying product matrices
Figure 13.1 Typical Aasted Mikroverk multistage tempering unit (temperers).
Figure 13.2 Chocolate precrystallization (cooling) curves showing how (a) optimally-tempered, (b) under-tempered and (c) over-tempered temper slopes were determined by the tempermeter.
Figure 13.3 Particle size distribution of dark chocolate with of (a) 18, (b) 25, (c) 35 and (d) .
Figure 13.4 Response plot showing chocolate temper slope for a sample of PS at 35% fat content.
Figure 13.5 Response plot showing chocolate temper slope for a sample of PS at 35% fat content.
Figure 13.6 Response plot showing chocolate temper slope for a sample of PS at 35% fat content.
Figure 13.7 Response plot showing chocolate temper slope for a sample of PS at 35% fat content.
Figure 13.8 Response plot showing chocolate temper slope for a sample of (a) PS at 35% fat content and (b) PS at 30% fat content.
Figure 13.9 Response plot showing chocolate temper slope for a sample of (a) PS at 35% fat content and (b) PS at 30% fat content.
Chapter 14: Tempering and fat crystallization effects on chocolate quality
Figure 14.1 Precrystallization (cooling) curves of different temper regimes from dark chocolate ( PS).
Figure 14.2 Effect of temper regime and PSD on hardness of dark chocolates.
Figure 14.3 Effect of temper regime and PSD on stickiness of dark chocolates.
Figure 14.4 Typical DSC thermograms of fat melting profile showing optimally tempered, over-tempered and under-tempered (bloomed) dark chocolates.
Figure 14.5 Typical DSC thermograms showing (A) fat and (B) sugar melting profiles of optimally tempered, over-tempered and under-tempered (bloomed) dark chocolates at PS.
Figure 14.6 Photographic images of (a) fresh and (b) matured (conditioned) optimally tempered, under-tempered and over-tempered dark chocolates ( PS).
Figure 14.7 Micrographs of surface (a) and internal (b) structures respectively of (1) optimally tempered, (2) under-tempered and (3) over-tempered dark chocolate ( PS).
Figure 14.8 Scanning electron micrographs showing crystalline network microstructures at magnifications of (i) ×800, (ii) ×1500 and (c) ×2500 for (a) optimally tempered, (b) over-tempered and (c) under-tempered (bloomed) dark chocolates at PS. C indicates some of the well-defined crystal structures, iC some of the ill-defined crystal structures and I some of the inter-crystal connections. The arrows indicate some of the pores, cracks and crevices, B some of solid bridges and L some of the large (crystal) lumps on the crystal structure. Source: Afoakwa
et al.
(2009a).
Chapter 15: Fat bloom formation and development in chocolates
Figure 15.1 Changes in hardness during blooming of dark chocolates.
Figure 15.2 Changes in surface whiteness during blooming of dark chocolates.
Figure 15.3 Changes in gloss during blooming of dark chocolates.
Figure 15.4 Scatter plots of (a) observed and predicted whiteness and (b) observed and predicted gloss with changes in hardness during blooming of dark chocolates.
Figure 15.5 Typical DSC thermograms showing changes in fat melting profile during blooming of dark chocolates with 25 µm PS.
Figure 15.6 Micrographs showing changes in surface appearance of dark chocolate with (i) 18, (ii) 25, (iii) and (iv) 50 µm PS after (a) on cooling (0 h), (b) 24 h, (c) 48 h, (d) 72 h and (e) 96 h in storage, showing liquid fat (lf), recrystallized fat (rcf) and cocoa solids (cs).
Figure 15.7 Micrographs showing changes in internal appearance of dark chocolate with 50 µm PS after (i) 0, (ii) 24, (iii) 48, (iv) 72 and (v) 96 h in storage, showing liquid fat (lf), recrystallized fat (rcf), growing recrystallized fat (grcf) and cocoa solids.
Chapter 16: Matrix effects on flavour volatiles character and release in chocolates
Figure 16.1 Typical GC–MS trace used to identify flavour volatiles.
Figure 16.2 PCA biplots of dark chocolate flavour volatiles as influenced by PSD and fat content.
Chapter 17: Process optimization and product quality characteristics during sugar-free chocolate manufacture
Figure 17.1 Estimated response surface plots showing effect of inulin (IN) and polydextrose (PD) concentrations on quality parameters: (a) Casson viscosity; (b) Casson yield stress; (c) ; (d) colour; (e) hardness; (f) moisture.
Figure 17.2 Typical flow curve for chocolate showing shear stress as a function of shear rate.
Figure 17.3 Effect of sugar substitute concentration on flow properties of chocolate.
Figure 17.4 Effect of sugar substitute concentration on PSD of chocolate. IN = inulin; PD = polydextrose.
Figure 17.5 Micrographs of molten chocolates obtained with Cell
D
imaging software. (a) Sucrose; (b) polydextrose; (c) inulin; (d) 25% inulin–75% polydextrose; (e) 75% inulin–25% polydextrose; (f) 50% inulin–50% polydextrose.
Figure 17.6 Contours of estimated response surface indicating the point where the optimum level was achieved. IN = inulin; PD = polydextrose.
Chapter 19: Application of ISO 22000 and hazard analysis and critical control points (HACCP) in chocolate processing
Figure 19.1 An example of decision tree to identify CCPs (answer questions in sequence).
Figure 19.2 Flow chart for processing of cocoa.
Figure 19.3 Flow chart for the processing of milk chocolate.
List of Tables
Chapter 1: History, origin and taxonomy of cocoa
Table 1.1 Characteristics of the different cocoa varieties
Table 1.2 Effects of origin, cocoa variety and fermentation duration on flavour character
Chapter 2: World cocoa production, processing and chocolate consumption pattern
Table 2.1 World cocoa production between 2005 and 2015 (thousand tonnes)
Table 2.2 Grindings of cocoa beans (thousand tonnes)
Table 2.3 World cocoa bean production, grindings and stocks
Chapter 5: Cocoa bean composition and chocolate flavour development
Table 5.1 Bean composition of unfermented West African (
Forastero
) cocoa
Table 5.2 Dominant odour-active volatiles in cocoa mass
Chapter 6: Cocoa processing technology
Table 6.1 Cocoa quality parameters and percentages of defective beans used to determine grade
Table 6.2 Melting point and chain packing of the polymorphic forms of cocoa butter
Chapter 7: Industrial chocolate manufacture – processes and factors influencing quality
Table 7.1 Major constituents of dark, milk and white chocolate
Table 7.2 Characteristics of dark, milk and white chocolate
Table 7.3 Particle size distribution of the dark chocolate
a
Chapter 8: The chemistry of flavour development during cocoa processing and chocolate manufacture
Table 8.1 Degradation products of amino acids found in cocoa products
Table 8.2 Flavour compounds identified in milk chocolates
Table 8.3 Flavour compounds identified in dark chocolates
Chapter 9: Alternative sweetening and bulking solutions in chocolate manufacture
Table 9.1 Characteristics of high-potency sweeteners
Table 9.2 Characteristics of polyols (sugar alcohols)'
Table 9.3 Health benefits and applications of tagatose
Table 9.4 Current and predicted applications of trehalose in food processing
Table 9.5 Common sources of inulin
Chapter 10: Sensory character and flavour perception of chocolates
Table 10.1 Sensory vocabulary of chocolates and their descriptions
Chapter 11: Nutritional and health benefits of cocoa and chocolate consumption
Table 11.1 Nutritive value of chocolate products
Chapter 12: Processing effects on the rheological, textural and melting properties during chocolate manufacture
Table 12.1 Recipes used for the formulation of the dark chocolate
Table 12.2 Particle size distributions of the dark chocolates
Table 12.3 ANOVA summary of
F
-ratios from particle size distribution
Table 12.4 ANOVA summary of
F
-ratios showing the rheological properties
Table 12.5 Effect of PSD and fat and lecithin contents on apparent viscosity and yield stress of dark chocolates
Table 12.6 Regression and correlation analyses between rheological parameters
Table 12.7 ANOVA summary of
F
-ratios of the textural properties
Table 12.8 Effects of particle size distribution and composition on colour measurements
Table 12.9 ANOVA summary of
F
-ratios of colour measurements
Table 12.10 Correlation between textural properties and colour measurements of dark chocolate
Table 12.11 Melting properties of dark chocolate from varying PSD and fat and lecithin contents
Table 12.12 ANOVA summary of
F
-ratios of the melting properties
Table 12.13 Regression and correlation analyses between dark chocolate rheological, textural and melting parameters
Chapter 13: Tempering behaviour during chocolate manufacture: Effects of varying product matrices
Table 13.1 Process variables and their levels used in the Central Composite RotaTable Design for
K
= 2
Table 13.2 Design matrix and variable combinations in experimental runs
Table 13.3 Design matrix, variable combinations temper slopes obtained from experimental runs for dark chocolates containing 35% fat with varying PSD
Table 13.4 Design matrix, variable combinations temper slopes obtained from experimental runs for dark chocolates varying in fat content (30 and 35%) and particle size (25 and 35 µm)
Table 13.5 Regression coefficients from second-order polynomials used for the response plots
Table 13.6 Satisfactory and unsatisfactory temper values and their temper regimes
Chapter 14: Tempering and fat crystallization effects on chocolate quality
Table 14.1 ANOVA summary of
F
-ratios of texture measurements
Table 14.2 Effects of temper regime and particle size on gloss and colour measurements
Table 14.3 ANOVA summary of
F
-ratios of colour and gloss measurements
Table 14.4 Effects of temper regime and particle size distribution on melting properties
Table 14.5 ANOVA summary of
F
-ratios of melting properties
Table 14.6 Thermal properties of fat and sugar components in dark chocolates from different temper regimes
Table 14.7 ANOVA summary of
F
-ratios of fat and sugar thermal properties
Chapter 15: Fat bloom formation and development in chocolates
Table 15.1 ANOVA summary of
F
-ratios of texture, whiteness, gloss and melting properties
Table 15.2 Changes in melting properties during storage
Chapter 16: Matrix effects on flavour volatiles character and release in chocolates
Table 16.1 Recipes used for the formulation of dark chocolates
Table 16.2 Key flavour volatiles identified in dark chocolate
Table 16.4 Abundant pyrazines in dark chocolates varying in PSD and fat content
a
Table 16.5 ANOVA summary showing
F
-ratios and regression coefficients of flavour compounds identified in dark chocolates with varying PSD and fat content
Table 16.3 Flavour volatiles in dark chocolates varying in PSD and fat content
a
Chapter 17: Process optimization and product quality characteristics during sugar-free chocolate manufacture
Table 17.1 Ingredients used in dark chocolate formulation
Table 17.2 Experimental design of two components in dark chocolate formulation
Table 17.3 Mean and standard deviation of quality parameters
Table 17.4 Regression models for quality parameters of dark chocolates
Table 17.5 Pearson's correlation matrix between dark chocolate properties: correlation (
p
-value)
Table 17.6 Predicted equations for the experimental data for dark chocolate formulations
Table 17.7 Combination of factors that achieved the overall optimum desirability
Table 17.8 Combination of factors that maximized the desirability function
Chapter 19: Application of ISO 22000 and hazard analysis and critical control points (HACCP) in chocolate processing
Table 19.1 Grade standards of cocoa
Table 19.2 Quantities of ingredients used for milk chocolate production per batch in the kneader
Table 19.3 Hazard analysis worksheet for semi-finished cocoa products
Table 19.4 Hazard analysis work sheet for milk chocolate production
Table 19.5 Identification of critical control points (CCPs) based on HACCP decision tree (Codex Alimentarius, 1999) for semi-finished products
Table 19.6 Identification of critical control points (CCP) based on HACCP decision tree (Codex Alimentarius, 1999) for milk chocolate production
Table 19.7 ISO 22000 analysis worksheet for the determination of prerequisite programmes for semi-finished cocoa products
Table 19.8 ISO 22000 analysis worksheet for the determination of prerequisite programmes for milk chocolate
Table 19.9 Comparative presentation of CCPs determined with HACCP and ISO 22000 analyses in conjunction with prerequisite programmes for cocoa processing
Table 19.10 Comparative presentation of CCPs determined with HACCP and ISO 22000 analysis in conjunction with prerequisite programmes for chocolate production
Chocolate Science and Technology
Emmanuel Ohene Afoakwa
University of Ghana, Legon - Accra, Ghana
Formerly of Nestlé Product Technology Centre, York, UK
Second Edition
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
This book is dedicated to my dear wife, Ellen, and our three lovely children, Nana Afra, Maame Agyeiwaa and Kwabena Ohene-Afoakwa (Jr), whose wisdom, prayers and support have helped me achieve great success in my life and professional career.
Preface
Since the publication of the first edition of this book in 2010, the chocolate confectionery industry has undergone dynamic changes due to the nature of the demand for chocolate. The trends have transformed towards the increasing appeal of premium chocolate, including organic, Fairtrade, single-origin, reduced-sugar, sugar-free, dark and high cocoa content chocolates. This has engendered not only new challenges but also opportunities for all participants in the sector. Until recently, the general perception was that consumption of chocolate in Europe and the United States was beginning to stagnate, as these major chocolate markets were reaching saturation. However, consumption behaviours across these mature markets have recently experienced major changes, also towards premium products. Indeed, the confectionery market has increasingly been characterized by consumer demand for quality, taste, convenience and health, and products addressing sustainability, traceability and ethical and environmental concerns.
New product developments and ‘functional foods’ with wholesome ingredients (foods that provide health benefits beyond basic nutrition) have played an important role in the upward trend of this emerging confectionery market. Many research activities have increasingly been conducted on the health and nutritional benefits of cocoa and chocolate. The findings indicate that flavanoids in cocoa may decrease low-density lipoprotein (LDL or ‘bad’ cholesterol) oxidation, helping to prevent cardiovascular diseases. In addition, cocoa's high content of antioxidants has been proven to reduce the risk of cancer. The demand for dark and high cocoa content chocolate in particular has surged in response to these positive findings.
The chocolate industry has demonstrated a strong ability to meet these challenges and to benefit from the new opportunities brought about through changing consumer demand. Companies traditionally known for milk chocolate products have been introducing new dark and high cocoa content varieties. The global market for dark chocolate is now estimated to represent about 13% of the total market for chocolate tablets (the others being plain milk, plain white and filled chocolate tablets), with a higher share in continental Europe than in the United States and the United Kingdom. Similarly, the certified organic and Fairtrade chocolate markets have been booming, increasing at double-digit percentage 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 the chocolate industry has responded proactively to this development, the need still exists for cocoa producers to have further information on the market trends to bolster their zest for increased production for the existing and emerging markets in the Far East such as Japan, China and India. Such information would provide cocoa-producing countries with a better basis for formulating and implementing policies and programmes regarding cocoa production. One of the main challenges facing producing countries, to enhance their revenues from cocoa, is to meet the changing face of consumer demand through improved breeding and farming techniques. As a result of the increasing chocolate consumption trends, the cocoa processing and chocolate manufacturing industry faces an enormous challenge in meeting the demand and quality criteria expected by the consuming populations. This has to be matched vigorously by increasing production capacities of the chocolate manufacturing industry, which also requires a detailed understanding of the science and technology of chocolates.
As chocolate manufacturing is complex and requires numerous technological operations and the addition of a range of ingredients to achieve products of suitable physical and chemical attributes, appearance and taste parameters with pre-specified ranges, understanding the science of its manufacture and the technological processes that can result in the expected product quality is paramount. Additionally, chocolate processing techniques differ as a result of historical development within a producing company and the geographical locations in which products are sold, and therefore require the necessary expertise to achieve the necessary quality attributes, rheological characteristics, flavour development and thus sensory perception that are needed to satisfy a particular consuming population. Explanations of the scientific and technological processes employed by the chocolate manufacturing industry today have been assisted by the scientific answers to many of the frequently asked questions on process improvements, quality control, quality assurance, product quality and safety management systems involved in the production of niche/premium products.
This second edition of Chocolate Science and Technology is therefore a combination of the conventional chocolate manufacturing processes and an overview of the innovative manufacturing processes being adopted by the industry for the manufacture of sugar-free, single-origin, reduced-sugar chocolates. It provides detailed information on the modern fundamental, scientific and technological knowledge and understanding of the processes involved in cocoa processing and chocolate manufacture to all who are engaged in the business of learning, making, consuming and using cocoa and chocolate products worldwide, especially confectioners, industrialists, food scientists, students and consumers.
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 I obtained the best education in spite of the numerous financial challenges that they faced in some periods of their lives. Their profound love, prayers, support and advice strengthened me from my childhood, giving birth to the many dreams and aspirations which have all become realities in my life today. I am also grateful to the Government of Ghana and to all cocoa farmers in Ghana whose toils and sweats were used to fund my education through the Ghana Cocoa Board Scholarship Scheme, which I earned throughout my secondary education, 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 Product Technology Centre (York, UK) for providing the funding and support for my training in chocolate technology at their Centre, and also to Dr Alistair Paterson, Centre for Food Quality, University of Strathclyde, Glasgow, UK, Mr Mark Fowler, former Head of Applied Science Department of Nestlé Product Technology Centre (York, UK) and Dr Steve Beckett (former Director of Communications, Nestlé Product Technology Centre, York, UK) for their support, encouragement, patience and friendliness during the period of my doctoral training in York. Many thanks also go to Dr Joselio Vieira, Dr Angela Ryan, Dr John Rasburn, Peter Cooke, Dr Philip Gonus, Angel Manéz, Jan Kuendigar, Dr Ramana Sundara and Sylvia Coquerel of Nestlé Product Technology Centre, York, UK, and to Dr Jeremy Hargreaves of Nestlé Head Office, Vevey, Switzerland, whose advice, guidance and support enhanced my understanding of the science and technology of chocolate.
My sincere thanks also go to the many friends and colleagues around the world who have mentored, encouraged and inspired me in various ways throughout my career, including Professor Samuel Sefa-Dedeh (formerly Dean, School of Engineering Sciences, University of Ghana), Professor George Sodah Ayernor, Professor Anna Lartey (Director of Nutrition, FAO Head Office, Rome, Italy), Professor Ebenezer Owusu (Provost, College of Basic and Applied Sciences, [Vice Chancellor Elect], University of Ghana), Professor Matilda Steiner-Asiedu (Dean, School of Biological Sciences, University of Ghana), Professor Esther Sakyi-Dawson (Acting Director, Academic Quality Assurance Unit, University of Ghana), Professor Kwaku Tano-Debrah, Professor Agnes Simpson Budu, Professor Firibu Kwesi Saalia, Dr William Bruce Owusu, Dr George Annor, Dr Maame Yaakwa Blay, Dr Angela Parry-Hanson Kunadu, Dr Agartha Ohemeng, Dr Esi Colekraft, Dr Seth Adu-Afarwuah, Dr Gloria Ethel Otoo 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 Knowledge Systems, 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 George Ekow Hayford, Quality Assurance and Regulatory Affairs Manager for Nestlé Central West African Region; Dr Gene White, Dr Janey Thornton, Mrs Barbara Belmont, Ms Penny McConnell, Mr Paul Alberghine and Mrs Mary Owens of the Global Child Nutrition Foundation, Washington, DC, USA.
I am indebted to my research collaborators in Belgium, including Professor Koen 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 chapters relating to sugar-free chocolates during the doctoral studies of Dr Roger Philip Aidoo at Ghent University, Ghent, Belgium.
My gratitude also goes to my master's students, Farida Adam, Nana Serwaa Boateng, Albert Gattor, Gideon Dendzo, Lauretta, Esi, Doreen and Louisa Ofosuah Obimpeh, and also to my doctoral students, John Edem Kongor, Michael Hinneh and Bobby Antan Caiquo, for their interest in cocoa processing and chocolate technology.
Finally, my profound appreciation and love go to my siblings Sammy, Juliana and Regina for their prayers and support throughout my education, and again to my dear wife, Ellen, and our lovely children Nana Afra, Maame Agyeiwaa and Kwabena Ohene-Afoakwa (Jr) for supporting me and most importantly providing the much needed love, encouragement and affection that have strengthened me throughout my career. We all have very good memories of the beautiful cities of London, York and Glasgow, the Nestlé Rowntree factory and the Nestlé Product Technology Centre in York, UK.
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 food science from the University of Ghana, Legon, Accra, Ghana. He also holds Certificates in International Food Laws and Regulations from the Michigan State University, East Lansing, MI, USA, and Food Quality Management Systems from the International Agricultural Centre of Wageningen University, Wageningen, The Netherlands. He is also a trained and a Licensed Food Auditor by the World Food Safety Organization, UK.
Dr Afoakwa has vast relevant experience in food science and technology and international food laws and regulations. He is a member of several professional bodies, including the Institute of Food Technologists (IFT), the Food Science and Nutrition Network for Africa (FOSNNA), the Information Technology for the Advancement of Nutrition in Africa (ITANA) society, the African Network for School Feeding Programmes (ANSFEP), the Ghana Institute of Food Science and Technology (GIFoST) and the Ghana Science Association (GSA). He has authored and co-authored 180 publications (including 86 peer-reviewed journal publications, 4 books, 4 book chapters, 2 encyclopaedia chapters and 84 conference presentations with published abstracts) in food science and technology. In the pursuance of his duties as a food technologist, he has travelled to 38 different countries around the world, where he has gained high international recognition of his work.
He is a Member of the International Expert Group and Head of the Ghana delegation working with the European Commission and ISO in setting international 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 Feeding Programmes, the Secretary to the Ghana Institute of Food Science and Technology (GIFoST) and the Scientific Secretary to the Information Technology for the Advancement 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 the Editorial Boards of several international journals and as a technical reviewer for more than 20 international peer-reviewed journals around the world. Further, he is a technical advisor to the International Foundation for Science (IFS) within the area of food science and nutrition, and also a trainer in scientific writing and grant proposal development for the African Women in Agricultural Research and Development (AWARD). He has wide experience in food technology and nutrition, and translates his research findings through process and product development into industrial production towards the achievement of the UN Millennium Development Goals (MDGs), mainly on food and nutrition security and sustainable agricultural development.
Dr Afoakwa is a research scientist and international expert in cocoa production and processing and chocolate technology. He has contributed extensively to many international journals, books, book chapters and encyclopaedias in the area of cocoa and chocolate technology, and has given numerous presentations at both national and international conferences across the globe.
Chapter 1History, origin and taxonomy of cocoa
1.1 Introduction
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 is indigenous 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 backbone of the economies of some countries in West Africa, South America and South-East Asia. It is the leading foreign exchange earner and a great source of income 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 million farmers and their families depend on it for their livelihood (Afoakwa, 2014).
Currently, in 2016, cocoa is cultivated on an estimated land size of 8 million hectares in the tropics and secures the livelihoods of about 50 million people globally. More than 8 million of them are mainly smallholder farmers with an average 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-growing region. Such families frequently live exclusively on cocoa farming and processing and are thus dependent mainly on cocoa for their livelihoods. Hence the economic importance of cocoa cannot be over-emphasized and the current global market 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 many producing countries, particularly in Africa, Latin America and South-East Asia. Africa's heavy dependence on cocoa and also on other primary commodities as a source of export earnings has been vulnerable to market developments, in particular price volatility and weather conditions. However, in some circumstances, real exchange rates, domestic marketing arrangements and government intervention have acted to buffer price movements for cocoa producers. Cocoa was the second source of export earnings in Ghana in 2014, after gold, generating US$2.0 billion.
