Chocolate is one of the world’s most beloved treats, a luxury, cherished for its rich taste and aroma, astringency but smooth texture. There are numerous and intricate processes involved in the production of chocolate and each one deserves special attention. Much of the quality depends on the type of cocoa used and then on the management of the process of manufacture. Chocolate is in fact a semi-solid suspension of fine solid particles of cocoa, sugar and milk solids. These are all suspended in a continuous phase of cocoa butter. Much of this article is based on knowledge that can be readily digested: Stephen T. Beckett has written extensively on the science of chocolate for The Royal Society of Chemistry and it is worth consulting.
I can’t think why anyone would not like chocolate but it now has health benefits – indeed it really is a “superfood”. Linnaeus certainly understood its power when he called in Theobroma cacao which means the ‘food of the gods’.
History Behind The Development Of Chocolate
We know that the Aztecs in Mexico grew and cultivated cacao trees for the production of the highly prized beans. They were not only a form of currency for the Aztecs but produced a spicy drink which they called ‘chocolatl‘. The great Aztec emperor Montezeuma is said to have quaffed up to 50 pitchers of chocolate beverage which he believed gave him aphrodisiac properties. The belief persisted in Europe when Columbus first introduced the cocoa bean to Europe and made the beverage popular in coffee and drinking houses. In the early days, chocolate was prepared by roasting the cocoa beans in clay pots, then ground between mill stones. Cold water was added to this unguent powder along with honey and spices and beaten to a frothy consistency. From that day we have enjoyed the benefits of chocolate but almost too much.
For many of us, the idea of eating chocolate sounds more like a guilt trip – all that sugar, and milk, and calories but it does contain some interesting components which make it an interesting proposition. Having studied the comments from readers of newspaper articles on how chocolate is good for you, there is still plenty of mistrust out there. I’m always surprised by the paranoia of those who fear the military-industrial-pharma complex but surely chocolate isn’t part of that package.
The difficulty for most of us is principally the fact that we over indulge on chocolate. It must make us fat, it’s associated with alleviating depression and definitely a guilty pleasure. If we call it a superfood, we are discussing products which are generally classed as high in antioxidants which are compounds that prevent oxidisation and stop our healthy cells being damaged by free radicals.
The Varieties of Cocoa Beans
Cocoa beans, the primary ingredient in chocolate, come in several varieties, each with distinct characteristics that influence the flavour and quality of the chocolate produced. The three main varieties of cocoa beans are Criollo, Forastero, and Trinitario.
1. Criollo
Characteristics
- Flavour Profile: Criollo beans are known for their complex and delicate flavors, often described as fruity, nutty, and floral with low bitterness and acidity.
- Rarity: Criollo beans are rare, making up only about 5% of the world’s cocoa production.
- Geographical Origin: Originally grown in Central America and northern South America, with notable production in Venezuela, Madagascar, and Indonesia.
- Yield and Resistance: Criollo trees are less resistant to diseases and pests and have lower yields compared to other varieties.
2. Forastero
Characteristics
- Flavour Profile: Forastero beans tend to have a more robust and straightforward chocolate flavor, often with higher bitterness and acidity. They are less complex than Criollo.
- Prevalence: They make up the majority of the world’s cocoa production, around 80-90%.
- Geographical Origin: Originated in the Amazon Basin and are now widely cultivated in West Africa, Brazil, and Southeast Asia.
- Yield and Resistance: Forastero trees are hardier, more disease-resistant, and produce higher yields than Criollo trees.
3. Trinitario
Characteristics
- Flavour Profile: Trinitario beans combine the best qualities of Criollo and Forastero, offering a balance of flavor complexity and robustness. They typically have a pleasant aroma and moderate bitterness.
- Prevalence: They account for about 10-15% of global cocoa production.
- Geographical Origin: Trinitario beans originated in Trinidad as a natural hybrid of Criollo and Forastero beans and are now grown in various regions including the Caribbean, South America, and Asia.
- Yield and Resistance: Trinitario trees are more resistant to diseases than Criollo and have better yields, similar to Forastero.
Other Considerations
1. Flavour Influences
- The flavour of cocoa beans is not only determined by the variety but also by factors such as soil, climate, and post-harvest processing (fermentation, drying, roasting).
2. Hybrid Varieties
- There are many hybrids of these main varieties developed to improve resistance, yield, and flavour. For example, CCN-51 is a high-yield hybrid that is particularly disease-resistant.
3. Single-Origin Cocoa
- Some chocolate makers emphasize single-origin cocoa, which comes from a specific geographic region, allowing the unique flavours of that region’s beans to shine.
Understanding these basic varieties helps chocolate makers and enthusiasts appreciate the diversity and complexity of flavours that can be found in different types of chocolate.
The Quality Of Cocoa
The quality of cocoa beans needed for the manufacture of chocolate depend on a host of factors:-
- farm practices (Clapperton et al., 1994),
- cultivars,
- cocoa tree genotypes,
- fermentation processes (Senanayake et al., 1996),
- roasting and drying processes (Suazo et al., 2014).
One of the key factors is the fat content in the chocolate because it determines the viscosity of the melted chocolate and the way it melts in the mouth in particular. Pulsed NMR is the method now used to measure both total and solid fat contents in chocolate so as to understand its performance in manufacturing, the product and its sensory appeal.
The International Office of Cocoa, Chocolate and Sugar Confectionery (OICCC) upholds the standards for chocolate. It started in 2022 following a merger of two organizations. The organization uses ISO standards of analysis.
The Fermentation of Cocoa Beans
The journey from cocoa bean to delectable chocolate involves several intricate processes, with fermentation being a pivotal initial step. Cocoa fermentation not only contributes to the development of chocolate’s flavor and aroma but also influences its texture and overall quality. In this part of the article, we’ll explore the fascinating world of cocoa fermentation, unraveling its significance and the techniques involved in this crucial stage of chocolate production.
The Importance of Cocoa Fermentation
Cocoa fermentation marks the beginning of chocolate’s transformation from a bitter seed to a flavourful delight. Without fermentation no characteristic flavour or aroma ever develops when cacao beans are roasted! (Lopez, 1994). It is during this stage that the raw cocoa beans finally die but with this comes key biochemical changes, unlocking a myriad of complex flavors and aromas while reducing bitterness and astringency. Additionally, fermentation initiates the breakdown of cocoa bean proteins and carbohydrates, rendering them more accessible during subsequent processing stages.
Fermentation also plays a vital role in cocoa bean sanitation and preservation. The rise in temperature and acidity during fermentation creates an environment hostile to pathogens, thereby reducing the risk of spoilage and ensuring the safety of the cocoa beans.
Fermentation usually takes between 4 and 6 days; this is the optimum length of time for the production of flavour precursors (Giacometti et al., 2015). This optimum depends on a well managed process which also depends on good practice in agronomy, farming and harvesting too. Some fermentations however can be over in 2 days or last until 10 days are up but that depends on individual farmers (Schwan & Wheals, 2004).
Process of Cocoa Fermentation
Cocoa fermentation typically occurs on cocoa plantations soon after harvesting. The process begins with the removal of cocoa pods from the trees, followed by the extraction of cocoa beans from the pods’ pulp. The beans, still encased in their mucilaginous pulp, are then transferred to fermentation bins or heaps, where microbial activity drives the fermentation process.
Microorganisms naturally present on the cocoa beans and within the fermentation environment, primarily yeasts and lactic acid bacteria, initiate fermentation by metabolizing sugars in the cocoa pulp. As a result, the temperature within the fermentation mass rises, reaching levels conducive to enzymatic reactions and microbial proliferation.
Over the course of several days, the cocoa beans undergo a series of biochemical transformations. Acetic and lactic acids accumulate, contributing to the acidity of the fermentation mass. This increase in acidity, combined with microbial activity, leads to the breakdown of complex compounds within the cocoa beans, including tannins and polyphenols responsible for bitterness.
During fermentation, the beans undergo color changes, transitioning from the vibrant white of freshly harvested beans to a rich brown hue. This visual indicator, along with sensory cues such as aroma and taste, guides farmers in determining the optimal duration of fermentation.
The first 2 to 3 days of fermentation involve a succession of micro-organisms. These include filamentous fungi, yeasts, lactic acid bacteria and acetic acid bacteria. The main species are Penicillium citrinum, Kloeckera apis, Saccharomyces cerevisiae, Candida tropicalis, Lactobacillus cellobiosus, Lactobacillus plantarum and Acetobacter pasteurianus. Unidentified micro-organisms still remain to be identified and undoubtedly have an impact on flavour. The later stages of fermentation were dominated by the presence of Bacillus species, mostly, Bacillus pumilus and Bacillus licheniformis (Ardhana & Fleet, 2003).
Yeasts are the main fermentors. To them, cocoa is a source of sugars such as sucrose, glucose and fructose, lipids and proteins. They also consume citric acid which raises the pH of the chocolate produced and in the process generate small amounts of ethanol. To help them access this rich resource, they release pectinolytic enzymes to help them break down the cell walls that then release their nutritious contents.
Variations in Fermentation Techniques
Cocoa fermentation is a nuanced process, influenced by factors such as climate, bean variety, and fermentation method. While traditional heap fermentation remains prevalent in many cocoa-producing regions, other techniques, such as box fermentation and tray fermentation, offer greater control over environmental variables such as temperature and aeration.
In box fermentation, cocoa beans are placed in wooden or plastic boxes, facilitating uniform fermentation and ease of turning. This method is favored in regions where rainfall or humidity poses challenges to traditional heap fermentation. It is a common method in the Carribean for example.
Tray fermentation involves spreading cocoa beans on elevated trays, allowing for better air circulation and temperature regulation. This technique is particularly suited to small-scale producers or specialty cocoa varieties, where meticulous attention to fermentation parameters is essential for flavor development.
Impact on Chocolate Quality
The quality of cocoa fermentation directly influences the sensory characteristics of the resulting chocolate. Well-fermented cocoa beans exhibit a balanced flavor profile, characterized by notes of fruitiness, floral undertones, and subtle acidity. Conversely, under-fermented or improperly fermented beans may retain undesirable flavors, such as bitterness or astringency, detracting from the chocolate’s overall appeal.
Furthermore, the fermentation process contributes to chocolate’s texture and mouthfeel. Proper fermentation promotes the breakdown of cocoa bean proteins and carbohydrates, resulting in smoother, more velvety chocolate with enhanced melt-in-your-mouth properties.
Thus, cocoa fermentation serves as a foundational step in chocolate production, shaping the flavor, aroma, and quality of the final product. Its role in promoting flavor development, reducing bitterness, and enhancing texture underscores its significance in the chocolate-making process. As consumers increasingly seek premium chocolates with distinctive flavor profiles, the art and science of cocoa fermentation continue to play a pivotal role in satisfying their discerning palates and elevating the chocolate experience.
The Art and Science of Roasting Cocoa Beans – Transforming Those Bitter Seeds into Blissful Chocolate
Roasting is a critical stage in the journey from raw cocoa beans to delectable chocolate. This process not only imparts distinctive flavors and aromas but also enhances the texture and color of cocoa beans. The roasting process is as important to chocolate manufacture as it is to roasting coffee beans. In this part of the article, we delve into the multifaceted world of cocoa bean roasting, unraveling its significance, techniques, and impact on chocolate production.
The Importance of Cocoa Bean Roasting
Roasting is a transformative step that unlocks the full potential of cocoa beans, turning them from bitter seeds into the flavorful essence of chocolate. Through controlled exposure to heat, cocoa beans undergo a series of biochemical reactions that intensify their aroma and flavor while reducing bitterness and astringency. Additionally, roasting promotes the Maillard reaction—a complex chemical process responsible for the development of desirable flavor compounds and characteristic brown color.
Beyond flavor enhancement, roasting also plays a crucial role in sterilizing cocoa beans, ensuring food safety by eliminating harmful pathogens and microbes. This sanitation step is essential for preserving the integrity of the cocoa beans and safeguarding the quality of the final chocolate product.
Process of Cocoa Bean Roasting
Cocoa bean roasting typically occurs after fermentation and drying, preparing the beans for further processing. The process begins with the preheating of roasting equipment, which may vary from traditional rotary drum roasters to modern fluidized bed roasters, each offering distinct advantages in terms of heat transfer efficiency and control.
Once preheated, the cocoa beans are loaded into the roasting chamber, where they undergo thermal treatment at temperatures ranging from 120°C to 150°C (248°F to 302°F). The duration of roasting varies depending on factors such as bean variety, desired flavor profile, and equipment specifications.
During roasting, several key reactions occur within the cocoa beans, contributing to flavor development and color transformation. The Maillard reaction, facilitated by the interaction between amino acids and reducing sugars, leads to the formation of a wide array of flavor compounds, including caramel, nutty, and fruity notes. Concurrently, the breakdown of precursor molecules such as polyphenols and proteins results in the reduction of bitterness and astringency.
As roasting progresses, skilled chocolatiers monitor critical parameters such as bean temperature, airflow, and roast profile to achieve the desired flavor intensity and depth. This careful control ensures consistency and quality in the roasted cocoa beans, laying the foundation for exceptional chocolate production.
Variations in Roasting Techniques
Roasting techniques may vary across regions, with chocolatiers employing distinct methods to achieve specific flavor profiles and sensory characteristics. In traditional roasting, cocoa beans are roasted in large drums or on heated surfaces, with periodic agitation to ensure uniform heat distribution. This method, prevalent in artisanal chocolate production, allows for greater control over roasting parameters and encourages the development of nuanced flavors.
In contrast, modern roasting technologies offer enhanced precision and efficiency, catering to the needs of large-scale chocolate manufacturers. Fluidized bed roasters, for instance, utilize hot air circulation to roast cocoa beans evenly, reducing processing time and energy consumption while maintaining flavor integrity.
Furthermore, chocolatiers may experiment with roast levels, ranging from light to dark, to achieve varying degrees of flavor complexity and intensity. Light roasts preserve delicate flavor notes and floral aromas, while dark roasts impart deeper, more robust flavors with hints of bitterness and roasted undertones.
Impact on Chocolate Quality
The quality of cocoa bean roasting profoundly influences the sensory attributes of the final chocolate product. Well-roasted cocoa beans contribute to a harmonious flavor profile, characterized by a balance of sweetness, acidity, and bitterness. The Maillard reaction and caramelization impart depth and complexity to the chocolate’s flavor, while the reduction of undesirable compounds enhances its palatability.
Furthermore, roasting influences the texture and mouthfeel of chocolate, as properly roasted beans yield smoother, creamier chocolate with a rich, velvety consistency. The controlled application of heat during roasting promotes the release of cocoa butter, contributing to the luscious mouthfeel and melt-in-your-mouth sensation synonymous with high-quality chocolate.
Cocoa bean roasting represents a pivotal stage in chocolate production, where bitter seeds are transformed into the sublime essence of chocolate. Its role in flavor enhancement, color development, and texture refinement underscores its significance in shaping the sensory attributes of chocolate. As chocolatiers continue to refine their craft and explore innovative roasting techniques, the art and science of cocoa bean roasting remain integral to the creation of exceptional chocolate experiences, delighting palates around the world.
Cocoa Nibs
Before cocoa is turned into chocolate, a portion of the roasted cocoa is used for a particular ingredient – the cocoa nib. Cocoa nibs are small pieces of crushed cocoa beans, typically obtained by removing the outer shell of roasted cocoa beans. They have a crunchy texture and a rich, intense chocolate flavor with hints of bitterness. Cocoa nibs are a versatile ingredient used in various culinary applications, including baking, cooking, and chocolate-making. They are prized for their nutritional benefits, being rich in antioxidants, fiber, and essential minerals such as magnesium and iron. Cocoa nibs are often sprinkled on desserts, added to granola or trail mix, or incorporated into chocolate bars and confections to add texture and depth of flavor.
Conching
Behind its indulgent flavor lies a meticulous process, with conching being a crucial step. Conching is not only essential for refining the texture but also for enhancing the flavor profile of chocolate (Augusto et al., 2022). We’ll delve here into the intricacies of the conching process, exploring its history, mechanics, and significance in chocolate production (Toker et al., 2019).
The history of conching comes from the late 1800s. The conching process was pioneered by Rodolphe Lindt, revolutionizing chocolate production. Prior to conching, chocolate had a gritty texture and lacked the smoothness we associate with modern chocolate bars. Lindt’s innovation involved a refining process where chocolate was continuously agitated and aerated in a conche—a vessel named after its shell-like appearance.
Mechanics of Conching
Conching involves a combination of heat, motion, and airflow to transform raw ingredients into velvety-smooth chocolate. The conche itself typically consists of a large basin with rotating blades or rollers. As the blades move, they knead and grind the chocolate mixture, reducing particle size and distributing cocoa butter evenly throughout the blend.
Temperature control is critical during conching. The process typically begins at higher temperatures, allowing the cocoa butter to melt and blend seamlessly with other ingredients. As conching progresses, the temperature gradually decreases, promoting crystallization and ensuring the desired texture and mouthfeel.
Duration also plays a significant role in conching. While modern conching machines can expedite the process, traditional methods often required several days of continuous agitation. During this time, flavors develop, volatile compounds evaporate, and the chocolate’s viscosity and texture evolve.
Effects on Flavor and Texture
Conching is instrumental in developing chocolate’s flavor profile. Through prolonged agitation and aeration, undesirable flavors, such as bitterness and acidity, are subdued, while desirable notes, such as richness and depth, are accentuated. This flavour enhancement is achieved through the release of volatile compounds and the oxidation of flavor precursors present in cocoa beans.
Furthermore, conching contributes to chocolate’s texture, imparting a silky-smooth consistency. The mechanical action of the conche breaks down cocoa particles, resulting in a finer, more homogeneous mixture. This refinement process eliminates grittiness and creates a melt-in-your-mouth sensation characteristic of high-quality chocolate.
Types of Conching
Over the years, various conching techniques have emerged, each with its unique characteristics and applications. Batch conching, the traditional method, involves processing chocolate in discrete batches over an extended period. Continuous conching, on the other hand, utilizes continuous-flow systems, allowing for greater efficiency and consistency in large-scale production.
Additionally, manufacturers may employ different conching durations and intensities to achieve specific flavor profiles. Light conching preserves delicate flavors and aromas, while heavy conching yields a more robust and pronounced chocolate taste. These variations underscore the versatility of the conching process in tailoring chocolate to diverse preferences.
The Cost of Conching
Of all the processes involved in chocolate making, conching is one of the costliest because of the high temperatures and long processing times. .
Significance in Chocolate Production
Conching is integral to chocolate production, influencing both quality and consumer appeal. The effect of conching has been directly related to the bahviour of chocolate in the mouth and its general sensory perception. A well-conched chocolate exhibits superior flavor complexity, smoother texture, and prolonged shelf life due to reduced moisture content and enhanced stability. Consequently, conching has become a hallmark of premium chocolate brands, symbolizing craftsmanship and attention to detail.
Moreover, the conching process aligns with consumer expectations for indulgent and satisfying chocolate experiences. Whether enjoyed on its own or as an ingredient in confections and desserts, properly conched chocolate offers a luxurious sensory experience that captivates the palate.
Conching represents a cornerstone of chocolate making, refining raw ingredients into the delectable treats enjoyed worldwide. Its historical significance, mechanical intricacies, and profound impact on flavor and texture underscore its indispensable role in chocolate production. As consumers continue to demand higher-quality chocolates, the art and science of conching will remain essential in meeting these expectations and elevating the chocolate experience to new heights.
Tempering of Chocolate
One of the most important unit operations in producing finished chocolates is tempering. It is the process and technique of controlled precrystallization of fat. It is used to induce the most stable form of cocoa butter which is the polymorphic fat in finished chocolate and one of the key factors in the taste texture of this product.
The process relies on shearing chocolate mass at a controlled temperature to encourage and promote crystallization of triacylglycerols (TAGs) in cocoa butter. This means a number of benefits from a processing perspective such as to effect good setting characteristics, foam stability, demoulding properties, product snap, contraction, gloss and shelf-life characteristics. Time–temperature protocols and shearing are employed to induce nucleation of stable polymorphs with the formation of three-dimensional crystal network structure influencing the microstructure, mechanical properties and appearance of products.
Types of chocolate
Chocolate, to remind ourselves, is a suspension of sugar and cocoa solids and in milk chocolate, milk powder particles. These are all reduced in size by roll refining to <40 μm, in a liquid matrix of mainly cocoa butter.
- Plain Chocolate – a dark or plain chocolate mass can contain 34 g total fat and 0.1 g moisture per 100 g chocolate.
- Milk Chocolate – a confection of cocoa, sugar, milk, emulsifiers such as lecithin. An average milk chocolate contains 12 g cocoa mass, 19 g whole milk powder, 48.5 g sugar and, additionally, 20 g added cocoa butter per 100 g chocolate (Cook, 1984; Schantz & Rohm, 2005; Becket, 2009b). The total solid content of this type of chocolate varies between 65% and 75% but is subject to consumer desire. The remainder will be about 20% milk powder content (Lucisano et al., 2006; Afoakwa et al., 2008). On this basis it can contain about 31 g total fat and have 0.37g moisture per 100g chocolate mass.
The Use of Emulsifiers
Emulsifiers have long been employed in liquid or melted chocolate. These surface-active ingredients lower the interfacial tension between the dispersed and the continuous phase because of their particular molecular structures. Not only do they affect rheology, they alter the sensitivity to moisture, tempering behaviour and melting temperature.
The role of emulsifiers in solid chocolate is reduce fat bloom, to minimise fat migration from fillings so that stability is maintained and then to reduce oxidation.
The most oft used emulsifier is still soy lecithin. It is added to concentration of between 3 and 6 g/kg. They can be used to reduce the addition of cocoa butter. The addition of 1 to 3 g/kg can reduce the viscosity of liquid chocolate to the same level as adding 10 times that amount of cocoa butter. This means there are potential cost savings by reducing cocoa butter.
Other emulsifiers that affect rheology specifically in chocolate are phosphoglycerides fractionated from natural soy lecithin, ammonium salts of phosphatide acids (YN), and polyglycerol polyricinoleate (PGPR).
YN is sometimes called synthetic lecithin but has a more consistent composition and is more efficient than natural lecithin. PGPR, which is prepared by partial esterification of condensed castor oil fatty acids with polyglycerol.
The addition of PGPR on its own decreases the yield stress far more effectively than soy lecithin addition but the viscosity is only slightly lowered (Rousset et al., 2002).
Blends of soy lecithin with PGPR have been explored by Schantz and Rohm (2005) in a total concentration up to 14g/kg to understand their effect on the flow behaviour of liquid chocolate. It appears that the yield stress of both dark and milk chocolate mass is most efficiently reduced by applying mixtures of approximately 30% lecithin and 70% PGPR. This is independent of the total amount of emulsifier.
Other findings: Total emulsifier concentrations of between 4 and 6g/kg are effective. The lowest viscosity values are the lecithin-PGPR blends are between 1:1 and 3:1 for dark and milk chocolate respectively. The findings show that the yield stress and viscosity can be manipulated for melted or liquid chocolate by adjusting both blending ration and emulsifier quantity. It is more than likely that other formulation details are held in commercial research collections.
The Flavour And Aroma of Chocolate
The study of chocolate, particularly its flavour and aroma have long been of interest to scientists and product developers because it is such a desirable food. Originally much of it centered on the essential oil. In a report by Bainbridge and Davies on essential oil, they reported on Dr. J. Sack in 1908 based at the Government Agricultural Laboratory in Surinam, who steam distilled ground fermented cocoa beans. About 1mL of essential oil was extracted from 20kg of beans and has the flavour and aroma of cacao.
Fermentation leads to the production of precursors of flavour. These include free amino acids, short-chain peptides, and
reducing sugars. Their reactions have long been investigated in other products so what they form is well known and understood but their concentration, type etc. all contribute to cacao flavour in its entirety. Fermentation generates organic acids, alcohols and aldehydes which are unique (Gill et al., 1984).
The list of compounds and studies investigating them is long. Dietrich et al., (1964) conducted solvent extractions of roasted cacao beans and found 43 compounds plus 29 additional compounds. One odourant of note is 4-Hydroxy-2,5-dimethyl-3(2H)-furanone which is found in other foods such as meat and coffee besides cacao Ziegleder (1991).
Strecker aldehydes include aldehyde derived from alanine.
The bitter compounds tend to form in roasted cacao. These are generally diketopiperazines which interact with theobromine (Pickenhagen et al., 1975).
Chocolate flavour is developed by yeasts during fermentation. Yeasts produce esters such as ethyl acetate, isoamyl acetate, propyl acetate and phenylethyl acetate, and some higher alcohols such as 3‐methyl‐1‐butanol, 2,3‐butanediol, 2‐methyl‐1‐propanol and furfuryl alcohol (Camu et al., 2007, 2008).
Flavour development doesn’t just end with fermentation it continues with roasting and other process activities.
Chocolate aroma is found in the volatile fraction. Over 500 compounds are identified. The complexity of the aroma is highly dependent on the compound composition which is extremely complex. A variety of polar and non-polar compounds are involved. Their concentrations are highly variable and the belong to a large range of chemical groups. The main types are the hydrocarbons, alcohols, ketones, aldehydes, furanones, acids, esters and pyrazines. The roasting of chocolate produces the aldehydes and pyrazines through various Maillard reactions.
The interesting feature is in the actual componentry – the polyphenols and especially the flavonols. Very dark chocolate contains a number of antioxidants and a major group are these rather dull sounding but incredibly interesting compounds. Read the research papers in the journals and you can see that chocolate will compete with fruit for polyphenol goodness.
The Chocolate Matrix
Chocolate is a semi-solid suspension of fine solid particles of sugar, cocoa and possibly milk solids in a continuous phase of cocoa butter.
The issue is in the manufacture of chocolate especially where heating is concerned. Any health benefits are severely compromised by destruction of those ‘good’ components which contribute to health. Interestingly, research at the Hershey Center for Health & Nutrition earlier this year compared the health componentry in single servings of dark chocolate, cocoa, hot chocolate mix, and fruit juices including acai berries, cranberries and pomegranates. The intention was to determine just how much antioxidant potential was present in each sample. It appears cocoa and dark chocolate have more antioxidant activity on a weight basis than any of these fruits. These are often attributed with high antioxidant levels.
The lead research author Dr Debra Millar has reported the findings and is quoted as stating chocolate is really a ‘superfruit’, which may seem odd.
“Cacao seeds should be considered a ‘super fruit’ and products derived from cacao seed extracts, such as natural cocoa powder and dark chocolate, as ‘super foods’,” she said.
There is still plenty of research to be conducted on the nature of the antioxidants in chocolate.
Regulations
In the European Union, up to 5% of tropical vegetable fats are permitted other than cocoa butter. In the USA, only cocoa butter is permitted. The fats allowed are palm oil (Elaeis guineensis, Elaeis olifera), Sal (Shorea robusta), Shea, kokum gurgi (Garcinia indica), mango kernel (Mangifera indica) and Illipe (Borneo tallow or Tengkawang; Shorea spp.). These are cocoa butter equivalents. They are all non-lauric vegetable fats, which are rich in symmetrical monounsaturated triglycerides of the type POP, POSt and StOSt. They are miscible in any proportion with cocoa butter, and are compatible with its physical properties (melting point and crystallisation temperature, melting rate, need for tempering phase). They are obtained only by the processes of refining and/or fractionation, which excludes enzymatic modification of the triglyceride structure (EU, 2000).
Products
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References
Books
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