Chocolate is made from the seeds of the tree theobroma cacao

Chocolate is made from the seeds of the tree theobroma cacao

Задание №7471.
Чтение. ЕГЭ по английскому

Установите соответствие между заголовками 1 — 8 и текстами A — G. Используйте каждую цифру только один раз. В задании один заголовок лишний.

1. Chocolate mania
2. History of chocolate
3. Like father, like son
4. Balanced diet
5. Friend or enemy
6. Safe sweetness
7. Help to dentists
8. Problems with weight

A. Chocolate is made from the seeds of the tree Theobroma cacao. The ancient Aztecs used the beans of the cacao tree as a form of money. The Aztecs discovered that by crushing the beans into a paste and adding spices, they could make a refreshing and nourishing drink. This drink was very bitter, not like our chocolate drinks today. 16th century European explorers brought the drink back from their travels, added sugar, and soon it was popular as an expensive luxury.

C. All modern chocolate products have large amounts of sugar, a fact which may partly explain why it becomes a sort of drug for some people. An ability to recognize sweet things, and a tendency to like them was very useful for our forefathers. Such a genetic quality made prehistoric humans look for energy-rich, healthy and tasty food such as fruit, and helped them avoid bitter-tasting poisonous plants.

D. Like other sweet food, chocolate helps endorphins, natural hormones, that give us the feelings of pleasure and well-being, to appear in our body. Chocolate also makes us feel good by reacting with our brains. Scientists say that some people may develop chocoholism — a dependency on chocolate. So it’s just possible that, with every bar of chocolate, your brain changes step by step in order to make you love chocolate more and more!

E. Back in the 17th and 18th centuries, many scientific works were written explaining the advantages of chocolate for medicine, and today it’s a regular food in army rations. Chocolate could help prevent tooth decay, according to scientists at Japan’s Osaka University. The cocoa beans from which chocolate is made have an antibacterial agent that fights tooth decay. These parts of the beans are not usually used in chocolate production, but in future they could be added back in to chocolate to make it friendly for teeth.

F. Californian scientist Professor Carl Keen and his team have suggested that chocolate might help fight heart disease. They say that it contains chemicals called flavinoids, which thin the blood. Researchers at Harvard University have carried out experiments that suggest that if you eat chocolate three times a month you will live almost a year longer than those who don’t do it. But it’s not all good news — chocolate has much fat, which means that eating too much of it may lead to obesity.

G. Being very fat, or obese, is linked to many health problems including heart disease and diabetes. The causes of obesity are not yet fully understood. Both genes and the environment play a role. The recent growth of the number of fat people seems to be linked to environmental factors: people are much less active nowadays, fatty and sugary foods like chocolate are cheap, people eat larger portions of food, and the calories per person have increased.

Решение:
Заголовок 2 (History of chocolate. — История шоколада) соответствует содержанию текста A: «The ancient Aztecs used the beans of the cacao tree. »

Заголовок 3 (Like father, like son. — Яблоко от яблони) соответствует содержанию текста B: «You can receive a ‘sweet tooth’ from your parents. »

Заголовок 6 (Safe sweetness. — Безопасная сладость) соответствует содержанию текста C: «. and helped them avoid bitter-tasting poisonous plants.»

Заголовок 1 (Chocolate mania. — Шоколадная мания) соответствует содержанию текста D: «Scientists say that some people may develop chocoholism. »

Заголовок 7 (Help to dentists. — Помощь стоматологам) соответствует содержанию текста E: «Chocolate could help prevent tooth decay, according to scientists. »

Заголовок 5 (Friend or enemy. — Друг или враг) соответствует содержанию текста F: «But it’s not all good news — chocolate has much fat, which means that eating too much. »

Заголовок 8 (Problems with weight. — Проблемы с весом) соответствует содержанию текста G: «Being very fat, or obese, is linked to many health problems. »

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Источник: ЕГЭ-2013. Английский язык: 25 вариантов под ред. М.В. Вербицкой
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Chocolate

Contents

Origin of Theobroma cacao

Chocolate is derived from the seeds of the tree Theobroma cacao. It is normally found in humid, tropical regions of northern South and Central America. Major producers of chocolate are Ivory Coast, Ghana, Indonesia, Brazil, Nigeria, Cameroon, Malaysia, and Ecuador. Several types of the tree have been discovered including Criollo, Forastero, and Trinitario. Most chocolate producers currently use Forastero and Trinitario, however, because Criollo is highly susceptible to disease. [2]

Fermentation

Fermentation is the first process cocoa beans are subjected to in making chocolate. The process usually lasts up to seven days. Fermentation takes place in the pectinaceous pulp surrounding beans of this tree. Biochemical and enzymatic reactions that take place inside the cotyledon cause a variety of flavor compounds [5]. The pulp surrounding the cocoa beans is fermented by various microbes including yeasts, lactic acid bacteria, and acetic acid bacteria. The resulting high temperature and products produced by these microbes, such as the ethanol from yeast, kill the beans and contribute to the flavoring of the chocolate [2].

Once the seeds are harvested, fermentation is usually begun immediately. The beans inside of the cocoa pods are in an environment such that no microbes can grow. However, upon cutting the cocoa pods open, the beans are exposed to microbes and the fermentation process is allowed to begin [2]. Microbes arise from hands of workers, knives, unwashed baskets, and dried mucilage on fermentation boxes [2].

Containers wrapped in banana leaves are used to ferment up to 2000 kg of beans [2]. The beans are covered in a white-cream, mucilaginous (protein/sugar coat) pulp that is solubilized, and the breakdown of the glue between the pulp cells walls and the cocoa honey (“sweatings”) are released through holes in the box containing the beans [1].

In the early stages of the fermenting process, yeasts produce ethanol and secrete enzymes that break down pectin. Bacteria (lactic acid and acetic acid bacteria) then appear, followed by aerobic spore-forming bacteria and filamentous fungi [2].

Physical Conditions

The bean pulp contains lots of fermentable sugars including glucose, fructose, and sucrose [1]. It is an ideal medium for microbes to grow on because it is rich in nutrients. It is made up of 82-87% water, 10-15% sugar, 2-3% pentsans, 1-3% citric acid, and 1-1.5% pectin, along with various other proteins, amino acids, vitamins, and minerals [2].

Changes to Physical Conditions

Due to the presence of citric acid, the pulp is an acidic environment, with pH 3.0 to 3.5. As yeasts use up citric acid, pH increases to around 4.8 to 5.0. The yeast also convert sugars (glucose, sucrose, and fructose) into ethanol, increasing the concentration of ethanol for one or two days. The concentration then decreases gradually as it is oxidatively metabolized to acetic acid by acetic acid bacteria. Temperature rises throughout process due to the release of heat as a by-product of biochemical processes carried about by the microbes, from around 20 to 25ºC to 48 to 50ºC [1].

Microbes

Yeast

Yeast grow well in acidic environments and low oxygen levels, such as in the beginning stages of fermentation. In these early stages, yeast are very important in paving the way for further fermentation by bacteria. They convert sugars, such as sucrose, glucose, and fructose, into ethanol and CO2, decrease the acidity of the pulp by using up citric acid, and produce aromatic compounds, which contribute to the chocolate aroma and are important to development of flavor. In order to deal with fluctuations in bean conditions, some yeast produce weak organic acids to buffer fluctuations such as pH. Yeast are also responsible for degrading pulp and producing enzymes that break down pectin [1]. This creates cavities in the cocoa where air can flow. However, this increased air flow, along with an increase in pH and concentration of alcohol, eventually kills off the yeast [2].

Prominent yeast in the first 24 to 36 hours of fermentation include Kloeckera apis (

70-90% of the total yeast grown), Kloeckera javanica and Kloeckera africana, Candida pelliculosa and Candida humicola (less than 5% of total yeast), Rhodotorula rubra and Rhodotorula glutinis. Saccharomyces cerevisiae and Candida tropicalis were also prominent during first 24-36 hours, but died off by the end of fermentation. Most grew only until about 37 to 40ºC, and up to around 5-10% ethanol [1].

Lactic-Acid Bacteria

Lactic acid bacteria begin to grow when the pulp and “sweatings” are degraded and drained, and the yeast are dying [2]. The main function of lactic acid bacteria is to metabolize pulp sugars (glucose and fructose) and citrate to produce lactic acid, acetic acid, ethanol, and mannitol. The production of lactic and acetic acid contributes to the decrease in pH. Lactic acid bacteria have also been thought to contribute to yeast’s ability to use citrate as a carbon source. These products are good for acetic acid bacteria growth, and allow them to convert ethanol into acetic acid, releasing heat as a byproduct for the eventual cocoa bean death [3].

Predominant lactic acid bacteria in the first 36 to 48 hours of fermentation include Lactobacillus cellobiosus (60-85% of the total lactic acid bacteria grown), Lactobacillus plantarum, Lactobacillus hilgardii (only 2% of the total bacteria) (1), Lactobacillus fermentum, Leuconostoc mesenteroides, and Lactococcus lactis [2]. Most grew well between 40 to 45ºC, and at 7 to around 10% ethanol [1].

Acetic-Acid Bacteria

Towards the end of fermentation, the presence of yeast and lactic acid bacteria decline and the fermenting heap becomes more aerated. These conditions can therefore lead to the development of acetic-acid bacteria. This bacteria oxidizes ethanol to acetic acid, and also further oxidizes the acetic acid to carbon dioxide and water. These organisms are metabolized due to the acidulation of cocoa beans at high temperatures, which causes diffusion and hydrolysis of proteins in the cotyledons. Acetic acid bacteria primarily form the precursors of chocolate flavor. These include members of the genus Acetobacter as well as Gluconobacter [2]

Aerobic Spore-Forming Bacteria

High temperatures and increase in pH along with increased aeration leads to the development of aeobic spore-forming bacteria of the genus Bacillus. This includes B. pumilus, Bacillus licheniformis, Bacillus subtilis, and Bacillus cereus. The Bacillus spp. found during the aerobic phase of fermentation have been found to be responsible for the flavoring of chocolate. Aerobic spore-forming bacteria form chemical compounds that cause acidity and sometimes off-flavoring if fermentation continues for too long [2].

Filamentous Fungi

Filamentous fungi are also found in the well-aerated parts of the fermented mass. They may cause hydrolysis of some of the pulp and produce acids, but are not considered important in microbial succession. Of the filamentous fungi, Aspergillus fumigatus and Mucor racemous are the most present in the fungal population up to the end of fermentation. These fungi cannot grow at temperatures higher than 45°C, but can be isolated at a temperature of around 50°C [2].

Drying & Roasting

The drying and roasting process contains a very small portion of microbes such as, lactic acid bacteria, acetic-acid bacteria, aerobic spore forming bacteria, and others. The residual microbes will begin to form endospores as conditions such as levels of heat increase and the humidity decreases, in addition to that mold can begin to form if the drying conditions are not correct, but not much else is known.

In the past bean drying involved the use of sunlight and spreading out the beans over a wide area; these days bean drying has evolved to using large machines that regulate temperature and humidity [7] although there are that some may still dry their beans the traditional way. Drying begins when the beans are placed in a box with a piece of plastic covering it, the beans are then turned while being roasted at around 50°C to 60°C degrees and dried over the course of a few days until the water content drops to about 7 to 10%. The rate at which the beans dry is also an important factor involved in the study of chocolate making if conditions are not right then microbes such as fungi may begin to form. At this stage of chocolate production the maker would want to minimize the amount of microbes since they can alter the flavor of the chocolate. Research has found that rapid drying at low humidity and slow drying at high humidity were more harmful to cocoa beans. They determined that this was due to a leakage of electrolytes and concluded that if one were to determine the optimal rate for drying, finding the point at which the least amount of damage done from mechanical and metabolic stresses would probably be the optimal point [10]. Another has found that conditions for getting good results were brought up by drying at low temperature or occasional breaks from drying if dried at high temperature [11]. A few years later, another group of researchers have specifically determined that the optimal conditions for drying cacao beans was at a temperature of 40°C and a depth of 8.3 cm this minimized the amount of free amino acids being produced however they did not mention how it affected the taste [12].

Once dried, the beans are cleaned to remove any remaining microbes and get rid of any excess material, they are then roasted at around 120°C, killing all remaining microbes, and bringing out the flavor and the scent. If should be known that some companies have been advertising the fact that bacteria and fungus that are involved in developing chocolate have been branded as dangerous when in fact they are not. After roasting the cacao beans are cleaned until there is just the nib portion of the bean left, and then they are grounded up and heated until the chocolate moves to a liquid state. The process ends in a step known as tempering where chocolate is given its shiny appearance [14].

Flavor and Aroma

There are several factors that appear to affect the flavor of chocolate, including the components that make up the bean pulp. Lipids comprise the majority of the cocoa bean (around 50%) of its overall weight. One study has claimed that the concentration of free fatty acids increases with the fungal degradation of the lipid matter in the cocoa bean, thus affecting the chocolate flavor [1].

Acids

During the fermentation of the bean pulp, bacteria produce various products such as alcohols, acetic acid, and organic acids, all of which can contribute to bean death. The chemical changes that arise from the bean death add to the initial aroma, coloring, and flavor of the cocoa; all of which are finalized in the drying and roasting stages [15]. Acetic acids, such as A. aceti, A. pasteurianus and Gluconobacter oxydans, play a role in the aroma and odor during cocoa bean fermentation. They can produce various byproducts from metabolizing sugars and organic acids, and these byproducts can contribute to the aroma of cocoa beans during fermentation [1].

Yeast

Yeast plays an important role in the fermentation of the cocoa bean by producing ethanol and ultimately acetic acid, which leads to bean death; thus setting off a series of biochemical changes that contribute to the flavor of the chocolate [1].Following the drying process, the water content of the bean pod is greatly reduced, at which point the beans are roasted in order to create the characteristic flavoring and odor of chocolate. Yeast plays a vital role in the final chocolate flavors of the roasted beans. It has also been found that the enzymes that the yeast releases are important for the chocolate precursor components. It is only when the cocoa beans have actually been roasted does the characteristic chocolate aroma occur [20].

Bacillus

Bacillus bacteria are also involved in the fermentation process of the cocoa beans, predominately in the end stages of fermentation when the environmental conditions of the process are more aerobic (oxygen containing) and less acidic. Some of these Bacillus bacteria that have been identified include Bacillus subtilis, Bacillus stearothermophilus, Bacillus cereus, Bacillus licheniformis, Bacillus coagulans, and Bacillus pumilus. The production of organic acids and pyrazines by Bacillus bacteria has been shown to affect the flavor of cocoa by allowing the enzymes produced to enter the cocoa beans and alter the chemical quantities inside [1].

Climate

Climate conditions, harvesting seasons, the ripeness of the cocoa pod (including the quality of the bean pulp) all affect the fermentation of the cocoa bean. In addition, the different flavors produced have been linked to the presence of esters in the chemical composition of the cocoa bean. These esters have been linked to the existence of yeasts and acetic acid bacteria such as Acetobacter and Gluconobacter. However, not all the chocolate odors are due to the presence of microbes. Some of the odors were due to the thermal conditions of the fermentation process. Some of these off-flavorings could have been the result of contamination in the drying process [19].

Health Benefits of Chocolate

It has been studied that the regular consumption of foods high in flavonoids can decrease the risk of cardiovascular disease [17]. Specific to cardiovascular health, a specific sub-group of flavonoids known as flavan-3-ols (falvanols), are found in cocoa products such as chocolate [16]. Various studies have shown improvements in blood pressure, and the functioning of endothelial cells and platelets due to the consumption of cocoa products that contain flavanols [17]. The reason that dark chocolate is better for one’s health versus milk chocolate is that per serving, dark chocolate has almost 2.5 times that amount of flavonoids than milk chocolate; this may partly be due to the milk in milk chocolate inhibiting the absorption of those flavonoids by the intestine. Dark chocolate also has greater concentrations of phenols and catechins than milk chocolate [18].

Diseases affecting Theobroma Cacao

There are several various fungal diseases that have had detrimental effects on Theobroma cacao plant. The primary two diseases native to South America are caused by the fungi Crinipellis perniciosa (also known as Witches’ Broom disease) and Moniliophthora roreri (frosty pod rot or moniliasis disease). These fungi infect Theobroma L., and Herrania Goudot, in particular, T. cacao, which is the source of chocolate. This infection causes hypertrophy and hyperplasia in the cacao, ultimately resulting in tissue damage. C. perniciosa basidiospores infect cacao meristems, which leads to a newly disordered growth of shoots, “witches’ broom,” in the host. C. perniciosa also infects the early phases of cacao bean pod growth by breaking through the plant’s husks and destroying the cacao seeds. The M. roreri (frosty pod rot) pathogen is found only in the Theobroma and Herrania species. It results in outer and inner cacao bean pod damage, and results in the complete death and loss of the bean pods [21].

Current Research

A. Glucosyltransferases allow bacteria to stick to surfaces such as a child’s tooth. A new type of mouth wash containing cocoa bean husk extract (CBHE) has been developed and found to aid in anti-glucosyltransferase and antibacterial activity. Studies are being conducted by observing the differences in mutans streptococci counts in placebo groups versus actual CBHE groups. The CBHE mouth wash is being tested as a means to lower mutans streptococci count and get rid of plaque build up on children’s teeth and studies have shown to have promising results [4].

B. To observe the interactions between microbial activities on the outside of beans and chemical processes inside, various tools can be used. Denaturing Gradient Gel Electrophoresis (DGGE) is used to monitor microbial changes during fermentation of cocoa. Near Infrared (NIR) spectroscopy is used to determine various components in cocoa beans. A number of cocoa fermentations bean samples are taken with 24 hour intervals to be dried and analyzed by NIR as well as simultaneously by DGGE. Using culture dependent and culture-independent methods, the microbiology of Ghanaian cocoa fermentations can be analyzed to determine whether fermentation determined using DGGE are correlated with that of NIR. [6]

C. Conjugation of the pUR400 gene into Escherichia coli HD701 from an Escherichia coli K12 strain gives them the ability to metabolize sucrose into hydrogen. Studies were done on Escherichia coli with and without the pUR400 that was conjugate into Escherichia coli, found that the parental strain was not able to metabolize sucrose into hydrogen although the recombinants were able to [23]. The applications for this stems out into bioremediation of toxic wastes to wastes from production of food such as chocolate [22]. Researchers have found that by taking chocolate waste and feeding it to Escherichia coli, the bacterium was able to produce hydrogen in return. Moreover the researchers were able to use this hydrogen to power a small fan through a fuel cell. [13]

D. Fermentation of Theobroma cacao is necessary in order to develop the flavor precursors of chocolate. This current study looks at a controlled study where the cacao seed, during fermentation, is inoculated with a hybrid yeast strain known as Kluyveromyces marxianus to see whether the increased pectinolytic activity would create a better quality of chocolate. The results showed that the hybrid yeast affected the overall degradation of the seed protein as well as reduced the titrable acidity; and overall, the beans inoculated with Kluyveromyces marxianus were preferred over the naturally fermented cacao beans. This preference in creating a better quality of the final product owes much of its success to improving the first 24 hours of fermentation by increasing the mass aeration of the fermenting seed. [5]

References

[1] Ardhana, MM, & Fleet, GH. (2003). The microbial ecology of cocoa bean fermentations in Indonesia. International journal of food microbiology, 86(1-2), 87-99.

[2] Schwan, RF, & Wheals, AE. (2004). The microbiology of cocoa fermentation and its role in chocolate quality. Critical reviews in food science & nutrition, 44(4), 205-21.

[3] Camu, N, De Winter, T, Verbrugghe, K, et al. (2007). Dynamics and biodiversity of populations of lactic acid bacteria and acetic acid bacteria involved in spontaneous heap fermentation of cocoa beans in Ghana. Applied and environmental microbiology, 73(6), 1809-24.

[4] Srikanth, RK, Shashikiran, ND, & Subba Reddy, VV. (2008). Chocolate mouth rinse: Effect on plaque accumulation and mutans streptococci counts when used by children. Journal of the Indian Society of Pedodontics and Preventive Dentistry, 26(2), 67-70.

[5] Leal, GA, Gomes, LH, Efraim, P, et al. (2008). Fermentation of cacao (Theobroma cacao L.) seeds with a hybrid Kluyveromyces marxianus strain improved product quality attributes. FEMS yeast research, 8(5), 788-98.

[6] Nielsen, DS, Snitkjaer, P, & van den Berg, F. (2008). Investigating the fermentation of cocoa by correlating denaturing gradient gel electrophoresis profiles and near infrared spectra. International journal of food microbiology, 125(2), 133-40.

[7] Taylor, DA. (2005). Sweet deal for cocoa production?. Environmental health perspectives, 113(8), A516-.

[8] Rubini, MR, Silva-Ribeiro, RT, Pomella, AW, et al. (2005). Diversity of endophytic fungal community of cacao (Theobroma cacao L.) and biological control of Crinipellis perniciosa, causal agent of Witches’ Broom Disease. International journal of biological sciences, 1(1), 24-33.

[9] Camu, N, González, A, De Winter, T, et al. (2008). Influence of turning and environmental contamination on the dynamics of populations of lactic acid and acetic acid bacteria involved in spontaneous cocoa bean heap fermentation in Ghana. Applied and environmental microbiology, 74(1), 86-98.

[10] Schwan, RF. (1998). Cocoa fermentations conducted with a defined microbial cocktail inoculum. Applied and environmental microbiology, 64(4), 1477-83.

[11] Faborode, MO. (1995). On the effects of forced air drying on cocoa quality. Journal of food engineering, 25(4), 455-.

[12] Hashim, P. (1999). Effect of drying time, bean depth and temperature on free amino acid, peptide-N, sugar and pyrazine concentrations of Malaysian cocoa beans. Journal of the science of food and agriculture, 79(7), 987-.

[13] Redwood, MD, Mikheenko, IP, Sargent, F, et al. (2008). Dissecting the roles of Escherichia coli hydrogenases in biohydrogen production. FEMS microbiology letters, 278(1), 48-55.

[15] Jespersen, L, Nielsen, DS, Hønholt, S, et al. (2005). Occurrence and diversity of yeasts involved in fermentation of West African cocoa beans. FEMS yeast research, 5(4-5), 441-53.

[16] Keen, CL, Holt, RR, Oteiza, PI, et al. (2005). Cocoa antioxidants and cardiovascular health. The American journal of clinical nutrition, 81(1 Suppl), 298-303S.

[17] Erdman, JW, Carson, L, Kwik-Uribe, C, et al. (2008). Effects of cocoa flavanols on risk factors for cardiovascular disease. Asia Pacific journal of clinical nutrition, 17 Suppl 1, 284-7.

[18] Ding, EL, Hutfless, SM, Ding, X, et al. (2006). Chocolate and prevention of cardiovascular disease: a systematic review. Nutrition & metabolism, 3, 2-. http://www.nutritionandmetabolism.com/content/3/1/2

[19] Lagunes Gálvez S., Loiseau G., Paredes J.L., Barel M., Guiraud J. P., Étude de la microflore et de la biochimie de la fermentation du cacao en République dominicaine, International Journal of Food Microbiology (in press). Barel M., Les arômes du chocolat, Chocolats et friandises, Académie française du chocolat et de la confiserie, 2001

[20] Jay, James Monroe, Martin J. Loessner, and David A. Golden. Modern Food Microbiology 7th ed. New York: Springer, 2005.

[21] Aime, MC. (2005). The causal agents of witches’ broom and frosty pod rot of cacao (chocolate, Theobroma cacao) form a new lineage of Marasmiaceae. Mycologia, 97(5), 1012-.

[22] Macaskie, Lynne E. «Cr(VI) reduction by bio and bioinorganic catalysis via use of bio-H2: a sustainable approach for remediation of wastes.» Journal of Chemical Technology & Biotechnology 82 (2007): 182182-89(8).

[23] Macaskie, Lynne E. «Production of H2 from sucrose by Escherichia coli strains carrying the pUR400 plasmid, which encodes invertase activity.» Biotechnology Letters 26 (2004): 1879-883.

Edited by Rebecca Law, Brian Lew, Jason Ly, and Sahar Salek, students of Rachel Larsen

How Chocolate Is Made

From raw beans to cocoa butter and bakers chocolate

Cocoa beans have a complex journey from jungle trees to foil-wrapped confections. Here is a simple breakdown of the steps involved in the cocoa making process.

Harvesting

Chocolate begins with Theobroma Cacao tree. Pods from this tree are harvested for the making of chocolate only once fully ripened. Unripened pods yield beans with low cocoa butter content and low sugar content. The natural sugars in cocoa beans fuel the fermentation process, which is responsible for much of the classic cocoa flavor.

Once harvested, the seeds are separated from the pods and pulp and allowed to begin the fermentation process.

Fermenting

Raw cocoa beans have a bitter and undesirable flavor. Fermentation transforms this bitterness making it into the more complex precursor to the classic cocoa flavor we are familiar with.

Fermentation is achieved with natural yeast and bacteria that are present in the cocoa beans. The beans are simply left out in the heat and moisture to ferment for approximately seven days. After fermentation, the beans are quickly dried to prevent mold growth.

Roasting

After fermentation and drying, the beans are thoroughly cleaned and removed of any sticks, stones, or other debris. Cocoa beans are typically roasted using the dry roast method, which employs constant stirring to ensure even heating. Dry roasting does not require the addition of extra oils or fats, which allows the flavor to stay pure. This is the final step in creating the classic cocoa flavor that we are all familiar with.

Processing

After roasting, the hull is removed from the bean and the inner nib is extracted. The nibs are then ground into a fine powder, which contains cocoa solids and cocoa butter. The cocoa butter usually liquifies from the frictional heat while grinding the nibs. This liquefied form of pulverized cocoa nibs is referred to as cocoa liquor.

Cocoa liquor is then poured into molds, allowed to cool, then sold and transported in these blocks. These blocks are known as unsweetened or bakers chocolate. Alternatively, cocoa liquor can be separated into two products, cocoa powder, and cocoa butter.

Blending

Cocoa liquor, baking chocolate, cocoa powder, and cocoa butter can be blended with various ingredients to create an endless number of cocoa products.

To produce the chocolate candies which we are all familiar with, cocoa liquor is combined with extra cocoa butter (for smoothness and mouthfeel), sugar, milk, and sometimes vanilla, emulsifiers, or stabilizers. The ratio of sugar and milk to cocoa creates varying degrees of milk or dark chocolate. The specific ratio in which ingredients are blended creates signature recipes, which specialty brands often guard closely.

Although chocolate manufacturers have lobbied to allow the use of hydrogenated vegetable oils, milk substitutes, and artificial flavors to be used in the making of chocolate, the USDA still does not allow the term «chocolate» to be used for products containing these ingredients. Only products made with real cocoa liquor (or a combination of cocoa solids and cocoa butter) may be called «chocolate.»

Cocoa powder, cocoa butter, and cocoa liquor are also used to make many products besides chocolate candy. Cocoa is used in a variety of savory dishes, especially in Central and South America. Cocoa butter is a prized ingredient in many skin products because of its skin-softening qualities.

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Задание № 2462

Установите соответствие тем 1 — 7 текстам A — F. Занесите свои ответы в соответствующее поле справа. Используйте каждую цифру только один раз. В задании одна тема лишняя.

1. the chocolate consumed today is made

2. that chocolate, eaten in moderation

3. central and southern America for

4. of the world’s most popular flavours

5. hand contains no cocoa solids and

6. cacao seeds are intensely bitter and have

7. many countries worldwide at

Chocolate is made from a number of raw and processed foods produced from the seeds of tropical cacao trees. Cacao has been cultivated in A ___ last 3000 years.

For most of this time it was made into a drink called, in translation — «bitter water». This is because В ___ to be fermented to develop a palatable flavour. After fermentation the beans are dried and roasted and the shell is removed to produce cacao nibs. These are then ground and liquefied into chocolate liquor.

The liquor is then processed into cocoa solids or cocoa butter. Pure chocolate contains primarily cocoa solids and butter in different proportions. Much of С ___ with added sugar.

Milk chocolate is sweetened chocolate that additionally contains either milk powder or condensed milk. White chocolate on the other D ___ is therefore not a true chocolate.

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Theobroma Cacao

Chocolate (Theobroma cacao) has been considered an unhealthy food due to its carbohydrate and fat content, nevertheless cacao consumption is associated with several health benefits such as diabetic control, cardioprotection, anticancer, anti-inflammatory and antioxidant effects.

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Cacao—Theobroma cacao

Origin and Botanical Aspects

Cocoa ( Theobroma cacao L.), known worldwide for being the raw material of chocolate, belongs to the class Magnoliopsida, order Malvales, family Malvaceae, genus Theobroma and species Cacao, being the main fruit of the genus cultivated, due to the value and importance of the seeds ( Argout et al., 2001; CEPLAC, 2001; Alexandre et al., 2015; Kongor et al., 2016 ).

The cacao tree originates from rainforest regions of tropical America, where until today, is found in the wild state, from Peru to Mexico. Charles de L’Ecluse was the first to cite the cacao in the botanical literature as Cacao fructus. Later (1737), Linneu described it as Theobroma fructus. However, in 1753, the same Linneu proposed the specific name of Theobroma cacao, which remains to this day.

According to Batalha (2009) the cocoa plant develops in the hot and humid climate in a geographic range comprised between the 20ºN and 20ºS parallels. Its cultivation extends from Venezuela, passing through Colombia, Central America and Mexico. When dispersing along the Amazon River, it also reaches the Guianas. However, about 70% of world production comes from West Africa, mainly from Ivory Coast (40%), Ghana (20%), Nigeria (5%), and Cameroon (5%). Brazil, before the introduction of the witch-broom disease (Moniliophtora perniciosa) in 1989, was the world’s second largest cocoa producer, falling to the fourth position, accounting for only 4% after this disease ( Leite, 2012 ).

Height: it can reach 5–8 m of height and 4–6 m of diameter of the crown. However, it can reach up to 20 m under forest condition, due to competition for light with other species.

Root system: consists of a pivoting root that has its length and shape varying according to the structure, texture, and consistency of the soil. In deep soils with good aeration it can have a growth of the pivoting root of up to 2 m. The secondary roots are responsible for the plant nutrition, and generally 70%–90% of these are in the first 30 cm of the soil.

Stem: it is erect, and with 2-years aged, the growth of the terminal yolk is stopped with 1.0–1.5 m of height. Afterwards, the first crowns appearing, composed of 3–5 main branches, that multiply in other lateral and secondary branches. In the first years, the cacao tree presents smooth stems bark. Later, due to development of flowers cushions, it becomes rough and rugged.

Leaves: the leaves are oblong, acuminate, and glabas with prominent central rib. When new, depending on the clone or cultivar, they have a color ranging from green (more or less rosy) to violet, depending on the amount of anthocyanin present. When old, the leaves lose their pigmentation, becoming pale green, and finally, dark green and stiff.

Flowers: cacao flowers appear in floral cushions on the trunk or woody branches, from buds that develop in the armpits of old leaves. The flowers are hermaphroditic and have the following constitution: five sepals, five petals, five estaminodes, five stamens and one pistil whose ovary has five ovules. The cacao flowers have structural characteristics that limit their pollination exclusively by insects. The main pollinating agents of cacao are a small group of insects belonging to the Ceratopogonidae family, genus Forcipomya. In the Amazon Region, the cacao tree has two flowering peaks: a minor that coincides with the beginning of the less rainy period and a main one that occurs at the end of the dry season and the beginning of the rainy season. Annually, an adult cacao tree can produce more than 100,000 flowers, but only about 0.1% turn into fruit. The unpollinated flowers fall within 48 h. On the other hand, the pollinated and fertilized flowers remain fixed on the peduncle, and they develop the fruit.

Fruit: it presents a fleshy pericarp composed of three distinct parts: the epicarp, which is fleshy and thick, whose outer epidermal extract may be pigmented. The mesocarp, which is thin and hard, but not very lignified, and the endocarp, which is fleshy and not very thick. Usually the fruit when immature is green, and yellow when ripe. Others are purple (red-wine) in the development phase and orange in the ripening period. The period between pollination and fruit ripening varies from 140 to 205 days, with an average of 167 days. The fruit index (number of fruits required to obtain 1 kg of commercial cocoa) is generally from 15 to 31 fruits ( Fig. 3 ).

Seed: the shape varies from ellipsoid to ovoid with 2–3 cm in length. It is covered by white mucilaginous pulp that has an acid-sweet taste. The embryo has two cotyledons with colors ranging from white to violet. Cocoa’s seeds are very sensitive to temperature changes and die in a short time when suffer from dehydration.

COCOA AND COFFEE FERMENTATIONS

Nature of the Crop

Cacao Fruit

Theobroma cacao bears small flowers in small groups on the trunks and lower main branches of the trees. Pollinated flowers develop into berries (‘pods’), maturing over a 5–6 month period. The berry is a drupe 2.5–4.0 cm by 1.25–1.75 cm in size, containing 20–40 seeds (beans) and surrounded by a mucilaginous pulp ( Fig. 1 ).

Harvesting

Theobroma cacao normally begins to bear berries after 3 years and the yield reaches a maximum after 8–9 years. Trees simultaneously bear flowers, developing berries and mature fruits. The pods develop on the trunk and branches. After about 5–6 months development the pods ripen and turn yellow or orange. Harvesting is carried out at varying frequencies (1–4 weeks). The pods are then opened either on the same day or after a few days in order to allow a sufficient quantity to accumulate for the fermentation stage. Beans are removed and separated from the placenta. At this stage they are covered in a sweet mucilaginous pulp.

Cocoa (Theobroma cacao) Seeds and Phytochemicals in Human Health

Historical Cultivation and Usage

Theobroma cacao was first cultivated in 250–900 AD by the ancient civilizations of the Mayas and Aztecs in the Mesoamerican region ( Knight, 1999 ). From its divine origins, cocoa was introduced to the Spanish Royal Court in the mid-1550s ( Dillinger et al., 2000 ). Cocoa had many uses, ranging from medicine to currency, in early Mesoamerican cultures ( Dillinger et al., 2000 ). More than 100 medicinal uses of cocoa have been documented in Europe and New Spain ( Dillinger et al., 2000 ).

Soft Scale Insects their Biology, Natural Enemies and Control

Introduction

Theobroma cacao L. (Family Sterculiaceae) is a long-lived understorey tree of tropical lowland forests. It is native to tropical South and Central America, where it has been cultivated since prehistoric times and from where cocoa production has spread throughout the tropics during the last 300 years ( Wood and Lass, 1985 ).

Over 90% of world cocoa production is from low-technology farms of less than two ha each ( Smith, 1994 ). It has been argued that accrual of pest species is favoured by small-plot agriculture simply because dispersed plots take a cumulatively larger sample from the native entomofauna ( McCoy and Rey, 1983 ). However, although forest and therefore cocoa hold large numbers of potential insect pests, these are kept at low population densities by parasites and predators that prey on them within the cocoa forest ecosystem ( Johnson, 1962 ).

The concept of superfoods in diet

4.10 Cocoa (Theobroma cacao L.)

Theobroma cacao is the cocoa tree, from which cocoa seeds are derived as dried, and either as fermented or unfermented. Cocoa is a significant crop for countries such as Ghana, Ivory Coast, Nigeria, Indonesia, and Malaysia. Evidence has shown the medicinal uses of cocoa in many ancient civilizations such as the Olmec, Maya, and Mexica (Aztec). Moreover, various documents were found to explain the use of cocoa in the treatment of some diseases of the liver (such as infirmities and hot distempers) and cancers (such as stomach cancer and hemorrhoid tumors) ( Amin et al., 2004 ). According to some other sources, the perception of cocoa not only as a beverage but also as a medicinal plant to treat some disorders such as angina and heart pain goes back to the 1600s and 1700s ( Keen, 2001 ).

The cocoa bean with its products (cocoa liquor, cocoa powder, and dark chocolate) is very rich in phenolic acids (10%–12%, dry weight) ( Waterhouse et al., 1996 ). Being one of the richest sources of flavanols (around 60% of total phenolics in raw coca beans)—a subclass of flavonoids—cocoa is considered as one of the most significant contributors of total dietary flavonoid intake in the human diet ( Martín et al., 2016 ). Cocoa flavonols are mostly flavanol monomers (epicatechin and catechin) and procyanidin oligomers (dimer to decamer), which have been reported as significant antioxidants. Catechins are flavan-3-ols and procyanidins are oligomeric flavonoids consisting of 2–10 covalently linked epicatechin and catechin moieties. More commonly, catechin and procyanidins groups in cocoa are together considered as total “cocoa flavonoids” ( Kerimi and Williamson, 2015 ). The flavonoid content per weight of cocoa has been reported as being higher than red wine, green tea, and black tea. Moreover, total amount of flavonoids in dark chocolate is higher than that of milk chocolate ( Lee et al., 2003 ).

In addition, cocoa has been found to contain some other polyphenols such as luteolin, apigenin, naringenin, quercetin, isoquercitrin, etc. and methylxanthines, mainly theobromine (3,7-dimethyl xanthine) and caffeine in small quantities ( Lamuela-Raventós et al., 2005 ; Martín et al., 2016 ; Martín and Ramos, 2017 ). The importance of theobromine has been mainly attributed to its benefits on lipoprotein levels, synergy with flavan-3-ols, and also role in increasing the absorption of epicatechins ( Berends et al., 2015 ; Yamamoto et al., 2014 ). The distinct mechanism of antioxidant activity for cocoa flavonols is explained by their structural properties as hydrogen donors (radical-scavenging) and metal-chelating antioxidants ( Martín et al., 2016 ). The lipid component of the cocoa is known as “cocoa butter.” Cocoa butter contains abundant stearic acid (C18:0) (reported as much as one third of the total lipid content) ( Fernández-Murga et al., 2011 ), palmitic acid (C16:0), and oleic acid (C18:1) ( Kerimi and Williamson, 2015 ). Cocoa butter also consists of plant sterols and fiber in small amounts. Cocoa beans, on the other hand, contain a variety of minerals like potassium, calcium, magnesium, and copper, with potential effects in reducing cardiovascular risk ( Fernández-Murga et al., 2011 ). Cacao liquor, prepared from fermented and dried beans, is characterized as having higher amounts of polyphenols in comparison to cacao powder. The cocoa butter content of cocoa liquor is around 55% ( Fernández-Murga et al., 2011 ). In addition to factors such as the type of cacao plant, growing location and conditions, and storage conditions, processing methods to produce cocoa and chocolate, particularly alkalization, are significant in causing a significant decrease in the flavan-3-ol content ( Lamuela-Raventós et al., 2005 ).

Unlike other superfoods, cocoa-related research attracted much attention in many perspectives, including research reviewing cocoa/chocolate consumption and cardiovascular health ( Fernández-Murga et al., 2011 ; Kerimi and Williamson, 2015 ), diabetes ( Mellor and Naumovski, 2016 ), and colon cancer ( Martín et al., 2016 ).

Functional Genomics of Cacao

I Introduction

Theobroma cacao L. (cacao), a member of the Malvaceae sensu lato ( Alverson et al., 1999 ), occurs naturally in Neotropical lowland rainforests as a small under-storey tree. The genus Theobroma contains 22 species classified into 6 sections, most native to the upper Amazon region in South America ( Cuatrecasas, 1964 ), whereas only T. cacao and T. grandiflorum (cupuassu) are explored commercially on a large scale. T. cacao is preferentially outcrossing, diploid (2n = 2x = 20) and has a genome which was first estimated at 0.43 pg or 0.415 × 10 9 bp ( Figueira et al., 1992 ) and at 0.40 pg or 0.388 × 10 9 bp ( Lanaud et al., 1992 ). More recent evaluations inside T. cacao sp. indicated a range of genome size variations from 411 to 494 Mbp (Lanaud et al., in preparation). From the Amazon, cacao was initially introduced by ancient people into Meso-America ( Motamayor et al., 2002 ), while after the Spanish Conquest, the species was spread to the Caribbean, West Africa and Southeast Asia. The traditional classification of cacao assumes three major groups with distinct historical, commercial and morphological features: the Forastero or the Amazon group, the ancient cultivar Criollo (‘native’), and the Trinitario (from Trinidad) group; presumably derived from crossings between the Forastero and Criollo types ( Motamayor et al., 2002, 2003 ). Forastero genotypes are traditionally cultivated in Brazil and West African countries, and represent most of the commercial production of cacao. Criollos were originally cultivated in small areas of Central and northern South America ( Wood and Lass, 1985 ).

Cacao produces fruits (pods) along the trunk and branches ( Fig. 1 A) that contain an average of 20–40 seeds (also known as cocoa beans) embedded in sweet, mucilaginous pulp ( Fig. 1 H). Cacao beans are usually commercialised after a preliminary on-farm processing, which includes fermentation and drying ( Figueira, 2008 ; Fig. 1 I–K). Cacao butter and solids, including cacao powder and liquor, are the main products extracted from fermented and dried seeds, providing major raw materials for the chocolate, confectionary, cosmetic or pharmaceutical industries. Economically, cacao is considered as one of the main tropical crops worldwide, with a total bean production of 4,012,310 tonnes in 2007 ( FAO, 2009 ). The fermentation step is necessary for full development of chocolate/cocoa flavour and aroma after roasting. The flavour precursors derive from enzymatic reactions involving hydrolysis of storage proteins (mainly vicilins), sugars, anthocyanins, purine alkaloids, and oxidation and condensation of polyphenols.

The three main groups of cacao are distinguishable by the pod morphology ( Fig. 1 D–G). The Criollo group produces large pods with rough husk ( Fig. 1 F and G), containing white or violet cotyledons. Criollo is one of the two cacao varieties providing fine chocolate flavour highly sought for by chocolate manufacturers. Criollo is considered as a grand cru of chocolate such as in wine classification. The culture of Criollo represents an important economic niche for several countries like Venezuela, which has established the development of Criollo cultivation as a priority. However, Criollo is susceptible to many fungi diseases and insect attacks, and through time, its aromatic qualities have been diluted, because of various crossings with genotypes of various genetic origins, leading to hybrids with higher disease resistance ( Motamayor et al., 2003 ). The current challenge is to cultivate high productive and resistant hybrid Criollo varieties, maintaining the original aromatic qualities. Forastero produces pods with highly variable shapes and number and size of seeds, which are generally violet ( Rosário et al., 1978 ; Fig. 1 D). Within Forastero, considered as the group with the highest genetic diversity and better agronomic quality than Criollo, there is an Amelonado variety (oval pod with smooth bark; Fig. 1 D) named cacao Comun da Bahia and cultivated in large areas in Brazil. Catongo is an albino mutant, from the Forastero group, with white staminodes and seeds that has originated from Bahia (Brazil) ( Marita et al., 2001 ). Trinitario is a group with characteristics depending on the repartition and effects of alleles from the two founding groups (Forastero and Criollo). During the colonial period, most of the cacaos introduced in Africa and Asia were originated from Venezuela, Trinidad and Brazil ( Wood, 1991 ), and corresponded, respectively, to Criollo, Trinitario and Amelonado cultivars.

Destructive and newly encountered diseases have frequently been the major factors that limit cacao production in nearly all producing countries ( Bowers et al., 2001 ). Besides fluctuations in production, important disease outbreaks have eliminated or strongly limited cacao cultivation in many tropical regions throughout the world. Cacao diseases represent an important factor in the economy of this crop, not only due to crop losses but also due to the high cost of control practices. Cacao trunk, branch, foliage, roots and pods may be affected by diseases. Cacao diseases are caused mainly by fungi (oomycetes such as Phytophthora spp., ascomycetes such as Ceratocystis cacaofunesta and basidiomycetes such as Moniliophthora roreri Cif. & Par and Moniliophthora perniciosa (Stahel) Aime & Phillips-Mora, among others); a single virus disease is known (cocoa swollen shoot virus, CSSV) with occurrence restricted to West Africa. Cacao is not affected by any serious bacterial disease. Cacao stems are also attacked by pests such as mirids (Sahlbergella singularis) or pod borer (Conopomorpha crammerella). On a global scale, pod diseases cause the greatest losses. Species of Moniliophthora and Phytophthora can reduce yields by up to 80–90% in some regions, resulting in abandonment of many production areas around the world.

Phytophthora pod rot has been the primary fungal disease affecting global cacao production since the 1920s, causing pod losses in the order of 30% of the world production ( Pereira et al., 1996 ). A high variability for resistance to Phytophthora pod rot has been described ( Iwaro et al., 2006; Lawrence, 1978; Luz et al., 1996 ). Limited to South America and the Caribbean, witches’ broom disease, caused by M. perniciosa, is a severe constraint to cacao production and it has been responsible for the collapse of the cacao industry in Surinam (1900s), Trinidad, Ecuador (1920s), and more recently, in Brazil (1990s). Breeding for resistance started in the 1930s in Trinidad and Scavina 6 (SCA6), a Forastero from Upper Amazon (Peru) has been widely deployed in many programs as one major source of resistance. Genomic regions associated with M. perniciosa resistance (quantitative trait loci—QTLs) have also been identified ( Brown et al., 2005; Faleiro et al., 2006; Queiroz et al., 2003 ). However, this resistance has been often overcome, posing a continuous demand for novel sources ( Albuquerque et al., 2010 ). Frosty pod disease caused by M. roreri occurs in most producing countries in the Americas (Bolivia, Peru, Ecuador, Colombia, Venezuela, Panama, Costa Rica, Nicaragua and Mexico). Losses inflicted by frosty pod can be as high as 90% ( Barros, 1977 ). Sources of resistance to frosty pod have been found (e.g. UF 273 cacao genotype) and QTLs for resistance have been identified ( Brown et al., 2007 ), and it appears that the disease co-evolved with cacao in some regions of Colombia ( Phillips-Mora et al., 2007 ). Fortunately, to date, the major devastating cacao pathogens have a restricted distribution. Phytophthora palmivora has a pantropical distribution, while P. megakarya, the most aggressive species, is confined to several countries of West Africa, and P. capsici occurs only in South and Central America and the Caribbean ( Brasier and Griffin, 1979 ). There are two other Phytophthora species: P. heveae causing pod rot in Malaysia ( Turner, 1968 ) and Mexico ( Lozano-Trevino and Romero-Cova, 1974 ) and P. megasperma Drechsler in Venezuela ( Reyes et al., 1972 ). Another species, P. citrophthora, has been identified in Bahia, Brazil. P. citrophthora is more virulent on unwounded, detached pods than P. palmivora or P. capsici ( Lawrence, 1978 ). The CSSV virus is confined to West Africa. M. roreri and M. perniciosa occur only in the Americas.

Unfortunately, the various methods of disease control (chemical, biological, cultural) available to farmers are difficult to be applied for significantly reducing losses, either because of limited effectiveness or high cost. Thus, there is an urgent demand for the development of improved cultivars with durable and sustainable resistance to these diseases. Resistance is the method of choice as it is both economically and environmentally safe. The use of molecular biology can be a key step to speed up the development of resistant cultivars.

The advent of genome sequencing has revolutionised the biology field, leading to a paradigm change in the way to conduct science. The advent of genome sequencing in the 1990s has been quickly followed by technological innovations, collectively known as Omics, which allow large-scale analysis of biomolecules present in the cell, including mRNA (transcriptomics), proteins (proteomics) and metabolites (metabolomics). Omics appeared as fundamental approaches in the post-genomic era to amplify the knowledge of biological processes at organism level by determining gene–protein–metabolite correlations. Genomics, defined as sequences and entire genome studies, is the most mature Omics. Transcriptomics research gives information about both presence and abundance of transcripts, highlighting the active genes of the cell. Macro- and micro-arrays ( Hardiman, 2004 ) represent the approaches mostly used in a large variety of organisms. Even if these studies give crucial information related to cell expression stage, they do not evidence the various levels of post-transcriptional control ( Mata et al., 2005 ). Proteomics research aims to identify and quantify the protein level in the cell based on two-dimensional (2D) electrophoresis and mass spectroscopy ( Patterson and Aebersold, 2003 ). Described in this review are various cacao functional genomic and some proteomic initiatives that have emerged during last 10 years.