Cocoa (Theobroma cocoa)

World Cocoa Production Cocoa plant is a small tree native to the American tropics. It is now grown in all tropical regions of the world. The chief cocoa producing countries of the world are Ghana, Nigeria, Ivory Coast and Brazil.  

Cocoa Production in India Cocoa was introduced to India from Sri Lanka and is a comparatively new crop. Its production is fast picking up and it is grown in Kerala, Karnataka and, to some extent, in Tamil Nadu.

Cocoa tree has the unusual habit, like the jackfruit tree, of bearing its flowers and, subsequently, its pods on the main trunk as well as on the branches. Cocoa pods, when mature, are yellow in some varieties and red in others. The pods are 10 to 18 cm in diameter, having thick leathery rinds containing 20-50 beans inside in rows. The seeds are embedded in white or pinkish pulp. Seeds are the principal source of cocoa or cocoa powder highly prized as a nutritious beverage, and chocolate used as food all the world over.

Cocoa Processing Cocoa pods, after harvesting, are cautiously opened. The beans and mucilage are scooped out and subjected to natural fermentation either in heaps, wooden boxes (sweat boxes) or baskets.  

Fermentation Fermentation generally takes five to ten days. At the end of fermentation, the pulp breaks down and there is a change in the colour of the seeds from pale yellow or violet to brown. The endogenous enzymes, activated by the heat of fermen­tation, bring about changes in proteins and polyphenols in the kernel and there is also a reduction in the astringency of the kernel.

Drying The beans are then dried to six to eight per cent moisture level in sun or in artificial dryers. The bean is then ready for export or further processing to manufacture cocoa products.

Roasting The dried beans are cleaned, sorted and roasted. Roasting develops the characteristic flavour. Although a large number of compounds have been identified in cocoa and chocolate, no single constituent is found responsible for the characteristic subtle aroma. Roasting also causes changes in the chemical structure of polyphenols, producing less astringent compounds.

While roasting, the beans are passed through corrugated rollers to break their shells and removed by winnowing. The cotyledons are known as 'nibs'. Usually there is some blending of the nibs from different varieties of cocoa before they are processed further.

The nibs are used for the manufacture of cocoa and chocolate. The nibs are ground using stone mills or other suitable mills to a fine paste or liquor. The heat produced during grinding causes cocoa fat to melt and the melted fat carries with it, in suspension, finely ground particles of cocoa. This is known as "cocoa mass", "chocolate liquor" or "bitter chocolate". This mass solidifies at about 30°C.

Cocoa mass is very rich (50-55 per cent) in fat and cannot be used directly for the preparation of any beverage. It is subjected to filter pressing to separate out a major part of fat (cocoa butter). The amount of fat left in the pressed cake can be varied by the conditions of pressing. The pressed cake is used for producing cocoa powder. The fat content of cocoa used for beve­rage is fixed by law. According to Indian Standards Institution (ISI) specifica­tions, cocoa used for beverage should contain 20 per cent cocoa fat. Medium fat cocoa, containing between 10 and 20 per cent fat and. Low fat cocoa, containing less than 10 per cent fat are made. Flavouring substances like vanilla and cinnamon are generally incorporated into cocoa powder.

The pressed cake, after the removal of cocoa butter, contains 1. 8-1 The pressed cake, after the removal of cocoa butter, contains 1.8-1.13 per cent free acids. In one of the methods of cocoa processing the acid is neutra­lized with the addition of a requisite amount of alkali. This is known as the "Dutch process", because it originated in Holland. Cocoa processed by this method is dark in colour and the flavour will be somewhat more bitter and astringent than the same material not treated with alkali.  

Chocolate Cocoa mass not treated with alkali is generally used for the manufacture of chocolate. There are many types of chocolate depending upon the level of cocoa mass, added cocoa butter, sugar, milk and other ingredients. Plain chocolate (sweet chocolate) is cocoa mass processed with cocoa butter and sugar. Milk chocolate contains, in addition to these ingre­dients of plain chocolate. milk solids. Plain chocolate contains 44-55 per cent sugar and 32-42 fat, while milk chocolate contains 35--55 per cent sugar, 28-39 per cent fat and 12 per cent milk solids. Plain and milk choco­late are extensively used in confectionery and ice cream.

Composition The analysis of cocoa beans (processed) gives the following values: Moisture 2.13 % Fat 54.68 % Total nitrogen 2.16 % Starch 6.14 % Pentosesans 11.19 % Tannins 6.15 % The total nitrogen includes that of protein, theobromine and related alkaloids. The theobromine content of cocoa is hgh (about 2.8 per cent). Cocoa is the natural source of theobromine. There is some loss of theobromine content during fermentation and roasting. Cocoa also contains caffeine (about 0.6 per cent). The proteins of cocoa bean are present in combination with polyphenols.

Unlike coffee and tea, which are strained forms of beverage, cocoa and chocolate remain in the beverage and contribute to the nutritive value of the beverage. Because of their high content of fat, cocoa products are good source of energy. Milk, a usual constituent of cocoa and chocolate drink, adds to the nutritive value of the beverage. The theobromine and caffeine contribute to the stimulating effect of the beverage.  

Cocoa butter Cocoa butter which accounts for more than 50 per cent of cocoa bean is a valuable byproduct of the cocoa industry. The world trade in 1979 in cocoa butter was of the order of 175,000 tonnes. The butter is mostly used in the manufacture of chocolate. The butter is a pale yellow liquid with a characteristic odour and flavour of chocolate. It is brittle at temperatures below 25°C, softens in the hand and melts (34°C) in the mouth. It is not greasy to touch. It is rich in saturated fatty acids (palmitic and lower acids 26.21, stearic and higher acids 34.4 per cent). Oleic and linoleic acids are present to the extent of 37.3 and 2.1 per cent respectively. The butter keeps well due to the presence of fat-soluble antioxidants in it.

Cocoa Beverages Cocoa and chocolate, apart from their many uses in cooking; find extensive use in the preparation of beverages. When chocolate is used, it sticks to the container and gets scorched when heated. This can be eliminated by heating chocolate over hot water or by heating it at a low temperature. The melted chocolate is then blended with other ingredients. Owing to its high starch content, cocoa will lump if put directly into a hot liquid. It should be mixed with a small amount of cold liquid before-being combined with other ingredients. Cocoa and chocolate thus treated are heated to boiling and held at that temperature for sometime to gelatinize the starch. This gives body and flavour to the beverage and reduces the amount of sediment that settles from either of the beverages.

Apart from coffee, tea and cocoa, a number of preparations are available in the market such as Ovaltine, Bournvita, Boost etc., which are consumed as hot drinks. While the former group of beverages are stimulants the latter are energy foods and are consumed as supplementary foods to regular diet. They. contain mainly malted cereals, creamy milk, sugar and artificial flavour, and sometimes are fortified with nutrients and minerals. Some preparations also contain cocoa. The drink is prepared by stirring the mate­rial in warm water or milk and is generally consumed as hot drink; but could also be used as a cold drink.