Cocoa bean shells

Cocoa beans are sometimes evaluated in the laboratory to distinguish and characterize flavors. Beans are roasted at a standardized temperature for a specific period of time, shelled, usually by hand, and ground or heated slightly to obtain chocolate Hquor. The Hquor s taste is evaluated by a panel of... 

Table 4. Analyses of Cocoa Shell from Roasted Cocoa Beans...

With the death of the bean, cellular structure is lost, allowing the mixing of water-soluble components that normally would not come into contact with each other. The complex chemistry that occurs during fermentation is not fully understood, but certain cocoa enzymes such as glycosidase, protease, and polyphenol oxidase are active. In general, proteins are hydrolyzed to smaller proteins and amino acids, complex glycosides are split, polyphenols are partially transformed, sugars are hydrolyzed, volatile acids are formed, and purine alkaloids diffuse into the bean shell. The chemical composition of both unfermented and fermented cocoa beans is compared in Table 1. 

The cacao plant, Theobroma cacao, is the source of chocolate which is well known and highly prized in international commerce. The cacao pods contain beans which are fermented and pressed to provide a brown liquid which is the raw material for chocolate. The press cake is ground and sold as cocoa and it also provides a brown colorant. The pods, beans, shells, husks and stems have also been suggested as colorants. They contain a very complex mixture of acyl acids, leucoanthocyanins, flavonoid polymers, tannins, and catechin-type polymers.33... 

In a study on model systems prepared from single amino acid and glucose in molar ratio 2 1, approximating the composition of shell-free cocoa beans, Rohan and Stewart (52) reported that amino acid destruction from heating was temperature dependent and practically ceased after one hour. Sugar destruction contintued at a rate dependent on reaction temperature until the end of the experiment (Table IX). 

Cocoa beans have a bitter principle which is somewhat reduced by a fermentation process. The quality of the cocoa made from the beans depends to a considerable extent upon the success of this fermentation. The cocoa beans grow in bunches of thirty to forty,1 surrounded by a soft husk or shell. The beans are collected and placed in fermentation boxes with proper air vents. The sweet outer covering of the beans begins to ferment immediately. This mucous lining of... 

Theobromine (3,7-dimethylxanthine), which is 1.2% in cocoa, provides a stimulating effect, which is less than that of caffeine in coffee. Therefore, it is of physiological importance. Caffeine is also present, but in much lower amounts (average 0.2%). A cup of cocoa contains 0.1 g of theobromine and 0.01 g of caffeine. Theobromine crystallizes in the form of small rhombic prisms which sublime at 290 °C without decomposition. In cocoa beans theobromine is often weakly bound to tannins and is released by the acetic acid formed during fermentation of the beans. Part of this theobromine then diffuses into the shell. 

Fatty acid tryptamides (3-80) can be employed as indicator substances for detecting the shell content in cocoa products. The shell content is an important quality parameter for products that are made from roasted cocoa beans. The relevant substances are docosanoyl-2-(3-indolyl)ethylamide (behenic acid tryptamide) andtetracosanoyl-2-(3-indolyl)ethylamide (Hgnoceric acid tryptamide). Cocoa shells contain 330-395 mg/kgbehenic acid tryptamide and Hgnoceric acid tryptamide, but the cotyledons only 7-10 mg/kg. 

Cocoa beans are used extensively in the manufacture of chocolate, but this chapter is confined to the use of cocoa as a beverage. To produce the cocoa powder used in the beverage, the beans are roasted at 150°C and the shell (hull) and meat of the bean (nib) are mechanically separated. The nibs, which contain about 55% cocoa butter, are then finely ground while hot to produce a liquid mass or liquor . This sets on cooling and is... 

In live cocoa seeds, the methylxanthines are localized in polyphenolic storage cells. Bean death, which occurs 24 to 48 h after initiation of fermentation, triggers diffusion of the methylxanthines from the nib to the shell. The early studies of Humphries state that cacao cotyledons lose about 40% of their theobromine during fermentation.17 According to Knapp and Wadsworth, the loss of theobromine and caffeine becomes significant on the third day when the methylxanthines begin to diffuse into the shell.18 This migration continues until the concentration of the methylxanthines in nibs and shell are almost equal. 

Cocoa-purple, in cocoa shell from roasted beans, 6 357t... 

L-ascorbic acid and, 25 751 as chelating agent, 5 731 in cocoa shell from roasted beans, 6 357t Oxalic-acid-catalyzed novolacs, in molding compounds, 75 786 Oxalic acid esterification, 72 652 Oxaloacetic acid, in citric acid cycle, 6 633 Oxalosuccinic acid, in citric acid cycle, 6 633... 

Star-branched butyl rubber, 4 437-438 copolymers, 4 445-446 Starch(es), 4 703-704, 20 452-453 as blood substitute, 4 111-112 cationic, 18 114-115 in cereal grains, 26 271-274 in cocoa shell from roasted beans, 6 357t compression effects in centrifuges, 5 513 depolymerization, 4 712 in ethanol fermentation, 10 534—535 etherified, 20 563 as a flocculant, 11 627 high-amylose, 26 288 Mark-Houwink parameters for, 20 558t modified and unmodified, 12 52-53 in paper manufacture, 18 122-123 performance criteria in cosmetic use, 7 860t... 

---