In fermenting cocoa

Biehl B, Brunner E, Passem D, Quesnel VC, Adomako D (1985) Acidification, proteolysis and flavour potential in fermenting cocoa beans. J Sci Food Agric 36 583-598... 

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. 

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. 

KI Tomlins, DM Baker, IJ McDowell. HPLC method for the analysis of organic acids, sugars, and alcohol in extracts of fermenting cocoa beans. Chromatographia 29(11/12) 557-561, 1990. 

Cleaning and sizing of the fermented cocoa bean with a water content of 6-8% are the first step. Any extraneous matter and broken beans are removed and selected sizing of whole beans is performed by specialized equipment. Sizing of the beans is important in order to later achieve uniform roasting. 

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... 

Cocoa flavor. Some of the over 500 known volatile components of C. f. are already present in raw cocoa, but most are formed after diying and roasting (at 110-130 °C), mainly by Maillard or Strecker reactions from amino acids, peptides, and sugars resulting from anaerobic fermentation. C. f. is not determined by one impact compound but is rather a composition of various aromas caramel-like ( maltol, Furaneol , and 2-hydroxy-3-methy 1-2-cyclopenten-1 -one), flowery ( linalool, 2-phenylethanol, phenylacetaldehyde). 

These three alkaloids are well-known compounds, as they are present in everyday foods and beverages, such as cocoa, drinking chocolate, tea, and cola, as well as in pharmaceutical products. In cocoa products, theobromine is the major alkaloid, followed by caffeine, which is found in small quantities. Slight traces of theophylline have been identified therefore, it is not considered relevant and is not reviewed in the cocoa products [22,23], The range of methylxanthines also depends on variables such as the origin of the cocoa beans, the fermentation process, and the cocoa production process. Thus, for instance, defatted cocoa beans may contain about 4% and 0.2% of theobromine and caffeine, respectively [24], Regarding their physiological effects in humans, methylxanthines have been related to various body systems, mainly the central nervous system, but also the cardiovascular, renal, and respiratory systems [25,26],... 

The compounds found in fermented and dried raw cacao, the basis for chocolate production, differ considerably from the compounds present in fresh-harvested cocoa seeds. The transition of fresh seeds to raw cocoa takes place in the... 

Bhattacharya A, Sood P, Citovsky V (2010) The roles of plant phenolics in defence and communication during Agrobacterium and Rhizobium infection. Mol Plant Pathol 11 705-719 Kim H, Keeney PG (1984) (-)-Epicatechin content in fermented and unfermented cocoa beans. J Food Sci 49 1090-1092... 

Kim H, Keeney PG (1984) (-)-Epicatechin content in fermented and unfermented cocoa beans. J Food Sci 49 1090-1092... 

Jinap Selamat M, Bakar J, Saari N (2002) Oxidation of polyphenols in unfermented and partly fermented cocoa beans by cocoa polyphenol oxidase and tyrosinase. J Sci Food Agric 82 559-566... 

Camu N, Gonzalez A, De Winter T, Schoor AV, De Bruyne K, Vandamme P, Takama JS, Addo SK, De Vuyst LD (2008) Influence of tuning and environmental contamination on the dynamics of populations of acetic acid and acetic acid bacteria involved in spontaneous cocoa bean heap fermentation in Ghana. Appl Environ Microbiol 74 86-98 Caro I, Palacios VM, Perez L (1998) Kinetic models for the acetic acid fermentation. Recent Res Dev Biotechnol Bioeng 1 203-211... 

Fig. 3.1 Cocoa bean box fermentation is a commonly used method for fermentation of the cocoa pulp-bean mass. A cascade of three boxes of about 1 m each is an optimal setup for this fermentation process. In a box fermentation process, fermentation of the cocoa pulp-bean mass starts in the upper box every 24 h, the fermenting cocoa pulp-bean mass is transferred to a lower box. At the end of the fermentation process, the fermented cocoa beans are collected...

Fig. 3.2 Microbial succession (a) and metabolic activities (b) of the key factors in the cocoa bean fermentation ecosystem. Dashed lines (b) represent the substrates present in the cocoa pulp-bean mass full lines represent metabolites produced by the microorganisms present...

Jespersen L, Nielsen DS, Hpnholt S, Jakobsen M (2005) Occurrence and diversity of yeasts involved in fermentation of West African cocoa beans. FEMS Yeast Res 5 441-453 Jung JY, Lee SH, Kim JM, Park MS, Bae J-W, Hahn Y, Madsen EL, Jeon CO (2011) Metagenomic analysis of kimchi, a traditional Korean fermented food. Appl Environ Microbiol 77 2264-2274... 

Papalexandratou Z, De Vuyst L (2011) Assessment of the yeast species composition of cocoa bean fermentations in differem cocoa-producing legimis using denaturing gradient gel electrophoresis. FEMS Yeast Res 11 564—574... 

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