Volatility chocolate processing

Besides their general flavor forming potential peptides are also reported to be unique precursors of composite food aromas. Peptides formed in the fermentative stage of cacao processing have been linked to roast generated chocolate aroma (5). Also, a methionine rich polypeptide has been associated vith roasted peanut volatiles (15). 

Discriminant analysis has been used in many of the analyses described in this chapter, in particular the classification of cocoa butters by origin and processing from pyrolysis MS data (Radovic et al., 1998), from triacylglycerol profiles obtained by HPLC (Hernandez et al., 1991) and from analysis of volatiles (Pino, 1992). Data from the analysis of mixtures of CBEs with cocoa butter, which model techniques for measuring CBEs in chocolate, have been treated by similar means (Anklam et al., 1996). 

For chocolate production, the raw cocoa is stored, shipped, and processed. The processing steps are roasting and liquor production. The heat treatment induces Maillard reactions, caramelization of sugars, protein degradation, and formatiiMi of volatile aroma components [85, 89]. An often applied step to cocoa is the dutching, the alkali treatment of cocoa powder in order to modify the color, and other physiochemical properties. The pH values of cocoa powders are adjusted from ph 5.3-5.8 in natural powders to higher than 7.6 in heavily dutched materials. The total flavanol contents are reduced from more than 34 to 3.9 g kg In the same way, the antioxidative properties of the powders are diminished [90]. 

Owusu, M., Petersen, M.A., and Heindal, H. (2011) Effect of fermentation method, roasting and conching conditions on the aroma volatiles of dark chocolate. J Food Process Pres 36,446-456. 

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