Fermentation-like incubation of cocoa seeds (Theobroma cacao L.) – Reconstruction and guidance of the fermentation process

The cacao tree (Theobroma cacao L.) is the only source for the key raw material in chocolate manufacturing. However, fresh cocoa seeds do not develop any chocolate flavour during chocolate manufacturing because they do not contain the precursors necessary. The latter are formed only during the fermentation process that the seeds are subjected to in the countries of origin. During this in most cases spontaneous fermentation of the fruit pulp surrounding the seeds, the pulp is degraded by yeasts and bacteria. This degradation results in heat and organic acid formation. Heat effect and tissue acidification are the key parameters guiding flavour precursor formation. Accordingly, not microorganisms themselves but exclusively their metabolites are necessary for successful fermentation. In the present study we subjected fresh cocoa seeds to three types of fermentation-like incubation with defined amounts of acetic acid, controlled temperature regime and in the absence of microorganisms. All raw cocoa samples were of high reproducible quality as determined by biochemical quality parameter analysis. We conclude that control of the heat effect and the acidity is the reason for these quality characteristics and that application of this technique may permit standardization and mechanization of cocoa fermentation.