Investigations on the Aroma of Cocoa Pulp ( Theobroma cacao L.) and Its Influence on the Odor of Fermented Cocoa Beans.

The odor-active constituents of cocoa pulp have been analyzed by aroma extract dilution analysis (AEDA) for the first time. Pulps of three different cocoa varieties have been investigated. The variety CCN51 showed low flavor intensities, in terms of flavor dilution (FD) factors, in comparison to varieties FSV41 and UF564, for which floral and fruity notes were detected in higher intensities. To gain first insights on a molecular level of how the cocoa pulp odorants affected the odor quality of cocoa beans during fermentation, quantitative measurements of selected aroma compounds were conducted in pulp and bean at different time points of the fermentation. The results showed significantly higher concentrations of 2-phenylethanol and 3-methylbutyl acetate in pulp than in the bean during the different time steps of the fermentation, whereas the reverse could be observed for the odorants linalool and 2-methoxyphenol. The findings of this study constitute a basis for further investigations on the aroma formation of cocoa during fermentation.

Determination of oligomeric proanthocyanidins and their antioxidant capacity from different chocolate manufacturing stages using the NP-HPLC-online-DPPH methodology.

Cocoa beans are a well-known source of antioxidant polyphenols. Especially individual oligomeric proanthocyanidins demonstrated a significant contribution to the total antioxidant activity of cocoa compared to monomeric compounds. An NP-HPLC-online-DPPH assay was developed for separating the homologous series of oligomeric proanthocyanidins and the simultaneous assessment of their antioxidant capacity in relation to the degree of polymerization (DP). The present study describes the influence of the different stages of a lab-scale chocolate manufacturing process on the content of oligomeric proanthocyanidins and their antioxidant capacity. The sum of the total proanthocyanidin content (∑ DP1-DP13) decreased from 30mg epicatechin equivalents per gram non-fat dry matter in raw fresh cocoa beans to 6mg epicatechin equivalents per gram in the final chocolate. The antioxidant capacity decreased accordingly from 25mg epicatechin equivalents per gram non-fat dry matter in raw fresh cocoa beans to 4mg/g in the final chocolate product.