Changes in Biochemical and Physico-chemical Qualities during Drying of Pulp Preconditioned and Fermented Cocoa (Theobroma cacao) Beans

Abstract

This study investigated the effects of post-harvest pod storage as a means of pulp preconditioning on the souring production, flavour precursors development and free fatty acids during drying of fermented Ghanaian cocoa beans. A 4 x 4 full factorial experiment was conducted with pod storage (0, 7, 14, 21 days) and drying times (0, 2, 4 and 6 days) as the principal factors. The souring/acidification indices (pH and titratable acidity), total sugar, total nitrogen and free fatty acids (FFA) were studied using standard analytical methods. The results showed that titratable acidity, total sugars and total nitrogen in cocoa beans decreased during drying and with increasing pod storage durations probably due to their participation in Maillard non- enzymatic reactions to form flavour volatiles and colour pigments as Amadori intermediates. By contrast, FFAs and pH increased during drying and with increasing pod storage durations. Pod storage for up to 7 days followed by 6 days of fermentation and drying respectively produced beans with acceptable FFA values below 1.75% whilst enhancing the flavour precursors development and reductions in nib acidity. However, these observed changes were more dependent on pod storage than on drying.