Factors associated with cacao bean acidity and the possibility of its reduction by improved fermentation. In: Theobroma v. 13 p. 233-248, 1983.

Abstract

An investigation of the agents responsible for the acidity of cacao beans was carried out by separating the total bound and free acids into their volatile and non-volatile components. The bound acids have Iittle influence on the acidity of cacao in contrast to the free acids, whose content was found to be related (correlation factor r = -0.9514) to the pH changes of lhe bean cotyledon during fermentation. Acetic acid is considered to be the chief volatile free acid in the fermented bean while citric, lactic and phosporic acids are the main non-volatile acids. Acetic and lactic acids originale from microbial activity of fermentation, citric acid is inherent to the cacao bean and phosphoric acid is produced during the germinating phase. In the fully fermented bean (6 days), acelic acid appears to be the principal free acid, the non-volatile acids playing secondary roles. However, in the case of under-fermenled cacao (3 to 5 days), the positions may be reversed. The discrepancies in the results presented when compared to analysis of commercial samples are attributed to this fact. Enforcing a 6 to 7 day fermentation period is recommended as an initial slep towards lowering the acidity of cacao beans.