Organic acids in cocoa beans - a review

Cocoa beans contain about 0.47 - 1.02 volatile and 1.01 - 1.88 nonvolatile acids (dry wt.). The volatile acids are acetic, propionic, butyric, isobutyric and isovaleric whereas nonvolatile acids are oxalic, citric, malic, succinic, lactic and tartaric. These acids are developed mainly through various microorganism actions in the pulp and then diffuse into the bean (cotyledon) during fermentation. Aeration, mass and period of fermentation, and the type and duration of heat applied during drying are the main factors governing the final pH, titratable acidity and concentration of acids in commercial beans. The volatile acids are also affected during bean roasting and chocolate conching. The accumulation of the acids during fermentation provides an acidic environment for bean death and enzymatic reactions leading to development of flavour precursors. The residual acid determines the acidic taste of the products made thereof. Acetic and lactic acids have been strongly implicated as the major cause for acidic taste in the final products