Effect of pulp preconditioning on the content of polyphenols in cocoa beans ( Theobroma Cacao) during fermentation

Abstract

Polyphenol components were extracted from Malaysian mix-hybrid cocoa beans from different treatments of fermentation namely; post harvest pod storage, bean spreading and pressing. The polyphenol compounds were analyzed using high pressure liquid chromatography. The (−)-epicatechin, (+)-catechin, theobromine and caffeine of control treatment at 5 days pod storages were 11.87, 4.31, 21.08 and 3.85 mg/g, respectively. Pre-fermentation treatments were found to be significant in affecting the changes in acidity, degree of fermentation and the polyphenol content of cocoa bean. During fermentation, all pre-treated samples showed decreased levels of (−)-epicatechin and (+)-catechin but the rate of decrease were found to be different. It was also found that the (−)-epicatechin and (+)-catechin content before and after fermentation was affected by the type of pre-fermentation treatment used. Percentage lost for (−)-epicatechin and (+)-catechin during fermentation at different degree of fermentation ranged from 6 to 17% and 0.95 to 1.62%, respectively. It was observed that pod storage treatments until 15 days have significant effect in the reduction of acidity, fermentation index (FI) and polyphenol contents compared to spreading and pressing methods. Recoveries (Rv) ranged from 90.90 to 93.92% with % coefficient of variances (CVs) of 6.51, 8.57, 2.42 and 6.37 for (−)-epicatechin, (+)-catechin, theobromine and caffeine, respectively. This study indicates that 15 days pulp preconditioning is the optimum conditions for the degradation of (−)-epicatechin and (+)-catechin, theobromine and caffeine.