Small-scale cacao (Theobroma cacao L.) fermentation process utilizing cacao pod husk

Abstract

Cacao fermentation is a postharvest process that yields cacao flavour precursors which eventually develop into distinct cacao flavour and aroma upon roasting. A standardized procedure to achieve quality fermented beans is the utilization of a large amount of cacao wet beans (25 kg – 500 kg) placed in fermentation boxes to achieve desired fermentation temperature, posing a challenge to small-scale farmers with a minimal amount of harvested beans. This study aimed to optimize a small-scale cacao fermentation treatment by enhancing volume requirement by utilizing cacao pod husk (CPH) in the fermentation matrix. Fermentation parameters such as bean temperature and pulp pH were factors considered during optimization. The optimization process used 9 treatments with varying ratios of beans and CPH. The temperature of CPH was also considered a factor that affected the temperature of beans. The treatments with CPH were observed to have significantly higher daily mean temperatures than those without (p = 0.01529). Test for correlation between the temperature of beans and CPH for treatments with CPH revealed 3 kg wet beans with 4 kg CPH (3FB+4CPH) have the highest correlation at 0.9806. It is based on this result that the treatment identified as the best small-scale set-up was the 3FB+4CPH. The high-temperature readings of CPH in the treatments with CPH (40o C or higher) indicate a complementing effect to the temperature of fermenting beans above it. It also suggests that added CPH in the treatments have the same effect in increasing the temperature of the fermenting beans. Results also showed that there was no significant difference in pulp pH among treatments (p = 0.9464). Based on the result of the pH reading for the various optimization treatments and considering results from different studies, the day 5 pH readings gave the best range of pH that is expected at the end of fermentation. The findings proved that the small-scale fermentation (3FB+4CPH) can be a practical and low-cost treatment compared with the traditional fermentation treatment.