Polyphenol and Microbial Profile of On-farm Cocoa Beans Fermented with Selected Microbial Consortia

Abstract

Background and Objective: Quality and preference of cocoa as raw material for various mcocoa products primarily depend on fermentation techniques that modulate the resultant flavour and the phytochemical properties. This study investigated the combined effect of selected microbial consortia and bioreactors on phytochemical profiles of fermented cocoa beans. Material and Methods: Three microbial consortia labeled as Treatments (T-1, T-2, T-3) were used as starter culture (≈105cells ml-1) for on-farm cocoa fermentation on three chambers (basket, woodbox, and plastic) for 7 days. These novel consortia were T-1, Staphylococcus spp + Pseudomonas spp+ Bacillus spp, T-2, Staphylococcus spp + Pseudomonas spp + L. lactis , and T-3, Bacillus spp+ Lactobacillus spp + Saccharomyces spp+ Torulopsis spp. Results and Conclusion: The microbial profile were significantly (P≤0.05) altered by all treatments (T-1, T-2, T-3) and microbial frequency was enhanced by 5 -22.5%. T-3 and T-1 significantly altered phenolic content in basket chamber. Tannin was significantly (p≤0.05) varied by T-1(basket, plastic, wood box) and T-2(plastic). Tannin: polyphenol conversion ratio adopted as fermented cocoa bean quality benchmark was significantly enhanced by T-1 (basket, woodbox) and T-2 (plastic), but was significantly suppressed by T-3 (basket). This study evidently concluded that the appropriate synergy of microbial flora and fermenting chambers could achieve good cocoa quality with low polyphenol content (best for cocoa beverages) or high polyphenol content (best for pharmaceutical, confectionery and nutraceutical industries). These findings would avail an economic alternative to the expensive polyphenol reconstitution of cocoa butter used for various industrial products, thereby maximizing economic benefits for both cocoa farmers and industrialists. Conflict of interest: The authors declare no conflict of interest.