Changes in total polyphenols, o-diphenols and anthocyanin concentrations during fermentation of pulp pre-conditioned cocoa (Theobroma cacao) beans

Abstract

Investigations were conducted to elucidate changes in total polyphenols, o-diphenols and anthocyanin concentrations during fermentation of pulp preconditioned Ghanaian cocoa beans. A 4x4 factorial experiment was conducted with the principal factors as pod storage and fermentation time, and samples were analyzed using standard analytical methods. Results showed that total polyphenol, o-diphenols and anthocyanin content of beans from the unstored pods were 180.87 mg/g, 24.17 mg/g, and 15.68 mg/kg respectively. Reductions in the concentrations of total polyphenols, o-diphenol and anthocyanin composition of the cocoa beans occurred with increasing pod storage and fermentation time. However, the rates of decreases were more dependent of fermentation time than on pod storage. Both total polyphenol and o-diphenol content reduced only slightly (<10%) in the beans fermented for 6 days after 7 days pod storage. Storage of cocoa pods for up to 7 days after harvesting retained about 88% and 90% of total polyphenols and o-diphenol content respectively after 6 days of fermentation. Further increase in pod storage above 7 days leads to drastic reductions in the polyphenolic content of the fermented beans. The observed changes would result in significant reduction in astringency and bitterness in their derived chocolates products during subsequent industrial manufacture.