Changes in Physico-Chemical and Microbiological Properties in Thai Cocoa Bean Fermentation

Abstract

The purpose of this research is to investigate the quality-related physical, chemical, and microbiological changes in Thai cocoa beans during fermentation in 2 types of wooden containers. The results will compose a book of guidelines for good Thai cocoa fermentation in order to educate Thai farmers. Fresh Thai cocoa beans have a low pH value (5.0 - 5.5) compared to those from other countries in general (6.0 - 7.0). However, fermented temperature is able to reach 40 - 45 °C in 6 days, which is a main criteria for finishing cocoa fermentation. The color of fresh cocoa beans changes from white to brown within 2 days; after that, cocoa beans are mixed from the top to the bottom of the containers. Three groups of microorganism are evaluated with 3 different sampling points in wooden containers. The results reveal that yeast is grown quickly in 2 days on the top of containers, and then acetic acid bacteria and lactic acid bacteria are grown by the utilized yeast’s metabolites. These behaviors were found in both of the 2 wooden containers; however, a heap of cocoa beans (200 - 250 kgs) in a wooden box showed better quality of cocoa fermentation than a small volume (40 - 50 kgs) in a wooden tray. HIGHLIGHTS Understanding changes in Thai cocoa beans fermentation based on traditional method Two type of wooden containers applied for comparing all quality-related cocoa fermentation Proper cocoa beans fermentation process composed to a book of guideline for Thai Farmers GRAPHICAL ABSTRACT