Effect of addition of yeasts and enzymes during fermentation on physicochemical quality of fine aroma cocoa beans

Abstract

Theobroma cacao is a recognized crop worldwide within the market for raw materials or processed products. Cocoa beans quality, industrial transformation and health benefits have been widely studied, but there are few studies on the fermentation process and even less on Ecuadorian cacao. In Latin America, this crop plays a very important role from an ecological and social viewpoint. Production is usually carried out by local farmers who also perform the natural fermentation of the beans, without specific management, which represents a challenge in terms of reliability and batch-to-batch homogeneity. This drawback can be effectively addressed by controlling the fermentation conditions. In addition, certain enzymes have the potential to improve the fermentation process. The aim of this work was to study the effect of using yeasts and/or enzymes during fermentation on the physicochemical quality characteristics of cocoa beans. Two trials were carried out, the first used yeasts (Saccharomyces cerevisiae), with and without molasses, and the second used enzymes (Polyphenoloxidase and Pectintranseliminase). During the fermentation process there was not external temperature control, although cocoa beans mass temperature was assessed. After the assay, the cutting test and physicochemical variables (percentage of testa, testa and cotyledon pH, moisture, ash, acidity, protein and fat contents) were evaluated. The yeasts trial stood out as the most favorable option, showing better fermentation in the cutting test, a slight increase in protein content and lower moisture. The inclusion of enzymes in the trials resulted in higher fermentation temperatures and fat content of the beans, but the samples showed lower fermentation percentage, higher moisture and mold presence, as enzymes make it difficult to completely dry the samples. It can be concluded that the addition of yeasts and/or enzymes influences fermentation and could improve the process in order to obtain high quality cocoa beans.