Study on the cocoa fermentation by using microbial enzymes produced by aspergillus niger and bacillus subtilis within molasses for high soluble solids extraction

Abstract

Cocoa is the basis material for chocolate production. However, in order to get the chocolate flavor and colour, the cocoa bean fermentation needs to be carried out. Generally, this process prolongs for 5-7 days. The main purpose of fermentation is to remove the viscous layer surrounding the bean to get the total soluble solids content inside. This study applied microbial enzymes collected from Aspergillus niger and Bacillus subtilis with the ultimate goals are to speed up the fermentation duration and increase the amount of total soluble solids content. Microorganisms were cultured in molasses media with supply of pectin and CMC in order to retrieve the highest yield of pectinase and cellulase. These enzymes are then determined activities using CMC assay (Ghose, 1987) and Pectinase assay (Khanh, 2014). After activities determination, enzymes were applied in cocoa fermentation. The total soluble solids content would be measured by refractometer. The result show that the duration lessened from 120 hours for control sample to 20 hours. Moreover, the total soluble solids content values increased up to 30.56 – 37.22% compare to control sample. In addition, no toxicity was detected. This means our products are safety. After the project finish, we will get the information about cocoa fermentation ability of pectinase and cellulase produced by A. niger and B. subtilis. This project will open a new path in food industry, especially in cocoa fermentation for chocolate producing. Keywords: Aspergillus niger Bacillus subtilis Cocoa beans Fermentation Total soluble solids content