Indigenous lactic acid bacteria as a biological control agent to prevent fungi contamination in the fermentation of cocoa beans

The contamination of mycotoxin-producing fungi during cocoa fermentation is a major concern of cocoa bean quality. This research aimed to investigate the effect of indigenous lactic acid bacteria starter culture, Lactiplantibacillus plantarum subsp. plantarum HL-15, on the fungi population and the quality of cocoa beans. Fermentation of cocoa beans was carried out by four treatments, namely, fermentation without starter culture in the used box, fermentation with starter culture in the used box, fermentation without starter culture in the new box, and fermentation with starter culture in the new box. The population dynamics of yeast, lactic acid bacteria, acetic acid bacteria, and fungi during fermentation were evaluated. The addition of L. plantarum subsp. plantarum HL-15 ensured the rise of temperature in the fermentation. There were changes in the growth pattern of these microorganisms during fermentation as the effect of starter culture addition. The addition of L. plantarum subsp. plantarum HL-15 effectively inhibited fungi growth. Fermentation using starter culture in newly made boxes was the most effective method to inhibit fungi growth and improve cocoa bean quality. Fermented cocoa beans produced by this method can adhere to the requirements of first-grade quality cocoa beans based on the Indonesian National Standard.