Biocontrol of Molds Growth during Cocoa Bean (Theobroma cacao L.) Fermentation Using Native Yeast Species: Saccharomyces cerevisiae and Candida incommunis

Abstract

Background: The overall quality of dry fermented cocoa beans is three-dimensional, including the market, aromatic, and health aspects. The molds that are present during post-harvest technological treatments up to the storage of fermented and dried cocoa beans play a harmful role by degrading the health quality of the cocoa beans. Cocoa from Ivory Coast is no exception to this problem; it is exposed to potential major risks of contamination with ochratoxin A, produced by mold. Aims: The present study investigated the reduction of contamination of cocoa beans by mold using potentially antagonistic biological agents including antifungal yeasts such as Saccharomyces cerevisiae and Candida incommunis. Study Design: Biocontrol of mycotoxigenic mold growth in cocoa using yeasts. Place and Duration of Study: Food Biotechnology and Microbiology Laboratory, Food Science and Technology Research Department, Nangui ABROGOUA University, Côte d’Ivoire, between March and June 2024. Methodology: After highlighting the antifungal properties of Saccharomyces cerevisiae and Candida incommunis by direct and indirect confrontation techniques on Aspergillus carbonarius, A. ochraceus, and A. niger isolated from cocoa fermentation, they were inoculated into the cocoa beans before fermentation. The physicochemical parameters were measured. Results: The main results obtained showed antagonistic effects of S. cerevisiae and C. incommunis against all the pathogenic molds A. carbonarius, A. niger, and A. ochraceus. After inoculation for fermentation, among the tested biological agents, only C. incommunis induced an increase in temperature reaching 49 °C. The titratable acidity of the inoculated cocoa beans was between 0.06 and 0.12 Eq. of NaOH.g-1 of cocoa during fermentation. No potentially antifungal biological agent tested had any effect on the marketability of cocoa. However, only C. incommunis showed a total biocontrol effect against molds during cocoa fermentation. Conclusion: The findings of this study could be applied to the bio-decontamination of fermented foods contaminated with pathogenic molds, and thus to reducing mycotoxin production using C. incommunis, which exhibits high fungal antagonistic potential.