Desarrollo de un inóculo microbiano optimizado a partir de cepas nativas de levaduras para la fermentación del cacao Theobroma cacao L

Abstract

The fermentation of cocoa represents a critical stage for the development of its sensory characteristics, directly associated with the commercial value and quality of the final product. In Ecuador, the world’s fourth-largest cocoa producer, this process continues to be carried out empirically, generating variability in aromatic profiles and affecting the economic stability of small farmers. Faced with this issue, there is a need to optimize fermentation through the use of native yeast strains, allowing for control and standardization of the process, improving the sensory quality of the beans, and ensuring their competitiveness in specialized markets. The methodology consisted of isolating fermentative yeasts native to CCN51 cocoa crops, collected during the alcoholic phase of fermentation. Microbiological plating was performed on PDA medium, followed by macroscopic, microscopic, and biochemical identifications (API 20C AUX V5.0), selecting Kloeckera apis as the strain of interest. Subsequently, its fermentative potential was determined through growth curves and biomass quantification via optical density (OD), as well as the consumption of reducing sugars by spectrophotometry. Finally, an optimized inoculum was applied in controlled fermentations, evaluating physicochemical parameters (pH, °Brix, and temperature) and sensory attributes through comparative tastings. The study concluded that the optimized microbial inoculum, based on Kloeckera apis, reduced fermentation time and improved the sensory profile of the cocoa, highlighting a decrease in astringency and a greater aromatic intensity. These results demonstrate the potential of using native yeasts as a biotechnological tool to standardize and improve the quality of cocoa fermentation in Ecuador.