Application of selected starter cultures in cocoa fermentation: effects on sensory-related volatile and non-volatile organic compounds.

Abstract

This study investigates the impact of a defined starter culture on the fermentation of cocoa beans and its influence on the production of volatile and non-volatile compounds related to sensory quality. A microbial consortium comprising Saccharomyces cerevisiae, Pichia kudriavzevii, Levilactobacillus brevis, and Acetobacter okinawensis was selected based on their enzymatic activity and acid regulation properties. Fermentation trials showed that the starter culture enhanced the synthesis of key volatile compounds, particularly esters and higher alcohols, such as 2-phenylethanol and 2-phenylethyl acetate, which contribute floral and fruity aromas. Compared to artisanal fermentation, treatments with starter cultures exhibited lower levels of lactic and acetic acids and an increase in succinic acid, indicating a balanced acid profile and potential metabolic synergy between inoculated and native microbiota. The study also identified specific volatile compounds as potential biochemical markers to monitor fermentation progress. These findings support the application of functional starter cultures to standardize and improve cocoa fermentation, offering opportunities to enhance quality and value in small-scale production systems.