BioProject

Hanseniaspora opuntiae is one of the most commonly found yeast species in naturally fermenting cocoa pulp-bean mass. More...

Hanseniaspora opuntiae is one of the most commonly found yeast species in naturally fermenting cocoa pulp-bean mass. However, its behaviour has not been explored during spontaneous nor starter culture-initiated cocoa fermentation processes. Therefore, the present study aimed at examining the effects of the cocoa isolate H. opuntiae IMDO 040108 as the sole inoculated yeast strain as well as in combination with a well-performing yeast strain of cocoa origin (Saccharomyces cerevisiae IMDO 050523), both in the presence of the lactic acid bacteria strain Limosilactobacillus fermentum IMDO 0611222 and the acetic acid bacteria strain Acetobacter pasteurianus IMDO 0506386. Those effects encompassed the microbial community, substrate consumption, and metabolite production dynamics, including volatile organic compound (VOC) and phytochemical compositions, as well as the compositions of the cocoa beans after fermentation, the cocoa liquors, and the chocolates produced thereof. All starter culture strains applied could be successfully monitored during fermentation by an amplicon sequence variant approach. It turned out that the inoculated H. opuntiae strain was unable to prevail over the background yeasts present in the fermenting cocoa pulp-bean mass. It led to under-fermented cocoa beans after four days of fermentation, which was reflected in higher levels of catechin, epicatechin, and proanthocyanidins. Oppositely, the spontaneous fermentation process, during which background Hanseniaspora species were predominant, yielded successfully cured cocoa beans. Cocoa fermentation processes inoculated with the S. cerevisiae strain enhanced the flavour production during the fermentation and drying steps, which was, in turn, reflected in the richer and more reproducible aroma profiles of the cocoa liquors and chocolates produced thereof. Finally, the sensory analysis of the cocoa liquors and chocolates produced demonstrated that the use of a starter culture comprising S. cerevisiae led to more acidic notes compared to those from cured cocoa beans obtained by spontaneous fermentation processes, as a result of an advanced fermentation degree. Further, different VOC profiles were found in the cocoa beans throughout the whole chocolate production chain, depending on the fermentation process, but no significant differences were found regarding fruitiness in the cocoa liquors and chocolates produced. Less...