Sucessão microbiana e dinâmica de substratos e metabólitos durante a fermentação de três híbridos de cacau (Theobroma cacao L.) cultivados no sul da Bahia

Abstract

During the 1980’s, Brazil was highlighted in the world cocoa market as a large producer, reaching historical marks of, 400,000 tons of dry almonds and a productivity of 750 kg/ha, for example, the largest in the global context at that time. From the 90’s, there was a decrease in the Brazilian productivity due to the dissemination of the “witch’s broom” disease (caused by the Moniliophtora perniciosa fungus). As a consequence, Brazil went from fermented and dry almond exporter to importer. Among the “witch’s broom” control measures in Brazil, researches on resistant and more productive cacao cultivars have received special attention. However, researches on the fermentation process of these new varieties were not taken into consideration. The objective of this work was to study the microbial succession and the physical-chemical characteristics during the fermentation of three hybrids produced in Southern Bahia (PH 9, PH 15 and PH 16). The microbial succession during the fermentation process of the three hybrids were similar, with yeast dominating the first 24 hours, subsequently Lactic Acid Bacteria (LAB), and, finally, Acetic Acid Bacteria (AAB) were the most representative until the end of the fermentation. However, the measures of LAB (3.91 CFU/mL), AAB (4.49 CFU/mL), yeast (3.13 CFU/mL) and mesophilic aerobic (2.48 CFU/mL) populations, during the fermentation of the PH9 clone, were more elevated than those found in the fermentation process of clones PH 15 and PH 16. Lactobacillus fermentum, L. Casei and L. rhammnosus were the predominant species in the fermentation of all the cocoa hybrids. However, the profile of the bacterial community detected by PCR-DGGE during the fermentation of the PH 9 clone was a lot more defined, with a higher number of bands. The Saccharomyces cerevidiae yeast was predominant in all the fermentations, followed by Hanseniaspora uvarum and the Pichia genus. A similar profile of substrate (glucose, sucrose, fructose and citric acid) and main metabolite kinetics (ethanol, acetic acid and lactic acid) consumption was also observed, but hybrid PH 16 presented the most elevated sugar, acid and alcohol concentrations.