Interação de Saccharomyces cerevisiae e Lactobacillus fermentum na produção de cachaça artesanal

Abstract

The production of Brazilian sugar-cane spirit (cachaça) is estimated at 1,5 billion liters a year being 90% industrial and 10% artisanal. The artisanal cachaça is a distilled beverage originating from natural fermentation of sugar-cane juice, with ethanol content varying from 38 to 48% (v/v). The microbial population in the must comprises yeasts and bacteria which interact during the fermentation process. Research done on microbiota of the must of alcoholic fermentation demonstrated that the genus of bacteria which predominates is Lactobacillus, being the Lactobacillus fermentum one of the most frequent species. The objectives of this work were to evaluate the efficiency of cultivation media in the multiplication of Lactobacillus fermentum 1407 and the interaction of Saccharomyces cerevisiae CA 116 and L. fermentum CCT 1407 during the fermentation and evaluate the quality of the final beverage. The alcoholic fermentation was accomplished in erlenmeyers of 2.000mL inoculated separately with CA116 and CCT 1407 and co-incubated, and in vats CA116 separately and co-incubated with CCT 1407. The cane juice broth 5ºBrix + 1% of yeast extract had the same efficiency for the growth of the L. fermentum when compared with MRS. The co-incubation with L. fermentum did not influence the growth of S. cerevisiae. The bacteria L. fermentum did not compete with the S. cerevisiae for the consumption of reducing sugars. The co-incubation of L. fermentum with S. cerevisiae did not contribute to reduce the pH value. Saccharomyces cerevisiae repressed growth of L. fermentum during the co-incubation causing cellular death of this bacteria after 12 hours. The concentration of higher alcohols in the beverage were below 300mg/mL of alcohol. The presence of L. fermentum during the alcoholic fermentation interfered negatively in the sensorial quality of the artisanal cachaça.