Linhagens de Saccharomyces cerevisiae isoladas de uvas do Vale do São Francisco como produtoras de vinhos

Abstract

The aim of this work was to select Saccharomyces cerevisiae strains isolated in the must fermented of grapes (Vitis vinifera L.) farmed in Vale do Submédio do São Francisco (VSF), as starters of the fermentative process in winemaking. A total of 368 yeast isolates were obtained. Among them, 259 S. cerevisiae and 109 non-Saccharomyces strains were identified. From mitochondrial DNA restriction analysis (RFLP-mtDNA), it was possible the identification of 184 S. cerevisiae indigenous strains and 75 S. cerevisiae representing commercial strains. Twenty-two different profiles of RFLP-mtDNA were found in S. cerevisiae indigenous strains in comparison with the six most used S. cerevisiae commercial strains in the VSF. Among 184 S. cerevisiae indigenous strains, 46 did not produce H2S. Eighty S. cerevisiae indigenous strains and six commercial strains were used for micro fermentation experiments with synthetic must. At the end of the alcoholic fermentation process, ethanol, secondary compounds and the sugar consumption were determined. Based on the micro fermentation results, nine S. cerevisiae indigenous strains were selected. These strains and two S. cerevisiae commercial strains were used for wine production in small scale. Furthermore, fermentation parameters of yeasts were similar during the winemaking. From 33 volatile organic compounds identified, sample of wine 8 presented the best concentrations of fruity aromatic compounds. The volatile compound 2-phenylethanol (floral aroma) was obtained in an elevated concentration in the wines 7, 8, and 9 with higher levels than the other ones. After further studies, these strains may be used to produce wines in Vale do São Francisco Region, contributing for the typicity of beverage produced in that area.