Selection, growth, and chemo-sensory evaluation of flocculent starter culture strains of Saccharomyces cerevisiae in the large-scale production of traditional Brazilian cachaca.

摘要

The physiological and kinetic capabilities of 233 Saccharomyces cerevisiae isolates, originating from traditional Brazilian cachaca fermentation, were evaluated under laboratory conditions to select flocculent and non-H₂S producing strains to be employed in beverage production. Three flocculent S. cerevisiae strains were selected, two non-H₂S producing and one H₂S producing, and their kinetic performances were analysed during two large-scale fermentation experiments in a traditional cachaca distillery. One non-flocculent H₂S-producing S. cerevisiae strain was also used for comparison with the flocculent strains. The results of mitochondrial DNA restriction analysis showed that the three flocculent starter S. cerevisiae strains, as well as the non-flocculent strain, remained in the process during the whole fermentation period, with cells numbering around 107 cfu/ml. All selected strains produced ethanol yields that were typically higher in the distillery than in the laboratory conditions, except for strain UFMGA-1240. The greatest diversity of non-Saccharomyces yeasts was observed prior to day 21 of cachaca fermentation; Pichia membranifaciens and Hanseniaspora guilliermondii were the most frequently isolated species. These yeasts were present in lower densities throughout the whole process. The cachaca produced by the selected strains contained concentrations of chemical compounds in accordance with current Brazilian legislation, and all cachacas scored well in sensory effective tests. In addition to the advantage of being flocculent, the strain UFMGA-1031 is non-H₂S producing and also produces cachaca with good sensory acceptance. Therefore, this flocculent and non-H₂S producing S. cerevisiae strain is highly suitable as a starter for production of high quality traditional cachaca.