Influence of temperatures and fermentation behaviour of mixed cultures of williopsis saturnus var. saturnus and saccharomyces cerevisiae associated with winemaking
Up to now, this has been the first study in which the influences of fermentation temperature on the yeast growth and the production of yeast-derived volatile compounds during the fermentation of Emir grape must at various temperatures were examined. The results demonstrate that the fermentation temperature plays an important role compared to all tested variables. Fermentations were completed in 6, 8 and 14 days at 12, 18 and 24°C, respectively. Increase in temperature resulted in an increase in glycerol, total acidity, acetic and tartaric acid, 2-methyl butanol, propan-1-ol, isobutanol, acetaldehyde and acetone, but in a decrease in ethanol, malic and citric acid, isoamyl acetate, ethyl acetate, isobutyl acetate, ethyl butyrate and ethyl hexanoate. Moreover, these mixed culture fermentations formed higher amounts of isoamyl acetate in comparison with pure culture of S. cerevisiae. According to chemical composition and volatile compounds the differences between obtained wines were found generally significant.