THE IMPACT OF THE FERMENTATION CONDITIONS ON THE ESTER PRODUCING CAPACITY OF DIFFERENT SACCHAROMYCES CEREVISIAE STRAINS AND THE ORGANOLEPTIC PROFILE OF CABERNET SAUVIGNON WINES

Abstract

The ester producing capacity of two strains of Saccharomyces cerevisiae was investigated, depending on the alcoholic fermentation conditions of grape pulp from Cabernet Sauvignon variety. The influence of the temperature (20°C, 24°C, 28°C) and the inoculum amount of yeast culture (2%, 3%, 4%) on the total esters synthesized during the process was monitored. Neural networks were implemented and mathematical models were derived, adequately describing the fermentation processes at the combination of grape variety – yeast strain – conditions. The results of gas chromatographic analysis identified methyl acetate, ethyl acetate, propyl acetate, isobutyl acetate, butyl acetate, isoamyl acetate, amyl acetate, ethyl hexanoate, ethyl octanoate, ethyl decanoate in the wines. It was found that the impact of esters produced by the yeasts on the organoleptic profile of the wines was not because of their total amount but mainly due to the ratio between the individual representatives. Under the experiment conditions the strain Saccharomyces cerevisiae 8-11, fermented at 28°C, with 3% inoculum yeast culture was identified as more suitable for the production of Cabernet Sauvignon wines.