Assessment of the technological performance of some Saccharomyces and non-Saccharomyces indigenous yeast strains

The study aimed to assess the technological potential of four indigenous Saccharomyces cerevisiae strains (S. cer. 4.1.11, S. cer. 4.3, S. cer. 4.6 and S. cer. 4.10), as possible sources for starter cultures. The experiments were carried out at micropilot level on the natural must of 'Fetească albă' cultivar. The evaluation of the yeasts was carried out according to the chemical parameters and volatile compounds analysed in the obtained wines compared to the wine obtained with a commercial starter culture (CSC). The values of the main physico-chemical parameters analyzed in the obtained wines were similar to those determined in the control wine. The average values of the volatile compounds with positive impact on the wine aroma ranged within the interval 177.46 - 217.81 mg/L, a higher value compared to the control wine, respectively 166.33 mg/L. The use of the indigenous strain Torulospora delbrueckii (T.d 10) in association with the strains S. cer. 4.1.11 or S. cer. 4.10 led to an increase of 12.56%, respectively 8.30% in glycerol concentrations, as well as an increase of 11.94% to 14.49% in the average concentration of volatile compounds. Harnessing the oenological potential of the yeasts tested in sequential fermentations proved dependent on the time allowed for the development of the strain T.d 10, namely 24 and 48 hours, as well as on the yeasts used. Thus, in the wines obtained by the association T.d 10/ S. cer. 4.10, in which the development of the culture T.d 10 was carried out for 48 hours, we noticed an increase of 12.52% and, respectively 32.95%, in the average of volatile compounds, compared to the monoculture wine for the same S. cer. 4.10 strain and to the control wine (CSC)