Evolution of cis and trans-resveratrol in wines obtained through inoculation with active dry yeast at pietroasa vineyard

This paper presents the results of the testing during the winemaking process using commercial active dry yeasts (CADY) in parallel with yeast biomass produced starting from yeasts isolated from Pietroasa area (Romania) (PAY). PAYs were obtained based on autochthonous yeasts isolated from Busuioaca de Bohotin (BB) and Tamaioasa Romaneasca (TR) grape varieties. Two variants of must for each grape variety were taken in study, i.e. obtained from early harvested grapes (TRD and BBD) and from late harvested grapes (TRS and BBS). Winemaking experiments were carried out with 7 types of commercial yeasts and two types of commercial nutrients. The alcoholic concentration of the experimental wines varied from 11.8 % for WTRD to 18.4% for WBBD. The WBBD & S samples showed a higher average trans-resveratrol content (1.716 and 1.555 mg/L, respectively) compared to the WTRD & S wine samples (0.590 and 1.365 mg/L, respectively). The variation in the cis-resveratrol content between the experimental variants produced with PAY was not significant.