Abstract

Yeasts from the wine fermentation were processed and used as nitrogen source to replace the diaminephosphate (DAP). Saccharomyces cerevisiae were autoclaved and later hydrolyzed to 15% of degree of hdyrolysis (DH) at pH 8 and 50 degrees C by using 6.75 mAU/g of subtilisin. The experiments consisted in fermentations of Cabernet sauvignon with Saccharomyces cerevisiae at 28 degrees C and pH 3.5, using as nitrogen source DAP, as the control, and yeast hydrolysate (YH), as the treatment. Fermentations were characterized measuring degrees Brix, redactor sugars and alcoholic degree. The average alcoholic degree was 12 degrees with residual sugar concentrations below 2 g/l. Empirical evidence of non-significant differences among experiments implies that there was no limitation by nitrogen and that the peptides from the YH were assimilated by yeasts. The volatile compounds and sensorial analysis indicated significant differences in higher alcohols and esters between control and treatments. Higher sweetness and lower acidity were detected in YH fermented wines compared with DAP fermented wines. The utilization of enzymatic hydrolysate of yeast protein as an organic nitrogen source for the wine fermentation is technically feasible and, in addition, beneficial for the organoleptic properties of wine.