Saccharomyces cerevisiae Inoculum Heat Shock Treatment – New Method for Enhanced Glycerol Production in Wine

Sa？etak The present research was focused on developing a new method to enhance glycerol production for the benefit of ethanol reduction in alcohol fermentation of grape must metabolism using thermal shocks on inoculum suspension of Saccharomyces cerevisiae yeast cells. The influence of applied heat shocks at intervals of 10, 20 and 30 minutes at 45 °C is presented. The significance of this method is in the homogenization of the quality and efficiency of the resistible cells that survived thermal shock. They represent a new active biomass that includes also a memory effect of heat exposure that enables increasing the production of glycerol from 6.3 to 8.4 g L–1 at 18 °C and 7.8 to 10.3 g L–1 at 22 °C. In the same experiments, the concentration of ethanol decreased from 89 to 81 g L–1 at 18 °C and from 104 to 97 g L–1 at 22 °C. These results represent a new and easily applicable method for high glycerol production at reduction of ethanol even in large scale