Effect of initial sulfur dioxide content in must on the kinetics of wine primary fermentation, using yeast immobilized in calcium alginate gel

Abstract

 Effect of initial sulfur dioxide content in must on the kinetics of wine primary fermentation, using yeast immobilized in calcium alginate gel was examined. Initial sulfur dioxide content in must was adjusted from 12ppm to 312ppm. Our experimental results indicated that the maximum specific growth rate of the immobilized yeast was 1-2 times less than that of the free yeast. On the contrary, the sugar uptake rate and ethanol production rate of the immobilized yeast were 1.23-1.90 times and 1.22-1.81 times, respectively, more than those of the free yeast. The volatile acid content and pH value of the final wine fermented by immobilized yeast were lower. Thus, the organoleptic properties and biological stability of the wine were ameliorated. In general, the yeast immobilized in calcium alginate gel was more resistant to sulfur dioxide than the free yeast.