Production of low alcohol wine by Saccharomyces cerevisiae and non-Saccharomyces spp. yeasts from reduced sugar grape must using glucose oxidase

In this study, sugar (Glucose) content of Emir grape must was converted to gluconic acid using glucose oxidase and then, low alcohol wines were produced using pure and mixed cultures of Saccharomyces (S.)cerevisiae, Kloeckera (K.) apiculata and Williopsis (W.) saturnus from reducedsugar grape must. For that reason, the sugar level of grape must which was used in the main fermentations was converted using 1 g/L of Hyderase at 20oC with mixing at 330 rpm and aerating with 4 L/min of filtered air for 30 h in a fermentor. The reducing sugar amount and total acidity were found 95.88 g/l and 488 meq/L, respectively.Pure and mixed cultures of S. cerevisiae, K. apiculata and W. saturnus were inoculated into reduced sugar grape must. The low alcohol wine obtained from untreated grape juice using pure culture of S. cerevisiae was used as a control. Unlike pure culture fermentation of W. saturnus, drop in the specific gravity of fermentations performed were quite rapid. When the ethyl alcohol content reached to 3.5-4 % (v/v), the fermentation was stopped by the addition of sulphur dioxide and cold treatment.The composition parameters of low alcohol wines were ethyl alcohol %3.52-4.04 by vol., total acidity 482.1-511.8 meq/L, reducing sugar 18.1-23.1 g/L, total higher alcohols 67.718-103.935 mg/L, total esters 18.472-32.285 mg/L ans acetaldeyhde 13.622-111.503 mg/L. According to the sensory analysis, the most preferred sample was the wine obtained using pure culture fermentation of S. cerevisiae from reduced sugar grape must, followed by the wines produced from mixed culture of S.cerevisiae and K. apiculata and then,pure culture fermentation of W. saturnus.