Statistical optimization of ethanol fermentation parameters for processing local grape cultivars to wines

摘要

Grape juice from two local grape cultivars viz. Punjab MACS purple and H-144 was subjected tornprefermentation skin treatment. Ethanol fermentation w.r.t agitation rate, temperature, inoculumrnsize, and nutrient supplementation were optimized using Triple M medium following response surfacernmethodology (RSM). RSM results were numerically optimized keeping temperature “in range”rnfor red wine and “low” for white wine which showed agitation rate of 80±1 rpm for 24 hr, diammoniumrnhydrogen orthophosphate supplementation @ 150 mg/100 ml, inoculum size of 6.1 andrn6.5% (vol/vol), and fermentation temperature of 24.6 and 21℃ as optimum for ethanol fermentationrnof red and white wines, respectively. Optimized results were validated on grape juice ofrnPunjab MACS purple and H-144 cultivars that lead to 12.0 and 11.2 (%vol/vol) ethanol production,rnrespectively. Gas chromatography mass spectrometry analysis revealed the presence of 41 volatilerncompounds in the form of phenols, alcohols, terpenes, esters, ketones, and amines that add to thernnutraceutical and antioxidant value of the wines.