Alcohol Dehydrogenase Activities of Wine Yeasts in Relation to Higher Alcohol Formation

Alcohol dehydrogenase activities were examined in cell-free extracts of 10 representative wine yeast strains having various productivities of higher alcohols (fusel oil). The amount of fusel alcohols (n-propanol, isobutanol, active pentanol, and isopentanol) produced by the different yeasts and the specific alcohol dehydrogenase activities with the corresponding alcohols as substrates were found to be significantly related. No such relationship was found for ethanol. The amounts of higher alcohols formed during vinification could be predicted from the specific activities of the alcohol dehydrogenases with high accuracy. The results suggest a close relationship between the control of the activities of alcohol dehydrogenase and the formation of fusel oil alcohols. Also, new procedures for the prediction of higher alcohol formation during alcoholic beverage fermentation are suggested.