Turgut Cabaroğlu

Wine flavor enhancement through the use of exogenous fungal glycosidases

Abstract The use of a pectinase enzyme preparation in winemaking containing relevant glycosidase activities for the hydrolysis of glycosidically bound aroma compounds allowed to increase the levels of volatiles, monoterpenes, C 13 -norisoprenoids, and benzene derivatives. The highest increase was for the wine obtained from the juice enriched by glycosides through the contact of juice with skin parts of grape berry. Enzyme treatment enhanced the attributes, honey, lime, and smoky. The enzyme-treated wines were highly significantly different from the control wines and preferred to control wines.

Effects of fermentation temperature and aeration on production of natural isoamyl acetate by Williopsis saturnus var. saturnus.

Isoamyl acetate is a natural flavour ester, widely used as a source of banana flavour by the food industry. Williopsis saturnus var. saturnus is a yeast which can produce isoamyl acetate by esterification of amyl alcohols with acetyl coenzyme A via fermentation. The evaluation of this kind of production as an alternative way to obtain natural banana flavour could be possible, if the levels produced were high enough to make a commercial product. In this study, the effects of temperature (15°C and 25°C) and aeration (aerobic, semiaerobic, and anaerobic) on the production of isoamyl acetate by Williopsis saturnus var. saturnus from sugar beet molasses were examined. According to the results obtained, isoamyl acetate production rate and specific productivity were higher at 25°C than at 15°C and at semiaerobic condition than aerobic and anaerobic conditions. Williopsis saturnus var. saturnus showed a production rate of 0.703 mg L−1 h−1 and a specific productivity of 0.0297 mg L−1 cell−1 h−1 isoamyl acetate with semiaerobic condition at 25°C. The maximum amount of isoamyl acetate reached with these conditions was 118 mg/L.