Immobilized ?-glucosidase And Its Application In Wine Aroma Enhancement

In the process of wine fermentation,aroma substances are released by hydrolyzing the binding aroma precursor in grape with ?-glucosidase,which is one of the important factors affecting wine quality.To study the effect of immobilized ?-glucosidase on the aroma components of red wine,In this paper,8 resin carriers were selected to immobilize ?-glucosidase and study the physicochemical properties of the immobilized enzyme,and the red wine was treated at different fermentation stages with the optimized immobilized enzyme,and the effects of different enzyme treatment processes on the quality of red wine were investigated.The results are as follows:(1)Study on the immobilization of ?-glucosidase.Through the selection of immobilized carrier and conditions,ES-103 B resin was determined to immobilize ?-glucosidase.The immobilization condition was optimized by response surface experiments:p H 4.8,reaction time 25 h,enzyme loading 3.0 mg/g.The maximumyield of immobilization yield was 46.82% under the above optimized conditions.(2)Study on the enzymatic properties of immobilized ?-glucosidase.The optimum p H of the optimized immobilized enzyme remains almost the same as for the free enzyme(p H 4.0).The optimum temperature for ?-glucosidase activity was increased by 5? after immobilization.Glucose and ethanol tolerance experiments showed that immobilized ?-glucosinase was sensitive to glucose and ethanol.(3)Effects of different enzymatic treatment on the quality of red wine.The wines were analyzed by gas chromatography-mass spectrometry(GC-MS)and a total of 55 aroma substances were detected by GC-MS,among which 5 species variety aroma were detected,including Linalool,3-methylthiopropanol,1-Hexanol,?-damascenone,2,4-Di-tert-butylphenol.The contents of varietal aroma and fermented aroma substances in Cabernet Sauvignon wine were significantly increased after the treatment of the free ?-glucosidase,and the longer the enzyme treatment time,the higher the total amount of aroma substances.Adding ?-glucosidase before alcohol fermentation,the content of aroma substances was the highest,which was 187.32% of the control group.The aroma substances of wine were significantly increased by immobilized ?-glucosidase treatment,and in the alcohol fermentation and aging period treatment,the wine aroma substances content is the largest,193.91% and 191.32% of the control group aroma substances content,are higher than the free enzyme aroma enhancement.Effects of enzyme treatment on phenols and color parameters of Cabernet Sauvignon wine.Free enzymes and immobilized enzymes at different fermentation stages had no significant effect on the content of polyphenols in wine,but the content of flavonoids decreased with the prolongation of enzyme treatment time.During fermentation,the longer the enzyme treatment time,the lower the anthocyanin content and the lower the color depth of the wine,but the 3 months of aging treatment did not significantly reduce the anthocyanin content and colour parameters.According to the comprehensive analysis of aroma substances,phenols and colour parameters,the optimal enzymatic treatment should be: immobilized glucosinase was used to treat red wine for 3 months in the aging period.