接种发酵对葡萄酵素多酚生物利用度及抗氧化活性的影响

为明确接种发酵对葡萄酵素多酚生物利用度及抗氧化活性的影响,研究葡萄酵素发酵过程中发酵特性、酚类物质及抗氧化活性的变化,并采用体外模拟胃肠道消化实验对其多酚的生物利用度进行评估.结果 表明:葡萄酵素发酵过程中还原糖质量浓度由31.91 g/L逐渐降低至0.46 g/L,pH值由3.77降至3.19,乙醇体积分数于发酵第6...

Effect of Inoculated Fermentation on the Bioaccessibility and Antioxidant Activity of Polyphenols from Grape Jiaosu

In order to clarify the effect of inoculated fermentation on the bioaccessibility of phenolic compounds and antioxidant activity in grape jiaosu (fermented grape juice), the changes in fermentation properties, phenolic composition and antioxidant activity during fermentation were studied, and the bioaccessibility of polyphenols was also evaluated by in vitro simulated gastrointestinal digestion. The results showed that the reducing sugar content decreased from 31.91 to 0.46 g/L and the pH decreased from 3.77 to 3.19 during fermentation. The ethanol content increased to 7.66% (V/V) on the sixth day, and then decreased to 0.47% on the 27th day. The release of phenolic compounds was promoted by inoculated fermentation. The contents of total phenols and flavonoids presented a fluctuant increasing trend during the fermentation process, and were increased by 2.16 and 1.83 folds at the end of fermentation. Compared with must, the contents of gallic acid, vanillic acid and myricetin were increased by 7.17, 5.18 folds and 60.29%, respectively. After in vitro gastrointestinal digestion, five phenolic acid showed higher bioaccessibility in the range from 39.11% to 57.77%. Among the tested flavonoids, myricetin and quercetin showed higher bioaccessibility of 35.78% and 42.34%, respectively. The antioxidant activity of grape jiaosu showed an overall increasing trend with fermentation time. Compared with must, the scavenging capacities against 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2’-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) cation radical increased by 51.45% and 82.23%, respectively at the end of fermentation. In conclusion, inoculated fermentation can increase the concentrations of specific phenolic compounds, improve the bioaccessibility of some polyphenols, and enhance the antioxidant activity of grape jiaosu. These results indicate that inoculated fermentation can be used as an effective way to prepare grape jiaosu, which can improve the nutrition and function of grape jiaosu and provide a basis for the development of other functional jiaosu products.