蓝靛果单宁的提取及对酵母发酵能力的影响

为确定酵母菌发酵蓝靛果果汁中的最适单宁含量，采用单因素实验及正交试验优化超声辅助法提取蓝靛果单宁工艺，将此条件下获得的单宁粗提液纯化、浓缩后得到单宁酸样品。将其添加到模拟蓝靛果果汁中，研究不同浓度单宁酸对酵母菌的影响，并验证最适单宁含量对发酵蓝靛果果汁的影响。结果表明，蓝靛果单宁最优提取条件为:乙醇体积分数50%，料液比1:60（g/mL），超声温度50 ℃，超声时间40 min，此条件下单宁得率为14.68%。浓度为400 mg/L单宁酸模拟果汁中酵母菌的生长趋势良好，稳定期内酵母菌活性最高。与原发酵果汁相比，采用单宁酶处理后，最适单宁含量的发酵果汁中酒精度及总酸含量分别提高84.21%和14.58%，残糖含量及涩度值分别降低57.91%和86.32%，总酯含量提高38.45%。该含量单宁对酵母菌的发酵效果具有明显促进作用，果汁涩感降低且酸甜适中，果香及发酵香浓郁。

Extraction of Tannin from Lonicera edulis and Its Effect on Yeast Fermentation Performance

In order to study the optimum tannin content in Lonicera edulis juice fermented by yeast,the processing of tannins extracted from Lonicera edulis by ultrasonic-assisted was optimized by single factors and orthogonal test.The purified and concentrated tannin extract was added to the simulated Lonicera edulis juice to study the effect of different concentrations of tannins on the yeast.In addition,the optimal tannin concentration was verified for yeast fermentation of Lonicera edulis juice.Results showed that,the optimal conditions for extracting tannins from Lonicera edulis were as follows:Ethanol volume fraction 50%,liquid to solid ratio 1:60(g/mL),ultrasonic temperature 50℃,ultrasound time 40 min,under which,the tannin extraction rate reached 14.68%.Yeast grew well and had the highest activity during the stable period when the tannic acid concentration of the simulated juice was 400 mg/L.Compared with the original fermented juice,the alcohol and total acid content of the fermented fruit juice with the optimum tannin content hydrolyzed by tannins increased by 84.21%and 14.58%,and the residual sugar content and astringency were reduced by 57.91%and 86.32%,respectively.Total ester content increased by 38.45%.The optimum tannin content had a significant promoting effect on the fermentation ability of yeast,the fruit juice reduced astringency and had the moderate sour and sweetness with a strong fruity and fermented aroma.