北五味子汁苹果酸-乳酸发酵工艺优化及其抗氧化性研究

探究北五味子汁苹果酸-乳酸发酵（MLF）工艺并研究发酵过程中抗氧化活性变化。利用新鲜北五味子作为原材料，通过单因素和响应面优化试验研究北五味子汁苹果酸-乳酸发酵工艺，并测定其体外抗氧化活性。结果表明最优工艺条件为：酒酒球菌接种量7%、发酵温度24 ℃、发酵时间8 d、初始pH 3.4。此优化条件下，北五味子汁经过MLF后，苹果酸降解率为59%。DPPH自由基清除率是发酵前的1.22倍，还原力是发酵前的1.44倍，铁离子还原能力（FRAP）是发酵前的1.03倍，ABTS自由基清除率是发酵前的1.10倍。结果表明北五味子汁通过苹果酸-乳酸发酵能提高抗氧化能力。

Malolactic fermentation process optimization of Schisandra chinensis juice and its antioxidant activity

The malolactic fermentation(MLF)process of Schisandra chinensis juice was explored and the changes of antioxidant activity were studied during MLF.Using S.chinensis as the main raw material,the fermentation technology of S.chinensis was studied by single factor and orthogonal experiments,and the antioxidant activity of fermented S.chinensis beverage in vitro was determined.The optimal conditions were as follows:S.chinensis inoculum 7%,fermentation temperature 24℃,time 8 d,and initial pH 3.4.Under these optimal conditions,the degradation rate of malic acid after MLF was 59%,the DPPH,reducing power,FRAP and ABTS free radical scavenging rates were 1.22,1.44,1.03 and 1.10 times that of before MLF,respectively.It was proved that S.chinensis MLF fermentation could improve the total antioxidant capacity.