桑椹醋自回淋发酵生产工艺及其DPPH清除能力研究

Study on the auto-circular fermentation and DPPH eliminating ability of mulberry vinegar

为了确定桑椹醋自回淋发酵工艺，并探讨桑椹醋对二苯代苦味酰基自由基（DPPH）的清除能力，以秦巴山区桑椹为原料，采用液态自回流发酵法生产桑椹醋，从原料菌群、酒精发酵主产物和醋酸发酵主产物的动态变化趋势等方面对其工艺进行了分析，并采用比色法对桑椹醋总黄酮含量及其对DPPH自由基的清除率进行了测定。结果表明，桑椹果实表面携带有大量的酵母菌而几乎不带其他杂菌，酒精发酵醪除含有大量的酵母菌之外未发现有其他杂菌，酒精度在发酵48h时达到高峰；桑椹醋生产前的醋酸菌床培育需要9～10d，投入生产后醋酸发酵周期仅需要24h；桑椹醋总黄酮含量高达6．68mg／mL，对DPPH的清除作用远大于山西陈醋、镇江香醋和山楂果醋，具有良好的抗氧化作用；利用桑椹醋自身色素颜色变化可判断酸度测定时酸碱滴定终点。桑椹醋自回淋发酵工艺安全可靠、科学实用，生产效率高。

In order to ascertain auto-circular fermentation technology of mulberry vinegar and find out the vinegar＇s ability to eliminate DPPH · ,the liquid fermentation techniques of mulberry vinegar produced by using auto-circular fermentor were analyzed,the micro-organism on the mulberry fruit surface was observed with microscope,and the total flavones content as well as the free radical-DPPH eliminating ability in several kinds of vinegars were tested. The results showed that the mulberry fruit surface carried large numbers of yeast but little other mixed fungi ; ethanol fermentation reached .the peak value in 48h＇;the acetification bed breeding took 9-10 d before vinegar production,but the vinegar fermentation cycle was only about 24h during production. Total flavones content in the mulberry vinegar reached as high as 6. 68 mg/mL. The mulberry vinegar had good capacity of anti-oxidation. The red colour change of mulberry vinegar could be taken as the end point for acid-base titration when the acidity analysis was performed.