龙眼果醋发酵前后主要营养品质差异研究

通过接种酵母和醋酸菌对龙眼汁进行发酵,比较发酵液随发酵时间基本参数的变化,确定制备龙眼果醋时的联合发酵时间,研究龙眼果醋发酵前后的主要营养品质差异。结果表明,酵母30℃静置发酵48 h,龙眼汁中总糖降至0.4 g/100 mL,酒精度达11.5%;醋酸30℃浅盘静置发酵60 h,同步发酵组(同时接种酵母和醋酸菌,发酵60 h)和适度发酵组(酵母发酵24 h,醋酸发酵60 h)中,乙酸含量分别达28.09和29.59 g/L。与龙眼汁相比,其总酚含量分别下降了14.75%和27.60%,抗坏血酸和抗氧化能力显著提高(P<0.05);色差分析显示龙眼果醋呈诱人的亮黄色,感观评价表明,同步发酵与适度发酵所得龙眼果醋总体结受度评分较高,较优的龙眼果醋浅盘发酵工艺。

Differences Study on the Main Nutritional Quality of Longan Vinegar before and after Fermentation

To determine the combined fermentation time of preparing longan vinegar,the changes of basic parameters of the broth fermented by yeast and acetic acid were compared. And the differences of main nutritional quality of longan vinegar before and after fermentation were analyzed. The results showed that after yeast fermentation for 48 h at 30 ℃,the total sugar in longan juice reduced to 0.4 g/100 mL and the alcohol content reached 11.5%. After acetic acid fermentation for 60 h at 30 ℃ on shallow plate,the contents of acetic acid of simultaneous fermentation group(yeast and acetic acid bacteria were inoculated at the same time and fermenting for 60 h)and moderately fermented group(acetic acid fermenting for 60 h after yeast fermenting for 24 h)reached 28.09 and 29.59 g/L. Compared with longan juice,the total phenol contents of longan vinegar produced by the two groups with better fermentation process decreased by 14.75% and 27.60%,while V_C and antioxidant capacity were significantly improved(P<0.05).The color difference analysis showed that the longan vinegar was attractive bright yellow,and the sensory evaluation results showed that the total acceptable level of the simultaneous fermentation group and moderately fermented group was high,and they had better shallow plate fermentation technology of longan vinegar.