龙眼果醋酒精发酵条件的优化

Optimization of the fermentation condition of longan fruit vinegar

在单因素的基础上探讨了温度、氮源、酵母接种量及龙眼汁含糖量和初始pH对酒精发酵的影响,以龙眼汁含糖量、温度和酵母接种量3个影响酒精发酵的主要因素设计3个因素5个水平的正交试验并进行了优化.结果表明,按固形物含量∶(NH4)2HPO4=900∶1的比例添加(NH4)2HPO4,龙眼汁初始pH为4-5时的最佳发酵条件为:温度27℃,龙眼汁含糖量20%,酵母接种量0.1%,酒精发酵后,酒精含量高达11.6%,VC含量为0.268 mg.mL-1,氨基酸态氮含量为1.13 mg.mL-1.

On the basis of the single factors, effects of temperature, nitrogen resource, inoculum size of yeast, initial pH and sugar content in juice on the alcoholic fermentation were studied and the alcoholic fermentation process was optimized by a three-factored, five-leveled orthogonal test. Results showed that the best fermentation parameters were temperature at 27 ℃, content of total sugar of longan juice at 20% and inoculum size of yeast at 0.1% on the premise of adding an amount of （NH4 ）2HPO4 with a ratio of total soluble slids： （NH4）2HPO4 =900：1 and on the condition of pH in the range from 4 to 5. Under the optimized condition, alcohol concentration was up to 11.6%, Vc concentration was 0.268 mg · mL^-1 and amino acid nitrogen concentration was 1.13 mg · mL^-1.