植物乳杆菌发酵桑葚酵素工艺优化及质量评价

Optimization of fermentation process and quality evaluation of Mulberry Jiaosu from Lactobacillus plantarum

目的:解决新鲜桑葚难以保存的问题,将新鲜桑葚制成桑葚酵素。方法:以新鲜桑葚汁为原料,植物乳杆菌为生产菌种,总酚含量为评价指标,通过单因素试验结合响应面试验优化了植物乳杆菌桑葚酵素的发酵工艺,并对桑葚酵素的理化、微生物及感官质量指标进行评价。结果:优化后发酵工艺条件为发酵时间40 h、发酵温度32℃、接种量25%,所制得的植物乳杆菌桑葚酵素的总酚含量达(43.48±0.67)μg/mL,是未经发酵的桑葚汁的1.62倍,可溶性固体物含量为5.36%,pH值为4.08±0.01,微生物指标满足国家标准;桑葚酵素呈紫红、色泽均匀,具有浓郁的桑葚果香和发酵的香味、无异味,酸味柔和、风味好,有光泽、无杂质及沉淀。结论:经植物乳杆菌发酵制得桑葚酵素的过程有生物活性物质产生,有利于提高桑葚酵素质量。

Objective:To solve the problem of difficult preservation of fresh Mulberry,fresh Mulberry is fermented by Lactobacillus plantarum to produce Mulberry Jiaosu.Methods:Using fresh Mulberry juice as the raw material,Lactobacillus plantarum as strain and total phenol as index,the fermentation process of Mulberry Jiaosu was optimized by single factor test and response surface test.Results:The optimized fermentation conditions were as follows:fermentation time was 40 h,fermentation temperature was 32℃,inoculation amount was 25%,and the total phenol content of Mulberry Jiaosu was(43.48±0.67)μg/mL,which was 1.62 times that of non-fermented Mulberry juice.Conclusion:The quality evaluation results showed that the Mulberry Jiaosu had purple red color,uniform color,strong mulberry fruit aroma and fermentation aroma,no peculiar smell,soft sour taste,good flavor,lustre,no impurities and precipitation.The indexes of the Mulberry Jiaosu meet the relevant national standards.