益生菌发酵甘薯汁的工艺优化

Process Optimization of Sweet Potato Juice Fermented by Probiotics

为改善甘薯汁口感,提高其营养价值,本文以适于发酵饮品的甘薯黄肉品种“运薯9801”和紫肉品种“漯紫4号”为原料,以乳酸菌葡聚糖明串珠菌(Polysaccharide actinomyces)为发酵菌株,研究了发酵时间、发酵温度、甘薯浆添加量、接菌量和加糖量对甘薯汁品质的影响。在单因素试验的基础上,分别构建4因素(发酵温度、发酵时间、甘薯浆添加量、接菌量)3水平的响应面设计,并建立发酵甘薯汁感官评分的二次回归方程。结果表明,益生菌发酵“运薯9801”甘薯汁的最优发酵工艺条件为:红薯浆添加量30.0%,接菌量10.4%,发酵温度34.0℃,发酵时间为36.0 h,加糖量为10.0%;益生菌发酵“漯紫4号”甘薯汁的最优发酵条件为:紫薯浆添加量39.6%,接菌量9.8%,发酵温度32.3℃,发酵时间31.0 h,加糖量10.0%。品种的筛选及工艺的优化可为发酵甘薯汁的研发提供指导。

The taste and nutritional values of sweet potato juice could be improved after fermented by probiotics.In the present study,the sweet potatoes juices were prepared using yellow meat variety‘Yunshu 9801’and purple meat variety‘Luozi 4’as raw materials and fermented by Polysaccharide actinomyces,subsequently,the effects of fermentation time,fermentation temperatures,substrate concentrations,inoculum amounts and sucrose additions on juices quality were studied.Then response surface design of 4 factors(fermentation temperature,fermentation time,substrate concentrations and inoculation amounts)and 3 levels was constructed on the basis of single-factor experiments,and the quadratic regression equation of sensory evaluation on fermented sweet potato juice was established.Results showed that the optimum fermentation conditions of‘Yunshu 9801’were obtained as follows:substrate concentration of 30.0%,inoculation amount of 10.4%,fermentation temperature of 34.1℃,fermentation time of 36.0 h and sucrose addition of 10.0%.The optimal fermentation conditions of‘Luozi 4’were determined as follows:substrate concentration of 39.6%,inoculation amount of 9.8%,fermentation temperature of 32.3℃,fermentation time of 31.0 h and sucrose addition of 10.0%.The selection of varieties and the optimization of technology would provide guidance for development and application of fermented sweet potato juice.