益生菌发酵甘薯汁的工艺优化

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。

Process Optimization of Sweet Potato Juice Fermented by Probiotics

The technology of making glutinous rice ball with fermented ginkgo seed powder as the main raw material was studied. The sensory quality, texture, frost cracking rate and turbidity of glutinous rice ball soup were taken as indexes. On the basis of single factor tests, the formula of glutinous rice ball with fermented ginkgo seed powder was optimized by response surface analysis using sensory score as response value. The results showed that the best formula was as follows: mixture flour consisted of glutinous rice flour and fermented ginkgo seed powder 100 g, among which fermented ginkgo seed powder 30 g, white granulated sugar 35 g, gluten powder 1.85 g and phosphate starch 0.30 g. The sensory score of the prepared fermented ginkgo seed powder glutinous rice ball (FGPG) was 97.7±0.8, which was basically consistent with the model prediction value of 97.63. The quality of FGPG was significantly higher than that of the control group, the sensory score increased by 11.3%, the frost crack rate and adhesiveness reduced by 75% and 40.7%, respectively. There was no significant change in turbidity and chewiness, while the hardness increased moderately. Moreover, the index of FGPG meeted the requirements of national standards, with high quality and broad market prospects, which will opens up a new way for the efficient utilization of ginkgo seed.