紫米酸奶的工艺优化及贮藏品质分析研究

以熟紫米粉和鲜牛奶为主要原料，研制具有抗氧化性能的紫米酸奶。将紫米酸奶的酸度、持水力和感官评分作为评价指标，在单因素试验基础上，利用响应面分析法对紫米酸奶的工艺进行优化，并对紫米酸奶的贮藏品质进行了研究。结果表明，紫米酸奶的最佳工艺为紫米粉添加量22 g/L，白砂糖添加量7%，接种量0.06%。在此优化条件下，紫米酸奶的感官评分为91.1分。在贮藏期间，紫米酸奶的感官评分、持水力、pH、酸度、乳酸菌数及对1,1-二苯基-2-三硝基苯肼（DPPH）自由基的清除率明显优于对照组。紫米酸奶具有更长的货架期和较强的抗氧化能力。

Process optimization and storage quality analysis of purple rice yogurt

Purple rice yogurt with antioxidant property was developed using purple rice flour and fresh milk as main raw materials. Using the acidity, water holding capacity and sensory scores of the yogurt as evaluation indexes, on the basis of single factor experiments, the fermentation process of purple rice yogurt was optimized by response surface methodology, finally the storage quality of purple rice yogurt was studied. The results showed that the optimal technology of purple rice yogurt was as follows: purple rice flour 22 g/L, sugar 7%, and inoculum 0.06%. Under the optimal conditions, the sensory score of purple rice yogurt was 91.1. During storage, the sensory score, water holding capacity, pH, acidity, lactic acid bacteria number and DPPH free radical scavenging rate of purple rice yogurt were significantly better than the control yogurt. Purple rice yogurt had longer shelf life and strong antioxidant capacity.