添加干酪乳杆菌的益生菌酸乳生产工艺条件的优化

Optimizing of the process conditions for the probiotic yogurt added with Lactobacillus casei

以添加干酪乳杆菌的益生菌酸乳代替传统的保加利亚乳杆菌和嗜热链球菌发酵的酸乳,采用单因素和正交实验设计,对影响酸乳生产工艺的菌种配比、接种量、发酵温度及发酵时间等主要因素进行了优化组合实验,以发酵过程中及后熟24h后的pH、酸度变化,并结合后熟酸乳的质构测定、感官评分和活菌数为综合指标,通过极差分析和方差分析,确定最佳生产工艺条件。本实验最终确定的最佳生产工艺条件为:乳酸菌(嗜热链球菌∶保加利亚乳杆菌=1∶1)∶干酪乳杆菌=2∶1,接种量3%,发酵温度40℃,发酵时间为9h,在此生产条件下得到酸乳的感官评分为93.65分,硬度、稠度、凝聚性和粘度分别为138.975g、3448.022g·s、99.018g和299.117g·s,后熟24h后的酸度和活菌数也分别达到122°T和3.13×1011cfu/mL。该实验方法所得到的最佳生产工艺参数真实可靠,具有实际意义。

Using the probiotic yogurt added with Lactobacillus casei in place of the traditional yogurt only including Lactobacillus bulgaricus and Streptococcus thermophilus, and determine the optimum process conditions of main factors such as strains inoculating proportion, inocuration amount, fermentation temperature and fermentation time by using single factor and orthogonal experiment. According to the changes of the pH and the acidity in the fermentation process and after ripening,and take the texture, the sensory score and the viable count of the probiotic yogurt into consideration, determined the optimum process conditions by the range analysis and variance analysis. The optimum process conditions were as follows, lactobacillus （Streptococcus thermophilus ： Lactobacillus bulgaricus = 1 ： 1 ） ： Lactobacillus casei= 2 ： 1, inoculation amount 3 %, fermentation temperature 40℃, fermentation time 9h. In the optimum process conditions the sensory score of yogurt reached 93.65 points, and firmness, consistency, cohesiveness and viscosity were 138.975g, 3448.022g·s, 99.018g and 299.117g.s respectively,the acidity and viable count also reached 122°T and 3.13×1011cfu/mL after ripening 24h. It was showed that the optimum technological parameters were reliable, and it had practical significance.