保加利亚乳杆菌冷冻干燥保护剂的研究

Study on the freeze-drying protective agents of Lactobacillus Bulgaricus

为获得对保加利亚乳杆菌最佳的真空冷冻干燥保护剂的配方,在以10%脱脂乳为基础保护剂的情况下,采用单因素和正交试验设计,以冻干后的存活率为指标,考察了不同冻干保护剂对保加利亚乳杆菌冷冻干燥的保护效果,获得了最优的保护剂配方,即脱脂乳100 g/L,谷氨酸钠25 g/L,抗坏血酸0.5 g/L,甘油60 mL/L,酵母浸粉1 g/L。使用此保护剂配方,保加利亚乳杆菌冻干后的存活率可达60.59%。

In order to obtain the optimal vacuum freeze-drying protectant formula for Lactobacillus bulgaricus, the effect of different protective agents on the survival rate of Lactobadllus bulgaricus was detected, while the 10% skim milk was utilized as the basic protectant. According to results of single-factor test and the Lg（34）orthogonal optimization experiments, the optimal protectant formula was finally obtained： skim milk, 100 g/L; sodium glutamate, 25 g/L; ascorbic acid 0.5 g/L; glycerol 60 mL/L and yeast extract 1 g/L. Under this protectant formula, the sur- vival rate of Lactobacillus bulgaricus after vacuum freeze-drying reached 60.59%.