植物乳杆菌真空冷冻干燥工艺的优化

Optimization of Vacuum Freeze-Drying Process of Lactobacillus plantarum

采用真空冷冻干燥法,在高密度培养、离心制备菌泥的基础上,通过正交试验,优化植物乳杆菌冻干保护剂及冻干条件,研究不同条件下的菌体存活率。结果表明:植物乳杆菌的最佳冻干保护剂为低聚果糖5 g/100 mL、脱脂乳粉12.5 g/100 mL、半乳糖4.5 g/100 mL、乳糖3 g/100 mL、脯氨酸2.5 g/100 mL、水溶性海藻糖3 g/100 mL;最佳冻干条件为菌泥比例50 g/100 mL、预冻温度-45℃、预冻时间4 h、冻干厚度1.0 cm、真空度0.2 mbar。此条件下制备的植物乳杆菌冻干粉菌体存活率为88.74%。

Vacuum freeze-drying method was adopted to optimize the lyophilized protective agent and conditions of Lactobacillus plantarum by orthogonal test on the basis of high density culture and centrifugation of fermentation broth, and to study the survival rate of Lactobacillus plantarum under different conditions. The results showed that the best lyophilization protectants for L. plantarum were oligosaccharides 5 g/100 mL, skim milk 12.5 g/100 mL, galactose 4.5 g/100 mL, lactose 3 g/100 mL, proline 2.5 g/100 mL and water-soluble trehalose 3 g/100 mL. The optimal lyophilization conditions were as follows: bacterial sludge 50 g/100 mL, pre-freezing temperature-45 ℃, pre-freezing time 4 h, lyophilization thickness 1.0 cm and vacuum degree 0.2 mbar. Under these conditions, the survival rate of lyophilized Lactobacillus plantarum powder was 88.74%.