双岐杆菌在冻干过程中的存活率影响因素研究

Study on the Influencing Factors on the Survival of Bifidobacterium during Freeze-drying Process

为了提高双岐杆菌冻干制品的存活率,对影响其存活率的各冻干因素,如保护剂、混合配比、预冻速率、升华温度、真空度及冷阱温度等,进行了研究。结果表明:保护剂能够提高存活率,且复合保护剂比单一保护剂效果更明显;湿菌体与保护剂为1:3时效果最好;快速冷冻可降低生物体损伤;升华温度接近共晶温度时能缩短冻干时间,降低能耗;采用循环压力法控制真空度,有利于提高冻干制品的质量与冻干速度;冷阱温度为(-40～-45)℃时效果最优。

In order to improve the survival of freeze-dried Bifidobacterium, each process factors such as the protectants, mixed proportion, pre-freezing rate, sublimation temperature, vacuum and cold trap temperature were studied. The results showed that： the protectants enhance the survival of bacteria, and the effect of composite protectants is better than single protectants; the optimal ratio of the wet biomass and the protectants was 1：3; rapid freezing would reduce the injury of living organisms; sublimation temperature close to the eutectic temperature would shorten the freeze-drying time and lower energy consumption; the cyclic pressure method of vacuum control would improve the quality of freeze-dried products and accelerate the freezing; the optimal temperature of cold trap was （-40～-45）℃.