Optimized study on the protective agent of lactobacillus pentosaceus R_1 for freeze drying
The protective agent constitute of Lactobacillus pentosaceus R1 for freeze-drying was optimized and studied, according to three factors Box-Behnken design base on single factor experiments and orthogonal experimental design. The good constitute was decided: skimmed milk 10.000%(w/w), glycerol 1.491%(w/w), sucrose 4.993%(w/w). The survival rate of R1 was above 95% under this freeze-drying conditions per-freezing: the slowdown of the temperature -3℃/min; drying: First, keep the temperature at -15℃, the vacuum degree at 150Pa for 14h; Then set the temperature to 10℃ and keep 10h; Finally, set the temperature to 25℃ and keep 5h; packing: inflate N2 when packing the finished product.