Abstract:In order to improve the freeze-dried survival rate of Lactobacillus fermentum BLHN3, the effect of cryoprotectant on the freeze-dried resistance of Lactobacillus fermentum BLHN3 and the storage stability of freeze-dried Lactobacillus powder were investigated. The experimental results showed that the survival rate of Lactobacillus fermentum BLHN3 was the highest with 3% L-glutamate +5% maltose +5% skim milk, and the number of viable count reached 1.48×1011 CFU/g. Scanning electron microscopy showed that cryoprotectants could maintain the integrity of the cell membrane of Lactobacillus after freeze-dried. The FTIR results showed that the cryoprotectant could reduce the damage of freeze-dried cells by binding with the cells. The activities of lactate dehydrogenase (LDH) and ATPase were significantly increased, but the pyruvate kinase (PK) activity was not significantly different after freeze-dried. In addition, the accelerated storage test showed that low temperature storage was an effective method for the preservation of powder. Conclusion: Lactobacillus fermentum BLHN3 could be prepared into a high activity freeze-dried starter with 3% L-glutamate sodium, 5% maltose, 5% skim milk as cryoprotectants.