Selection of technological regime and cryoprotector for lyophilization of lactobacteria (Lactobacillus spp.)

Abstract

Despite the success achieved in the comprehensive study of probiotic cultures, today there are a number of problems associated with the low viability of lactic acid bacteria during their processing and long-term storage in probiotics. Our work aimed to select the optimal technological regime and cryoprotectant to preserve the viability of lactic acid bacteria Lactobacillus spp. during their lyophilization. According to the results of the conducted researches, it is established that for freeze-drying of probiotic cultures Lactobacillus spp. in the facility LZ-45.27 (Frigera, Czech Republic) the most optimal is the mode which provides a rise of temperature within 45 hours from minus 70.0±1.0 °C to plus 26.0±1.0 °C with a speed of 2.2±0.1 °C/hour. It is effective to use protective media for lactobacilli, which consist of: skim milk (90%) and sucrose (10%); skim milk (90%) and lactose (10%); skim milk (90%), glucose (2.5%), sucrose (2.5%), lactose (5.0%) (P≤0.05). Freeze-drying of lactic acid bacteria under optimal conditions and the addition of cryoprotectants will avoid the problems associated with a significant reduction in the number of microbial cells. The results of research can be used for long-term storage of cultures of lactobacilli by their lyophilization.