Preparation and Preservation Technology of Probiotic Lactobacillus plantarum G1-28 Composite Lyophilized Starter

In order to prolong the preservation time of probiotic bacteria and improve the cell survival rate, the conditions of centrifugation, formulation and preservation of lyophilized fermentation protection agent werestudied and optimized with Lactobacillus plantarum G1-28, which has the function of lowering cholesterol and triglyceride in vitro. Effects of centrifugal speed and time on cell collection rate of bacterial suspension were studied by living cell collection rate. And the effects of vacuum conditions and preservation temperature on the preservation effect of Lactobacillus plantarum G1-28 lyophilized starter were studied by single factor test and orthogonal test. The experimental results showed that the centrifugal collection condition of Lactobacillus plantarum G1-28 suspension was 5000 r/min and 20 min, and the collection rate of live cells was 96.26%. The cell survival rate could reach 93.20% under this condition of skim milk 7%, trehalose 2%, sorbitol 3%, glycerol 4%. The best preservation condition was −20 ℃ under vacuum condition, and the survival rate was 97.1% after 4 months. As a result, the research could lay a foundation for the preparation of Lactobacillus plantarum G1-28 probiotic starter and the development of cholesterol-lowering triglyceride functional food.