Screening, identification, and application of selenium‐enriched Lactobacillus in goat milk powder and tablet

Abstract

In this study, Lactobacillus L20 was screened by measuring the tolerance to the inorganic selenium and the resistance to the gastrointestinal fluid of 11 Lactobacillus preserved in the laboratory. Next, the selenium-enriched L20 was produced into the corresponding selenium-enriched L20 goat milk powder and milk tablet. The storage stability of the prepared powder and tablet were investigated by the accelerated test. The results indicated that the conversion rate of inorganic selenium of L20 was 87.65% and the viable count was 2.925 × 108 CFU/ml. The results of 16S rDNA homology of partial sequences of molecular characterization suggested that Lactobacillus L20 was Lactobacillus rhamnosus. More notably, the inactivation rate constants and the predicted shelf life of selenium-enriched L. rhamnosus L20 goat milk powder and milk tablet were 2.40 × 10–4 and 1.90 × 10–4 day–1 and 285 and 406 days under 25°C, respectively, exhibiting a considerable long-term stability. Practical applications Selenium is one of the necessary microelements in human metabolism. Lactic acid bacteria can transform the inorganic selenium into organic selenium and selenium-enriched Lactic acid bacteria can supply organic selenium and play its probiotic function. In this study, Lactobacillus rhamnosus L20 with strong selenium-enriching ability was obtained and freeze-dried powder was prepared. Selenium-enriched probiotic goat milk powder and goat milk tablets were developed. The shelf life was predicted and prepared for selenium-enriched probiotic powder. This work also provides a technical support for the subsequent industrialization of Se-enriched probiotic goat milk powder and tablets.