Abstract
Probiotics have many benefits for human intestinal health. However, Probiotics have poor tolerance to gastric acid and bile salts of the stomach. Microencapsulation could confer protection to probiotic against harsh environments effectively. In this experiment, Lactobacillus casei L61 was embedded by extrusion with gellan gum and chitosan as wall material. The viable cells and encapsulation yield of microcapsules were used as the indexes, the optimum values of each factor were determined by a single factor experiment. Chitosan concentration 0.50%, chitosan pH 4.5, gellan gum concentration 1.50%, the volume ratio of bacterial suspension to gellan gum is 1:6, the volume ratio of bacterial gum to chitosan is 1:4, the stirring time is 40min.