Abstract:The survival of Lactobacillus casei was investigated through four kinds of composite wall materials by internal emulsification method followed in simulated gastric and intestinal juice. The results suggested that the microencapsulated L. casei was prepared by using 2% of alginate, with the ratio of alginate to whey protein content 11, the quality of oil to water volume 31, alginate to calcium carbonate content 31, and the maximum embedding rate of microcapsules was 87.50% with the global microcapsules. Taking gelatin and alginate as composite wall material, the minimum particle size of microcapsule was 89.88 μm. When soy protein isolates and alginate were used as composite wall material, the survival rate of microencapsulated L. casei in simulated gastric juice was around 90.39% after 2 h. When using casein and alginate as composite wall material, the microcapsule had good intestinal soluble, and microencapsulated L. casei was basically released after 30 min. Because the microcapsule used protein as composite wall material was safe to eat and has good embedding effect, it could be widely used in food processing.