Microencapsulation of probiotics by calcium alginate-gelatinized starch with chitosan coating and evaluation of survival in simulated human gastro-intestinal condition

Microencapsulation as one of the most modern methods has remarkable effects on probiotic survival. In this study Lactobacillus casei (ATCC 39392) and Bifidobacterium bifidum (ATCC 29521) were encapsulated using calcium alginate-gelatinized starch, chitosan coating and inulin via emulsion technique, and were incubated in simulated gastric juice (along with pepsin, pH=1.5) and simulated intestinal juice (along with pancreatin and bile salts, pH=8) for 2 hours at 37 oC. The morphology and size of microcapsules were measured by scanning electron and optical microscopy. The results indicated that the survival of microencapsulated probiotic increased significantly in simulated gastro-intestinal condition (P<0.05). Chitosan coating played a significant role in the protection of probiotic bacteria in simulated gastro-intestinal condition and the diameter of the microcapsules increased with the addition of chitosan coating. In general, this study indicated that microencapsulation with alginate-gelatinized starch coated with chitosan could successfully and significantly protect probiotic bacteria against adverse condition of simulated human gastro-intestinal condition.