Abstract: Lactobacillus casei is extremely sensitive to environmental stress. In order to improve the survival rate of L. casei during storage， methods for preparation of L. caseiloaded microcapsules were studied. Capsule wall materials and additives were evaluated based on the oxygen permeation rate test， water vapor transmission rate measurement， and biocompatibility test. The L. caseiloaded solidcore and multifluidcore microcapsules were prepared through extrusion method. The storage property at room temperature and survival rate after drying at 37℃ were also tested. The results indicated that the storage property was significantly improved after coated in microcapsules; when vegetable oil was applied as storage medium， the high survival rate was observed; the survival rate reached 831% after the L. caseiloaded multifluidcore microcapsules were dried for 8 h at 37℃. A high residue viable rate “water/oil/water” L. caseiloaded multifluidcore microcapsules system was established in this research. And this system showed remarkable L. casei survival property and potential application property.

Key words: Lactobacillus casei, microencapsulation, survival rate