Abstract:Objective: The microcapsules of synbiotic Lactobacillus casei/ lactitol were prepared by enzymatic method. The effect of lactitol concentration on the microcapsules characteristic was studied, and the application of the microcapsules was assessed. Method: Synbiotic L. casei/ lactitol was microencapsulated in casein using internal emulsion technique with Zea mays transglutaminase (TGZ) induced gelation and alginate coating. The particle size of microcapsules and the survivability of L. casei in casein beads coated with alginate in simulated gastrointestinal conditions were studied to determine the amount of lactitol. Moreover, the morphology of microcapsules was observed by scanning electron microscope (SEM). Finally, prepared microcapsules were added into orange juice to evaluate the survival of L. casei in low temperature storage. Result: TGZ could used as an enzyme to cross-link casein to encapsulated L. casei/lactitol. The small particle size and high encapsulation efficiency (61.73%) achieved with the addition of 1.0 g/100 mL lactitol. In simulated gastrointestinal tests, the survivability of L. casei was improved by 1.0 g/100 mL lactitol. Result from SEM observations showed complete encapsulation of probiotic cells in the wall materials, suggesting that the protection was provided by the strong penetration-resistant physical barriers of the microcapsules. The storage experiment indicated that the number of cells with lactitol were higher than those of without lactitol by 0.56 logarithmic number. Conclusion: The double-layer microcapsule has a very good protective effect on the survival of Lactobacillus, and the existence of lactitol can also improve the survival rate of probiotics, so probiotics/ lactitol synbiotics microcapsules have a broad application in food, especially in functional food.