Résumé
A new type of L. Bulgaricus microcapsule was prepared to improve stability and resistance of L.Bulgaricus probiotics in harsh environments. An optimal method of preparation of L. Bulgaricus microcapsule is as follow. L. Bulgaricus was mixed with 3% alginate solution. The concentration of bacterial suspension was 1×109 cfu·mL-1. The mixture was microencapsulated by extrusion into 2% CaCl2 solution with a dispensing equipment. After 30 min solidification, the gel beads were lyophilized to obtain L.Bulgaricus microcapsules. The microencapsulation technology was aimed to improve the stability and survival rate of L. Bulgaricus. The microcapsule was spherical with uniform particle size and intact structure. The tolerance of acid, high temperature, high humidity and the long-term stability of freeze-dried powder and microcapsule were evaluated. The results indicated that microencapsulation technic could greatly improve stability and resistance of L. Bulgaricus probiotics in harsh environments.