Preparation of alginate/chitosan/carboxymethyl chitosan complex microcapsules and application in Lactobacillus casei ATCC 393

Lactobacillus casei ATCC 393 was encapsulated with alginate, chitosan and carboxymethyl chitosan by extrusion method and the product could increase the cell numbers of L. casei to be 108 cfu/g in the dry state after storage at 4 °C for 4 weeks. After incubation in simulated gastric (pH 2.0, 2 h) and bile juices (1%, 6 h), the encapsulated L. casei cell numbers were 7.91 and 7.42 log cfu/g, respectively. Results indicated that alginate–chitosan–carboxymethyl chitosan microcapsules could successfully protect L. casei against adverse conditions and this approach might be useful in the delivery of probiotic cultures as a functional food.