Microencapsulation of probiotic strains for swine feeding

Probiotics are live microorganisms which have health-promoting attributes. These bacteria must overcome biological barriers, including acid in the stomach and bile in the intestine to exert beneficial effects. The encapsulation consists in a provision of an outer layer to protect the core material from damage. Microencapsulating in calcium alginate, nowadays, is being used to bacteria immobilization owing to its easy handling, nontoxic nature, and low cost. The aims of this study were to improve the microencapsulating method for probiotic bacteria and to investigate whether the material used as coating, afford an increase on strain survival under simulated gastrointestinal conditions. Lactic acid bacteria used in this work were isolated from feces of young and healthy pigs and they were selected because of their probiotic properties. Our results showed that the optimal encapsulation process was achieved using 1 : 1 (v/v) 20% non fat milk cell suspension mixed with 1.8% sodium alginate solution. Alginate capsules hardening was carried out using 0.1 m calcium chloride solution for 30 min. This microencapsulating technique could protect the probiotic bacteria against gastric environment, allowing viable cells get to the intestinal tract. So it could be a useful way to deliver these beneficial bacteria to host.