Survival and behavior of free and encapsulated probiotic bacteria under simulated human gastrointestinal and technological conditions

The present study was designed with the objective to compare the viability and stability of free and encapsulated probiotics under simulated technological and human gastrointestinal conditions. L. acidophilus was encapsulated using two wall materials (sodium alginate, soy protein isolate, and SA-SPI) by extrusion method for enhanced viability under stressed conditions. Free and encapsulated probiotics were subjected to some simulated technological and gastrointestinal conditions. Furthermore, free and encapsulated probiotics were also incorporated in dairy dessert to evaluate the viability and stability during storage. Encapsulation using sodium alginate and SPI as a coating materials significantly (p <.05) improved the survival of probiotics under simulated gastrointestinal and thermal conditions. The buffering effect of microbeads prolonged their survival and stability of under simulated conditions. The number of surviving probiotic cells encapsulated with sodium alginate, SPI, and SA-SPI over 120 days of product storage was 7.85 ± 0.39, 7.45 ± 0.37, and 8.50 ± 0.43 cfu/ml, respectively. In case of free cells, the surviving cells were just 3.5 ± 0.18 cfu/ml over the period of storage. In short, the study depicted that encapsulation provides protection during exposure to various hostile conditions.