Effect of addition of inulin and galactooligosaccharide on the survival of microencapsulated probiotics in alginate beads coated with chitosan in simulated digestive system, yogurt and fruit juice

- GOS provided a good protection to the encapsulated probiotics in simulated digestive system.
- Level of encapsulated probiotics containing GOS was high in yogurt and orange juice during storage.
- The number of encapsulated probiotics and prebiotics was above therapeutic minimum level.

Galactooligosaccharides (GOS) and inulin were added during microencapsulation of Lactobacillus acidophilus 5 and Lactobacillus casei 01 in alginate beads coated with chitosan at the concentrations of 0, 0.5, 1.0 and 1.5%. Addition of prebiotics significantly (p < 0.05) increased the bead size by approximately 3.8%. The presence of GOS (0.3%) in the microencapsulation provided the best protection with only 3.1 and 2.9 logs reduction for L. acidophilus 5 and L. casei 01, respectively, after incubation in simulated gastric juice (pH 1.55), followed by simulate intestinal juice containing 0.6% bile salt. The viabilities of microencapsulated probiotics containing 1.5% GOS in commercial yogurt and orange juice were also performed at refrigerated storage for 4 weeks. In yogurt, the numbers of cells with GOS were higher than those of without GOS by approximately 1.1 and 0.4 logs for L. acidophilus 5 and L. casei 01, respectively. In orange juice, the numbers of cells with GOS were higher than those of without GOS by approximately 0.5 and 0.4 logs for L. acidophilus 5 and L. casei 01, respectively. The numbers of probiotic bacteria were maintained above the recommended therapeutic minimum (107 cfu g−1 or mL−1 of product) throughout the storage in both products.