Background: Microencapsulation of probiotics can be used to increase their viability during the process and delivery to target areas in the gut and intestinal tract. The aim of this study was to investigate the effect of microencapsulation on viability of probiotics bacteria (Lactobacillus acidophilus and Bifidobactrium animalis subs lactis) in bile salt solution and simulated gastrointestinal juice conditions.
Methods: First, 1 gram of probiotic bacteria was mixed in 100 ml of MRS broth and incubated at 37°C for 24 h until bacteria were activated. Microencapsulation of probiotics with sodium alginate/resistant starch and sodium alginate/chitosan were done by extrusion method. The number of viable bacteria was evaluated in bile salt solution (0.6%, w/v) and simulated gastric juice (0.08 mol/L HCl solution contained 0.2% NaCL and pH: 1.55 without pepsin), followed by incubation in simulated intestinal juice (0.05 mol/L KH2PO4 solution with 0.6 % bile salts and pH: 7.43).
Results: The microencapsulation could successfully and significantly protect probiotic bacteria against adverse condition of simulated human gastro-intestinal condition. Microcapsules containing sodium alginate/resistant starch had the highest survival rate at the end of the incubation time in bile salt solution (6.3±0.2 × 106 and 4.6±0.3 × 107 for Lactobacillus acidophilus and Bifidobacterium animalis, respectively) and simulated gastrointestinal condition (4.5±0.4 × 107 and 1.7±0.2 × 106 for Lactobacillus acidophilus and Bifidobacterium animalis, respectively).
Conclusion: Generally, the microencapsulation process improved the survival of probiotic bacteria under simulated gastrointestinal conditions and bile salts solution and in this case, sodium alginate / resistant starch coating was more effective than sodium alginate/ chitosan.