Effect of added prebiotic (Isomalto-oligosaccharide) and Coating of Beads on the Survival of Microencapsulated Lactobacillus rhamnosus GG

The study aimed to encapsulate Lactobacillus rhamnosus GG (LGG) with the selected prebiotic, using co-extrusion technology with a poly-L-lysine (PLL) coating and evaluate probiotic survival in simulated gastrointestinal conditions. Selection of ideal prebiotic was conducted using inulin, fructo-oligosaccharide (FOS) and isomalto-oligosaccharide (IMO) and its optimal concentration to be incorporated in microencapsulation was determined. Microcapsules without coating (S-1: no prebiotic and S-3: with prebiotic) and with coating (S-2: no prebiotic and S-4: with prebiotic) produced were evaluated based on its physical properties and survival in simulated gastrointestinal environment. The IMO with a concentration of 3.0% (w/v) was selected due to its best effect in promoting growth of LGG after 24 h (8.63 +/- 0.07 log CFU/mL). The morphology analysis revealed that all microcapsules produced were spherical with a diameter ranging from 491.3 to 541.7 mu m and microencapsulation efficiency ranged from 84.16 +/- 5.30% to 90.56 +/- 3.33%. The incorporation of IMO and coating with PLL improved the survival of LGG by 3% up to 52% after 2 h of incubation in simulated gastric digestion. Among all formulations, PLL coated microcapsules added with IMO was the most effective in protecting LGG during the first hour of simulated gastric digestion (6.52 log CFU/mL) with cell viability greater than the minimum recommended level of 10(6) CFU/mL.