Synbiotic microencapsulation of corncob xylooligosaccharide and in vitro study for bioactivity and stability upon digestion and storage

Xylooligosaccharides (XOS) are emerging prebiotic that may improve the viability of probiotics and gastrointestinal health. XOS derived from corncob was evaluated for its prebiotic activity with three different probiotic strains. The present study focused on XOS to encapsulate Lactobacillus rhamnosus (LGG) and explore it’s in vitro survival & stability upon storage through structural interactive optimization of encapsulation materials. L. rhamnosus (LGG) showed the highest viability 9.86 ± 0.04 log CFU/mL upon XOS. Among three different carrier types namely, Sodium alginate (SA), Chitosan & Sodium tripolyphosphate (STPP), Whey protein liquid -maltodextrin complex, the SA showed the highest encapsulation efficiency 87.6 ± 0.1%, yield and cost effectiveness. XOS and SA were used for encapsulation of LGG with different formulations. The stability of free and encapsulated LGG was assessed using gastrointestinal conditions. All the treatments provided better encapsulation efficiency > 80 %. M2 formulation showed the highest encapsulation efficiency 92 ± 1%, maximum viability in simulated gastric juice 8.7 ± 0.1 log CFU/mL and bile solution 8.6 ± 0.2 log CFU/mL, resulting significantly (p < 0.05) improved survival when compared with free bacteria. The microcapsules were then incorporated into yoghurt and the results showed that there was an increased survival of probiotics because of the protection of cells by microencapsulation and the promoting effect of XOS on the probiotics growth. The XOS extracted from corncob was successfully incorporated as a prebiotic encapsulation material for effective delivery of L. rhamnosus LGG. The different combinations of wall materials with XOS provided an opportunity to produce beads with better structure and protection.