Enhanced encapsulation efficiency and controlled release of co-encapsulated Bacillus coagulans spores and vitamin B9 in gellan/Κ-carrageenan/chitosan tri-composite hydrogel

The current study, for the first time, attempts to co-encapsulate Bacillus coagulans spores as probiotics and vitamin B9 in the polysaccharide-based matrix for their targeted delivery. Instead of vegetative cells, probiotic spores were chosen owing to their higher stability. The matrix, tri-composite hydrogel, was synthesized from gellan, kappa-carrageenan, and chitosan through self-assembly devoid of chemical cross-linkers. Hence, it was found suitable for application in the co-encapsulation of bioactive compounds. The synthesized hydrogel showed remarkable encapsulation efficiency for folic acid and probiotic spores, both individually and in combination. At acidic pH, loaded hydrogel exhibited 28.42 % and 45.14 % release of spores and folic acid, respectively, which was comparatively lower than the trends observed under neutral and alkaline pH. These results were correlated with the release pattern observed during in vitro digestibility studies. Moreover, spore conversion to vegetative cells and its high colonization were observed in the simulated intestinal phase. Therefore, the matrix maintained viability and stability of co-encapsulated folic acid and bacterial spores in gastric pH while they were slowly released in the intestinal phase. These promising findings pave the way to develop a natural matrix for co-encapsulating various bioactive compounds and probiotics.