Structural, physicochemical, and in vitro digestion properties of microgel-reinforced synbiotic hydrogel beads filled with pectic oligosaccharides as a delivery system for Limosilactobacillus reuteri

Pea protein microgel (MG)-reinforced synbiotic low methoxyl pectin (LMP) hydrogel beads filled with different concentrations (0 %, 0.2 %, and 0.4 %) of pectic oligosaccharides (POS) were developed as a delivery system for Limosilactobacillus reuteri (L. reuteri). SEM results revealed that incorporating POS into the hydrogel beads made the gel matrix smoother and more compact, reducing probiotic leakage and higher encapsulation efficiency. FT-IR analysis observed new ionic crosslinking between LMP and calcium ions. In vitro digestion results suggested that MG-reinforced synbiotic hydrogel beads showed higher survival rates throughout the upper gastrointestinal tract than MG, and the highest values were observed in the hydrogel beads with 0.4 % of POS. Most L. reuteri was released from the developed system after exposure to simulated colonic conditions for 48 h. MG-reinforced synbiotic hydrogel beads showed higher thermal and storage stability than MG alone, indicating that adding hydrogel bead layer to MG can efficiently protect L. reuteri from environmental stresses.