Preparation, physicochemical characterization and in vitro release behavior of resveratrol-loaded oxidized gellan gum/resistant starch hydrogel beads

Hydrogel beads composed of oxidized gellan gum (OGG) and resistant starch (RS) were successfully fabricated by ionic cross-linking and used as delivery carriers for resveratrol. Firstly, OGG with different degrees of oxidation were prepared through 2, 2, 6, 6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation, and characterized by Fourier transform infrared spectroscopy and carbon-13 nuclear magnetic resonance to prove that carboxyl groups were successfully introduced into the gellan gum molecules. Molecular weight, thermal stability, zeta potential and gelation temperature of OGG were also investigated. Subsequently, resveratrol was encapsulated into OGG/RS hydrogel beads in the form of resveratrol/β-cyclodextrins inclusion complexes. The addition of RS significantly influenced the morphological structure and swelling capacity of OGG/RS hydrogel beads. The OGG/RS hydrogel beads exhibited a pH-sensitivity and high encapsulation efficiency of resveratrol (84.95 %–90.73 %). Furthermore, the in-vitro release behaviors demonstrated that OGG/RS hydrogel beads showed good stability in simulated gastric fluids and sustained release of resveratrol in simulated intestinal fluids. The obtained results indicate that OGG/RS hydrogel beads show a potential as delivery system for resveratrol in the food industry.