Modification of the interface of oleogel-hydrogel bigel beads for enhanced stability and prolonged release of bioactives.

In this study, novel bigel beads based on alginate hydrogel and monoglycerol oleogel were developed using tea saponin (TS) for interfacial modification. We investigated the impact of the structures of oleogel-hydrogel interface on the stability and bioactives release of bigel beads, with curcumin as the model hydrophobic bioactive. With higher TS content, the particle size and ζ-potential of the bigel emulsions was first decreased and then increased. Beads with lower TS levels (0-1 %) showed reduced shrinkage and enhanced swelling as TS content was increased, while higher TS levels (1 %-2 %) led to increased shrinkage and decreased swelling. The interfacial modification with TS also significantly enhanced the mechanical strength and reduced lipid oxidation of the beads. Moreover, TS-stabilized beads demonstrated prolonged curcumin release during intestinal digestion, indicating the potential for sustained delivery of bioactives. These findings highlighted the roles of interfacial engineering in improving the functionality of bigel beads for bioactives delivery.