Synergistic co–delivery of curcumin and N–acetylneuraminate via bigel: Enhanced stability, antioxidant performance, and controlled release during in vitro digestion

This study develops a bigel system for co–delivery of hydrophilic N–acetylneuraminate (NeuAc) and hydrophobic curcumin, evaluating its encapsulation, stability, antioxidant properties, and release behavior during in vitro digestion. After 28 days of storage, the retention rates of curcumin and NeuAc were significantly higher than those in single–gel systems. The antioxidant performance, measured by peroxide value (PV) and thiobarbituric acid (TBA) value, was significantly improved. The synergistic antioxidant effect was confirmed by interaction index values greater than 1 over 28 days. In vitro digestion showed that the bigel inhibited curcumin and NeuAc release during gastric digestion and enhanced bioavailability in the intestinal phase. In conclusion, the O/W–type bigel exhibits superior performance in nutrient protection, synergistic antioxidant action, and controlled release. The bigel system effectively enhances the stability and bioavailability of curcumin and NeuAc while delaying fatty acid release, showing great potential for functional foods and nutrient delivery systems.