Compound hydrogels derived from gelatin and gellan gum regulates the release of anthocyanins in simulated digestion

Anthocyanins need be absorbed in the small intestine for prevention and therapy of intestinal diseases. However, they are usually degraded in the stomach during digestion process. Therefore, it is necessary to protect anthocyanins from degradation and maximize the release of anthocyanins in the small intestine. In this study, we encapsulated anthocyanins with Gelatin/Gellan gum in five proportions (Gelatin/Gellan gum: 10/0, 9/1, 8/2, 7/3, 6/4, w/w). The results of embedding efficiency, morphology and gel strength of the Gelatin/Gellan gum-Anthocyanins (Gel/Gen-Ans) system showed that Gelatin/Gellan gum = 8/2 (H 2) had the most compact and stable structure, as proved by the distribution analysis and structural characterization of anthocyanins. In vitro simulated digestion experiments demonstrated that anthocyanins were mainly retained inside Gel/Gen-Ans in the stomach, and subsequently released in the intestine. Moreover, biocompatibility results showed that compound hydrogels did not inhibit the proliferation of normal rat intestinal epithelial cells (IEC-6), which indicated the safety of this compound hydrogels. Taken together, this system was an effective and safe method to ensure the target release of anthocyanins.