Anthocyanins from Liangshan Purple Yam and Their Hydrogel Characteristics

Objective: This study systematically investigated the efficient extraction process of purple yam anthocyanins, a gelatin/carrageenan composite-hydrogel delivery system was constructed, and the stability and biosafety in gastrointestinal digestion environments were elucidated. Methods: Anthocyanins were extracted using acidic ethanol method. The apparent viscosity, gel strength, and encapsulation efficiency of gelatin-carrageenan composite-hydrogels (ratio 8:2, w/w) at different concentrations were characterized by a rheometer and texture analyzer. The digestion models in vitro were used to evaluate the stability and swelling properties of anthocyanins in gastric fluid (pH3.0, 2 h) and intestinal fluid (pH6.8, 6 h), and the effect of the hydrogel on IEC-6 cell proliferation was assessed using the CCK-8 assay. Results: Acidic ethanol-assisted extraction achieved an anthocyanin yield of 57.20 mg/g, which was significantly higher than that of the conventional maceration method (P0.05), confirming its high biosafety. Conclusion: The gelatin/carrageenan composite hydrogel significantly enhanced the gastrointestinal stability and targeted delivery efficiency of purple potato anthocyanins, providing a theoretical basis for its application in functional food development. Future studies should verify its bioavailability enhancement effect through in vivo experiments.