Study on the in Vitro Digestion Characteristics of Polysaccharides Emulsion from Clinacanthus nutans

This study aimed to investigate in vitro digestion characteristics of emulsion stabilized use Clinacanthus nutans polysaccharide (CNP-P2) as an emulsifier and its ability to support the astaxanthin (AST) delivery system, providing theoretical and methodological guidance for the processing of C. nutans and its application in food. The gastrointestinal behavior of CNP-P2 emulsion was evaluated by droplet size, Zeta potential, microstructure, and FFA release in a controlled experiment using Gum acacia (GA). The results showed that CNP-P2 emulsion could remain stable in the stomach stage with a free fatty acid (FAA) release of 32.41%, and the final release of GA emulsion was 31.68%. A CNP-P2 emulsion delivery system loaded with AST was constructed to evaluate its ability and bioaccessibility for astaxanthin (AST) stabilization. CNP-P2 emulsion could retain AST content well under ultraviolet irradiation, with an FAA release of 27.22% during gastrointestinal digestion and a bioaccessibility of 44.43%±1.63%. CNP-P2 emulsion could significantly improve the bioaccessibility of AST in soybean oil (2.5%) (P<0.05). Based on the above results, under the premise of effectively delaying lipid digestion, the slow digestion emulsion prepared by CNP-P2 can effectively deliver astaxanthin.