Effects of in vitro saliva, gastric and intestinal digestion on the chemical properties, antioxidant activity of polysaccharide from Artocarpus heterophyllus Lam. (Jackfruit) Pulp

Polysaccharides are one of the most widely distributed and abundant compounds in plants, animals and microorganisms. In this study, we investigated the effects of in vitro saliva, gastric and intestinal digestion on the reducing sugar contents, molecular weight and structure change of polysaccharide from Artocarpus heterophyllus Lam. Pulp (JFP-Ps). Digested samples of JFP-Ps were also subject to antioxidant assays including DPPH scavenging assay, hydroxyl radical scavenging assay, superoxide radical scavenging assay and ferric reducing power assay. Results revealed that in vitro digestion could significantly increase the reducing sugar contents and decrease the molecular weight of JFP-Ps. FT-IR results showed that structure and conformation of JFP-Ps were remarkably altered after simulated digestion. The intestinal digested samples of JFP-Ps exhibited obvious DPPH, hydroxyl radical, and superoxide radical scavenging activities in a time-dependent manner during digestion, but with a relatively low reducing power. These results indicated that digestion remarkably affected the chemical properties, structure and antioxidant activity of JFP-Ps during gastrointestinal digestion, and might help maximize the potential applications of JFP-Ps as a dietary source of antioxidant phytochemicals that survive the gastrointestinal digestion process.