Effect of in Vitro Simulated Digestion on Flavonoid and Reducing Ability of Fresh-cut Apple Residue

The in vitro simulation of gastrointestinal digestion was performed on the flavonoid of fresh-cut apple pomace residue to determine the changes of flavonoids content and their reducing ability during the simulated digestion process, in order to provide reference values for the further development and utilization of flavonoids in fresh-cut apple peels and pomace. The results showed that flavonoids content and reducing ability during the gastric digestion simulation increased significantly in 2 h compared with the undigested group(P<0.05). Pepsin and sour chemical environment had a facilitating effect on both the release and reduction ability of flavonoids. During the intestinal digestion simulation, the flavonoids obviously increased during 2~3 h of digestion compared with the undigested group(P<0.05), and the reducing ability also significantly increased. The flavonoid content and reducing ability of intestinal juice digestion group (with pancreatic enzyme) were higher than that of blank group (without pancreatic enzyme), the pancreatic enzyme also played a positive enhancing effect on both the release of flavonoids and their reducing ability.