Enhancement of the gut-retention time of resveratrol using waxy maize starch nanocrystal-stabilized and chitosan-coated Pickering emulsions

To enhance its gut health-promoting activity and bioaccessibility, resveratrol was loaded in emulsions stabilized by octenyl succinic anhydride-modified waxy maize starch nanocrystals and then coated with chitosan. Resveratrol loaded in > 0.1% chitosan-coated emulsions adhered more robustly onto porcine intestinal mucosa than did resveratrol powder (23-fold) and chitosan-uncoated emulsions (7-fold). Unlike chitosan-uncoated emulsions, chitosan-coated emulsions were stable during gastric digestion and slowly hydrolyzed in a small intestinal environment. After in vitro digestion, > 90% of the soluble fractions of resveratrol loaded in chitosan-coated and chitosan-uncoated emulsions were 14-fold greater than that of resveratrol powder. The findings suggest that the chitosan-coating can enhance both the gut-retention time of resveratrol and its bioavailability, resulting in prolonged bioactivity of non-oxidized resveratrol. Moreover, the colloidal stability of resveratrol-loaded and chitosan-coated emulsions was maintained for 2 months (pH 4; 25 °C). This study provides useful information to guide development of an effective oral delivery system for resveratrol.