Controlled release and antioxidant activity of chitosan or its glucosamine water-soluble derivative microcapsules loaded with quercetin

The controlled release and antioxidant properties of the flavonoid quercetin (Qr) incorporated into crosslinked microcapsules using chitosan (Ch) or its derivative modified with glucosamine by Maillard reaction (GACh) as wall materials were evaluated. The microcapsules containing Qr (Qr-MC) were obtained by the spray-drying technique with high microencapsulation efficiency of Qr, and with spherical shape of average size of 2.0 +/- 1.5 mu m. Under gastrointestinal simulated conditions, the Qr-MC showed controlled release within few hours, being the release rate faster under gastric than intestinal conditions. The rate of release of Qr by GACh-MC was almost double than those made with Ch under gastric conditions, but the same release rate was observed for both Qr-MC under intestinal conditions. Efficient antioxidant activity of the Qr-MC against reactive oxygen species (ROS) including hydroxyl radical HO center dot, anion superoxide O-2(center dot-) and singlet oxygen O-1(2) was observed, indicating that Ch bio-polymers are also suitable functional coating materials for flavonoid microencapsulation, regarding the gastro resistance, antioxidant activity and controlled release properties that could increase the bioavailability of the flavonoid. (C) 2018 Published by Elsevier B.V.