The Encapsulation of Green Tea Extract in Cyclodextrin and Loading into Chitosan-Based Composites: Controlled-Release Behavior and Antioxidant Properties

Abstract

Green tea extract was encapsulated in cyclodextrin to form an inclusion complex. Fourier transform infrared, X-ray diffraction, and 1H-nuclear magnetic resonance were employed to elucidate the complex structure. Only 10–50 wt% of green tea extract and cyclodextrin complex was incorporated into the chitosan and polyvinyl alcohol-based hydrogel composite. The structural, thermal, and mechanical properties of the complex loaded into the chitosan-based composite were investigated. Swelling characteristics and degradation behavior were also reported. The complex played an important role in the swelling and degradation curves. Antioxidant properties were then determined by 2,2′-diphenyl-1-picrylhydrazyl (DPPH·) and 2,2-azinobis (-ethylbenzothioazoline-6-sulfonic acid) (ABTS·+) assays, and the total phenolic content was determined by the Folin–Ciocalteu method. The green tea extract and cyclodextrin inclusion complex loaded into the chitosan-based polyvinyl alcohol-based hydrogel exhibits potential for use in cosmetics and nutraceutical foods.