Encapsulation of quercetin in cellulose porous microspheres: improving antioxidant activity and storage stability

In this study, quercetin in cellulose porous microspheres were prepared by quasi-emulsion solution diffusion method. The formulation of microspheres was optimized by Box-Behnken Design and their antioxidant activity was evaluated. Morphological structures and physicochemical properties of the microspheres were investigated. The findings of porous microspheres particle size ranged from 150 to 200 μm. The encapsulation efficiency and loading capacity were of 90.32% and 20.54%. Respectively, prepared using polyvinyl alcohol (0.16%), ethyl cellulose and quercetin (41:19, w/w), stirred in dichloromethane/ethanol solution (4:1, v/v). The scanning electron microscopy confirmed porous structure of the microsphere surface. Fourier transform infrared spectroscopy revealed structural changes between quercetin and ethyl cellulose. X-ray diffraction and thermal analysis showed that the encapsulated quercetin was amorphous. Compared with free quercetin, the antioxidant capacity and stability of quercetin in porous microspheres were significantly improved. This research reveals the development of porous microsphere carrier that facilitated improved antioxidant activity and stability of quercetin.