Comparative Study on Preparation, Characterization and Antioxidant Activity of Encapsulated Viola odorata L. Extract Based on Gum Arabic-Gelatin and Lepidium Perfoliatum L. Seed Gum Nanoemulsions

Viola odorata L. (Sweet violet) has been known with various biologic activities due to its secondary metabolites including flavonoids, glycosides, alkaloids, tannins and saponins. Nanoencapsulation of its extract can be an effective approach to improve the pharmaceutical application of Sweet violet phytochemicals. This study aimed to prepare encapsulated violet extract by two encapsulation methods and compare the antioxidant activity, and evaluate the encapsulation efficiency and physicochemical properties. The extract was encapsulated by double nanoemulsion (gum Arabic-gelatin complex) and nanoemulsion (Lepidium perfoliatum seed gum) methods and using the spray and freeze-drying processes. As a result, the highest encapsulation efficiency (85.82%) and more than antioxidant activity (136.67%) was in double nanoemulsion with freeze-drying. Nanoemulsions showed a higher stability index (97.75%) and greater emulsifying ability (99.84%) than double nanoemulsion due to higher zeta potential. . Due to Dynamic light scattering analysis, the nanoemulsion particle size (306.5 nm) was smaller than that of double nanoemulsion (798.3 nm). Density and moisture content of the double emulsion with freeze-drying were higher than those of nanoemulsions. The results implied elected methods effectiveness to prepare encapsulated Sweet violet extract, and obtained encapsulated extracts have the potential to be used in further pharmaceutical and food studies.