evaluation and comparison of antioxidant effects of different extracts of vitis vinifera l. var. ghizil uzum skin and seeds extracted by ultrasonic and deep eutectic solvents (dess) methods

Extraction of antioxidants from plant tissues can be done using traditional extraction processes such as solid-liquid extraction, solvents and steam distillation (1). one of the simplest techniques for extraction is ultrasonic extraction which is easy to perform using common laboratory equipment like an ultrasonic bath. in recent years, a new generation of green solvents called deep eutectic solvents (des) has been introduced (2). for this study, samples of vitis vinifera l. var. ghizil grapes were collected from urmia city. grape seeds and skin extracts were extracted using ultrasonic and dess methods. antioxidant activity of different extracts was evaluated using total phenol, dpph and reducing power tests. the results of this study showed that the extraction method played an important role in determining the antioxidant properties of the extract. there was a significant difference in the antioxidant capacity of skin and seed extracts that were extracted using each of the ultrasonic and dess methods compared to the control group (p < 0.05). the highest antioxidant capacity per mg of grape skin and seed extract was observed in the extract prepared by the combined method of ultrasonic and deep eutectic solvents (p < 0.05). the highest amount of total phenol and antioxidant capacity was observed in the seed extract compared to the skin extract. therefore, it could be concluded that ghizil grape extracts extracted using the combined ultrasonic method and deep eutectic solvents had higher antioxidant effects compared to other conventional methods of extract preparation.