Using natural deep eutectic solvents for the extraction of antioxidant compounds from cornelian cherry (Cornus mas L.) fruits

Traditionally used extraction methods are usually based on toxic and/or flammable solvents. Therefore, currently, increased attention has been focused on environmentally friendly green extraction techniques. We aimed to develop a green extraction procedure by using natural deep eutectic solvents (NADES) to recover antioxidant compounds from cornelian cherry fruits (Cornus mas L.). Natural deep eutectic systems combined with maceration with shaking extraction were tested to recover of antioxidant compounds from cornelian cherry fruits. In this study, four different independent variables, namely solvent type (Glu-CA; Glu-Gly; LA-Glu), water concentration (30, 50, and 70 %; v/v), extraction time (30, 60, 90, and 120 min), and extraction temperature (25, 40, and 50 degrees C) were investigated. Glucose-glycerin (Glu-Gly; 1:1 M ratio) based solvent provided the best results. In addition, one-factor-at-a-time (OFAT) optimization showed that a temperature of 25 degrees C, 120 min of extraction time, and water concentration of 50 % (v/v) to be the best extraction parameters for Glu-Gly based NADES extraction. The developed method has been successfully applied for the extraction of antioxidant compounds from 13 different cornelian cherry cultivars. NADES can be used safely to extract phenolic compounds from cornelian cherry fruits compared to conventional extraction solvents (water and 80 % (v/v) ethanol).