Green Extraction of Flavonoids from Orange Peels Using Deep Eutectic Solvents

The aim of this study was to optimize and compare four different natural deep eutectic solvents (NADES) for the extraction of flavonoids in orange peels (Navel cultivar) from Valencia (Spain). Four NADES systems with two components were obtained in their corresponding molar ratios. Three independent variables were used for the optimization: solid-liquid ratio, extraction time and the percentage of NADES in water. The results showed the highest extraction was with choline chloride: fructose (NADES-1) with 50% water content, a solid–liquid ratio of 1:25 and extraction time of 23 min. The results demonstrate that the use of NADES is an efficient and ecofriendly alternative to extracted flavonoids from orange peels.