Ultrasound-assisted extraction of active compounds from Beta vulgaris using deep eutectic solvents

Abstract

The aim of this study is to investigate the application of ultrasound in the extraction of betanin from beets (Beta vulgaris) using Deep eutectic solvents (DES). The extraction process was optimized using response surface methodology. The time variable was found to be correlated with the extraction performance. Three DES (choline chloride: urea (CC:U), choline chloride: glycerol (CC:G), and choline chloride: citric acid (CC:Ac)) were studied. The concentration of betanin extracted with CC:U, CC:G, and CC:Ac was 41.27-67.51, 82.46-104.45, and 50.06-111.93 mg/100 g. The maximum betanin extraction of 111.193 mg/100 g was achieved with CC:Ac in 38 min using 44% DES in water in an ultrasonic bath. These results demonstrate that DESs are excellent solvents for the extraction of betanin with superior efficiency to conventional extraction solvents. Ultrasound significantly improved the efficiency of betanin extraction from beets. However, a higher betanin content in the extracts did not translate into greater active antioxidant capacity, which may be related to the synergistic effects of other compounds present in the beet extracts. This study is the first attempt to optimize the parameters for ultrasound extraction of betanin from B. vulgaris using eutectic solvents.