Influence of ultrasonic-assisted deep eutectic solvent extraction on bioactive compounds from germinated mung beans (Vigna radiata) and greenness assessment

In this study, the ultrasonic-assisted method was applied to extract phenolic, flavonoid, and antioxidant compounds from germinated mung beans. In addition, deep eutectic solvents (DESs) were chosen as solvents to support the green concept and to increase their applicability. Choline chloride is a quaternary ammonium salt and was used as the hydrogen bond acceptor (HBA), and compounds from the alcohol, organic acid, sugar, and amide groups were combined as hydrogen bond donors (HBD) to obtain 8 different DESs. Higher yields were obtained with ultrasonic-assisted DESs compared to the traditional method (maceration) when total phenolic compound and antioxidant activities were evaluated. While the most effective solvent for total phenolic compound yield was choline chloride:fructose, the highest antioxidant activity values were obtained with solvents using organic acids as HBD. Moreover, Blue Applicability Grade Index (BAGI) was used to assess the greenness of the applied ultrasonic-assisted spectrophotometric extraction and DESs. As a result, using green technology and green solvents was influential in the extraction of bioactive compounds, and their applicability was especially effective for mung beans.