Ultrasound-Assisted Green Natural Deep Eutectic Solvent Extraction of Flavonoids from Wild Blueberry: Process Optimization, Composition Identification, and Antioxidant Activity

To improve the deep processing and utilization of wild blueberries, this study presents a green and highly efficient method for extracting flavonoids from blueberries. The approach combines natural deep eutectic solvents (NADESs) with ultrasound-assisted extraction. Among the 22 tested NADES, Betaine/urea (BU), was the most effective solvent for ex- tracting flavonoids from blueberries. The extraction parameters of ultrasound-assisted betaine/urea (UABU) were optimized using a response surface...