Ultrasonic-assisted Extraction of Flavonoids from Navel Orange Peel

Ultrasonic treatment was applied to the ethanol extraction of flavonoids from navel orange peel.The effects of four crucial variables such as ultrasonic power,ethanol concentration,material/liquid ratio and ultrasonic treatment time on the yield of flavonoids were investigated by single-factor method.An orthogonal array design leading to a set of 9 combinations of these variables was performed to obtain the highest yield of flavonoids.Under the optimized conditions as follows:ultrasonic power 125 W,60% alcohol as the extraction solvent,material/liquid ratio 1:35,and extraction time 60 min,a yield of flavonoids of 49.3 mg/g was achieved.