Abstract: Response surface methodology was used to optimize the ultrasonic-assisted extraction of total flavonoids from hovenia seeds. A regression model describing total flavonoid yield with respect to ultrasonic power, material-to-liquid ratio and ethanol concentration was established. Ethanol concentration was the most important affecting factor of the total flavonoid yield resulting from 60 min extraction at 65 ℃, followed by material-to-liquid ratio and ultrasonic power. The optimal extraction conditions for total flavonoids from hovenia seeds were ultrasonic power of 374.4 W, material-to-liquid ratio of 1:69.4 (g/mL), ethanol concentration of 64.5%, extraction temperature of 65 ℃ and extraction time of 60 min, and the resultant total flavonoid yield was (0.819± 0.003)%, which was close to the predicted value of 0.823%. Therefore, the established regression model is feasible and has good prediction capability.

Key words: hovenia seeds, ultrasonic, extraction, response surface, total flavonoids