Abstract: With the aim of developing an ultrasonic-assisted procedure for the extraction of total flavonoids from Zanthoxylum bungeanum Maxim fruit peel, we performed an orthogonal array design based on one-factor-at-a-time experiments to determine optimal extraction conditions. A 45% ethanol/water solution was found to be the best solvent for total flavonoids and the optimal solid-to-solvent ratio was 1:30 (g/mL). An extraction duration of 50 min was found to be optimum. Under these conditions, the yield of total flavonoids was spectrometrically determined to be 3.56%. The IC50 values of the obtained extract for scavenging DPPH and hydroxyl free radicals were 0.855μg/mL and 132.18μg/mL, respectively. Moreover, the total flavonoids extracted from Zanthoxylum bungeanum Maxim fruit peel possessed stronger reducing power than BHT.

Key words: ultrasonic-assisted extraction, Zanthoxylum bungeanum Maxim fruit peel, total flavonoids, orthogonal array design, antioxidant activity