Abstract: In this study,ultrasonic-assisted extraction was developed to optimize the extraction process of proanthocyanidins (PC) presented in Hippophae rhamnoides seed meal.Cellulase was introduced into the process for improving the extraction efficiency.The extraction conditions were optimized using response surface methodology (RSM) while extraction yield of PC were recorded as response and three key factors including extraction duration,ratio of solid to liquid and pH value of extraction solvent were selected by single-factor tests.Box-Behnken design and a quadric regression equation for predicting the extraction yield of PC were established and the optimized extraction conditions were determined as follows:extraction duration as 55 min,ratio of solid to liquid as 1:30 (g/mL),pH value of extraction solvent as 5.0 and times of extraction as 3,while ultrasonic power was set at 250 W,extraction temperature was set at 25 ℃ with cellulose dosage of 3%.Under these optimized conditions,the extraction yield of PC was 3.07%.

Key words: Hippophae rhamnoides seed meal, proanthocyanidins, cellulose, response surface methodology