Abstract:The response surface method was used to optimize the ultrasonic assisted extraction of procyanidins from grape seeds.Using the extraction rate of procyanidins as the index，the effects of extraction time，temperature，ethanol concentration and liquid-solid ratio on the extraction rate were investigated.The Box-Behnken central composite method was used to design the response surface optimization test scheme，and the prediction model was established by least square regression analysis to optimize the ultrasonic assisted extraction process parameters.The effect order of factors on the extraction rate of procyanidins were extraction time＞extraction temperature＞liquid-solid ratio＞ethanol concentration.Based on response surface optimization，the optimum ultrasonic extraction conditions were room temperature for approximately 20 min，hot reflux extraction time of 1.0 h，extraction temperature 70 ℃，ethanol concentration 60% and liquid-solid ratio 15∶1（mL/g）.Under these conditions，the extraction rate of procyanidins was 4.68%，which was close to the predicted value of 4.71%.The relative standard deviation was 1.22% and the optimized conditions had good repeatability.The reported optimized parameters will be a reference for industrialized extraction of procyanidins from grape seeds.