Abstract:The extraction process of peanut skin procyanidins （PSPc）was optimized via ultrasonic-microwave co-treatment，and the antioxidant activity of the PSPc was evaluated.In this experiment，the pretreatment of peanut skin was used as the research object.PSPc were extracted via ultrasonic-microwave assisted ethanol extraction.Based on the single factor test and Plackett-Burman design，the Box-Behnken center design was used to optimize the process.The effects of various factors on the extraction process of PSPc were studied by setting the ultrasonic power，ultrasonic exposure time，microwave power，microwave exposure time，ethanol concentration，material/liquid ratio and extraction temperature as single factors and the content of PSPc as an indicator.The antioxidant activities of PSPc obtained via different extraction methods were evaluated based on the hydroxyl radical scavenging ability，DPPH free radical scavenging activity，and ferric ion reducing antioxidant power.The results showed that the optimal conditions for ultrasonic-microwave assisted extraction of PSPc were as follows：ultrasonic power of 160 W，ultrasonic time of 10 min，microwave power of 240 W，microwave exposure time of 90 s，ethanol concentration of 70%，extraction temperature of 50 ℃，extraction time of 20 min，and material/liquid ratio of 1∶40 （g/mL）.Under these conditions，the extraction yield of PSPc was 186.38 mg/g.The PSPc yield obtained via ultrasonic-microwave assisted extraction was significantly higher than those obtained via ultrasonic extraction and microwave extraction （p＜0.05）；moreover，the antioxidant activity of the PSPc obtained via ultrasonic-microwave assisted extraction was better than those of PSPc obtained via other extraction methods.