Research of extraction and antioxidant activity in vitro of polyphenols from pine nut coat

The ultrasonic- assisted ethanol extraction method was used to extract polyphenols with antioxidant activity in pine nut coat.Single factor test and orthogonal experiment were applied to analyze the effects of ethanol concentration, extraction temperature, the ratio of material- to- liquid, ultrasonic time, ultrasonic wave power on polyphenols yield of Pine Nut Coat. The optimal extraction conditions were as follows: ethanol concentration 60%, extraction temperature 60℃, material- to- liquid ratio 1 ∶ 20 ( g / m L) , ultrasonic time 90 min, ultrasonic wave power300 W, the maximum yield was 2.36%.By antioxidant experiments in vitro, the poloyphenols of pine nut coat showed scavenging effects on the OH·, DPPH· and H2O2.