| Polyphenols was extracted from peony seed shell by ultrasound-assisted method, and the effects of volume fraction of ethanol，ratio of liquid to solid, extraction time and extraction temperature were studied by single factor experiment with content of polyphenols as index, then the extraction conditions of polyphenols from peony seed shell were optimized by response surface methodology. Using VC and BHT as control, the antioxidant activity of polyphenols from peony seed shell was assessed by DPPH and FRAP methods. The results demonstrated that the optimal ultrasound-assisted extraction conditions of polyphenols from peony seed shell were obtained as follows: ultrasonic power 100 W, volume fraction of ethanol 70%, ratio of liquid to solid 25∶1, extraction time 80 min, extraction temperature 60℃；under these conditions, the content of polyphenols was 5.75%. The IC50 value of polyphenols from peony seed shell on scavenging DPPH free radical was 71.0 μg/mL and its FRAP value was 18.33 mmol/L, which indicated that the polyphenols from peony seed shell had certain antioxidant activity. |
