Supercritical carbon dioxide technology was used to extract walnut green peel polyphenols, and orthogonal test was used to optimize the separation parameters, and the antioxidant activity of the extract in vivo was investigated. The results of orthogonal test showed that the optimum conditions for supercritical carbon dioxide extraction of walnut green peel polyphenols were as follows: extraction temperature 50 C, extraction pressure 30 MPa, extraction time 6 h, ethanol volume fraction 75%, entrainer dosage 3 mL/g, and CO2 flow rate 30 kg/h. Under these optimum conditions, the extraction amount could reach 8.83 mg/g; the order of factors affecting the extraction amount was as follows: extraction temperature > CO2 flow rate > ethanol volume fraction > extraction pressure > The amount of entrainer > extraction time; the extract could significantly reduce the content of malondialdehyde (MDA) and increase the activity of superoxide dismutase (SOD) in mice (p < 0.05), indicating that Walnut Green Peel Polyphenols had significant antioxidant activity in vivo.
Key words: Supercritical carbon dioxide, walnut green peel extract polyphenols, antioxidant in vivo