| The ultrasound-assisted cellulose extraction of polysaccharide from peony seed cake was optimized. According to single factor experiment, the significances of nine factors(pH, celluase dosage, enzymolysis time, enzymolysis temperature, ultrasonic time, ultrasonic power, ultrasonic temperature, ratio of liquid to solid and particle size)affected the extraction quantity of polysaccharide were evaluated by PB design. Then the extraction conditions were optimized by BBD response surface methodology, and the antioxidant activity of peony seed polysaccharide was evaluated by DPPH method. The results showed that the optimal extraction conditions of polysaccharide from the peony seed cake were obtained as follows: pH 4.5, celluase dosage 0.45%, enzymolysis time 60 min, enzymolysis temperature 45?℃, ultrasonic time 19 min, ultrasonic power 300 W, ultrasonic temperature 40?℃, ratio of liquid to solid 19∶?1 and particle size 60 meshes. Under these conditions，the extraction quantity of polysaccharide was 196.87 mg/g.The peony seed polysaccharide had certain scavenging activity on DPPH free radical with IC50 31.19 μg/mL, but the scavenging activity was weaker than that of VC. |
