Abstract: We optimized the polysaccharide extraction from the peony pod and studied its antioxidant activity. By single factor design, we identified extraction parameters of particle size of material, extraction temperature, extraction time, liquid-solid ratio and final concentration of ethanol in precipitation step. A 3-factor, 3-level central composite design involving three independent variables followed by response surface analysis was performed for the further optimization of the extraction parameters. The optimal extraction conditions were 60-80 mesh of particle size, extraction temperature of 100℃, extraction time of 40 min, liquid-solid ratio of 20 mL·g^-1, and precipitated ethanol with the final concentration of 80%. Under these conditions, the predicted and experimental extraction yields of pod polysaccharides were 8.76% and 8.77%, respectively. The antioxidant capacity of pod polysaccharide was determined by DPPH and reducing activity. The pod polysaccharide has the antioxidant capacity.

Key words: peony tree pod, polysaccharide, response surface method, antioxidative activity