Optimization of Ultrasonic-assisted Extraction of Polysaccharides from Chinese Yam Peel and Its Antioxidant Activity

This present study focused on extraction of polysaccharides from Chinese yam peel by ultrasonic as-sisted method, and the antioxidant activity of polysaccharides from Chinese yam peels was also evaluated. The extraction conditions of polysaccharides were optimized using response surface methodology on the basis of sin-gle factor experiment. The DPPH radical scavenging capacities and hydroxyl radical(·OH) scavenging capaci-ties were measured. Results showed that the optimal parameiers of ultrasonic extractin were solid/liquid ratio 1/20 (g/mL), ultrasonic time 110 min, extraction time 40 min, extraction temperature 70℃. Under these condi-tions, the polysaccharides extraction rate reached 185.12 mg/g, increased by 48.89%compared with the con-trol without ultrasonic assisted extration. The polysaccharides obtained possessed potent antioxidant activity, and the antioxidant activity of polysaccharides from Chinese yam peel was found in does dependent manner. Un-der the concentration of 3.2 mg/mL, the radical scavenging rate on DPPH and·OH were 87.67%, 71.20%, re-spectively.