Study on optimization of water-soluble polysaccharides extraction from Malus prunifolia (wild) Borkh using response surface methodology and its antioxidant activities in vitro

Box-Behnken design was used to optimize the extraction conditions of water-soluble polysaccharides from Malus prunifolia (wild) Borkh. The experimental data were fitted to a second-order polynomial equation using multiple regression analysis and also examined using the appropriate statistical methods. The optimum extraction conditions were:optimized extraction time 4h, extraction temperature 86℃, and ratio of water to raw material 1∶28g/mL, the predicted yield of polysaccharides extracted was 8.33%. The antioxidant activity of the extraction was evaluated by scavenging hydroxyl radical (·OH) , superox ide an ion free radical (O2-·) , 1-diphenyl-2-picrylhydrazy (DPPH·) and reducing power. The in vitro antioxidant results showed that the inhibition effects of MPB on ·OH, O2-·, DPPH significant, MPB showed significant inhibitory effects on DPPH with IC50values of 1.181mg/mL, when the concentration of polysaccharides up to 1mg/mL, the scavenging capacity reached 87.12%, close to 94.47% by VC.