Optimization of two-phase extraction of polysaccharide from blueberry

The polysaccharide was extracted by ultrasonic water extraction,then purified by aqueous two phase. With the percentage of solution,the concentration of K_2HPO_4 and the concentration of PEG6000 as the single factor,and extraction rate of polysaccharides from the lower phase as the index,the double phase extraction technology of blueberry polysaccharide was optimized by response surface methodology. The results showed that the percentage of liquid medicine 60%,PEG6000 16%,K_2HPO_4 16.9%,the next phase of blueberry polysaccharide yield was the highest,up to 95.03%.And the purity of polysaccharide was significantly higher than that of the traditional water extraction and alcohol precipitation method.The model was highly significant( R~2= 0.9920),good fitting,can be used for extraction of polysaccharides from blueberry.