Extraction of anthocyanin from grape skin with aqueous two- phase system

Grape skin was used as the raw material to explore the effect of Aqueous two- phase system on yield of anthocyanin.Four extraction parameters including p H,ethanol concentration,ammonium concentration,solid- liquid ratio were optimized by using Plackett- Burman design based on single factor investigations for achieving yield of anthocyanin.The interaction of the respective variables and their influence on the yield were studied by using BoxBenhnken central composite design and response surface analysis theory,the simulated quadratic polynomial regression equation of prediction model was set up. The optimal parameters were optimized by response surface analysis. The ethanol concentration,ammonium sulphate concentration,p H and solid- liquid ratio were 28%,18.14%,3.00 and 1∶35 g / m L,respectively.The optimal yield of anthocyanin was 4.43 mg / g.The research will provide theoretical support for the anthocyanin of practical application.