Optimization of microwave-assisted extraction conditions of polyphenol from Picea koraiensis Nakai by response surface methodology

The microwave-assisted extraction conditions of polyphenol from Picea koraiensis was optimized by response surface methodology. Based on single factor test,a 3-factor,3-level Box-Behnken experimental was adopted,including dependent variables(ratio of material to liquid,microwave power and extraction time) and independent variable(yield of polyphenols). Results showed that the regression model fit well with experimental data. The optimum conditions were ratio of material to liquid 1∶31(g/mL),microwave power 295W,extraction time 46s,ethanol concentration 40%. Under these conditions,the predicted value of yield of polyphenol was 17.51%,compared to the measured value 17.38%,the relative error<1%. Result showed that the conditions were reasonable and feasible.