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.