Optimization of Microwave-Assisted Extraction of Total Flavonoids from Fructus Aurantii Immaturus by Response Surface Methodology

This paper deals with the optimization of the process conditions for the microwave-assisted extraction of total flavonoids from Fructus Aurantii Immaturus using response surface methodology(RSM).Based on one-factor-at-a-time experiments,a quadratic regression model indicating the individual and interactive effects of microwave power,extraction time and ethanol concentration on the yields of naringin and hesperidin was established using a Box-Behnken experimental design.From the response surface and contour plots drawn for the model,the optimal extraction conditions were obtained as follows: size reduction ratio 40-60 mesh,liquid/solid ratio 100:1,ethanol concentration 58.8%(V/V),microwave power 447 W,and extraction time 3.9 min.Under these conditions,the experimental yields of naringin and hesperidin were 50.21 mg/g and 4.96 mg/g,respectively,which were in substantial agreement with the theoretically predicted values.