Optimization of extraction of Xiaoxianggou total flavonoids by Box-Benhnken design

Objective: To optimize the extraction technique of Xiaoxianggou total flavonoids(XGTF) by Box-Benhnken design.Methods: The method of response surface analysis with 3 factors and 3 levels was adopted with the extraction rate of XGTF(%) as the response value according to the Box-Benhnken center-united experimental design principles.The factors influencing the technological parameters were determined by means of regression analysis.Response surface and contour were finally graphed with the extraction rate of XGTF(%) as the response value.Results: The factors which affect the extraction rate of XGTF(%) according to priority was ethanol concentration,ultrasonic extraction time,and liquid-solid ratio.The optimum extraction conditions of XGTF(%) were concluded as follows: ultrasonic extraction time of 40.0 min,ethanol concentration of 65%,liquid-solid ratio of 46:1.Under these conditions,the yield of XGTF was up to 3.50% and its experimental value was 3.41%.Conclusion: The mathematical model that the present study established is significant(P0.0001),and it might be applied to analysis and prediction the extraction technique of XGTF.