3.2.2. Analysis of variance
Fig. 2. Response surfaces and contours plots for flavonoids extracted from C. paliurus leaves using MAE. (a) extraction temperature (X1) and extraction time (X2), (b) extraction temperature (X1) and ethanol concentration (X4), (c) extraction time (X2) and ratio of solvent to material (X3), and (d) ratio of solvent to material (X3) and ethanol concentration (X4).