The results suggest that the changes of extraction time
and ethanol concentration had a significant effect on flavonoids
extraction ratio. It may be found that the operational parameters
turned out to be significant (P < 0.05) for the extract are the quadratic
terms as solid to liquid ratio (P = 0.00130), the linear term
as extraction time (P = 0.00110). To obtain simplified model for
interpretation, all non-significant terms (P > 0.05), such as liner
term as solid to liquid ratio (P = 0.19401) and the interactive solid
to liquid ratio with ethanol concentration and extraction time
(P = 0.06883 and P = 0.49423, respectively), were eliminated. The
simplified model (1) for variables were stated as