Table 3.

Analysis of variance (ANOVA) for the experimental results of the CCD model.

	SS	df	MS	F	p
Model	169.13	11	15.38	105.04	<0.0001
X1	39.32	1	39.32	268.64	<0.0001
X21	0.49	1	0.49	3.37	0.0831
X2	16.90	1	16.90	115.46	<0.0001
X22	0.92	1	0.92	6.30	0.0219
X3	27.52	1	27.52	188.02	<0.0001
X4	69.16	1	69.16	472.47	<0.0001
X24	3.15	1	3.15	21.49	0.0002
X1 X2	7.78	1	7.78	53.18	<0.0001
X1 X3	0.88	1	0.88	6.04	0.0244
X2 X3	1.61	1	1.61	11.02	0.0038
X3 X4	2.09	1	2.09	14.27	0.0014
Residual	2.63	18	0.15
Lack of fit	2.29	13	0.18	2.55	0.1540
Pure error	0.34	5	0.07
Total SS	171.76	29

SS, sum of squares; df, degree of freedom; MS, mean square; X₁, extraction time; X₂, ethanol concentration; X₃, solid-to-liquid ratio; X₄, extraction temperature.