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Table 2 Analysis of variance (ANOVA) for the model

From: Optimization of phenolics and flavonoids extraction conditions of Curcuma Zedoaria leaves using response surface methodology

Sources Sum of squares Degree of freedom Mean squares F-value p-value
Phenolic content (mg/g GAE)
 Model 1191.21 9 132.36 1662.76 < 0.0001
 X 1 -temperature 450.69 1 450.69 5661.84 < 0.0001
 X 2 -Time 56.30 1 56.30 707.27 < 0.0001
 X 3 -solvent ratio 229.32 1 229.32 2880.92 < 0.0001
 X 1 X 2 135.30 1 135.30 1699.75 < 0.0001
 X 1 X 3 20.87 1 20.87 262.13 < 0.0001
 X 2 X 3 61.38 1 61.38 771.14 < 0.0001
 X 2 1 25.87 1 25.87 325.02 < 0.0001
 X 2 2 20.46 1 20.46 257.06 < 0.0001
 X 2 3 181.23 1 181.23 2276.79 < 0.0001
 Residual 0.80 10 0.080   
 Lack of fit 0.63 5 0.13 3.74 0.0870
 Pure error 0.17 5 0.034   
Cor total 1192.01 19    
R2 = 0.9993
Adj. R2 = 0.9987
CV% = 0.24
Flavonoid content (mg QE/g of extract)
 Model 0.22 9 0.024 229.66 < 0.0001
 X 1 -temperature 0.002 1 0.002 21.86 0.0009
 X 2 -Time 0.003 1 0.003 31.89 0.0002
 X 3 -solvent ratio 0.11 1 0.11 1065.88 < 0.0001
 X 1 X 2 0.0006 1 0.0006 5.82 0.0365
 X 1 X 3 0.033 1 0.033 308.93 < 0.0001
 X 2 X 3 0.012 1 0.012 114.14 < 0.0001
 X 2 1 0.044 1 0.044 421.70 < 0.0001
 X 2 2 0.0006 1 0.0006 57.66 < 0.0001
 X 2 3 0.0008 1 0.0008 8.25 0.0166
 Residual 0.001 10 0.0001   
 Lack of fit 0.0005 5 0.0001 0.97 0.5115
 Pure error 0.0005 5 0.0001   
 Cor total 0.22 19    
R2 = 0.9952
Adj. R2 = 0.9909
CV% = 0.17