Table 5.

Regression coefficient of the predicted second order polynomial models (BBD) for antioxidant properties.

Regression coefficient	Total phenolic compound	Total flavonoid content	Antioxidant activity by DPPH assay	Antioxidant activity by FRAP assay
Intercept
X0	574.6*	17.994*	1754.38*	2111.4*
Linear
X1	35.40*	−0.837*	20.72*	12.1
X2	−4.78	−1.331*	−84.18*	−237.5*
X3	44.15*	−0.054	67.62*	21.4
Quadratic
X12	−0.91*	0.00678*	−1.8696*	0.176
X22	−0.043	−0.03610*	−1.3244*	−1.569*
X32	−0.727*	−0.02115*	−2.3839*	−2.414*
Cross product
X1X2	0.15	−0.00637*	0.6489*	−0.405
X1X3	0.336*	0.0008	0.0121	0.141
X2X3	−0.327*	0.01145*	2.6545*	3.138*

*Level of significance p ≤ 0.05.