Table 3.

The regression coefficients of second-order polynomial equations.

	Coefficients	TPC	TFC	DPPH	ABTS	OH
Intercept	K0	113.5**	61.78**	530.7**	3.69**	12.50**
Linear	K1	−3.2**	−2.36	−10.1	−0.20**	0.19
	K2	2.8**	−4.25*	−3.5**	−0.07	−0.69**
	K3	−5.4**	−8.32*	−31.9	−0.03	−1.28**
	K4	−0.3	−1.37	2.8	−0.01	−0.06
Interaction	K12	−1.56	3.62	4.7	0.004	0.09
	K13	−2.0*	0.03	5.0	0.11	0.15
	K14	4.2**	2.05	1.7	0.13	−0.54
	K23	2.8**	7.36*	−3.8	−0.09	−0.01
	K24	−1.0	−0.33	−9.2*	0.14	−0.19
	K34	−0.7	−2.31	−3.2	0.09	0.17
Quadratic	K11	3.1**	−17.34**	−115.8**	−0.42**	−0.75**
	K22	1.5	−22.46**	−116.3**	−0.43**	−1.36**
	K33	−1.6**	−11.17**	−10.6**	−0.79**	−6.79**
	K44	2.1*	−19.90**	−122.9**	−0.47**	−0.67*
Degree of freedom		14	14	14	14	14
F-values		58.84	19.86	237.5	22.13	23.62
p-values		<0.0001	<0.0001	<0.0001	<0.0001	<0.0001
R2		0.9481	0.9521	0.9958	0.9568	0.9847
Adjusted R2		0.8963	0.9041	0.9916	0.9135	0.9695

Notes: * significant statistical differences (p < 0.05), ** highly significant statistical differences (p < 0.01).