Table 4.

Linear and non-linear relations obtained for different antioxidant concentrations (μM) applied against DPPH radicals in ethyl acetate (radical solution in methanol or ethyl acetate), dichloromethane (radical solution in methanol or dichloromethane) and hexane (radical solution in acetone or hexane) after standard reaction time. In case of linear relations, slope (a), correlation coefficient (r) and lower linearity limits if occurring (MIN–as % of A_contr) were shown; in case of a non-linear relationship, equation type and correlation coefficient were shown.

Antioxidant	EtOAc + MeOH 30 min	EtOAc 30 min	DCM + MeOH 30 min	DCM 30 min	Hex + Acn 30 min	Hex 30 min
gallic acid	a = −57 r = 0.993 MIN = 25%	power r = −0.993	N.A. 1	N.A.	N.A.	N.A.
ferulic acid	expon. r = −0.993	power r = −0.993	N.A.	N.A.	N.A.	N.A.
catechin	a = −21 r = −0.999	expon. r = −0.998	N.A.	N.A.	N.A.	N.A.
quercetin	a = −33 r = −0.991 MIN = 35%	N.R. 2	N.A.	N.A.	N.A.	N.A.
propyl gallate	a = −50 r = −0.999	power r = −0.998	N.A.	N.A.	N.A.	N.A.
ascorbic acid	N.A.	N.A.	N.A.	N.A.	N.A.	N.A.
ascorbyl palmitate	a = −25 r = −0.998	a = −25 r = −0.999	N.A.	N.A.	N.A.	N.A.
α-tocopherol	a = −24 r = −0.998 MIN = 15%	a = −23 r = −0.999 MIN = 15%	a = −25 r = −0.999	a = −25 r = −0.999	a = −24 r = −0.999	a = −24 r = −0.999
tocopheryl acetate	N.D. 3	N.D.	N.D.	N.D.	TR. 4	N.D.
Trolox	a = −25 r = −0.999 MIN = 20%	a = −4 r = −0.999	N.A.	N.A.	N.A.	N.A.

¹ N.A.—not applicable. ² N.R.—no relationship between concentration and activity. ³ N.D.—activity not detected. ⁴ TR.—traces of activity.