Table 1.

Linear regression analysis for the reactions of oleuropein, rutin, cyanidin-glucoside, and gallic acid with the Folin–Ciocalteau reagent expressed as mg/mL or in millimolar concentration.

	Oleuropein	Rutin	Cyanidin-Rutinoside	Gallic Acid
Regression coefficient (r)	0.9996	0.9977	0.9992	0.9998
Determination coefficient (R2)	0.9992	0.9954	0.9985	0.9995
RSDb	0.4231	1.1464	0.7469	0.4873
Intercept (a)	−0.0031	0.0266	0.0032	−0.0102
S a	0.0019	0.0046	0.0032	0.0026
Concentration as mg/mL
Slope (b)	0.1256	0.1457	0.2116	0.3802
S b	0.0005	0.0017	0.0016	0.0019
LOD	0.0827	0.1540	0.0763	0.1203
LOQ	0.2757	0.5133	0.2544	0.4011
Concentration as mM
Slope (b)	0.0679	0.0890	0.1260	0.0647
S b	0.0003	0.0010	0.0009	0.0003
LOD	0.0447	0.0940	0.0454	0.0205
LOQ	0.1490	0.3133	0.1515	0.0682