*2.5. ABTS+ Assay*

The antioxidant capacity of the extracts was determined using the ABTS•<sup>+</sup> assay as described by Re et al. [14] with some modifications. An aliquot of ABTS solution (7 mM) was reacted with 2.45 mM potassium persulfate to produce an ABTS radical cation (ABTS+). The solution was incubated in the dark for 12 h at 22 ◦C to ensure its stability. Before use, the ABTS+ stock solution was diluted with ethanol to an absorbance of 0.70 ± 0.02 at 734 nm and 30 ◦C. The diluted ABTS+ solution (3 mL) was mixed with 30 μL of sample, and the absorbance was measured after 6 min. The ABTS+ scavenging activity was calculated using the following equation:

$$\% \text{ Inhibition} = ((\text{A}\_0 - \text{A}\_c)/\text{A}\_0) \times 100 \tag{2}$$

where A0 is the absorbance of the blank and Ae is the absorbance at 6 min. The results were expressed as μM Trolox equivalent (TE)/mL of extract, using a dose–response curve for Trolox (0–350 μM; R<sup>2</sup> = 0.996) as the standard. Each sample was evaluated in triplicate.

### *2.6. Reversed Phase-HPLC-Diode Array Detector Analysis*

A reversed-phase HPLC coupled with a Thermo-Finnigan Spectra System diode array detector (Thermo-Finnigan, Waltham, MA, USA) was used to quantify the phenolic components in the extracts. The instrument was equipped with an SCM 1000 degasser, an AS 3000 automatic injector, a P2000 binary gradient pump, and a Finnigan Surveyor PDA Plus detector. ChromQuest software (version 5.0; Thermo-Finnigan, Waltham, MA, USA) was used for data acquisition. Separation was performed using a reverse-phase Kinetex Phenyl-Hexyl C18 column (150 × 4.6 mm id and 5 μm particle size; Phenomenex, Torrance, CA, USA) at a flow rate of 1 mL/min. The mobile phase was composed of formic acid at 0.1% *v*/*v* (A) and acetonitrile (B), and the sample injection volume was 10 μL. The following gradient elution was utilized: 5% B for 0–7 min; a linear gradient

from 5% to 50% B for 7–35 min; a linear gradient from 50% to 80% B for 35–37 min; a linear gradient from 80% to 90% B for 37–38 min; and a linear gradient until 90% A and 10% B were reached for 38–41 min. Gallic acid, protocatechuic acid, catechin and epicatechin, and quercetin were quantified by measuring the absorbance at 271, 293, 279, and 366 nm, respectively. Quantification was performed using the external standard linear calibration curves obtained under the same conditions.
