2.7.1. DPPH Radical Scavenging Assay

DPPH free radical scavenging activity of samples was performed according to Tomás et al. [4] with some modifications. Of the phenolic extracts 0.15 mL, with concentrations ranging from 0.03 to 0.43 mg/mL were mixed with 0.15 mL of DPPH (50 mg/L) and the absorbance was read at 515 nm using an ELX800 Microplate Reader (Bio-Tek Instruments, Inc., Winooski, VT, USA). The percentage of radical inhibition was calculated using the following equation:

The amount of antioxidant necessary to decrease the initial DPPH concentration by 50% (EC₅₀) was achieved plotting the inhibition percentage against the extract concentration.