*3.3. Total Phenolic Content*

The total phenolic content (TPC) was determined by the Folin–Ciocalteu colorimetric method [7]. A small quantity (0.2 mL) of each extract and 1.5 mL of Folin–Ciocalteu reagen<sup>t</sup> (20% *v*/*v*) were mixed thoroughly. Four mL of Na2CO3 (7%) were added, then made up to 10 mL with water. The mixture was kept in the dark at room temperature for 90 min. The absorbance was then measured at 760 nm using a UV-spectrophotometer (UV-1800, Shimadzu, Kyoto, Japan). TPC was calculated using a calibration curve of gallic acid.
