2.3.7. Total Phenolic Content

A fresh leaf sample (0.5 g) was extracted with 20 mL of 80% (*v*/*v*) methanol and then used for determining the total phenolic content. Total phenols were determined with a spectrophotometer, employing the modified Folin–Ciocalteu colorimetric method [25]. The methanolic extract (1 mL) was diluted 1:10, then mixed with 1 mL of Folin–Ciocalteu reagent in a test tube and allowed to stand for 6 min, followed by the addition of 5 mL of 1M Na2CO3 (*w*/*v*). Then, 3 mL of distilled water was added. The samples were incubated for 90 min at room temperature in the dark, and the absorbance at 760 nm was measured using the JENWAY 6300 spectrophotometer, Staffordshire, UK. The results were expressed as mg gallic acid (GAE) g−<sup>1</sup> fw.
