*2.4. Determination of Total Flavonoid Content (TFC)*

Total flavonoid content was measured following the method described by Moreno et al. [34]. An aliquot of 500 μL of plant extract (at a concentration of 1 mg mL<sup>−</sup>1) was mixed with 100 μL KCH3COO (1 M) and 100 μL of 10% Al(NO3)3 in a 10 mL test tube and homogenized manually, and incubated for 50 min at room temperature. Then, the absorbance was measured using a spectrophotometer (Jasco V530 UV-VIS spectrophotometer, Tokyo, Japan) at 415 nm against the blank. The experiment was carried out in triplicate, and the results are expressed as the mean ± standard deviation in mg of the quercetin equivalent (QE) per g of the dry sample. A calibration curve was prepared using 20–500 mg/L quercetin (R2 = 0.9970).
