2.3. Total phenolic and flavonoids content

The total phenolic content of ME and HE was determined using a slight modification of the Folin-Ciocalteu assay [25]. A 1 mL aliquot of ME and HE was added to 1 mL of 10% Folin-Ciocalteu solution. The solution was vortexed and left for 3 min at 25 °C. Then, 3 mL of 2% sodium carbonate (Na₂CO₃) solution was added and kept for 2 h at 25 °C. The absorbance was measured with a spectrometer at 760 nm. The total phenolic content was expressed as mg gallic acid equivalents (GAE).

The total flavonoid content was measured by a slightly modified aluminum chloride (AlCl₃) colorimetric assay [26]. An aliquot (1 mL) of ME and HE was dissolved in 1 mL deionized water. This solution (1 mL) was added to 3.0 mL of 95% alcohol, 0.2 mL of 10% aluminum chloride, 0.2 mL of potassium acetate (1 M), and 5.6 mL of deionized water. Then, the reaction mixture was incubated at 25 °C for 40 min, and the absorbance was measured with a spectrometer at 415 nm. The total flavonoid content was expressed as mg quercetin equivalents (QE).