2.10.3. Total flavonoids contentTotal flavonoids content was determined by following the spec-trocolorimetric method of Arvouet-Grand et al. (1994). The 0.5 mLof 75% methanol extract solution (1 mg/mL) was mixed with 1.5 mLof 95% ethanol, 0.1 mL of 10% aluminum chloride, 0.1 mL of 1 Mpotassium acetate, and 2.8 mL of distilled water, and then incubatedat room temperature for 90 min. The absorbance was measured at415 nm using a Hitachi U2000 UV–vis spectrophotometer (HitachiCo., Japan). Total flavonoid contents were calculated from a calibra-tion curve using various concentrations of quercetin solution.