The total polyphenols content was determined by spectrophotometry according to the Folin–Ciocalteu's method using gallic acid as standard (Hosseinzadeh, Khorsandi, & Hemmaty, 2013 ). The lyophilized extract was weighted and dissolved in distilled water. Briefly, a sample of 1.0 ml of the extract was transferred to separate tubes containing 7.0 ml distilled water, 0.5 ml of Folin–Ciocalteu′s reagent, and 1.5 ml of a 20% sodium carbonate anhydrous solution. Solutions were then allowed to stand at room temperature for 60 min, and then, the absorbance at 765 nm was measured by employing a ultraviolet‐vis spectrophotometer. The concentration of polyphenols in samples was derived from a standard curve of gallic acid ranging from 10 to 50 μg/ml (Pearson's correlation coefficient: r2 = .9996). Results were expressed as mg GAE/g extract.
Total flavonoids were also determined on the AE by spectrophotometry. Briefly, the extract was mixed with aluminum trichloride and potassium acetate and incubated during 30 min. The absorbance at 415 nm was measured. Results were expressed as mg quercitrin/g extract derived from a calibration curve made with known concentrations of the flavonoid quercitrin (Sigma) (Dantas Fernandes et al.,2012 ).
Total flavonoids were also determined on the AE by spectrophotometry. Briefly, the extract was mixed with aluminum trichloride and potassium acetate and incubated during 30 min. The absorbance at 415 nm was measured. Results were expressed as mg quercitrin/g extract derived from a calibration curve made with known concentrations of the flavonoid quercitrin (Sigma) (Dantas Fernandes et al.,