Total phenolic compound content in each extract was spectrophotometrically determined in accordance with the Folin–
Ciocalteu procedure by reading the absorbance at 725 nm against a methanol blank (Lakenbrink, Lapczynski, Maiwald, & Engelhardt, 2000). Briefly, samples (20 ll, water added to 1.6 ml) were introduced into test tubes, and then 100 ll of Folin–Ciocalteu reagent and 300 ll of sodium carbonate (20%) were added. The tubes’ contents were mixed and
incubated at 40 C for 40 min. Absorption at 725 nm was measured. The total phenolic contents were expressed as milligrams per gram of MLPE for gallic acid (GA) and rutin