Determination of Total Flavonoid and Total Phenolic Contents

The total flavonoidal and phenolic contents of various extracts have been determined according to Olajuyigbe and Afolayan (2011). Folin–Ciocalteu reagent was used in the assay of total phenolic content using gallic acid as standard. The concentration of phenolic contents was described as gallic acid equivalents (GAEs) for 1 g of extract.

For flavonoid content determination, methanolic aluminum chloride (2% v/v) was used and absorbance of the yellow color developed was measured at 420 nm. Quercetin was used as a standard and concentration of flavonoids was expressed as mg Quercetin equivalent (QE) for 1 g of the tested extract.