Determination of total phenolic content Total phenolic compounds were determined according to Folin- Ciocaltue method (Velioglu et al., 1998; Zzaman et al., 2013). A 1.0 ml aliquot of sample was added to 1.5 ml of deionized water and 0.5 ml of 0.1 M Folin-Ciocaltue reagent, and the
contents were mixed thoroughly. After 1 min, 1.0 ml of 20% sodium carbonate solution was added, and the mixture was again mixed thoroughly. The control contained all reaction reagents except the sample. After 30 min of incubation at 37°C, the absorbance was measured at 750 nm, and compared to gallic acid calibration curve. Total phenolics were estimated as gallic acid equivalent (GAE).