Total phenolic content was assayed by the Folin–Ciocalteu colorimetric method with slight modification (Bao et al., 2005; Cai et al., 2004). Briefly, aliquots (1.0 mL) of appropriately diluted extracts or standard solutions were mixed with 0.5 mL 0.5 N Folin–Ciocalteu reagent, then the reaction was neutralized with saturated sodium carbonate (75 g/L). The absorbance of the resulting blue color was recorded using a spectrophotometer after incubation for 2 h at 23 C. A calibration curve was prepared using gallic acid solution. Total phenolics contents were expressed as milligrams of gallic acid equivalent (mg GAE) per 100 g of dry weight.