About 1.0 ml of extract solution containing 1 mg extract in a volumetric flask was diluted with 10 ml of distilled water.
To this, 1.5 ml of Folin–Ciocalteu reagent was added.
The above mixture was kept for 5 min. and then 4 ml of 20% sodium carbonate solution was added and made the volume up to 25 ml with the distilled water.
This mixture was kept for 30 min and the absorbance of the blue color developed was measured at 765 nm, using Shimadzu 1800 spectrophotometer.
The percentage of total phenolics was calculated from calibration curve of Gallic acid and total phenolics were expressed as % Gallic acid.