The reducing power was determined according
to the method of Benzie and Strain (1996), with a
slight modification. A 200 µl sample at 5 mg/ml was
mixed with 1 ml of 0.2 M phosphate buffer (pH 6.6)
and 1 ml of 1% potassium ferricyanide. The mixture
was incubated at 50ºC for 30 min, followed by the
addition of 1 ml of 10% tricholroacetic acid. To
an aliquot (1 ml) of this reaction mixture, 1 ml of
distilled water and 200 µl of 0.1% FeCl3
were added.
The absorbance of the resultant solution was read at
700 nm. Increased absorbance of the reaction mixture
indicated increased reducing power.