2.6. Reducing power assay
The reducing power of filtrates was measured according to the
modified method of Pownall et al. (2010). An aliquot (250 lL) of
the sample dilutions was added to 250 lL of 100 mM phosphate
buffer pH 6.6 and mixed with 250 lL of 1% potassium ferricyanide
solution. Reaction mixture was incubated at 50 C for 20 min. After
incubation, 250 lL of 10% trichloroacetic acid was mixed with
250 lL of the incubated mixture, 50 lL of 0.1% ferric chloride and
250 lL of distilled water. Prior to absorbance measurement, sample
was additionally incubated for 10 min at room temperature
and absorbance was recorded at 700 nm. Absorbance at 700 nm
was considered as a measure of reducing power.