The ability of TRMHs to reduce iron(III) was determined according
to themethod of Yildirimet al. [24]with slightmodifications. An aliquot
of 1 ml sample of each hydrolysate at different concentrations (1 to
5 mg/ml) was mixed with 2.5 ml of 0.2 M phosphate buffer (pH 6.6)
and 2.5 ml of 1% (w/v) potassium ferricyanide solution. The mixtures
were incubated for 30 min at 50 °C. After incubation, 2.5 ml of 10%
(w/v) TCA was added and the reaction mixtures were then centrifuged
for 10 min at 10,000 g. Finally, 2.5 ml of the supernatant solution from
each sample mixture was mixed with 2.5 ml of distilled water and
0.5 ml of 1% (w/v) ferric chloride. After a-10 min reaction time, the absorbance
of the resulting solutionswas measured at 700 nm. Higher absorbance
of the reaction mixture indicated higher reducing power. The
control was conducted in the same manner, except that distilled water
was used instead of sample. The test was carried out in triplicate.