After incubation for 10 min at room temperature, the absorbance was
measured at 562 nm. Distilled water (100 mL) instead of sample
solution was used as a control. Distilled water (10 mL) instead of
ferrozine solution was used as a blank. L-ascorbic acid, citric acid
and EDTA-Na2 were used as reference standards. The ferrous ionchelating
ability was calculated as follows: