The FRAP value was determined according to the method of
Benzie and Strain (1996) using a Cobas Bio centrifugal analyser
(Roche Diagnostics Systems, Branchburg, NJ). Duplicate samples
(10 g) were extracted with 15–20 ml of high purity water,
and after centrifugation (2000 ×g at 4 °C for 10 min) and
appropriate dilution of the supernatant the sample was analysed
by the FRAP assay. Briefly,10 ul of sample was added to 300 ul
of FRAP reagent and the absorbance at 593 nm recorded after a
4 min incubation at 37 °C.The FRAP value was obtained by
comparing the change in absorbance of the test mixture to that
of Fe
2+
standard solutions. The results were expressed in umol
of Fe
2+
equivalents per kg fresh weight (FW).