The method described by Kitts, Wijewickreme, and Hu
(2000) was used with slight modifications in order to assess
the DPPH radical-scavenging capacity of wheat extracts. A
0.075 mM (final concentration) DPPH solution in ethanol
was mixed with wheat extracts and vortexed thoroughly.
The absorbance of the mixtures at ambient temperature
was recorded for 60 min at 10 min intervals. The absorbance
of the remaining DPPH radicals was measured at
519 nm using a diode array spectrophotometer (Model
8452A, Agilent Technologies Canada Inc., Mississauga,
ON). The scavenging of DPPH was calculated according
to the following equation:
% scavenging ¼ fðAbscontol AbssampleÞ=Abscontrolg 100;
where Abscontrol = absorbance of DPPH radical + methanol;
Abssample = absorbance of DPPH radical + wheat extract/standard.
The scavenging capacity was expressed as lmol DPPH
radical scavenged/g of defatted material.