methanol for preparing the DPPH reagent solution.
The bran extract solution which was reconstituted with
6.0 mL of methanol for being employed to measure
TPC was used for the DPPH free radical scavenging
test. Two milliliters of DPPH solution was mixed with
50, 100 and 150 μL of the extract/methanol solution
and transferred to a spectrophotometer cuvette. The
reaction solution was carried out at 25°C for 30 min
in a dark room. Then the absorbance of the reaction
mixture was monitored at 515 nm using a UV-visible
spectrophotometer. The inhibition percentage of the
absorbance of the DPPH solution was calculated
using the following equations: