Where Abs t0 min was the absorbance of DPPH at zero
time and Abs t30 min the absorbance of DPPH after 30
min of incubation for the reaction.
The inhibition percentage of the absorbance of
DPPH was plotted against each quantity of the extract
solution to obtain a regression line. Trolox (0.5 mM)
in methanol was used as a standard to convert the
inhibition capability of the extract solution to the
trolox equivalent antioxidant activity. The ratio
of the slopes of the regression lines of the extract
solution and the Trolox solution was defined as the
trolox equivalent antioxidant capacity. Then, it was
converted to μmol of trolox equivalent (TE)/g of
rice.