One millilitre of rice extract was mixed with 2.0 mL of a 0.1 mM methanolic solution of DPPH
The mixture was kept at room temperature in the dark for 30 min
The absorbance was measured at 517 nm against a blank, using a UV-vis spectrophotometer
The percentage of radical-scavenging ability was calculated by using the formula:
Scavenging ability (%) = [1 – (Asample/Acontrol)] x 100
The scavenging activity of rice extract was expressed as 50% inhibitory concentration,
IC50 (mg/ mL) and was obtained by interpolation from linear regression analysis
* Blank is prepared identically except methanol is used instead of rice extract.