Gamma oryzanol content in RBO was determined spectropho- tometrically (UVeVIS 1700, Shimadzu, Japan) following the method of Mezouari and Eichner (2007), slightly modified. Briefly, RBO samples were diluted in heptane. The content of gamma oryzanol was determined by UV absorption at 315 nm gamma oryzanol, contents in RBO were quantified against the standard curve. The calibration curve was obtained with pure oryzanol in a concentra- tion range of 0e200 mg/L. The concentration of gamma oryzanol was calculated and expressed as g/100 g oil.