Quantification and Determination of Composition of Steryl Ferulates in Refined Rice Bran Oils Using an UPLC‐MS Method

Abstract

Abstract Gamma‐oryzanol contains a mixture of steryl ferulates found in rice bran oil. Several studies have attributed nutraceutical properties to this mixture, such as hypocholesterolemic and anti‐inflammatory activities. A method based on ultra‐performance liquid chromatography coupled with electrospray ionization mass spectrometry was developed and evaluated for the simultaneous quantification of gamma‐oryzanol and identification of five major steryl ferulates directly in refined rice bran oils (RBO) samples. The proposed method was evaluated according to linearity by obtaining standard curves with R 2 values above 0.990, and limit of detection values ranged from 1.9 to 5.9 µg/mL, whereas limits of quantification ranged from 5.9 to 17.9 µg/mL; inter‐ and intraday accuracy and precision were within the range required by the US Food and Drug Administration guidelines; recovery levels ranged from 78 to 85% for gamma‐oryzanol, and from 84 to 119% for steryl ferulates. The method can be considered robust in relation to the NH 4 OH (ammonium hydroxide) content and cone voltage variations, with coefficient of variation and average relative percentage deviation values lower than 7.0 and 4.4%, respectively. The stability during the storage test was maintained in concentrated samples (18.5 µg/mL), with recovered values between 93 and 113%. This method was successfully applied to the analysis of RBO samples, demonstrating that it could be easily used for quality control purposes.