Characterization and determination of free phytosterols and phytosterol conjugates: The potential phytochemicals to classify different rice bran oil and rice bran

•Lipid profiles of RB and RBO were identified by using HTGC-MS.•Quantification of FS and SG was achieved by applying SSDMC method.•SF was the predominant phytosterol form in RB and RBO.•FS, SF and SG can be used to classify different RB and different RBO. Phytosterols are important beneficial compounds found in rice bran (RB) and rice bran oil (RBO). Although relationships have been confirmed between the forms of phytosterols and their bioactivities, the analysis of different forms of phytosterols in RB and RBO has been lacking. In this study, high temperature gas chromatography-mass spectrometry (HTGC-MS) was combined with the single standard to determine multi-components (SSDMC) method to determine free sterols (FSs) and steryl glycosides (SGs) in RB and RBO. High-performance liquid chromatography (HPLC) was used to determine steryl ferulates (SFs). There was clear variation in the composition of FS, SF and SG, indicating that different forms of phytosterols can discriminate between different RB and RBO. The developed method may be also useful for the detection of other compounds of interest in oils, oil seeds or cereals.