Differentiation of rice varieties using small bioactive lipids as markers

Steryl ferulates (γ‐oryzanol) are a group of important lipid antioxidants found in rice. This study uses OMIC‐technologies to differentiate between rice varieties based on these minor bioactive lipids. The γ‐oryzanol rich‐lipid fractions were first extracted from six types of common cargo rice and two types of wild rice, which were subsequently analyzed using ultra performance liquid chromatography with high‐resolution quadrupole time‐of‐flight mass spectrometric detection (UPLC‐HR‐Q‐TOF‐MS). Unique spectral profiles were produced for each rice variety, and the MS data was further converted into markers. Multivariate statistical analysis including principal component analysis (PCA) and the observed partial least squares‐discriminant analysis (OPLS‐DA) was utilized to find the characteristic markers, enabling us to differentiate between various rice varieties based on their steryl ferulate profiles and other small lipids. Practical applications: This study provides a targeted method to distinguish between various common rice varieties as well as wild rice from different geographic regions, which could be a new approach for rice authentication. Additionally, this sensitive analytical technique may reveal several new compounds of bioactive lipids in rice. Furthermore, the OMIC approach to rice differentiation also has the potential to lead to the selection of rice varieties with optimal profiles of bioactive lipids for food use. Our study provides a novel and targeted method to distinguish between rice varieties using UPLC‐HR‐Q‐TOF‐MS with the OMIC technique. We were able to find characteristic markers that can classify different rice types based on their steryl ferulate profiles and other potential small lipids.