Phytosterols are bioactive plant-derived compounds widely present in vegetable oils and known for their beneficial effects on human health. However, due to their unsaturated structures, phytosterols are prone to oxidation, leading to the formation of phytosterol oxidation products (POPs), that may negatively impact health and oil quality. Mass spectrometry is widely used to analyze POPs, but the lack of commercially available pure POP standards (with the exception of 7- ketositosterol) limits method accuracy. Thus, reliable detection of these compounds is challenging due to the lack of pure standards and limitations of conventional methods.
The aim of the present work was to isolate pure POPs (α-epoxy, β-epoxy, 7-keto, 7α- and 7β-hydroxy isomers of β-sitosterol, campesterol, and stigmasterol) using a semi-preparative LC system, and to validate a robust, sensitive, precise, and accurate LC-Orbitrap-HRMS method.