Proceedings of 2022 AOCS Annual Meeting & Expo, 2022
DOI: 10.21748/ndzl9672
Lipid oxidation is a chemical process that is detrimental for the quality of oil-based foods. Historically, hydroperoxides and aldehydes are considered the most important molecules in the assessment of lipid oxidation. While they do provide insights in kinetics of primary and secondary oxidation, it has been proposed that a third class of oxidation products, the epoxides, could help resolve mechanistical anomalies that are hitherto unexplained.Here, we developed a 2D 1H-13C HSQC NMR method that allows for a quantitative assessment of epoxides in real food products. The method was applicable in vegetable oils and mayonnaises in a reproducible (RSD ‰¤ 11.6 %) and repeatable (RSD ‰¤ 8.2 %) manner with an LoD and LoQ of respectively 0.18 and 0.62 mmol/kg.This novel method was applied in combination with existing NMR methods to simultaneously quantify lipid hydroperoxides, aldehydes and epoxides, providing a more comprehensive view on lipid oxidation pathways under different conditions. Epoxides showed to be a major product during intermediate and late stage of oxidation. However, its potential as an early marker for lipid oxidation appeared to be limited. A combination of hydroperoxides, epoxides, and aldehydes, on the other hand, could be a powerful combination to capture the main radical mechanisms during oxidation. Moreover, the characterization and quantification of individual epoxide sub-classes by 2D 1H-13C HSQC NMR enables mechanistical oxidation studies.