Application of metabolomics to explore the automatic oxidation process of hazelnut oil

The oxidation metabolites of hazelnut oil are complex and vary with different degrees of oxidation. At present, few studies have investigated the change law of metabolites during the oxidation process of hazelnut oil. In this study, ultrahigh-performance liquid chromatography tandem Q-Exactive high-resolution mass spectrometry (UPLC-QE/MS) was used to analyze the differential metabolites resulting from the oxidation of cold-pressed hazelnut oil during storage for 40 days with accelerated oxidation. The oxidation level of cold-pressed hazelnut oil was evaluated by monitoring the free radical relative strength during accelerated oxidation. A total of 1010 metabolites in 12 super classes were detected in fresh hazelnut oil. Based on multivariate statistical analysis of all metabolites and the change law of free radicals in hazelnut oil, it was found that hazelnut oil enters the deep oxidation stage after accelerated oxidation for 30 days. A statistical analysis of differential metabolites and metabolic pathways was also carried out. The metabolite map obtained in this study can further distinguish hazelnut oil with different degrees of oxidation. Bioinformatics analysis indicated that linoleic acid metabolism and sphingolipid (SP) metabolism are the most important metabolic pathways in the entire oxidation process. These results provide a basis for better understanding the composition of hazelnut oil metabolites with different oxidation levels, identifying markers for oxidation level evaluation and analyzing the oxidative metabolism mechanism of hazelnut oil. This study provides new resources and new ideas for studying methods to prolong the shelf life of edible oils.