Revealing the changes in lipids, volatile flavors, sensory effects and their correlations in cold fresh rainbow trout meat under different electron beam irradiation doses using lipidomics and flavoromics

This study investigated the effects of electron beam irradiation at doses of 1, 3, 5, and 7 kGy on cold fresh rainbow trout meat, using non-irradiated samples as a control. Changes in sensory scores, volatile flavor compounds, and lipids were analyzed using comprehensive two-dimensional gas chromatography-mass spectrometry (GC × GC-MS) and untargeted lipidomics. The results showed that irradiation at doses ≥3 kGy significantly reduced sensory scores. GC × GC-MS analysis indicated an increase in the total content of volatile flavor compounds after irradiation. Specifically, at doses ≥3 kGy, levels of lipid oxidation products-such as hexanal, (<i>R</i>)-2-octanol, and (<i>S</i>)-2-octanol-increased significantly (<i>P</i> < 0.05). Lipidomics analysis identified 583 differential lipids across treatment groups, revealing decreases in phosphatidylcholine, triglyceride, and diglyceride levels, alongside an increase in phosphatidylethanolamine following irradiation. These findings demonstrate that electron beam irradiation promotes volatile compound formation by accelerating lipid oxidation. While doses below 3 kGy did not substantially alter flavor or sensory quality, doses of 3 kGy or higher induced a distinct "irradiation odor", ultimately leading to a marked reduction in acceptability.