Untargeted lipidomics and targeted mass spectrometry unravel lipid profiles and PAH/OPAH compositions in supercritical CO₂-extracted and cold-pressed Brazil nut oils

Brazil nuts are rich in lipids, but the effects of supercritical CO₂ extraction (SC-CO₂) on their oil quality remain unclear. This study investigated the lipid composition and polycyclic aromatic hydrocarbon (PAH) contamination of Brazil nut oils obtained via SC-CO₂ and cold pressing (SFEO and PO) using untargeted lipidomics and targeted mass spectrometry. A total of 156 lipids were identified across all the samples, with significant compositional differences. SFEO contained fewer phospholipids (9 species, 0.85 μg/g) than PO (20 species, 35.67 μg/g), but higher levels of diglycerides and free fatty acids. The most abundant triacylglycerol in oils was TG 18:1_18:1_18:1. SFEO contained relatively high concentrations of PAHs and oxygenated PAHs, with naphthalene and 9-fluorenone at the highest levels. Toxic equivalency quotients (TEQs) were 0.35 μg/kg for PO and 2.49 μg/kg for SFEO. These findings provide new insights into the impact of supercritical CO₂ extraction on oil quality and PAH safety risks.