Untargeted metabolomics analysis using UPLC-QTOF/MS and GC–MS to unravel changes in antioxidant activity and compounds of almonds before and after roasting

Almonds are a commonly consumed nut. They possess significantof nutritional and health benefitsand are commonly processed by roasting. This study aimed to investigatthe effects of roasting on the compound composition and antioxidant activity of almonds. Metabolomics analysis, performed via UPLC-QTOF/MS, and fatty acid analysis, conducted via GC–MS, employed, and the results demonstrated a significant increase in antioxidant activity of post-roasting and in vitro digestion, ranging from 1.16 to 3.44 times. Untargeted metabolomics identified a total of 172 compounds, with notable differences observed in organic oxides, fatty acids, and their derivatives. Correlation analysis identified fatty acids as the primary influencers of changes in antioxidant activity following roasting. Taken together, these findings suggest that roasting enhances the antioxidant activity of almonds, primarily due to alterations in fatty acid analogs, thereby providing valuable insights into optimizing almond consumption for health benefits.