Associations between Maillard α-dicarbonyl intermediates and aroma compounds in fragrant Camellia oleifera seed oil

Temperature, time, molar ratio, and pH shaped α-dicarbonyl formation. • Sensory, E-nose, and HS-SPME/GC–MS identified key aroma-active compounds. • Heating increased benzaldehyde and phenethyl alcohol by 12.21 and 3.71 μg/kg. • A preliminary α-dicarbonyl-associated aroma pathway was proposed for FCSO. Fragrant Camellia oleifera seed oil (FCSO) acquires its characteristic aroma primarily through roasting. This study elucidates the potential role of α-dicarbonyl compounds (α-DCs), including glyoxal (GO), methylglyoxal (MGO), and 3-deoxyglucosone (3-DG), as Maillard reaction intermediates in flavor formation, particularly in oil-phase systems. Through a simplified glucose-phenylalanine model, the effects of temperature, time, substrate molar ratio, and pH on α-DC generation were systematically evaluated. The results showed 140 °C for 120 min as optimal for α-DC generation. HS-SPME/GC–MS and multivariate analysis revealed aldehydes, ketones, and alcohols as dominant volatiles. In the model system, GO was significantly correlated with benzaldehyde, whereas 3-DG was significantly correlated with phenethyl alcohol. The authentic FCSO showed an increase of 12.21 μg/kg for benzaldehyde and 3.71 μg/kg for phenethyl alcohol. These findings potentially demonstrated the α-DC-mediated flavor formation mechanism and might provide a theoretical foundation for targeted aroma enhancement in FCSO processing.