Effect of triacylglycerols and derivatives on the variation of the volatile profiles of virgin olive oils during microwaves and conventional heating

Lipid oxidation is one of the major degradation reactions in heated oils, which result in a significant loss of quality. As for the conventional heating, microwave heating is commonly applied in both domestic cooking and food catering. The aim of this work was to evaluate the influence of micronutrient composition on the volatile profile of the headspace of vhétoui virgin olive oil exposed to microwave and conventional heating during 0, 2, 5, 7, 10, and 15 min, and 0, 2.5, 5, 7.5 and 10 h at 180°C, respectively. Oxidation of the triacylglycerol and their derivatives (Fatty acids) in virgin olive oil causes changes in the volatile profile of the studied oils. During thermo-oxidation, the ECN44 (LLO, and OLnO), and the ECN46 (OLO, and PLO + SLL) compounds decreased, whereas, the ECN48 (OOO, and PPO), and the ECN50 (SOO) compounds increased when temperature and heating time increased. The several variations of the volatile compounds depend to the fatty acid composition and the heating processes. Hexanal, (Z)-2-heptenal, (E)-2- octenal, (E)-2-nonenal, (E,E) and (E,Z)-2,4-decadienal, and (E,E)-2,4-nonadienal derived from linoleic acid (C18:2). The alkadienal, (E,E)-2,4-nonadienal, can be formed not only from linoleic but also from oleic acyl groups. Heptanol, octanal, nonanal, decanal, (E) and (Z)-2-decenal, (E)-2-undecenal, and (E,E)-2,4- nonadienal are emitted after degradation of oleic acid (C18:1).