Study by proton nuclear magnetic resonance of the thermal oxidation of oils rich in oleic acyl groups

The oxidation process of olive, hazelnut, and peanut oils at 70°C with circulating air has been studied by means of 1H NMR. The evolution of the process, including the rate of degradation of the acyl groups and of formation and degradation of primary oxidation products, as well as the rate of formation of secondary oxidation products such as aldehydes, is commented on and compared with the oxidation of oils rich in polyunsaturated acyl groups. Differences that are due not only to the rate of the processes but also to the nature and concentration of the generated aldehydes are observed. Oils rich in monounsaturated acyl groups generate smaller amounts of the geno‐and cytotoxic oxygenated aldehydes than oils rich in polyunsaturated acyl groups.