Oxidation process of oils with high content of linoleic acyl groups and formation of toxic hydroperoxy‐ and hydroxyalkenals. A study by 1H nuclear magnetic resonance

The oxidation process of sunflower and corn oils at 70 °C with circulating air has been studied by means of 1H nuclear magnetic resonance (NMR). The changes produced in the two oils are compared not only in relation to the rate of degradation of acyl groups but also with reference to both the rate of formation and degradation of primary oxidation products as well as the rate of formation of secondary oxidation products such as aldehydes. Special attention is paid to the evolution of the different kinds of aldehydes formed throughout the process. The great ability of these oils to produce geno‐ and cytotoxic aldehydes under the above conditions is proved. Moreover, peroxide and anisidine values of corn oil throughout its oxidation process have also been determined and the results obtained have been compared with those provided by the 1H NMR spectra, showing good agreement.