Study by means of 1H nuclear magnetic resonance of the oxidation process undergone by edible oils of different natures submitted to microwave action

The oxidation processes of virgin olive, corn and linseed oils, repeatedly submitted to the effect of microwave heating until the temperature reached 190 °C, have been studied by means of 1H nuclear magnetic resonance. These oxidation processes are very different to those produced at 70 °C with aeration; differences have been found not only in the rate of degradation and in the oxidation mechanisms but also in the nature and proportions of the aldehydes generated. It has also been shown that these oxidative conditions affect the three oils studied in very different ways; virgin olive oil is the least affected by this process and in addition its degradation produces lower proportions of harmful aldehydes.