Deep-frying. A study of the influence of the frying medium and the food nature, on the lipidic composition of the fried food, using 1H nuclear magnetic resonance.

Extra virgin olive, soybean and sunflower oils were used in three different series of fourteen experiments to deep-fry three foods of very different lipidic content and composition. The aim of this study was to analyze how much the composition of the frying medium influenced the lipidic composition of the fried food. To achieve this, the compositions both of the frying medium throughout fourteen deep-frying experiments carried out with each kind of oil, as well as that of the unfried food were studied by 1H NMR. This same technique was used to study the lipidic composition of each fried food. The study focussed on the changes in the molar percentage of the different kinds of acyl groups, sterols and diglycerides as well as on the occurrence of compounds or functional groups coming from lipid degradation, such as aldehydes, epoxy groups and primary and secondary alcohols, all of them determined from 1H NMR spectral data. [ABSTRACT FROM AUTHOR]