Determination of Fatty Acid Profile of Sunflower Oil Samples by NMR 1H Spectroscopy

Abstract

Sunflower oil with a high content of oleic acid (Omega-9) and a sufficiently low content of polyunsaturated linoleic acid (Omega-6) is characterized by a lower nutritional value but greater chemical stability at high temperatures and in the presence of oxidizing agents, therefore, it has several advantages for the food and chemical industries, and also as a raw material for the production of biofuels. The determination of the TAG composition o f oil is very important, because due to selection there is a large number o f sunflower varieties. The spectra o f oil samples extracted from seeds o f various sunflower varieties were investigated by NMR 1H spectroscopy to determine fatty acids composition. This method based on estimation and comparison the proton integral intensities of allylic and bis-allylic CH2 groups with intensity o f glycerol protons that allows to determine the amounts o f these unsaturated fatty acids. Each oil sample obtained has its individual TAG profile determining its physicochemical properties and nutritional value. Method 1H-NMR spectroscopy is rapid and non-destructive, so it is perspective for determination o f oil fatty acid composition.