Ozonización del aceite de girasol. Seguimiento de la reacción por Resonancia Magnética Nuclear protónica

Abstract

Prior studies have proven that proton Nuclear Magnetic Resonance technique can be used to follow up ozone reaction with unsaturated fatty acids. In this paper, ozonation of sunflower oil at a different applied ozone dosage was carried out and peroxide index and aldehydes contents were determined. The reaction products were identified using Proton Nuclear Magnetic Resonance Spectroscopy (1H NMR). The principal signal intensities values were used for following the reaction course between ozone and sunflower oil. The reaction was following up to peroxide index values of 1 202 mmol-equiv/kg. The intensities of olefinic proton signals decreased with the gradual increase in ozone concentration but without disappearing completely. The Criegee ozonides obtained at 107.1 mg/g of ozone doses were approximately 7.4 folds higher than that at the beginning of reaction. The aldehyde protons were observed as a weak intensity signal in all the spectra. The signals belonging to olefinic protons from hydroperoxides appeared weak with the increase in ozone doses. Signals from other oxygenized groups were assigned. It was concluded that the higher applied ozone doses the higher the ozonation reaction advance corresponding with a higher oxygenized compounds formation.