Spectroscopic Characterization of Ozonated Sunflower Oil

Ozonation reactions are very important in vegetable oil chemistry since their ozonation products are involved in antimicrobial effect in therapeutical uses for several microbiological etiology diseases. Information on the spectroscopic characterization of the products generated by ozonolysis of sunflower oil is limited. In the present study ozonized sunflower oil with 650 mmol-equiv/kg of peroxide index is chemically characterized. Ozonation of sunflower oil produced ozonides, aldehydes and hydroperoxides which were identified by 1H, 13C and two-dimensional 1H Nuclear Magnetic Resonance (NMR). The virgin sunflower oil and ozonized sunflower oil show very similar 1H NMR spectra except for the resonances at δ = 9.74 and δ = 9.63 ppm that correspond to both triplet from aldehydic protons, δ = 5.6 ppm (olefinic signal from hydroperoxides), and δ = 5.15 ppm (multiplet from ozonides methylic protons). Other resonance assignments are based on the connectivities provided by the proton scalar coupling constants. These are the following: δ = 3.15 ppm (doublet from methylenic group in α position respect to olefinic proton), δ = 2.45 ppm (multiplet from methylenic group allylic to ozonides methynic protons) and δ = 1.62 ppm (multiplet methylenic protons in β position respect to ozonides methynic protons). From the 13C NMR and 1H-13C two- dimensional spectrum of the ozonized sunflower oil, the presence of ozonides was confirmed by the signals δ = 103.43 and δ = 103.49 ppm, respectively. The others new signals found in δ = 42.5 and δ = 42.76 ppm confirm the presence of methylenic carbons from hydroperoxides and ozonides. These results indicate that NMR Spectroscopy can provide valuable information about the amount of reaction compounds of ozonized vegetable oil. From the chemical structural elucidation of ozonated sunflower oils, relevant biochemical and chemical information can be achieved. Keywords: OzoneNMRSunflower OilOzonidesOzonated Sunflower Oil ACKNOWLEDGMENTS This work was supported by CYTED, INTERCAMPUS, and CITMA-CSIC project. Notes 3. Codex Alimentarius Commission. “Proposed Draft Standard for Named Vegetable Oils,” (issued by the Joint FAO/WHO Food Standards Program, via delle Terme di Caracalla 00100 Rome, CX 16/1993)