The autooxidation process in linoleic acid screened by Raman spectroscopy


M. P. M. Marques, Department of Life Sciences, Faculty of Science and Technology, University of Coimbra, Ap. 3046, 3001-401 Coimbra, Portugal.



The chemical changes associated to the autooxidation process of linoleic acid (LA) were detected by Raman spectroscopy and interpreted in the light of density functional theory (DFT) calculations performed for both the fatty acid and its main oxidation products. The present methodology, applied for a six-day period upon induction of oxidation (through heating), allowed to understand the chemical modifications occurring during the oxidation process. Raman spectroscopy was shown to be a suitable and reliable technique for assessing the oxidation degree of fatty acid samples, particularly pure fatty acids, mainly when computational methods are used alongside to predict the spectral features of the distinct chemical entities involved. Screening of the oxidation process was mostly based on the loss of intensity of the bands assigned to LA cis-double bonds. Copyright © 2012 John Wiley & Sons, Ltd.