Discrimination of vegetable oils using NMR spectroscopy and chemometrics

In this study, 44 samples, either pure or combined into binary blends of vegetable oils with different botanical and geographical origin have been analyzed. H-1 and C-13 NMR analysis was used to determine the saturated fatty acids, oleic acid, linoleic acid, linolenic acid and iodine value. Oil samples were separated according to the botanical origin using principal component analysis. Results found virgin olive oils clustered close together in spite of the different geographical origin while walnut oil varied greatly with country of origin. Blends of 1% olive oil in sun-flower oil were detected using specific H-1 and C-13 signals. The results strongly support the capability of NMR and chemometrics to be used in quality assessment of vegetable oils in terms of their botanical origin. (C) 2014 Elsevier Ltd. All rights reserved.