Determination of degree of unsaturation in edible oils using coherent anti-Stokes Raman scattering spectroscopy

We demonstrate the use of coherent anti-Stokes Raman scattering (CARS) spectroscopy for determination of degree of unsaturation in edible oils. To this end, we have measured CARS spectra of six kinds of commercial edible oils having different degree of unsaturation, and it was found that the spectral intensity ratio (I=C-H/IC-H) of two specific bands in C-H stretch region depends on the degree of unsaturation of sample. Based on this relation, the mass unsaturation (N-C-H/NC-H) of six oils was estimated through the results of CARS spectroscopy in five fatty acids (FA), which are major component of edible oils. In addition, we obtained the calibration curve for determining iodine value (IV), and the result of our work was well matched with referred IV. Copyright (C) 2014 John Wiley & Sons, Ltd.