Title : Application of Coherent Anti-Stokes Raman Scattering (CARS) spectroscopy to the determination of degree of unsaturation and the authentication of edible oils
Abstract:
We demonstrate the use of Coherent anti-Stokes Raman Scattering (CARS) spectroscopy for determination of degree of unsaturation and the authentication of edible oils. We have measured CARS spectra of commercial edible oils having different degree of unsaturation, and found the spectral intensity ratio of two specific bands in C–H stretch region depends on the degree of unsaturation of sample. The mass unsaturation of different oils could be estimated through the results of CARS spectroscopy in fatty acids, 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. Also a comparative analysis on five edible oils with the same chemical composition but different composition ratios was performed. Intensity ratio in C-H stretching region was obtained according to the mixing ratio of the two types of edible oil, and we found that the results were quite well matched with theoretical fitting curves and they were well matched with the referred values. And finally, we will discuss that the CARS spectroscopy might be used as a method of authenticati
