Preliminary studies about thermal degradation of edible oils through attenuated total reflectance mid-infrared spectrometry

Degradation of edible oils during their heating process has been evaluated through the determination of cis-unsaturation and trans-fatty acids together with free fatty acids as a function of time and temperature heating.Two types of cooking oils, sunflower and seed (mixture of different seeds non-detailed), were heated at three different temperatures (147, 171 and 189 °C) during a total time of 1920 min (32 h) shared out in four sessions of 8 h each one, and samples were studied from their spectra obtained by Fourier transform infrared spectrometry using attenuated total reflectance measurements.A critical comparison between different multivariate calibration models built based on full spectra or selected wavenumbers, using both PLS1 and PLS2 algorithms, was carried out for a preliminary evaluation of the heating conditions (temperature and time) of oil samples.