Fourier transform infrared spectra data versus peroxide and anisidine values to determine oxidative stability of edible oils

Different edible oils, including safflower, sunflower, rapeseed and olive oils, were submitted to oxidation in a convection oven with air circulating at 70 °C. Their oxidation process was monitored by Fourier transform infrared spectroscopy by periodically collecting duplicate spectra from films of pure oil between two KBr disks. The frequency and absorbance of each infrared band were automatically registered by a macro program. Classic chemical methods for determining primary and secondary oxidation products, such as peroxide value and anisidine value respectively, were determined periodically. Changes observed in infrared data are useful indicators of edible oils oxidative stability and are closely related to changes observed in peroxide and anisidine values in the course of the oxidation of the samples. Fourier transform infrared spectroscopy may be able to substitute classic oxidation indices in the determination of oxidative stability or antioxidant activity due to its simplicity, low cost and time saving.