NMR and FTIR analysis of overheated cooking oil

Abstract

In this study, we combined different physico-chemical methods to show the effect of overheating on the quality of golden fry cooking oil. Those methods include spectroscopic methods such us 1H-NMR, 13 C-NMR and FTIR. Results showed that both overheating and excessive reuse of golden fry cooking oil seriously affected its quality by increasing its density, viscosity and different indexes like refractive, saponification, esters, peroxide values and also by decreasing its iodine value. Both NMR and FTIR spectroscopic methods confirmed these changes and indicated the presence of some carbonyl compound derivatives in overheated samples.