FTIR spectroscopy used for study the thermal degradation of lard

Aim Recent developments in Fourier transform infrared (FTIR) spectroscopy instrumentation extend the application of this technique to the field of food research, in particular facilitating studies on edible oils and fats. Materials and methods In this work, an attenuated total reflection-FTIR spectroscopy method was used as an effective analytical tool to monitor the oxidation process of lard samples during heating. The process was interpreted according to the peaks data. Results and discussion FTIR spectroscopy has been found to be a versatile technique for evaluating the oxidative stability of lard and for providing information on the oxidation degree of a sample in a simple, fast and accurate way. To follow the oxidation process during the period of frying, about 40 min, the samples were subjected to increasing heat up to a temperature of 300°C, and samples were withdrawn every 10 min. Attenuated total reflection spectra were obtained and the process was interpreted according to the peaks data modifications. Conclusion FTIR spectroscopy has been found to be a versatile technique for evaluating the oxidative stability of lard and for providing information on the oxidation degree of a sample in a simple, fast, and accurate way. A slight decrease in the intensity was observed for the band at 721 cm-1, which implies the loss of cis double bonds during oxidation, a fact also confirmed by the decrease in intensity at 3006 cm-1, assigned to the same cis-double bonds in C=CH.