Rapid determination of oxidative stability of edible oils by FTIR spectroscopy using disposable IR cards

Abstract

Abstract Disposable polytetrafluoroethylene (PTFE) polymer IR (PIR) cards were used as substrates to rapidly oxidize edible oils and simultaneously monitor the extent of oxidation by FTIR spectroscopy. Four edible oils were oxidized on PIR cards and in bulk at moderate temperature (58°C), and real‐time oxidation plots were obtained by measuring changes in the IR hydroperoxide (ROOH) absorbance as a function of time. The relationship between the ROOH absorbance and PV was developed using a reference method to define absorbances corresponding to PV end points of 100 and 200 meq ROOH/kg for the oils oxidized in bulk and on cards, respectively. The real‐time oxidation plots obtained for the oils oxidized in bulk and on cards were similar in appearance, but the oils on the cards reached the PV end point 20 times faster than the oils oxidized in bulk. The results indicate that the use of disposable PIR cards coupled with moderate heating and aeration provides a simple, practical, and rapid means for monitoring oxidation and determining the oxidative stability of edible oils at a normal storage temperature.