The determination of peroxide value by fourier transform infrared spectroscopy

Abstract

A rapid method for the quantitative determination of peroxide value (PV) of vegetable oils by Fourier transform infrared (FTIR) transmission spectroscopy is described. Calibration standards were prepared by the addition of tbutyl hydroperoxide to a series of vegetable oils, along with random amounts of oleic acid and water. Additional standards were derived through the addition of mono-and diglyeeride spectral contributions, as well as zero PV spectra obtained from deuterated oils. A partial least squares (PLS) calibration model for the prediction of PV was developed based on the spectral range 3750-3150 cm-k Validation of the method was carried out by comparing the PV of a series of vegetable oils predicted by the PLS model to the values obtained by the American Oil Chemists' S(~ciety iodometric method. The reproducibility of the FTIR method [coefficient of variation (CV) = 5%)] was found to be better than that of the chemical method ICV = 9%), although its accuracy was limited by the reproducibility of the chemical method. The method, as structured, makes use of a l-ram CaF2 flow cell to allow rapid sample handling by aspiration. The spectrometer was preprogrammed in Visual Basic to guide the operator in performing the analysis so that no knowledge of FTIR spectroscopy is required to implement the method. The method would be suitable for PV determinations in the edible oil industry and takes an average of three minutes per sample.

Lipid Oxidation of Catfish (<i>Arius maculatus</i>) after Cooking and Smoking by Different Methods Applied in Cameroon

“…The decrease of the absorbance band was observed in the case of smoking treatment and cold smoked catfish oil had a lower band. The decrease of the absorbance band after smoking also suggests the decomposition of hydroperoxide to yield secondary lipid oxidation products [49]. These results coincide with the decrease in peroxide value obtained during chemical analysis.…”

Study of the oxidative degradation of farmed salmon lipids by means of Fourier transform infrared spectroscopy. Influence of salting

“…27 -29 In addition, changes observed in the infrared spectra of edible oils have been shown to be simultaneous with changes observed in classic parameters such as peroxide value and anisidine value. 30,31 In this paper the characterisation of the lipids of farmed salmon and the monitoring of the degradation process, under conditions to accelerate the oxidation, are carried out by means of Fourier transform infrared spectroscopy. In addition, the effect of the salting process on the oxidative stability of these fish lipids is studied.…”

Spectroscopic Monitoring of Biodiesel Aging

“…A possible explanation could be the creation and destruction of transient oxidation by-products such as peroxides. Similar spectral variability in vegetable oils (feedstock for BD) has been ascribed to uncontrolled amounts of OH-containing components (alcohols, free fatty acids and water) and variations in triglyceride composition, which may cause interference due to overlapping absorption bands [12]. Although these uncertainties may be overcome by chemical methods, for instance, adding TBHP and applying PLS chemometric techniques, or implementation of several spectral references [13], the complexity of such FT-IR analysis was seen as limiting its suitability for the purposes of this study.…”