Determination of Lipid Oxidation in Edible Oils by near Infrared Spectroscopy

Abstract

The relationship between near infrared (NIR) second derivative spectra and lipid oxidation was investigated to develop a method for the determination of lipid oxidation in edible oils by NIR spectroscopy, using peroxide value (POV) as the index of oxidation. Although several absorption peaks were found in the difference second derivative spectra of oxidised edible oils, the intensity of the peak at 2084 nm only was highly correlated to POV. In the spectra of purified hydroperoxides of methyl oleate and methyl linoleate, the intensity of the peak at 2084 nm was also highly correlated with POV, which demonstrates that the absorption is due to hydroperoxide. In addition, this peak shifted and weakened after reduction of hydroperoxide to hydroxide, which shows the absorption is specific for the hydroperoxyl group. These results suggest that 2084 nm is the key wavelength for lipid peroxide and can be used for the determination of lipid oxidation in edible oils.

Multivariate determination of free fatty acids and moisture in fish oils by partial least-squares regression and near-infrared spectroscopy

“…The highest standard deviations are observed around 1700 nm and between 2200 and 2300 nm, related with several classes of oxygenated compounds (Murray, 1986). Those wavelength regions are mainly related with oxidation and hydrolytic degradation of lipids in fish oil (Holman & Edmondson, 1956;Murray, 1986, Takamura et al, 1995aMiller, 2001).…”

“…Several references in the use of NIR spectroscopy to analyse animal fats and vegetable oils were found in the literature, but none of these related to fish oil. One of the earliest reports on the use of the NIR region to analyse oils was related to the analysis of fatty acid composition (Holman & Edmondson, 1956), the analysis of patterns of fatty acids in both fats and oils (Sato, Kawano, & Iwamoto, 1990;Sato, Kawano, & Iwamoto, 1991;Boot & Speek, 1994), the prediction of lipid oxidation in edible oils (Takamura, Hyakumoto, Endo, Matoba, & Nishiike, 1995a;Takamura, Hyakumoto, & Matoba, 1995b), the use of optic probes to analyse oxidation in frying fats (Bu¨nin-Pfaue & Kehraus, 2001) and the determination of hydrogen peroxides (Kangming, Van de Voort, & Ismail, 1997;Pimenta et al, 2003). The use of both NIR spectroscopy and chemometrics (e.g.…”

Vibrational Spectroscopy of Food and Food Products

“…The feasibility of employing NIR spectroscopy to evaluate the extent of oxidation of oils and the quality of used frying oils has also been examined. 28,124,125 …”

Quality Evaluation of Olives, Olive Pomace and Olive Oil by Infrared Spectroscopy

“…In fact the application of optical on-line NIR sensor for olive oil characterization is an appealing approach for real-time chemical evaluation, allowing the estimation of acid value, bitter taste (K 255 ) and fatty acids (Marquez et al 2005). Near infrared spectroscopy has been valuable for the assessment of physicochemical parameters of vegetable oils (Sato 1994;Hourant et al 2000;Takamura et al 1995;Franco et al 2006). Infrared spectroscopy (NIR and MID), has also been applied successfully for olive oil evaluation and geographical origin determination using chemometric approaches (Tapp et al 2003;Iñón et al 2003;Galtier et al 2007).…”