Development and Validation of a Gas Chromatography–Flame Ionization Detection Method for the Determination of Epoxy Fatty Acids in Food Matrices

Mubiru, Edward; Shrestha, Kshitij; Papastergiadis, Antonios; Meulenaer, Bruno De

doi:10.1021/jf405664c

Cited by 38 publications

(19 citation statements)

References 31 publications

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“…Oxylipins can be synthesized in vivo from their precursor fatty acids via oxygenase enzymes 10–12 , or obtained through food or dietary oils 13–16 . Ingested hydroxyl, epoxy and dihydroxy oxylipins are bioavailable 17–21 .…”

Section: Introductionmentioning

confidence: 99%

Lipidomic Analysis of Oxidized Fatty Acids in Plant and Algae Oils

Richardson¹,

Hennebelle²,

Otoki

et al. 2017

J. Agric. Food Chem.

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Linoleic acid (LA) and alpha-linolenic acid (ALA) in plant or algae oils are precursors to oxidized fatty acid metabolites known as oxylipins. Liquid chromatography tandem mass spectrometry was used to quantify oxylipins in soybean, corn, olive, canola and four high-oleic acid algae oils at room temperature or after heating for 10 minutes at 100°C. Flaxseed oil oxylipin concentrations were determined in a follow-up experiment that compared it to soybean, canola, corn and olive oil. Published economic disappearance data for soybean, canola, corn and olive oil were used to estimate daily oxylipin intake. The LA and ALA fatty acid composition of the oils was generally related to their respective oxylipin metabolites, except for olive and flaxseed oil which had higher LA-derived mono-hydroxy and ketone oxylipins than other oils, despite their low LA content. Algae oils had the least amount of oxylipins. The change in oxylipin concentrations was not significantly different amongst the oils after short-term heating. Estimated oxylipin intake from non-heated soybean, canola, corn and olive oil was 1.1 mg per person per day. These findings suggest that oils represent a dietary source of LA- and ALA- derived oxylipins and that the response of oils to short-term heating does not differ amongst the various oils.

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Section: Introductionmentioning

confidence: 99%

Lipidomic Analysis of Oxidized Fatty Acids in Plant and Algae Oils

Richardson¹,

Hennebelle²,

Otoki

et al. 2017

J. Agric. Food Chem.

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“…Several approaches have been reported previously for the determination of epoxides in oil samples, including methods utilizing hydrogen bromide (HBr) [6], 4-(p-nitrobenzyl) pyridine (NBP) [7], N,N-diethyldithiocarbamate (DTC) [8], and gas chromatography-flame ionization detection (GC-FID) [9]. The HBr method is the most commonly used method to determine epoxides in industrial applications where they are important intermediates.…”

Section: Introductionmentioning

confidence: 99%

“…However, secondary lipid oxidation products, such as conjugated dienes and some unsaturated carbonyls, interfere with the HBr method, thereby causing the overestimation of epoxide content in oxidized oils [6]. The NBP, DTC, and GC-FID methods require derivatization and are relatively time-consuming [7][8][9].…”

Section: Introductionmentioning

confidence: 99%

¹H‐NMR Characterization of Epoxides Derived from Polyunsaturated Fatty Acids

Xia

Budge

Lumsden

2016

J Americ Oil Chem Soc

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and a re-evaluation of several previous epoxide-related studies.Abstract In recent years, 1 H NMR has been used to study epoxides in lipid oxidation and industrial processes, but the peak assignments reported for monoepoxides and diepoxides have been inconsistent. Lack of clear assignments for chemical shifts of epoxides derived from polyunsaturated fatty acids (PUFA) has also limited the use of 1 H NMR in detecting and quantifying these products during both oxidative degradation and industrial epoxidation. In this study, 1 H NMR was used to characterize the epoxides synthesized from trilinolein, trilinolenin, canola oil, and fish oils by reaction with formic acid and hydrogen peroxide. Assignments for epoxides derived from PUFA in canola oil and fish oil were between 2.90-3.23 ppm and 2.90-3.28 ppm, distinct from other chemical groups in these oils. Chemical shifts of epoxy groups moved downfield with an increasing number of epoxy groups in the fatty acid chain. Hence, peaks for diepoxides appeared at 3.00, 3.09, and 3.14 ppm and for triepoxides at 3.00, 3.16, and 3.21 ppm. Results also suggested that stereoisomers of diepoxides and triepoxides were formed during the epoxidation process under the conditions of this study. These new assignments for diand tri-epoxide stereoisomers were supported by GC-MS analysis of their methyl esters, H-H COSY experiments, Electronic supplementary material The online version of this article (

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“…All samples of the official food control were analyzed using an internal standard and a clean‐up with a silica SPE‐cartridge in order to ensure the absence of any co‐elution of unchanged fatty acids with epoxy fatty acids. The used method is very similar to the method first described by Mubiru et al . Differences were described in detail below.…”

Section: Methodsmentioning

confidence: 99%

“…At the same time, there was a good correlation observed between total epoxy oleates and epoxy stearates ( R 2 = 0.974). In addition, a method using methyl‐ cis ‐10,11‐epoxyheptadecanoate as an internal standard and pre‐separation of monoepoxy fatty acids with a SPE silica cartridge was validated for different matrices such as vegetable oils and others .…”

Section: Introductionmentioning

confidence: 99%

Epoxy fatty acids in used frying fats and oils, edible oils and chocolate and their formation in oils during heating

Brühl

Weißhaar

Matthäus

2015

Euro J Lipid Sci & Tech

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The occurrence of monoepoxy fatty acids in used frying oils and in other common foods has been determined. Monoepoxy fatty acids with trans-9,10-and cis-9,10-epoxystearate and trans-12,13-, trans-9,10-, cis-12,13-and cis-9,10-epoxyoctadecenoate were found at average levels of 3.7 g/kg in used frying fats and oils, but also at about 2 g/kg in the fat fraction of chocolate. They were also detected in pumpkin seed, sweet almond, groundnut, sunflower, and olive oils at average levels of 3.4, 1.7, 1.4, 1.0, and 0.2 g/kg, respectively. Their formation during heating at 175°C was observed for sunflower, rapeseed, soybean, and linseed oil and compared with the increase of polar compounds and polymerized triacylglycerols as other important quality indicators for frying oils. During heating for 16 h, the level of monoepoxy fatty acids increased to about 30, 18, 8, and 4 g/kg for olive, sunflower, linseed, and rapeseed oils, respectively. The influence of the heating temperature was surveyed for refined soybean oil at 160, 170, 180, and 200°C. Heating of two sets of five different refined and virgin rapeseed oils revealed a significant lower formation of monoepoxy fatty acids for refined oils at a median level of 4.6 g/kg compared to 7.7 g/kg for virgin oils.Practical applications: Determination of fatty acid methyl esters is one of the most common analyses for the evaluation of oils and fats. The assessment of the monoepoxy fatty acids as part of these analyses can provide a first indication about used frying fats and oils, which reached the end of their applicability. The formation of monoepoxy fatty acids is affected by the fatty acid composition of the oil, the heating temperature, and the production of the oil. Therefore, frying oils may contain varying amounts of monoepoxy fatty acids at the maximum limit for polar compounds and polymerized triacylglycerols as used in the official food control. However, all used frying oils investigated by the official food control showing more than 7 g/kg of monoepoxy fatty acids had to be rejected due to the limits exceeded for polar compounds and polymerized triacylglycerols. Therefore, this limit of 7 g/kg monoepoxy fatty acids level is proposed as a level for screening the usability of used frying fats and oils.

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Development and Validation of a Gas Chromatography–Flame Ionization Detection Method for the Determination of Epoxy Fatty Acids in Food Matrices

Cited by 38 publications

References 31 publications

Lipidomic Analysis of Oxidized Fatty Acids in Plant and Algae Oils

Lipidomic Analysis of Oxidized Fatty Acids in Plant and Algae Oils

¹H‐NMR Characterization of Epoxides Derived from Polyunsaturated Fatty Acids

Epoxy fatty acids in used frying fats and oils, edible oils and chocolate and their formation in oils during heating

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Development and Validation of a Gas Chromatography–Flame Ionization Detection Method for the Determination of Epoxy Fatty Acids in Food Matrices

Cited by 38 publications

References 31 publications

Lipidomic Analysis of Oxidized Fatty Acids in Plant and Algae Oils

Lipidomic Analysis of Oxidized Fatty Acids in Plant and Algae Oils

1H‐NMR Characterization of Epoxides Derived from Polyunsaturated Fatty Acids

Epoxy fatty acids in used frying fats and oils, edible oils and chocolate and their formation in oils during heating

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¹H‐NMR Characterization of Epoxides Derived from Polyunsaturated Fatty Acids