Analysis of autoxidized fats by gas chromatography‐mass spectrometry: II. Methyl linoleate

Frankel, E. N.; Neff, W. E.; Rohwedder, W. K.; Khambay, B. P. S.; Garwood, R. F.; Weedon, B. C. L.

doi:10.1007/bf02533310

Cited by 117 publications

(29 citation statements)

References 23 publications

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“…Unsaturated fatty acids are much more susceptible to oxidation than their saturated analogues, especially at elevated temperature. The formation and decomposition of hydroperoxide intermediates is predicted by the number and location of ethylenic bonds (23)(24)(25). We previously found that cholesterol was oxidized in conjunction with the oxidation of coexisting unsaturated fatty acid esters of triacylglycerols (17).…”

Section: Discussionmentioning

confidence: 98%

Effects of Grilling on Formation of Cholesterol Oxides in Seafood Products Rich in Polyunsaturated Fatty Acids

Ohshima¹,

Shozen²,

Ushio³

et al. 1996

LWT - Food Science and Technology

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Section: Discussionmentioning

confidence: 98%

Effects of Grilling on Formation of Cholesterol Oxides in Seafood Products Rich in Polyunsaturated Fatty Acids

Ohshima¹,

Shozen²,

Ushio³

et al. 1996

LWT - Food Science and Technology

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“…One mole of linoleic acid reacts with 1 mol of oxygen and forms the hydroperoxide [16] and this reaction changes non-conjugated diene of linoleic acid to conjugated diene [17], which can be determined by the POV test and the absorbance at 233 nm. Figure 1 shows that the changes in the POV, UV absorbance, and HMB, TBA, and CV values.…”

Section: Correlation Among 5 Tests For the Determination Of Peroxidesmentioning

confidence: 99%

What do thiobarbituric acid and hemoglobin-methylene blue tests evaluate in the endogenous lipid peroxidation of rat liver?

Kanazawa

Inoue

Ashida

et al. 1989

J. Clin. Biochem. Nutr.

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SummaryTo detect the endogenous lipid peroxides in rat liver, the thiobarbituric acid (TBA) and hemoglobin-methylene blue (HMB) tests were used. The endogenous lipid peroxidation in rat liver was induced by peroxidative drugs, and then these tests were carried out. When CC14, paraquat or phenobarbital was intraperitoneally injected, the HMB values were significantly increased only at the early period after the doses (1 h), whereas two peaks of TBA value were observed at 1 h and around 24 h after the doses. When peroxidation was induced by thiopental or alcohol, the TBA value also gave two peaks. It was suggested that the agreement between detections by both HMB and TBA (the early peak) indicated the peroxide formation, and that the independent increase in TBA value (second peak) the accumulation of aldehydes in the liver. The life span of HMB-reactive substances was short in vivo compared with that of the TBA-reactive substances. It is considered that the TBA test was useful to detect the endogenous lipid peroxidation under the conditions that TBA test could detect aldehydes originating from lipid peroxidation because lipid peroxides were unstable in vivo.

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“…It is well known that the free radical peroxidation of methyl linoleate produces four conjugated regio-geometric isomers: the 9-and 13-perhydroxy cis, trans (c,t) and trans,trans (t,t) isomers (30,31). In contrast, singlet oxygen oxidation of methyl linoleate yields both conjugated and nonconjugated isomers in approximately equal amounts (32,33), presumably by the concerted ene reaction with singlet oxygen, rather than via a peroxyl radical intermediate.…”

Section: Resultsmentioning

confidence: 91%

Photo‐initiated peroxidation of lipids in micelles by azaaromatics

Barclay¹,

Crowe²,

Edwards³

1997

Lipids

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The monoazaaromatics, pyridine (1), hexyl nicotinate (2), and quinoline (3) and diazaaromatics, pyrimidine (4) and purine (5), readily act as photo-initiators for the peroxidation of methyl linoleate in 0.50 M SDS at 37 degrees C giving free radical chain oxidations of linoleate. Quantitative kinetic runs on the order in substate, RH, and in the rate of chain initiation, Ri, showed that the classical rate law for autoxidation, -d[O2]/dt = (kp/(2 kt 1/2))[RH] x Ri 1/2, is applicable to these photo-initiated oxidations. The oxidizability of methyl linoleate under these conditions is 2.92 x 10(-2) M-1/2 s-1/2. These peroxidations were inhibited by chromanol phenolic antioxidants of the vitamin E class, such as lipid-soluble 2,2,5,7,8-pentamethyl-6-hydroxychroman (PMHC) and water-soluble 2-carboxy- 2,5,7,8-tetramethyl-6-hydroxychroman (Trolox) and derived rate constants for inhibition of peroxidation were kinh (PMHC) = 4.35 x 10(4) M-1 s-1 and k(inh) (Trolox) = 2.81 x 10(4) M-1 s-1 during inhibited oxidation of methyl linoleate photo-initiated by 4. The products from photo-initiated peroxidation of methyl linoleate by 1 through 5 were determined by reduction and high-performance liquid chromatography analyses to be the 9- and 13-positional hydroperoxides of the four geometrical isomers: cis-9, trans-11 (6), trans-10, cis-12 (7), trans-9, trans-11 (8), and trans-10, trans-12 (9)-octadecadienoates typical of the free radical chain mechanism of lipid peroxidation. Products from dye-sensitized oxidation by Methylene Blue or Rose Bengal of methyl linoleate gave a product distribution of six hydroperoxides typical of oxidation by singlet oxygen. Thermal or photo-initiated peroxidation of methyl linoleate in SDS gave some selectivity of oxidation at the 13-position of the linoleate chain. The ratio of 13- to 9-oxidation varied in the range 1.23 to 1.14 as the cis/trans to trans/trans ratio of geometrical isomers varied from 0.44 to 1.25 during photooxidation of increased amounts of linoleate in SDS. This selectivity is attributed to loss of the pseudo symmetry around the pentadienyl system in the lipid chain in the SDS system during the peroxidation.

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Analysis of autoxidized fats by gas chromatography‐mass spectrometry: II. Methyl linoleate

Cited by 117 publications

References 23 publications

Effects of Grilling on Formation of Cholesterol Oxides in Seafood Products Rich in Polyunsaturated Fatty Acids

Effects of Grilling on Formation of Cholesterol Oxides in Seafood Products Rich in Polyunsaturated Fatty Acids

What do thiobarbituric acid and hemoglobin-methylene blue tests evaluate in the endogenous lipid peroxidation of rat liver?

Photo‐initiated peroxidation of lipids in micelles by azaaromatics

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