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Fenton reagents may...
Fenton reagents may not initiate lipid peroxidation in an emulsified linoleic acid model system
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Yin, D. (författare)
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Lingnert, Hans (författare)
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- Ekstrand, Bo (författare)
- RISE,SIK – Institutet för livsmedelsforskning
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Brunk, U.T. (författare)
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(creator_code:org_t)
- 1992
- 1992
- Engelska.
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Ingår i: Free Radical Biology & Medicine. - 0891-5849 .- 1873-4596. ; 13:5, s. 543-556
- Relaterad länk:
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http://www.scopus.co...
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Abstract
Ämnesord
Stäng
- This study includes two parts. First, the Fe2+ autooxidation and chelation processes in the presence of the chelators ethylenediaminetetraacetic acid (EDTA) and diethylenetriamine pentaacetic acid (DTPA) were studied by measuring UV light absorbance alterations. Competition for Fe3+ between chelators and water or phosphate buffer (PB) ions was confirmed. The addition of EDTA or DTPA to Fe3+ in water or PB only slowly turned the water/PB-Fe3+ complexes to EDTA-Fe3+ or DTPA-Fe3+ complexes. In the second part of this study, the initiation mechanisms of Tween 20 emulsified linoleic acid peroxidation under stimulation by chelator-Fe-O2 complexes were studied by measuring changes in UV light absorbance following diene conjugation. Fe3+ in the presence of EDTA or DTPA did not stimulate diene conjugation. Fe2+ (0.10 mM) and EDTA (0.11 mM) stimulated diene conjugation of the linoleic acid emulsion, but only after apparent Fe2+ autooxidation. Fe2+ and DTPA, as well as premixed DTPA-Fe2+ complex, resulted in very fast diene conjugation in a wide range of concentrations. A nonlinear, mainly square root relation between Fe2+ concentration and peroxidation rate was noted. Superoxide dismutase (SOD), catalase, and mannitol did not prevent the lipid peroxidation. H2O2 substantially decreased the DTPA-Fe2+ stimulated, otherwise rapid, diene conjugation but slightly enhanced the slower one stimulated by EDTA-Fe2+. Without ambient oxygen, Fenton reagents did not result in 'H abstraction-related diene conjugation. The findings suggest that 'OH resulting from Fenton reagents may not be the main cause for the initiation of peroxidation in this model system. Furthermore, a study with different combinations of Fe2+ and Fe3+ did not support the Fe2+/Fe3+ (1:1) optimum ratio hypothesis. We therefore conclude that perferryl ions or chelator-Fe-O2 complexes may be responsible for the first-chain initiation 2 of lipid peroxidation, at least in this model system.
Ämnesord
- LANTBRUKSVETENSKAPER -- Lantbruksvetenskap, skogsbruk och fiske -- Livsmedelsvetenskap (hsv//swe)
- AGRICULTURAL SCIENCES -- Agriculture, Forestry and Fisheries -- Food Science (hsv//eng)
Nyckelord
- Food Engineering
- Livsmedelsteknik
Publikations- och innehållstyp
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- art (ämneskategori)
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