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Lipid hydroperoxidase activity of myoglobin and phenolic antioxidants in simulated gastric fluid
Year:
2005
Authors :
Granit, Rina
;
.
Kanner, Joseph
;
.
Volume :
53
Co-Authors:
Lapidot, T., Department of Food Science, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel
Granit, R., Department of Food Science, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel
Kanner, J., Department of Food Science, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel
Facilitators :
From page:
3391
To page:
3396
(
Total pages:
6
)
Abstract:
Our recent study demonstrated the potential of gastric fluid at pH 3.0 to accelerate lipid peroxidation and cooxidation of dietary constituents in the stomach medium. Metmyoglobin is known to catalyze the breakdown of lipid hydroperoxides to free radicals, a reaction that could enhance the propagation step and general lipid peroxidation. During this reaction, a part of the free radicals is autoreduced by metmyoglobin. At pH 3.0, metmyoglobin at low concentration was almost 7 × 10 4 times as effective as at pH 7.0 in enhancing the rate of lipid peroxidation. Our study demonstrated that metmyoglobin, at a low concentration (∼1:30), as compared with that of the hydroperoxides in the lipid system, worked prooxidatively increasing the amounts of linoleate hydroperoxides. However, at a high concentration (∼1:3), metmyoglobin acted antioxidatively and decomposed hydroperoxides, whose concentrations then remained at zero for a long time. Catechin, a known polyphenol, supports the inversion of metmyoglobin catalysis, from prooxidation to antioxidation. The antioxidative activity of the couple metmyoglobin-catechin was better at pH 3.0 than at pH 7.0, indicating that this reaction is more dependent on metmyoglobin than on catechin. During this reaction, catechin or quercetin not only donates reducing equivalents to prevent lipid peroxidation but also prevents the destruction and polymerization of metmyoglobin. The results of this research highlighted the important and possible reactions of heme proteins and polyphenols as couple antioxidants, working as hydroperoxidases or as pseudo-peroxidases. We hypothesize that the occurrence of these reactions in the stomach could have an important impact on our health and might help to better explain the health benefits of including foods rich in polyphenol antioxidants in the meal, especially when consuming red meat. © 2005 American Chemical Society.
Note:
Related Files :
antioxidants
chemistry
lipid peroxidation
metabolism
Models, Biological
myoglobin
peroxidase
pH
phenols
red meat
Show More
Related Content
More details
DOI :
10.1021/jf040400w
Article number:
Affiliations:
Database:
Scopus
Publication Type:
article
;
.
Language:
English
Editors' remarks:
ID:
31331
Last updated date:
02/03/2022 17:27
Creation date:
17/04/2018 01:01
Scientific Publication
Lipid hydroperoxidase activity of myoglobin and phenolic antioxidants in simulated gastric fluid
53
Lapidot, T., Department of Food Science, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel
Granit, R., Department of Food Science, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel
Kanner, J., Department of Food Science, Agricultural Research Organization, Volcani Center, Bet Dagan 50250, Israel
Lipid hydroperoxidase activity of myoglobin and phenolic antioxidants in simulated gastric fluid
Our recent study demonstrated the potential of gastric fluid at pH 3.0 to accelerate lipid peroxidation and cooxidation of dietary constituents in the stomach medium. Metmyoglobin is known to catalyze the breakdown of lipid hydroperoxides to free radicals, a reaction that could enhance the propagation step and general lipid peroxidation. During this reaction, a part of the free radicals is autoreduced by metmyoglobin. At pH 3.0, metmyoglobin at low concentration was almost 7 × 10 4 times as effective as at pH 7.0 in enhancing the rate of lipid peroxidation. Our study demonstrated that metmyoglobin, at a low concentration (∼1:30), as compared with that of the hydroperoxides in the lipid system, worked prooxidatively increasing the amounts of linoleate hydroperoxides. However, at a high concentration (∼1:3), metmyoglobin acted antioxidatively and decomposed hydroperoxides, whose concentrations then remained at zero for a long time. Catechin, a known polyphenol, supports the inversion of metmyoglobin catalysis, from prooxidation to antioxidation. The antioxidative activity of the couple metmyoglobin-catechin was better at pH 3.0 than at pH 7.0, indicating that this reaction is more dependent on metmyoglobin than on catechin. During this reaction, catechin or quercetin not only donates reducing equivalents to prevent lipid peroxidation but also prevents the destruction and polymerization of metmyoglobin. The results of this research highlighted the important and possible reactions of heme proteins and polyphenols as couple antioxidants, working as hydroperoxidases or as pseudo-peroxidases. We hypothesize that the occurrence of these reactions in the stomach could have an important impact on our health and might help to better explain the health benefits of including foods rich in polyphenol antioxidants in the meal, especially when consuming red meat. © 2005 American Chemical Society.
Scientific Publication
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