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Acide rumenique : presence dans le beurre et influence des procedes de fabrication ; incidence sur l'atherosclerose experimentale chez le hamster.

Martial Ledoux
Abstract : Conjugated linoleic acids (CLA) are positional and geometrical isomers of linoleic acid 18:2 c9,c12, mainly represented by 2 isomers: rumenic acid 18:2 c9,t11, and the t9,c12 isomer. Rumenic acid occurs naturally in milk fat and dairy products; food composition data are very poor regarding the levels of this special fatty acid in dairy products and related food. CLA, and especially rumenic acid, have been shown to exhibit interesting biological properties for human health, particularly considering atherosclerosis. However, most of the studies on this topic used mixtures of CLA. Consequently the properties of each individual isomer are still not well defined. The first part of this study consisted in determination of the rumenic acid content of milk fat in different areas in France, at several periods of the year, and in evaluating the variations of rumenic acid levels during the processing of milk to butter through cream. Our results showed that rumenic acid contents vary depending on regions and seasons. These differences could be mainly due to the content of polyunsaturated fatty acids in the cows' diets. No rumenic acid variation was noticed during butter making; skimming of milk, cream ripening, and churning do not seem to modify the rumenic acid contents of milk fat. The second part of our study dealt with the determination the particular effect of the two major CLA isomers, and especially rumenic acid, on the development of atherosclerosis in hamster fed on an pro-atherogenic diet rich in cholesterol and lipids. Our experiments showed rumenic acid to have a protective effect against early atherosclerosis. But, this favourable effect disappeared when repeating the experience with another strain of hamsters more sensitive to atherosclerosis, showing more severe fatty streaks. In conclusion, there is a need for further experiments on rumenic acid properties regarding atherosclerosis works using a more pertinent animal model.
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https://pastel.archives-ouvertes.fr/pastel-00003476
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Submitted on : Thursday, February 28, 2008 - 8:00:00 AM
Last modification on : Wednesday, July 25, 2018 - 1:23:46 AM
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Martial Ledoux. Acide rumenique : presence dans le beurre et influence des procedes de fabrication ; incidence sur l'atherosclerose experimentale chez le hamster.. Life Sciences [q-bio]. INAPG (AgroParisTech), 2005. English. ⟨NNT : 2005INAP0012⟩. ⟨pastel-00003476⟩

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