Conjugated linoleic acid is synthesized endogenously in lactating dairy cows by Delta(9)-desaturase.
J. M. Griinari,Benjamin A. Corl,Shannon H. Lacy,P. Y. Chouinard,K. V. V. Nurmela,Dale E. Bauman +5 more
TLDR
Results demonstrate that endogenous synthesis of CLA from trans-11 18:1 represented the primary source of CLA in milk fat of lactating cows.Abstract:
Conjugated linoleic acid (CLA) is a naturally occurring anticarcinogen found in milk fat and body fat of ruminants. Although CLA is an intermediate in ruminal biohydrogenation of linoleic acid, we hypothesized that its primary source was from endogenous synthesis. This would involve Delta(9)-desaturase and synthesis from trans-11 18:1, another intermediate in ruminal biohydrogenation. Our first experiment supplied lactating cows (n = 3) with trans-11 18:1 by abomasal infusion and examined the potential for endogenous synthesis by measuring changes in milk fat CLA. By d 3, infusion of trans-11 18:1 resulted in a 31% increase in concentration of cis-9, trans-11 CLA in milk fat, demonstrating that an active pathway for endogenous synthesis of CLA exists. Our second experiment examined the quantitative importance of endogenous synthesis of CLA in lactating cows (n = 3) by abomasally infusing a putative stimulator (retinol palmitate) or an inhibitor (sterculic oil) of Delta(9)-desaturase. Infusion of retinol palmitate had no influence on milk fatty acid desaturation, and yield of CLA in milk fat was not altered. However, sterculic oil infusion decreased the concentration of CLA in milk fat by 45%. Consistent with Delta(9)-desaturase inhibition, the sterculic oil treatment also altered the milk fat concentration of other Delta(9)-desaturase products as indicated by the two- to threefold increase in the ratios of 14:0 to 14:1(,) 16:0 to 16:1 and 18:0 to cis-18:1. Using changes in the ratio of 14:0 to 14:1 as an indication of the extent of Delta(9)-desaturase inhibition with the sterculic oil treatment, an estimated 64% of the CLA in milk fat was of endogenous origin. Overall, results demonstrate that endogenous synthesis of CLA from trans-11 18:1 represented the primary source of CLA in milk fat of lactating cows.read more
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Functional foods from animal production
TL;DR: In the Victorian Northern Irrigation Area, the concentration of conjugated linoleic acids (CLA) in milk fat ranged from 1.1-35.4 mg/g fat with a major peak in spring as discussed by the authors.
Journal ArticleDOI
Effects of high-oil corn on feedlot performance, carcass characteristics, fatty acid profiles, beef palatability, and retail case life traits of beef top loin steaks.
B. D. Price,Andrea J. Garmyn,H. M. Derington,M. L. Galyean,S. P. Jackson,Stephen B. Smith,M. F. Miller +6 more
TL;DR: Overall, ADG and G:F were less and marbling score was decreased, but there were no differences between treatments in beef palatability, retail case life, or concentrations of fatty acids in strip loins.
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Microbial conjugated linoleic acid production - a novel probiotic trait?
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Lipid composition and nutritional quality of intramuscular fat in Charneca-PDO beef
José M. Pestana,José M. Pestana,Ana S. H. Costa,Cristina M. Alfaia,Paulo J. Costa,Susana Martins,Susana P. Alves,Rui J.B. Bessa,José A. M. Prates +8 more
TL;DR: Intramuscular fat of Charneca-PDO beef has good human health–related parameters, with small carcass variation, since the PUFA/SFA and n-6/n-3 ratio values are inside or very close to the recommended figures for the human diet, and the content of α-tocopherol is very high.
References
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Official Methods of Analysis of AOAC International
William Horwitz,George W Latimer +1 more
TL;DR: In this article, the authors present official methods of analysis of AOAC International, official methods for analysis of aOAC-related project, and a set of methods for the analysis of their work.
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Lipid extraction of tissues with a low-toxicity solvent
Atsushi Hara,Norman S. Radin +1 more
TL;DR: An improved method for extracting the lipids from tissues consists of the use of hexane:isopropanol, followed by a wash of the extract with aqueous sodium sulfate to remove nonlipid contaminants.
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Dietary sources of conjugated dienoic isomers of linoleic acid, a newly recognized class of anticarcinogens
TL;DR: In this article, an improved method for quantifying linoleic acid (CLA) in food was developed, which was used to produce a data base of more than 90 food items including meat, poultry, seafood, dairy products, plant oils, and infant and processed foods.
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A simple procedure for rapid transmethylation of glycerolipids and cholesteryl esters
TL;DR: A simple procedure suitable for rapid transmethylation of triacylglycerols, other neutral lipids, and glycerophospholipids is described, which can occur within a few minutes with no hydrolysis.
Journal ArticleDOI
Regulation of stearoyl-coa desaturase by polyunsaturated fatty acids and cholesterol
TL;DR: The goal of this review is to provide an overview of the genetic regulation of the stearoyl-CoA desaturase in response to dietary polyunsaturated fatty acids and cholesterol.