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Dugan M.E.R.,Agriculture and Agri Food Canada | Aldai N.,Institute Ganaderia Of Montana | Aalhus J.L.,Agriculture and Agri Food Canada | Rolland D.C.,Agriculture and Agri Food Canada | Kramer J.K.G.,Agriculture and Agri Food Canada
Canadian Journal of Animal Science

Trans fatty acids are found naturally in foods, particularly in those derived from ruminant animals, such as beef and dairy cattle. Over the past few decades, human consumption of trans fatty acids has increased, but this has been mainly from products containing partially hydrogenated vegetable oils. The correlation of trans fatty acid consumption with diseases such as coronary heart disease has been cause for concern, and led to recommendations to reduce their consumption. Trans fatty acids, however, have differing effects on human health. Therefore, in foods produced from ruminant animals, it is important to know their trans fatty acid composition, and how to enrich or deplete fatty acids that have positive or negative health effects. This review will cover the analysis of trans fatty acids in beef, their origin, how to manipulate their concentrations, and give a brief overview of their health effects. Source

Reichardt N.,University of Aberdeen | Reichardt N.,University of Glasgow | Duncan S.H.,University of Aberdeen | Young P.,University of Aberdeen | And 7 more authors.
ISME Journal

Propionate is produced in the human large intestine by microbial fermentation and may help maintain human health. We have examined the distribution of three different pathways used by bacteria for propionate formation using genomic and metagenomic analysis of the human gut microbiota and by designing degenerate primer sets for the detection of diagnostic genes for these pathways. Degenerate primers for the acrylate pathway (detecting the lcdA gene, encoding lactoyl-CoA dehydratase) together with metagenomic mining revealed that this pathway is restricted to only a few human colonic species within the Lachnospiraceae and Negativicutes. The operation of this pathway for lactate utilisation in Coprococcus catus (Lachnospiraceae) was confirmed using stable isotope labelling. The propanediol pathway that processes deoxy sugars such as fucose and rhamnose was more abundant within the Lachnospiraceae (based on the pduP gene, which encodes propionaldehyde dehydrogenase), occurring in relatives of Ruminococcus obeum and in Roseburia inulinivorans. The dominant source of propionate from hexose sugars, however, was concluded to be the succinate pathway, as indicated by the widespread distribution of the mmdA gene that encodes methylmalonyl-CoA decarboxylase in the Bacteroidetes and in many Negativicutes. In general, the capacity to produce propionate or butyrate from hexose sugars resided in different species, although two species of Lachnospiraceae (C. catus and R. inulinivorans) are now known to be able to switch from butyrate to propionate production on different substrates. A better understanding of the microbial ecology of short-chain fatty acid formation may allow modulation of propionate formation by the human gut microbiota. © 2014 International Society for Microbial Ecology. All rights reserved. Source

Aldai N.,Institute Ganaderia Of Montana | Dugan M.E.R.,Agriculture and Agri Food Canada | Rolland D.C.,Agriculture and Agri Food Canada | Aalhus J.L.,Agriculture and Agri Food Canada
Meat Science

Due to significant variation in polyunsaturated fatty acid biohydrogenation products in beef it would be useful to determine if levels of trans-18:1 isomers in samples collected ante-mortem are correlated with those collected post-mortem. Beef blood (RBC), subcutaneous fat (SC) and muscle (intramuscular fat; IM) samples were collected from an experiment with dietary vitamin E with/without flaxseed (n = 80) and fatty acids analyzed. Across treatments, correlation analysis of total and individual trans-18:1 isomers were performed between tissues. Correlations between SC and IM were highly significant for all individual and total trans-18:1. RBC trans-18:1 were also well correlated with other tissues except for vaccenic acid. Levels of 10. t-, 12. t- and 13. t/14. t- were amongst the best correlated between RBC and SC and IM profiles. Levels of 6. t/7. t/8. t-, 9. t-, and 15. t-18:1 showed significant but lower correlation factors particularly between RBC and SC. These results confirm the possibility of utilizing blood as a non-destructive sample to predict the total and isomeric profile of trans-18:1 in beef. © 2012. Source

Nassu R.T.,Agriculture and Agri Food Canada | Dugan M.E.R.,Agriculture and Agri Food Canada | He M.L.,Agriculture and Agri Food Canada | He M.L.,University of Saskatchewan | And 5 more authors.
Meat Science

This study was conducted to investigate changes in fatty acid profiles of beef cows fed grass hay or barley silage based diets, with or without flaxseed supplementation. Both flaxseed and hay feeding increased levels of α-linolenic acid (LNA; 18:3n-3) in longissimus thoracis and backfat (P<0.001). A forage type by flaxseed level interaction was observed for most LNA biohydrogenation intermediates (P<0.05) that indicated feeding hay combined with flaxseed led to the greatest levels of total conjugated linolenic acid, total conjugated linoleic acid, total non-conjugated dienes and total trans-18:1. Predominant biohydrogenation intermediates included t11,. c15-18:2, rumenic acid (c9,t11-18:2) and vaccenic acid (t11-18:1). © 2011. Source

Aldai N.,University of the Basque Country | Lavin P.,Institute Ganaderia Of Montana | Kramer J.K.G.,Agriculture and Agri Food Canada | Jaroso R.,Institute Ganaderia Of Montana | Mantecon A.R.,Institute Ganaderia Of Montana
Meat Science

This study was designed to compare the quality of veal produced from 'Tudanca × Charolais' cross (n = 6) and Limousin (n = 6) breeds when allowed to feed freely on mountain pastures and suckle naturally from birth to 7. months of age. After 80. days of age calves also had access to concentrate (maximum of 3. kg/day), while mothers did not. At slaughter, Limousin calves were heavier (P< 0.01) and provided better carcass yield (P< 0.05) and conformation (P< 0.001) than Tudanca calves. Tudanca beef provided higher fat content (P< 0.05) was less tough (P< 0.05), and was scored as more tender and juicy (P< 0.1) with higher acceptability than Limousin beef (P< 0.1). In general, Tudanca had a better fatty acid profile than Limousin beef, especially in terms of the content of polyunsaturated (P< 0.05), long-chain polyunsaturated fatty acids (P< 0.05) and their n-6/n-3 ratios (P< 0.1), as well as vaccenic acid (P< 0.1) and the overall trans-18:1 isomer profile. © 2012 Elsevier Ltd. Source

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