Extensive Analysis of Long-Chain Polyunsaturated Fatty Acids, CLA, trans-18:1 Isomers, and Plasmalogenic Lipids in Different Retail Beef types

Abstract

The objective of this investigation was to provide a comprehensive analysis of the total lipid composition of present-day retail beef meat available at the consumer level and to evaluate the total lipid composition with special emphasis on the nutritional value. For this purpose, 40 beef cuts were obtained from four cattle farms based on either a natural grazing system (NGS) or an intensive production system (IPS). The total lipid composition was analyzed using complementary chemical and chromatographic procedures. The content of n-3 LC-PUFA, CLA, total trans-18:1, and branched-chain fatty acids was significantly higher in NGS beef than in IPS beef. The trans-18:1 and CLA profiles were affected by the different production systems, whereby they can be utilized empirically to differentiate between feeding regimen and production management. Fatty acid ratios that have health implications ( n-6/ n-3, LA/alphaLNA, and AA/EPA) were remarkably beneficial for NGS beef compared with IPS beef. In conclusion, from the human health perspective, beef raised on NGS is clearly superior with regard to a more favorable fatty acid profile in comparison to IPS beef.

Length of concentrate finishing affects the fatty acid composition of grass-fed and genetically lean beef: an emphasis on trans-18:1 and conjugated linoleic acid profiles

“…The n-3 content in the meat of grass-fed animals in this study was high in comparison with others (Ponnampalam et al, 2006;Kraft et al, 2008), whereas the n-6/n-3 was also higher (3.3) than reported by Enser et al (1998;2.0 to 2.3 for British cattle), Nuernberg et al (2002;1.3 for German Simmental bulls and Holstein steers) and Alfaia et al (2009;1.8 for Alentejano purebred). These differences could be in part explained by differences in breed (Raes et al, 2003;Aldai et al, 2007b;Kraft et al, 2008), forage species (Collomb et al, 2002;Fraser et al, 2009) and/or stage of pasture maturity (Dewhurst et al, 2001;Vanhatalo et al, 2007), or the relatively high content of 18:2n-6 in the concentrate.…”

“…The significantly higher absolute and relative contents of trans-18:1 found in concentrate-finished beef compared with grass-finished beef were mainly due to higher contents of 6t/7t/8t-18:1, 9t-18:1 and 10t-18:1 as observed by Alfaia et al (2009) and Leheska et al (2008). High contents of 10t-18:1 have been observed in tissues of concentrate-fed ruminants (Aldai et al, 2008b and2010b), whereas 11t-18:1 has been consistently associated with forage feeding in beef (Bessa et al, 2006;Dugan et al, 2008;Kraft et al, 2008;Alfaia et al, 2009; Figure 1). In Figure 1b, the trans-18:1 profile of concentrate-fed bulls from two studies Aldai et al, 2010a) using different breeds are presented for comparison purposes.…”

“…Grain-based diets contain relatively high levels of linoleic acid, which can lead to unfavourable n-6/n-3 ratios (Aldai et al, 2008b) and trans-18:1 profiles (Aldai et al, 2008b;Kraft et al, 2008) in beef. The 10trans (t )-18:1 accumulates in intensively or concentrate-finished beef (Purchas et al, 2005;Leheska et al, 2008) and this has been associated with increased atherogenicity in animal models Roy et al, 2007).…”

“…Forages are good sources of linolenic acid that leads to an enhanced n-3 polyunsaturated fatty acid (PUFA) content in beef products with a more desirable fatty acid composition for human health (Gleissman et al, 2010). Moreover, rumenic acid (RA, 9cis (c ), 11t-18:2) and its precursor vaccenic acid (VA, 11t-18:1) have been found to accumulate in forage-finished ruminants (Dugan et al, 2007;Kraft et al, 2008;Alfaia et al, 2009) and their consumption has been linked to a number of potential health benefits Field et al, 2009;Bassett et al, 2010).…”

Influence of α-tocopherol supplementation on trans-18:1 and conjugated linoleic acid profiles in beef from steers fed a barley-based diet

“…It is also important to note that, on average, t10-18:1 and t11-18:1 would constitute about 52% and 15% of total t18:1, respectively, in both regular ground beef and lean steak. Current results also indicate that feeding a high barley-grain diet like most concentrate-based diets (Dugan et al, 2007;Kraft et al, 2008;Leheska et al, 2008) increased levels of trans fatty acids other than t11-18:1 in beef compared with high-forage diets. In this context, it could, therefore, be important to re-examine the exclusion of t18:1 isomers from compulsory labelling of trans fatty acids in ruminant-derived foods.…”