Beef quality attributes as affected by increasing the intramuscular levels of vitamin E and omega-3 fatty acids Manuel Juárez a, ⁎, Michael E.R. Dugan a , Noelia Aldai a , John A. Basarab b , Vern S. Baron a , Tim A. McAllister c , Jennifer L. Aalhus a a Agriculture and Agri-Food Canada, Lacombe Research Centre, 6000 C & E Trail, Lacombe, AB, Canada T4L 1W1 b Alberta Agriculture and Rural Development, Lacombe Research Centre, 6000 C & E Trail, Lacombe, AB, Canada T4L 1W1 c Agriculture and Agri-Food Canada, Research Centre, 5403-1st Ave. S. Lethbridge, AB, Canada T1J 4B1 abstract article info Article history: Received 15 April 2011 Received in revised form 2 June 2011 Accepted 2 November 2011 Available online xxxx Keywords: Flaxseed Linseed Meat quality Oxidation Tocopherol In order to investigate the effects of increasing beef n-3 fatty acid content and the protective effects of vitamin E antioxidant activity on meat quality characteristics, 80 feedlot steers were fed 4 different diets (control, high vitamin E, 10% ground flaxseed or high vitamin E–10% ground flaxseed). While dietary treat- ments had no effect (P > 0.05) on meat composition or tenderness values, the increase in oxidation products was lower (P = 0.046) in meat from vitamin E supplemented steers and higher (P = 0.006) in meat from flaxseed fed animals. The increase in α-tocopherol tissue levels (P b 0.001) in meat from animals fed flaxseed and increased dietary vitamin E resulted in the lowest drip loss values (P = 0.013). As expected, display time had a large effect on retail traits in both steaks and patties (P b 0.001). While retail traits of steaks were not affected by the dietary treatments (P > 0.05), feeding flaxseed decreased (P b 0.05) ground beef retail scores, which were not corrected by higher levels of dietary vitamin E. Finally, although no effect (P > 0.05) was observed among treatments for sensory attributes in steaks, the correlations of a combined n-3:α-tocopherol ratio against retail and sensory attributes (P b 0.05) suggest that increased n-3 fatty acids levels require increased dietary antioxidants, such as vitamin E to avoid negative effects on meat quality from a loss in oxidative stability. Crown Copyright © 2011 Published by Elsevier Ltd. All rights reserved. 1. Introduction Lipid peroxidation in meat is an important factor limiting both the quality of meat and its consumer acceptability (Aalhus & Dugan, 2004). Peroxidation of lipids in meat becomes apparent to consumers by the development of rancid odours or flavours, and “warmed-over” flavour in previously cooked meats. Oxidation of meat pigments is recognisable by the development of brown discolouration replacing the normally acceptable bright cherry red colour. Typical lipid perox- idation in meat involves the phospholipid fraction (Frankel, 1998), located in the membranes and containing over 40% polyunsaturated fatty acids (PUFA). Due to their high level of unsaturation and their proximity to the haeme catalysts of the mitochondria and micro- somes, they are susceptible to oxidation. Despite the numerous known deleterious quality changes associated with oxidation of PUFA (Wood et al., 2004), there is considerable interest along the meat value chain in enhancing the PUFA content of meat so that niche products with health label claims can be marketed (Juárez et al., 2010; Ruxton, Reed, Simpson, & Millington, 2004). In this regard, dietary flax supplementation has been used by several authors in order to increase omega-3 (n-3) fatty acid content in beef (e.g. Bartoň, Marounek, Kudrna, Bureš, & Zahrádková, 2007; Juárez et al., 2011; Raes, De Smet, Balcaen, Claeys, & Demeyer, 2003; Scollan et al., 2001). However, as expected, some side-effects on meat quality, including early development of off-flavour and off-colour, have been reported (LaBrune, Reinhardt, Dikeman, & Drouillard, 2008). Consequently, increasing lipid stability by addition of elevated levels of antioxidant compounds could be a means of overcoming this problem, as observed in pork (Rey et al., 2001). Thus, vitamin E is widely used as an antioxidant in biological systems, and its accumulation in muscle has been shown to have a positive impact on colour and lipid stability of fresh and frozen beef (Liu, Lanari, & Schaefer, 1995). The present study was undertaken to elucidate the effects of in- creasing beef total n-3 content and the protective effect of vitamin E antioxidant activity on meat quality characteristics. 2. Material and methods Experimental design, animal handling, dietary treatments, slaughter process and sampling were previously reported by Juárez et al. (2011). Briefly, 80 feedlot steers were housed in 8 feedlot pens (2 pens per die- tary treatment, 10 steers per pen, n=20 steers per dietary treatment) Meat Science xxx (2011) xxx–xxx ⁎ Corresponding author at: Agriculture and Agri-Food Canada, Lacombe Research Centre, 6000 C & E Trail, Lacombe, Alberta, Canada T4L 1W1. Tel.: +1 4037828118. E-mail address: Manuel.Juarez@AGR.GC.CA (M. Juárez). MESC-05559; No of Pages 6 0309-1740/$ – see front matter. Crown Copyright © 2011 Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.meatsci.2011.11.010 Contents lists available at SciVerse ScienceDirect Meat Science journal homepage: www.elsevier.com/locate/meatsci Please cite this article as: Juárez, M., et al., Beef quality attributes as affected by increasing the intramuscular levels of vitamin E and omega-3 fatty acids, Meat Science (2011), doi:10.1016/j.meatsci.2011.11.010