|Scholljegerdes, E - New Mexico State University|
|Maddock, R - North Dakota State University|
|Barcelo-coblijn, Gwendolyn - University Of North Dakota|
|Murphy, E - University Of North Dakota|
Submitted to: European Journal of Lipid Science and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/20/2016
Publication Date: 7/1/2017
Citation: Kronberg, S.L., Scholljegerdes, E.J., Maddock, R.J., Barcelo-Coblijn, G., Murphy, E.J. 2017. Rump and shoulder muscles from grass and linseed fed cattle as important sources of n-3 fatty acids for beef consumers. European Journal of Lipid Science and Technology. 119(7):1600390. doi:10.1002/ejlt.201600390.
Interpretive Summary: Sources of omega-3 fatty acids are needed that are readily accepted, relatively inexpensive and sustainably produced. Lean ground beef has potential as a source of omega-3 fatty acid for many people who don’t regularly eat fish and other foods that contain omega-3 fatty acids. Therefore, we evaluated the potential of a muscle from the shoulder and another from the rump, which are used for ground beef, from grass and flaxseed consuming cattle, as good sources of omega-3 fatty acids and compared them with a loin muscle from the same cattle. Muscle lipids (fat) from rump, shoulder and loin were analyzed for fatty acids in the muscle cell membrane lipids and in the obvious white marbling fat within the muscles using gas liquid chromatography. Amounts of the muscle cell membrane fatty acids of commonly called ALA, EPA, DPA and DHA were higher in shoulder and rump muscles compared to loin muscle and higher in the rump compared to shoulder muscle except for DHA. Amounts of ALA in the rump and shoulder muscles were 1.5- and 1.3-fold greater, respectively, than in the loin muscle. Amounts of EPA in the rump and shoulder muscles were 1.8- and 1.3-fold more, respectively, than in the loin muscle. Amount of DPA was 1.5-fold higher in the rump muscle than in the loin muscle and amounts of DHA was 1.6- and almost 1.4-fold higher in the rump and shoulder muscles, respectively, than in the loin muscle. Lean ground beef made with rump and shoulder muscles from grass and flaxseed consuming cattle has potential to be a significant source of omega-3 fatty acids for many people.
Technical Abstract: Ground beef has potential to be a relatively inexpensive and sustainable source of n-3 FA for people who frequently consume it, but don’t consume n-3 containing fish. To enhance n-3 FA content in ground beef, we evaluated FA content in pertinent muscles from grass-fed cattle that were supplemented with flaxseed for 75 days before slaughter and compared them with loin muscle from these cattle. Lipids from rump (m. biceps femoris), shoulder (m. triceps brachii) and loin (m. longissimus dorsi) were separated into neutral and phospholipids and FA mass determined using gas liquid chromatography. In phospholipids, mass of a-linolenic acid (ALA; 18:3n-3), ecosapentaenoic acid (EPA; 20:5n-3), docosapentaenoic acid (DPA; 22:5n-3) and docosahexaenoic acid (DHA; 22:6n-3) were significantly higher in shoulder and rump compared to loin (p < 0.0001). Compared to shoulder, FA mass was higher in the rump (p < 0.0001) except for DPA (p = 0.53). Masses of n-3 FA, ALA, EPA, DPA, and DHA were increased between 1.5-1.8 fold in the rump and 1.3-1.5-fold in the shoulder compared to loin, respectively. Lean ground beef made with rump and shoulder muscles from grass-fed cattle supplemented with flaxseed has potential to be a source of dietary n-3 FA for many people.