Off-campus UNL users: To download campus access dissertations, please use the following link to log into our proxy server with your NU ID and password. When you are done browsing please remember to return to this page and log out.
Non-UNL users: Please talk to your librarian about requesting this dissertation through interlibrary loan.
Antemortem factors affecting off -flavor development in beef
This body of research was conducted to gain a better understanding of the antemortem factors affecting beef off-flavors with particular interest in the liver-like off flavor. The first study examined the effects of varying (0, 10, 20, 30, 40, and 50%) levels of wet distillers grains plus solubles (WDGS) on flavor of beef aged 7 d. No significant treatment effects were reported (P ≥ 0.07), but USDA Choice steaks had more panelists indicate the presence of metallic off-flavor. The second study tested a selection procedure as a means to obtain more liver-like off flavored samples. Although the two panelists had moderate agreement as indicated by a kappa statistic, a post-hoc power analysis revealed that there were not two distinct flavor populations. Therefore, the efficacy of the selection procedure would needs further testing. Samples generated from the selection procedure were tested by a trained sensory panel and regression equations were derived to predict the incidence of liver-like off flavor. Unsaturated fatty acids and sodium significantly explained 46% of the variation in the incidence of liver-like off flavor. The final phase of this research evaluated chemical and sensory attributes of source-verified cattle finished on 30% WDGS enriched with varying levels of alfalfa hay, corn silage, or corn stalks based on NDF. Significant (P ≤ 0.050) treatment effects were observed for intramuscular amounts of 16:0, 18:1(n-9), 18:2(n-6), 20:4(n-6), 22:5(n-3), MUFA, PUFA, and omega 6 fatty acids. No significant (P ≥ 0.670) treatment or location effects were noted for liver-like off flavor, so correlation coefficients were derived to explain the relation between the liver-like off flavor and chemical properties. Subcutaneous amounts of 18:2(n-6t) (r = −0.17) were inversely related the incidence of liver-like off flavor, while 20:1(n-9) (r = 0.21), CLA 9c,11 t (r = 0.16) were directly related. Results from this research indicate that unsaturated fatty acids and sodium explain some of the variation in liver-like off flavor. Additionally, cattle source or finishing cattle on WDGS-based diets does not appear to contribute to liver-like off flavor.
Jenschke, Blaine Edward, "Antemortem factors affecting off -flavor development in beef" (2007). ETD collection for University of Nebraska - Lincoln. AAI3271905.