Browsing by Author "Wheeler, Tommy L."
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Item Influence of Aging Temperature and Duration on Flavor and Tenderness Development of Vacuum-Packaged Beef Longissimus(2023) Hernandez, M. Sebastian (TTU); Woerner, Dale R. (TTU); Brooks, J. Chance (TTU); Wheeler, Tommy L.; Legako, Jerrad F. (TTU)The objective of this study was to investigate the influence of beef wet-aging temperature and duration on beef palatability. Paired beef strip loins were obtained from USDA Choice carcasses (n = 60) at a commercial processing facility. Paired strip loins were assigned to a storage temperature (−2°C, 0°C, or 4°C). Strip loins were portioned into half loins and further assigned to an aging duration (14, 28, 42, or 56 d). Loins were aged in commercial upright refrigerators. After aging, loins were fabricated into 2.54-cm steaks and assigned to either volatile compound analysis, descriptive sensory analysis, or consumer sensory analysis. Data were analyzed as a split-plot in which carcass served as the whole plot and loin portion served as the subplot. An alpha of P < 0.05 was used. For descriptive sensory analysis, an interaction was observed for beef identity, bloody/serumy, fat-like, liver-like, bitter, sour, and musty/earthy (P < 0.05). Loins aged for 56 d at 4°C were the most intense for liver-like, sour, and musty/earthy notes compared with all other treatments (P < 0.05). An interaction was observed for consumer juiciness, tenderness, and overall liking (P < 0.05). Steaks from loins aged for 14 d at −2°C were rated the least for juiciness, tenderness, and overall liking (P < 0.05). Ethanol, acetic acid, 1-penten-3-ol, and 2-methylbutanal were each greatest in loins aged for 56 d (P < 0.05). Aging at 4°C yielded the greatest concentrations of ethanol and heptanoic acid (P < 0.05). Off-flavor development increased during extended aging but was dependent on storage temperature. Extended aging (>28 d) conducted at colder temperatures did not negatively influence palatability. Aging for 14 d at −2°C was detrimental to consumer liking. It may be concluded that both aging temperature and duration should be considered when seeking to optimize beef palatability.Item Post-harvest influences on beef flavor development and tenderness(2020-05) Vierck, Kelly R.; Legako, Jerrad F.; Brooks, J. Chance; Miller, Markus F.; Wheeler, Tommy L.; Woerner, Dale R.The objective of these studies was to determine: the influence of dry-heat cookery method on beef flavor development in two USDA quality grades following sous vide preparation; the influence of dry heat cookery on beef flavor development of multiple beef muscles; the influence of package and muscle type on postmortem proteolysis and subsequent release of flavor contributing free-amino acids during storage and distribution. In study 1, there were no cooking method × quality grade interactions (P ≥ 0.076) for all consumer traits evaluated. Overall, salamander cooked (SALA) steaks were preferred (P < 0.05) by consumers over clamshell (CLAM) steaks for all palatability traits. Oven steaks had greater liking scores (P < 0.05) than CLAM steaks for juiciness, tenderness, and overall liking but were similar to CLAM steaks (P > 0.05) for flavor. Charbroiler (CHAR) steaks were similar (P > 0.05) to CLAM steaks for flavor but were preferred (P < 0.05) for tenderness, juiciness, and overall liking. Steaks cooked using the OVEN method produced a greater concentration of lipid derived volatiles, such as alcohols, aldehydes, and carboxylic acids. In direct contrast, CHAR steaks produced a higher concentration of pyrazines and Strecker aldehydes, which are derived from the Maillard reaction. In study 2, no interactions were observed between cooking method and muscle (P ≥ 0.344) for any palatability traits evaluated. Consumers preferred CHAR steaks (P < 0.05) to CLAM steaks for flavor, tenderness, juiciness, and overall liking. Additionally, CLAM steaks were rated lower (P < 0.05) than all other methods for tenderness and juiciness. Oven (OVEN) and SALA steaks were rated higher (P < 0.05) than CLAM steaks by consumers for tenderness and juiciness but were similar (P > 0.05) to CLAM steaks for overall liking. Charbroiler steaks produced a greater concentration of Maillard compounds, including Strecker aldehydes, pyrazines, and sulfur-containing compounds compared to the other cooking methods. Steaks cooked using OVEN and SALA (P < 0.05) produced more lipid oxidation products, including carboxylic acids and esters. Additionally, CHAR steaks produced the greatest (P < 0.05) total volatiles compared to all other treatments, which may be a result of the combination of Maillard reaction products and the lipid degradation products. In study 3, high oxygen (HIOX) steaks exhibited (P < 0.05) the highest Warner-Bratzler shear force values, lowest desmin degradation rate (P < 0.05), and the highest ratings for fishy, bitter, sour, and oxidized flavors, the lowest overall tenderness scores (P < 0.05), and, in general, produced the lowest amount of free amino acids (P < 0.05) compared to all other treatments. Contrastingly, rollstock (ROLL) packaging produced the highest ratings for beef flavor identity, brown/roasted, bloody/serumy, and umami flavors (P < 0.05). Additionally, ROLL packaging exhibited (P < 0.05) greater desmin degradation in comparison to HIOX steaks. Beef flavor development and tenderness are readily impacted by dry heat cookery method and packaging types. Sous vide cooking could minimize the effects between USDA quality grades. Steaks should not be cooked using a clamshell grill or packaged in a high oxygen environment to provide the optimum combination of flavor and tenderness.Item Salmonella in peripheral lymph nodes of healthy cattle at Slaughter(2017) Webb, Hattie E. (TTU); Brichta-Harhay, Dayna M.; Brashears, Mindy M. (TTU); Nightingale, Kendra K. (TTU); Arthur, Terrance M.; Bosilevac, Joseph M.; Kalchayanand, Norasak; Schmidt, John W.; Wang, Rong; Granier, Sophie A.; Brown, Tyson R.; Edrington, Thomas S.; Shackelford, Steven D.; Wheeler, Tommy L.; Loneragan, Guy H. (TTU)To more fully characterize the burden of Salmonella enterica in bovine peripheral lymph nodes (PLN), PLN (n = 5,450) were collected from healthy cattle at slaughter in 12 commercial abattoirs that slaughtered feedlot-fattened (FF) cattle exclusively (n = 7), cattle removed (or culled) from breeding herds (n = 3), or both FF and cull cattle (n = 2). Qualitative and quantitative methods were used to estimate prevalence and concentration of Salmonella in PLN. Isolates were subjected to a variety of phenotypic, serological, and molecular assays. Overall, Salmonella prevalence in PLN from FF and cull cattle was 7.1 and 1.8%. However, burden varied by season in that observed prevalence in PLN collected in cooler or warmer seasons was 2.4 and 8.2%, respectively. Prevalence in PLN from cull cattle in the southwest region of the US was 2.1 and 1.1% for cool and warm seasons, respectively; however, prevalence in FF PLN was far greater in that it was 6.5 and 31.1%, respectively. Salmonella was recovered from 289 (5.6%) PLN and 2.9% (n = 160) of all PLN tested had quantifiable concentrations that varied from 1.6 to 4.9 log10 colony forming units/PLN. The most common serotypes isolated from PLN were Montevideo (26.9%), Lille (14.9%), Cerro (13.0%), Anatum (12.8%), and Dublin (6.9%). In all, 376 unique isolates were collected from the 289 Salmonella-positive PLN. Antimicrobial susceptibility testing revealed the majority (80.6%) of these isolates were pansusceptible; however, 10.7% of isolates were found to be resistant to two or more antimicrobial classes. We were able to document an observed increased in prevalence of Salmonella in PLN during the warmer season, particularly in FF cattle from the southwest region of the US. The mechanisms underlying the observed association between season, region, and production source have yet to be elucidated. Nevertheless, these findings increase our understanding of the sources of contamination of beef products and shed light on transmission dynamics that may be useful in targeting these sources.