Location: Meat Safety and Quality
2020 Annual Report
Objectives
Objective 1: Develop strategies to manage and improve variation in meat quality, composition, and healthfulness traits.
Sub-objective 1.A: Identification of genetic markers for myoglobin content of pork muscles to increase redness of pork products.
Sub-objective 1.B: Estimate effects of three maternal lines and two mating systems on lamb carcass merit.
Sub-objective 1.C: Genomic control of dark cutting and other beef quality traits.
Sub-objective 1.D: Genomic control of pork fat quality and fatty acid profile.
Sub-objective 1.E: Identify and validate novel single-nucleotide polymorphisms (SNP) for beef lean color stability.
Sub-objective 1.F: Determine the effect of VQG' pork loin grading camera tenderness class on optimal aging time of boneless pork loins.
Sub-objective 1.G: Impact of backgrounding strategies on beef carcass merit.
Sub-objective 1.H: To determine the effects of replacing tylosin phosphate (Tylan®) with an essential oil containing limonene in the diet of finishing beef cattle on carcass characteristics.
Objective 2: Characterize biological variation in meat quality, composition, and healthfulness traits.
Sub-objective 2.A: Determine the impact of sire line on the meat quality defect characterized by a band of very pale, almost white, muscle tissue on the superficial portion of ham muscles (halo).
Sub-objective 2.B: Characterize the effect of muscle metabolic efficiency, particularly in mitochondrial efficiency on beef tenderness and lean color stability attributes across varying pH classes in beef carcasses exhibiting normal lean color.
Sub-objective 2.C: Determine if there are metabolomic differences between tender and tough beef across postmortem aging times.
Sub-objective 2.D: Identification of differentially expressed proteins in beef longissimus steaks classified as tender with stable lean color during simulated retail display compared to steaks classified as tough with labile lean color during simulated retail display.
Sub-objective 2.E: Develop technologies for measuring and predicting important traits relating to meat product quality and consistency and the biological mechanisms that control these traits.
Approach
The overall goal of this project is to develop approaches to improve quality and healthfulness while reducing the variation in meat products. This will be accomplished by providing the red meat industries with the information and tools necessary to facilitate equitable valuation of carcasses and meat, improve the quality and consistency of meat, and optimize carcass and meat composition of beef, pork, and lamb. The two objectives of this project address needs in improving consistency of quality, composition, and healthfulness of red meat products by developing strategies and instrumentation to manage and improve these traits using basic and applied research approaches. Genetic and genomic strategies will be developed that may be combined with animal and meat management strategies to optimize quality and composition traits. Research will be conducted using proteomics and other biochemical tools to characterize variation in quality and composition as well as to evaluate and facilitate implementation of instrumentation for measuring or predicting value determining traits such as carcass grade traits, tenderness, lean color stability, and fat quality.
Progress Report
Under Objective 1. Interaction of beef dark cutting genotype and implant strategy on lean color. Current data indicate that both genomic variation and implant strategy impact lean color and the percentage of carcasses with dark lean color. Work is ongoing to assess the interaction of these factors. Preliminary analyses suggest that the impact of implant strategies is greatest for cattle that are genetically predisposed to produce dark colored lean.
Under Objective 2. Lean color is the primary factor considered by consumers when making beef purchasing decisions, and products that lose their bright red color during retail display are often discarded. Thus, insufficient color-life is a large source of food waste. Tenderness is the primary driver determining beef customer satisfaction. These two economically important meat quality traits are generally considered separately in experiments. However, recent results indicate that variation in energy producing systems exists that beneficially affect both traits. Moreover, previous research indicates that beef flavor is impacted by similar variation in energy production. We have initiated an experiment to determine the influence of the “fingerprint” of small molecules within beef samples (metabolic profile) on these three traits. Beef carcasses have been selected to represent predicted tenderness and color stability classes (i.e. tender-stable, tender-labile, tough-stable, and tough-labile). Strip loins were obtained from each carcass and stored for either 12 or 26 days in refrigeration. Aged steaks were cut from each strip loin and used to quantify lean color stability, tenderness, or trained sensory panel flavor ratings. Moreover, component traits describing mechanisms regulating variation in these traits as well as metabolic biomarkers previously identified to be predictive of these traits are being measured. Analysis of these data is in progress. These results will be independent validation of previous metabolic fingerprinting experiments. Also, these results, will allow selection of samples to represent the most extreme combinations of tenderness, flavor, and color stability for metabolic profiling. The metabolic profiles of these groups will be contrasted to identify metabolites contributing to these important meat quality traits.
Under Objective 2. Objective measurement of meat tenderness. Slice shear force is a rapid method of tenderness measurement that allows for greater throughput than the traditional Warner-Bratzler shear force method. For some muscles, slice shear force procedures have required knowledge of whether the muscle originated from the left or right side of the carcass. To overcome this problem, methods were developed for sampling perpendicular to the cut surface of the steak rather than parallel to the muscle fiber orientation. A concern was that when a similar approach was attempted with Warner-Bratzler shear force, sampling perpendicular to the cut surface of the steak resulted in a substantial reduction in the mean shear force value and the repeatability of shear force. Preliminary data indicate that for slice shear force, sampling perpendicular to the cut surface of the steak allowed sampling up to 6 slices per steak with improved repeatability and little effect on mean slice shear force values.
Accomplishments
1. Classification of beef carcasses for top sirloin tenderness. The recent development of tenderness claims certification standards has given the beef industry added impetus to implement a tenderness-based marketing system. For retailers to effectively execute a tenderness-based marketing strategy, retailers need to be able to market all loin and rib cuts from a qualifying carcass as certified tender. Yet, at present, the certification protocols do not favor inclusion of top sirloins, which represent a substantial retail meat cut feature. USDA-ARS scientists in Clay Center, Nebraska, determined that tenderness classes based on the VBG2000 beef grading camera allowed for identification of carcasses with more favorable top sirloin tenderness. This work showed that tenderness testing with the beef grading camera in combination with refrigerated aging for 28 days can be used to produce consistently tender top sirloin steaks that qualify for a guaranteed tender marketing claim. This potentially could lead to over $18,000,000 of added annual revenue for the U.S. beef industry.
2. Improving meat tenderness and lean color simultaneously. Premature color change resulting in loss of bright red color of beef products during retail display results in those products being discarded, causing significant food waste. Beef tenderness is the primary driver of consumer satisfaction in beef products. Thus, both traits have been extensively studied but are generally thought to be unrelated by scientists. However, USDA-ARS scientists at Clay Center, Nebraska, identified some commonalities in the molecular fingerprints associated with favorable outcomes for both traits. Currently, 10% of retail beef products are discounted and 5% are discarded, costing the industry greater than $1 billion, annually. Meanwhile insufficient tenderness reduces repeat purchases. These findings should lead to strategies to improve both tenderness and color stability to mitigate food waste and improve consumer satisfaction with beef adding millions of dollars in revenue to the U.S. beef industry.
3. New measure of meat tenderness. Tenderness is a primary driver of customer satisfaction of beef products. However, despite substantial research efforts, a large portion of the variation in tenderness cannot be explained by known factors influencing tenderness. USDA-ARS scientists in Clay Center, Nebraska, validated a new approach to measuring protein degradation that is a primary determinant of meat tenderness. This methodology provides scientists with an improved tool to identify animals that produce more tender meat and better understand the biology controlling meat tenderness. A better understanding of variation in meat tenderness could lead to the ability to guarantee meat tenderness which will improve consumer satisfaction and demand for beef products and add millions of dollars in revenue to the U.S. beef industry.
Review Publications
Rice, E.A., Lerner, A.B., Olson, B.A., Prill, L.L., Drey, L.N., Price, H.E., Lowell, J.E., Harsh, B.N., Barkley, K.E., Honegger, L.T., Richardson, E., Woodworth, J.C., Gonzalez, J.M., Tokach, M.,D. DeRouchey, J.M., Dritz, S.S., Goodband, R.D., Allerson, M.W., Fields, B., Shackelford, S.D., King, D.A., Wheeler, T.L., Dilger, A.C., Boler, D.B., O'Quinn, T.G. 2019. Effects of increased pork hot carcass weights. II: Loin quality characteristics and palatability ratings. Meat and Muscle Biology. 3(1):447-456. https://doi.org/10.22175/mmb2019.07.0027.
Rice, E.A., Lerner, A.B., Olson, B.A., Prill, L.L., Drey, L.N., Price, H.E., Lowell, J.E., Harsh, B.N., Barkley, K.E., Honegger, L.T., Richardson, E., Woodworth, J.C., Gonzalez, J.M., Tokach, M.D., DeRouchey, J.M., Dritz, S.S., Goodband, R.D., Allerson, M.W., Fields, B., Shackelford, S.D., King, D.A., Wheeler, T.L., Dilger, A.C., Boler, D.D., O'Quinn, T.D. 2019. Effects of increased pork hot carcass weights. 1: Chop thickness impact on consumer visual ratings. Meat and Muscle Biology. 3(1):433-446. https://doi.org/10.22175/mmb2019.07.0026.
Overholt, M.F., Arkfeld, E.K., Bryan, E.E., King, D.A., Wheeler, T.L., Dilger, A.C., Shackelford, S.D., Boler, D.D. 2019. Effect of hot carcass weight on the rate of temperature decline of pork hams and loins in a blast-chilled commercial abattoir. Journal of Animal Science. 97(6):2441-2449. https://doi.org/10.1093/jas/skz131.
Price, H.E., Lerner, A.B., Rice, E.A., Lowell, J.E., Harsh, B.N., Barkley, K.E., Honegger, L.T., Richardson, E., Woodworth, J.C., Tokach, M.D., Dritz, S.S., Goodband, R.D., DeRouchey, J.M., O'Quinn, T.G., Allerson, M.W., Fields, B., King, D.A., Wheeler, T.L., Shackelford, S.D., Dilger, A.C., Boler, D.D. 2019. Characterizing ham and loin quality as hot carcass weight increases to an average of 119 kilograms. Meat and Muscle Biology. 3(1):330-343. https://doi.org/10.22175/mmb2019.06.0019.
Gredell, D.A., Schroeder, A.R., Belk, K.E., Broeckling, C.D., Heuberger, A.L., Kim, S., King, D.A., Shackelford, S.D., Sharp, J.L., Wheeler, T.L., Woerner, D.R., Prenni, J.E. 2019. Comparison of machine learning algorithms for predictive modeling of beef attributes using rapid evaporative ionization mass spectrometry (REIMS) data. Scientific Reports. 9:5721. https://doi.org/10.1038/s41598-019-40927-6.
Schulte, M.D., Johnson, L.G., Zuber, E.A., Steadham, E.M., King, D.A., Huff-Lonergan, E., Lonergan, S.M. 2020. Investigation of the sarcoplasmic proteome contribution to the development of pork loin tenderness. Meat and Muscle Biology. 4(1):8, 1-14. https://doi.org/10.22175/mmb.9566.
