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ARS Home » Research » Publications at this Location » Publication #78633


item Shackelford, Steven
item Wheeler, Tommy
item Koohmaraie, Mohammad

Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 4/25/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The objective was to develop a system for automated tenderness classification of beef and determine the efficacy of that system. At the time carcasses are normally ribbed for determination of quality and yield grade, a 2.54-cm thick rib steak is removed from the 12th rib region of the right side of each carcass. The steak is trimmed of fat and bone and the longissimus is rapidly (7.33 min) cooked to an internal temperature of 70 deg C. A 5-cm long, 1-cm thick slice is removed from the cooked steak parallel to the muscle fibers. The slice is sheared by a flat, blunt-end blade attached to an electronic testing machine and the slice shear force (SSF) value is determined. The process is completed during the 10 min that the ribeye blooms for quality grading. Thus, tenderness classification does not interfere with production rates. The repeatability of tenderness classification was .89 (n = 204). Tenderness classification conducted at 3 d postmortem on A-maturity carcasses (n = 131) predicted with 95% accuracy whether or not a given sample would be "Tender" (standard Warner-Bratzler shear force < 5 kg) at 14 d postmortem. Carcasses were classified into three groups based on SSF (< 23, 23 to 40, and > 40 kg) at 3 d postmortem which differed greatly (P < .001) in mean Warner-Bratzler shear force (3.4, 4.1, and 6.8 kg) and the percentage (100, 88, and 0%) of "Tender" samples at 14 d postmortem. Thus, tenderness classification could be used to accurately segregate beef carcasses into expected palatability groups.