Submitted to: Journal of Animal Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/27/2011
Publication Date: 2/21/2012
Citation: Shackelford, S.D., Wheeler, T.L., Koohmaraie, M. 2012. Validation of a model for on-line classification of U.S. Select beef carcasses for longissimus tenderness using visible and near-infrared reflectance spectroscopy. Journal of Animal Science. 90:973-977. Interpretive Summary: U.S. Select cuts are currently marketed at a discount relative to U.S. Choice cuts despite the fact that many cuts from U.S. Select carcasses are very tender. Consumers have shown a strong willingness to pay a premium for "Tender Select" cuts that combine superior tenderness with the leanness of Select. Therefore, meat retailers have expressed strong interest in marketing a "Tender Select" product line. Thus, there was a need to develop a non-invasive method to accurately identify U.S. Select carcasses that excel in meat tenderness. We developed a highly-repeatable method for on-line evaluation of ribeye quality traits of beef carcasses and determined that the system was capable of predicting beef tenderness. The current experiment was conducted to validate a statistical model for on-line application of this technology to U.S. Select carcasses during commercial beef carcass grading procedures to predict how tender ribeye steaks from a carcass would be after 14 days of refrigerated storage. The present data supports our previous work showing that visible and near-infrared spectroscopy can be used to non-invasively classify U.S. Select carcasses for ribeye tenderness and establishes that this technology could also be applied to aged U.S. Select loins. This technology would allow packing companies and other segments of the beef marketing chain to identify U.S. Select carcasses or loins that excel in loin tenderness for use in branded beef programs.
Technical Abstract: The present experiment was conducted to provide a validation of a previously developed model for on-line classification of U.S. Select carcasses for LM tenderness based on visible and near-infrared (VISNIR) spectroscopy and to determine if the accuracy of VISNIR-based tenderness classification could be enhanced by making measurements after postmortem aging. Spectroscopy was conducted on-line, during carcass grading, at a large-scale commercial fed-beef processing facility and the strip loin was obtained from the left side of U.S. Select carcasses (n = 467). Slice shear force (SSF) was measured on fresh steaks at 2 and 14 d postmortem. On-line VISNIR tenderness classes differed in mean SSF values at both 2 (29.4 vs. 33.6 kg) and 14 (18.0 vs. 21.2 kg) d postmortem (P < 10^-7). On-line VISNIR tenderness classes differed in both the percentage of carcasses with LM SSF values greater than 40 kg at 2 d postmortem (5.1 vs. 21.0%; P < 10^-6) and the percentage of carcasses with LM SSF values greater than 25 kg at 14 d postmortem (6.8 vs. 23.2%; P < 10^-5). Whereas 15.0% of the carcasses sampled for this experiment had LM SSF values greater than 25 kg at 14 d postmortem, only 6.8% of the carcasses classified as tender by VISNIR had LM SSF values greater than 25 kg. All of the carcasses sampled that had LM SSF values greater than 35 kg at 14 d postmortem were accurately classified as tough by VISNIR. Prior to measurement of SSF on d 14, VISNIR spectroscopy was conducted on the SSF steak. Tenderness classes based on d 14 VISNIR spectra differed both in mean SSF value at 14 d postmortem (17.7 vs. 21.6 kg; P < 10^-11) and the percentage of carcasses with LM SSF values greater than 25 kg at 14 d postmortem (7.3 vs. 22.7%; P < 10^-5). This data supports our previous work showing that VISNIR spectroscopy can be used to non-invasively classify U.S. Select carcasses for LM tenderness and establishes that this technology could also be applied to aged U.S. Select strip loins. This technology would allow packing companies and other segments of the beef marketing chain to identify U.S. Select carcasses or strip loins that excel in LM tenderness for use in branded beef programs.