Submitted to: American Meat Science Association Conference Reciprocal Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: 5/10/2010
Publication Date: 6/20/2010
Citation: King, D.A., Shackelford, S.D., Wheeler, T.L. 2010. Use of VIS/NIR Spectroscopy to Predict Beef Lean Color Stability [abstract]. Proceedings Reciprocal Meat Conference. 63:62.
Technical Abstract: Technology to identify carcasses producing cuts with insufficient color-life for case-ready programs would be a benefit to beef processors and retailers. To evaluate visible and near-infrared (VIS/NIR) spectroscopy as a means for segregating carcasses based on beef longissimus color-life, spectra (350 to 1050 nm) were collected on the exposed ribeye of carcasses (n=464) as they were presented for grading. Ribeye rolls were obtained from each carcass and aged until 18 d postmortem, when a 2.54-cm steak was removed and placed in simulated retail display. Instrumental color values [CIE L*, a*, b*, hue angle, and overall color change (delta E)] were determined on the longissimus muscle on d 0 and 6 of display. Partial least squares regression was used to develop models using VIS/NIR spectra to predict a principal component (PC1) explaining 48% of the variance of d 0 and 6 color variables, which was strongly associated with color change. The resulting model was applied to spectra collected on an independent sample of carcasses (n=100) as they were presented for grading. Carcasses were segregated into two color stability groups based on the predicted PC1 values. Strip loins were collected and aged for 14 d before a 2.54-cm steak was placed in simulated retail display. Color space values were collected on d 0, 1, 3, 6, and 9 of display. Steaks classified as stable had higher L* values on d 0 (43.4) than those classified as labile (42.6). In steaks classified as stable, L* values decreased (P < 0.05) between d 0 and 1 (43.4 vs. 42.9) and between d 6 and 9 (42.4 vs. 40.3), whereas L* values of steaks classified as labile decreased (P < 0.05) progressively between d 1 and 9 (42.0, 41.3, 40.5, and 39.3 on d 1, 3, 6, and 9, respectively). Values for a* were higher (P < 0.05) for steaks classified as labile than steaks classified as stable on d 0 (34.1 vs. 31.5) and 1 (33.7 vs. 32.5), but also declined more rapidly so that on d 9 labile steaks had lower (P < 0.05) a* values than steaks classified as stable (21.3 vs. 17.9). Yellowness (b*) values were higher (P < 0.05) in steaks classified as labile than in steaks classified as stable on d 0 (27.6 vs. 25.3) and 1 (28.2 vs. 26.9). No differences in b* were detected between stability classifications on d 3, 6, or 9. Conversely, hue angle did not differ between stability classifications on d 0, 1, 3, or 6, but steaks classified as labile had higher (P < 0.05) hue angle values on d 9 of display. Overall color change differed (P < 0.05) between color stability classes such that steaks classified as labile had progressively greater delta E values than steaks classified as stable on d 3 (4.7 vs. 3.6), 6 (9.5 vs. 6.9), and 9 (17.8 vs. 12.4) of display. These results indicate that VIS/NIR spectroscopy can be utilized to sort beef carcasses based on longissimus color stability.