Using measurements of muscle color, pH, and electrical impedance to augment the current USDA beef quality grading standards and improve the accuracy and precision of sorting carcasses into palatability groups.

Abstract

This research was conducted to determine whether objective measures of muscle color, muscle pH, and(or) electrical impedance are useful in segregating palatable beef from unpalatable beef, and to determine whether the current USDA quality grading standards for beef carcasses could be revised to improve their effectiveness at distinguishing palatable from unpalatable beef. One hundred beef carcasses were selected from packing plants in Texas, Illinois, and Ohio to represent the full range of muscle color observed in the U.S. beef carcass population. Steaks from these 100 carcasses were used to determine shear force on eight cooked beef muscles and taste panel ratings on three cooked beef muscles. It was discovered that the darkest-colored 20 to 25% of the beef carcasses sampled were less palatable and considerably less consistent than the other 75 to 80% sampled. Marbling score, by itself, explained 12% of the variation in beef palatability; hump height, by itself, explained 8% of the variation in beef palatability; measures of muscle color or pH, by themselves, explained 15 to 23% of the variation in beef palatability. When combined together, marbling score, hump height, and some measure of muscle color or pH explained 36 to 46% of the variation in beef palatability. Alternative quality grading systems were proposed to improve the accuracy and precision of sorting carcasses into palatability groups. The two proposed grading systems decreased palatability variation by 29% and 39%, respectively, within the Choice grade and decreased palatability variation by 37% and 12%, respectively, within the Select grade, when compared with current USDA standards. The percentage of unpalatable Choice carcasses was reduced from 14% under the current USDA grading standards to 4% and 1%, respectively, for the two proposed systems. The percentage of unpalatable Select carcasses was reduced from 36% under the current USDA standards to 7% and 29%, respectively, for the proposed systems. These grading systems, which included requirements for maturity, marbling, hump height, and colorimeter readings, could be implemented into the current USDA beef quality grading standards and improve the accuracy and precision of sorting beef carcasses into palatability groups. At the least, measurements of muscle color or pH could be used in a branded-beef program to increase the palatability consistency of its beef products.

Genetic and phenotypic characterisation of animal, carcass, and meat quality traits from temperate and tropically adapted beef breeds. 3. Meat quality traits

“…If single-trait selection was practiced, theoretically, the accuracy of direct selection on LTL_TEND would be 0.56 compared with the indirect single-trait selection on LTL_SF, LTL_L*, and LTL_a*, which would be 0.43, 0.23 and 0.08, respectively. No other literature estimates were found for these genetic relationships; however, several studies have reported similar phenotypic or residual correlations between shear force and L* colour (Dubeski et al 1997;Wulf et al 1997;Wulf and Page 2000). Correlations between cooking loss % and other traits varied between TEMP and TROP.…”

Instrumental meat quality characteristics associated with aged m. longissimus thoracis from the four Canadian beef quality grades

“…Steaks from Canada AA carcasses, however, with a mean WBSF value of about 4.0 kg when converted from Newtons to kg (1 kg = 9.8066 N) would be considered unacceptably tough if measured against the tenderness thresholds of 34 N (3.5 kg) of Wulf et al (1998) or the 37.95 N (3.87 kg) of Rodas-González et al (2009).…”

A review of the development and use of video image analysis (VIA) for beef carcass evaluation as an alternative to the current EUROP system and other subjective systems

“…Several studies have investigated how VIA can supplement the visual USDA carcass grading system for assignment of yield grade, (Belk, Scanga, Tatum, Wise, & Smith, 1998;Cannell et al, 1999Cannell et al, , 2002Steiner et al, 2003;Wulf & Page, 2000;Wyle et al, 2003) and quality grade (Wulf & Page, 2000;Wyle et al, 2003). Some of these integrated approaches have resulted in commercial developments as outlined in Section 3.5.…”