Background 

Several beef industry entities are considering tenderness-based marketing strategies, which have the potential of increasing beef consumption. The recent development of tenderness claims standards by ASTM and USDA-AMS has given the 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 as certified tender. Yet, at present the ASTM and USDA-AMS protocols do not favor inclusion of top sirloins, which represent a substantial retail meat cut feature. We have determined that some quality grade programs excel in top sirloin tenderness. However, in some cases top sirloin don’t have acceptable tenderness. The ASTM F10 committee has sought additional information regarding shear force values for the GM to make a decision if it could be guaranteed tender based on LD measurements. We have determined that classification of carcasses for tenderness based on prediction with the VBG2000 beef carcass grading camera allows for identification of carcasses with more consistent longissimus (strip loin) tenderness. If VBG2000 allows for identification of carcasses with consistently tender top sirloins, this would greatly facilitate tenderness-based marketing strategies.

The objective of this study was to determine the effects of quality grade program, VBG tenderness class and postmortem refrigerated aging period and the interaction of those factors on slice shear force (SSF) to determine the appropriate specifications for tenderness claims of beef top sirloin.

Methodology 

On each of four selection days in two large-scale commercial fed-beef packing plants, carcasses were evaluated on-line with the beef carcass grading camera. Overall, 56 carcasses that were certified by USDA for a premium Choice program, 56 commodity Choice carcasses that were predicted tender by the grading camera, 56 commodity Choice carcasses that were not predicted tender by the grading camera, 56 commodity Select carcasses that were predicted tender by the grading camera, and 56 commodity Choice Select that were not predicted tender by the grading camera were sampled for this study. The 184 Beef Top Sirloin and the 180 Beef Strip Loin were obtained from the left side of each of the 280 selected carcasses. Cuts were aged and slice shear force, which is an instrumental measurement of tenderness was measured after 14, 28, and 42 d of aging. Sensory panel was conducted after 14 d of aging.

Findings

Top loin steaks from commodity USDA Choice and commodity USDA Select carcasses predicted tender by the VBG2000 beef carcass grading camera had lower mean SSF values at 14 (P < 0.05), 28 (P < 0.01), and 42 (P < 0.01) d postmortem compared to steaks from carcasses not predicted tender. Center-cut top sirloin steaks from commodity USDA Choice and commodity USDA Select carcasses predicted tender by the VBG2000 beef carcass grading camera had lower mean SSF values at 14 (P < 0.01) and 28 (P < 0.05) d postmortem compared to steaks from carcasses not predicted tender. By 42 d postmortem, GM steaks from carcasses not predicted tender had tenderized enough that they no longer had higher SSF than steaks from carcasses predicted tender by VBG2000. Top sirloin cap steaks from carcasses predicted tender had lower SSF at 14 d postmortem, which was the only aging period tested for that muscle.

implications

These data support the concept of using VBG2000 grading camera predicted slice shear force to identify carcasses that produce cuts that excel in tenderness. Top sirloin steaks are central to retail beef marketing. Use of the grading camera to identify carcasses that will consistently produce tender center-cut top sirloin steaks (gluteus medius) will benefit the longevity of such efforts. This will also require aging specifications. The present work suggests that 28 d of postmortem storage in combination with tenderness prediction is needed to consistently produce tender top sirloin steaks. While the present work is encouraging for top sirloin cap steaks, additional work is needed to determine if aging in combination with tenderness prediction will allow for consistent control of top sirloin cap steak tenderness.