Effects of postmortem aging and USDA quality grade on Warner-Bratzler shear force values of seventeen individual beef muscles

• Published in: Journal of animal science 2006-12, Vol.84 (12), p.3387-3396
• Main Authors: Gruber, S.L, Tatum, J.D, Scanga, J.A, Chapman, P.L, Smith, G.C, Belk, K.E
• Format: Article
• Language: English
• Subjects: Animal productions; Animals; beef; beef quality; Biological and medical sciences; Cattle; cold storage; Food Handling - methods; Food industries; Fundamental and applied biological sciences. Psychology; Meat - standards; meat aging; Meat and meat product industries; meat carcasses; meat grades; meat tenderness; Muscle, Skeletal; muscles; regression analysis; steaks; Terrestrial animal productions; Time Factors; United States; United States Department of Agriculture - standards; Vertebrates; Warner-Bratzler shear force values
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/jas.2006-194

Forty USDA Select and 40 upper two-thirds USDA Choice beef carcasses were used to determine the effects of postmortem aging on tenderness of 17 individual beef muscles. Biceps femoris--long head, complexus, gluteus medius, infraspinatus, longissimus dorsi, psoas major, rectus femoris, semimembranosus, semitendinosus, serratus ventralis, spinalis dorsi, supraspinatus, tensor fasciae latae, teres major, triceps brachii--long head, vastus lateralis, and vastus medialis muscles were removed from each carcass. Seven steaks (2.54-cm thick) were cut from every muscle, and each steak was assigned to one of the following postmortem aging periods: 2, 4, 6, 10, 14, 21, or 28 d postmortem. After completion of the designated aging period, steaks were removed from storage (2°C, never frozen), cooked to a peak internal temperature of 71°C, and evaluated using Warner-Bratzler shear force (WBSF). Analysis of WBSF revealed a 3-way interaction (P = 0.004) among individual muscle, USDA quality grade, and postmortem aging period. With the exception of the Select teres major, WBSF of all muscles (both quality grades) decreased with increasing time of postmortem storage. Nonlinear regression was used to characterize the extent (aging response) and rate of decrease in WBSF from 2 through 28 d postmortem for each muscle within each quality grade. In general, WBSF of upper two-thirds Choice muscles decreased more rapidly from 2 to 10 d postmortem than did corresponding Select muscles. Muscles that had greater aging responses generally had greater 2-d WBSF values. The upper two-thirds Choice psoas major, serratus ventralis, and vastus lateralis muscles required similar aging times to complete a majority of the aging response (=7 d longer than those for corresponding upper two-thirds Choice muscles. Results from this study suggest that muscle-to-muscle tenderness differences depend on quality grade and aging time and that postmortem aging should be managed with respect to individual muscle and USDA quality grade.