Beef of Nellore cattle has limited tenderization despite pH decline in Longissimus lumborum

Abstract

Bos taurus indicus temperament is variable and affects beef tenderization. Our objective was to investigate temperament and performance of non-castrated Nellore and identify groups based on Longissimus lumborum (LL) pH decline as well as beef characteristics produced by those groups. We investigated 94 animals with a subset of carcasses (n = 24) selected based on LL pH at 24 h postmortem (pm) to represent two groups: resistant to pH decline (> 5.8 called pH-Res; n = 10) and normal (< 5.7 called pH-Nor; n = 14). Steaks were fabricated from the LL muscle and randomly assigned to aging (2, 7, 14, and 21 days). Sarcomere length, cooking loss, myofibrillar fragmentation index (MFI), and Warner-Bratzler shear force (WBSF) were determined.Data on temperament were investigated in a multivariate approach, while beef data were compared between groups using the analysis of variance. Rectal temperature at the beginning of the finishing phase and total weight gain were greater and related to animals in the pH-Res group (p < 0.01 and p = 0.03, respectively). Temperature and pH decline curves, sarcomere length, and cooking loss revealed that pH-Res produced beef with lower quality compared to the pH-Nor group. Results for MFI and WBSF did not show differences between groups within each time pm; however, overall steaks from pH-Res were tougher (p = 0.06). Incidence of LL pH between 5.8 and 5.9 at 24 h pm did not compromise the tenderization rate or extension; however, it affected the water holding capacity in this population of Nellore cattle.

Improvement of Color and Oxidative Stabilities in Nellore Bull Dark Meat in High-Oxygen Package by Lactate and Rosemary Oil Extract

“…The combination of Bos taurus indicus bulls’ irritable behavior [ 5 ], greater muscle oxidative efficiency and pH drop resistance [ 6 ], and grass finishing diet may result in lower muscle glycogen content and increased oxidative metabolism [ 7 ]. These factors contribute to limiting the postmortem pH drop to a normal range of 5.4–5.8 and then producing a greater-than-normal pH u (ultimate pH), which affects meat color development [ 8 , 9 ].…”