Beef of Nellore cattle has limited tenderization despite pH decline in Longissimus lumborum
Ramos, Patricia MalosoSantos-Donado, Priscila Robertina dosOliveira, Giuliana Micai deContrerasCastillo, Carmen JosefinaScheffler, Tracy L.Silva, Saulo da Luz eMartello, Luciane SilvaDelgado, Eduardo Francisquine
ABSTRACT: Bos taurus indicus temperament is variable and affects beef tenderization. Our objective was to investigate temperament and performance of noncastrated 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 pHRes; n = 10) and normal ( 5.7 called pHNor; 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 WarnerBratzler 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 pHRes group (p 0.01 and p = 0.03, respectively). Temperature and pH decline curves, sarcomere length, and cooking loss revealed that pHRes produced beef with lower quality compared to the pHNor group. Results for MFI and WBSF did not show differences between groups within each time pm; however, overall steaks from pHRes 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.
Texto completo