Effect of postmortem pH on the physical, biochemical, and sensory characteristics of bovine longissimus thoracis et lumborum muscle

Abstract

From a large feeding trial study consisting of 299 bulls and steers, 15 carcasses exhibited stress‐related syndromes manifested by atypical color and pH which were then selected for subsequent analysis. Samples of longissimus thoracis et lumborum muscle with postmortem pH in the range of 5.5–6.9 were subjected to a 14‐day aging period at 2°C. Sensory panel tenderness, connective tissue, juiciness, and flavor intensity of high pH (6.4–6.9) meat were significantly different (p < .05) from samples of intermediate pH (6.0–6.1) as well as normal pH (5.5). Muscles at pH 6.0–6.1 were the toughest samples. This was confirmed by Warner–Bratzler shear force (WBSF), residual force, and myofibril fragmentation index. Palatability attributes of normal pH (5.5) samples were significantly different (p < .05) from dark‐cutting beef in terms of tenderness and flavor and at the high pH extreme. The increase in WBSF at pH 6.0–6.1, lack of extensive degradation of muscle proteins, and the decreased sarcomere length resulted in tougher meat than low or high pH muscles. Sodium dodecyl‐sulfate polyacrylamide gel electrophoresis of meat at the high pH extreme (6.7–6.9) revealed that the breakdown of troponin‐T to 30 kD was complete while at intermediate pH (6.0–6.1) was incomplete. In addition, the appearance of a ‘doublet’ on high‐molecular‐weight resolution gels may also account for the greater tenderness experienced by sensory panelists.

Quality and safety of pork meat after cooling and treatment with lactic starters

“…The cooling rate of pork carcasses impacts the meat's sensory properties [25], [26]. The rapid decrease of the core temperature of the meat determines the intensity of post-slaughter metabolism [27] and the formation of volatile and non-volatile compounds in it, which create the aroma of the final product and its appeal to the consumer [28].…”

Integrated Analysis of Transcriptome and Metabolome Profiles in the Longissimus Dorsi Muscle of Buffalo and Cattle

“…Furthermore, muscles with a low pH have more light scattering, which can explain the observed high lightness in this study. Meanwhile, the concentration of myoglobin and the content of deoxymyoglobin are also important factors that affect the color of meat [28,29]. In summary, genes and metabolites in the niacin and niacinamide metabolism pathway likely play important regulatory roles in meat color differences between Xinglong buffalo and Hainan cattle.…”