Post Mortem Glycolysis in Normal and Exudative Longissimus Dorsi Muscles of the Pig in Relation to So-Called White Muscle Disease

Selenium deficiency associated porcine and human cardiomyopathies

Selenium (Se) is a trace element playing an important role in animal and human physiological homeostasis. It is a key component in selenoproteins (SeP) exerting multiple actions on endocrine, immune, inflammatory and reproductive processes. The SeP family of glutathione peroxidases (GSH-Px) inactivates peroxides and thereby maintains physiological muscle function in humans and animals. Animals with high feed conversion efficiency and substantial muscle mass have shown susceptibility to Se deficiency related diseases since nutritional requirements of the organism may not be covered. Mulberry Heart Disease (MHD) in pigs is an important manifestation of Se deficiency often implicating acute heart failure and sudden death without prior clinical signs. Post-mortem findings include hemorrhagic and pale myocardial areas accompanied by fluid accumulation in the pericardial sac and pleural cavity. Challenges in MHD are emerging in various parts of the world. Se is of fundamental importance also to human health. In the 1930s the Se deficiency associated cardiomyopathy named Keshan Disease (KD) was described for the first time in China. Various manifestations, such as cardiogenic shock, enlarged heart, congestive heart failure, and cardiac arrhythmias are common. Multifocal necrosis and fibrous replacement of myocardium are characteristic findings. Pathological findings in MD and KD show striking similarities.

Characteristics of pale, soft, exudative broiler breast meat

The objective of the study was to characterize pale breast meat, compare it with normal colored breast meat, and determine whether it should be considered pale, soft, and exudative (PSE). Characteristics of 20 normal and 20 pale broiler breasts, obtained at a commercial slaughter plant, were evaluated. Compared with normal meat, the pale breast meat had a significantly (P < 0.05) lower pH (5.7 vs. 5.9), higher color L* value (60.0 vs. 55.1), higher drip loss (1.34 vs. 0.87%), lower marinade uptake (31.2 vs. 44.3%), and lower cooking yields (95.2 vs. 105.8%). Protein solubility in pale samples was slightly (P < 0.05) lower than in normal samples, which suggests increased protein denaturation in the pale breasts. Correlations between pH and L* value (r = -0.76), pH and marinade uptake (r = 0.64), sarcoplasmic protein solubility and L* value (r = -0.71), and sarcoplasmic protein solubility and moisture uptake (r = 0.66) and cooking yield (r = 0.66) were significant (P < 0.05). Correlations between total protein solubility and moisture uptake or cooking yields were not significant. The low ultimate pH of pale breast muscle appears to be the main determinant of its low water-holding capacity (WHC). This lower pH was unrelated to a higher lactate concentration or glycolytic potential of the pale muscle. Further research is needed to determine the causes of the low pH and possible measures to increase the pH (and functionality) of pale broiler breast muscle. Because the pale breast muscle has a low WHC, it can be considered PSE.

Post-mortem glycolysis in ox skeletal muscle. Effect of temperature on the concentrations of glycolytic intermediates and cofactors

1. Post-mortem changes in the concentrations of the following compounds in ox sternomandibularis muscles stored in nitrogen at 1 degrees , 5 degrees and 15 degrees are reported: P(i) creatine phosphate, hexose monophosphates, fructose diphosphate, triose phosphates, alpha-glycerophosphate, phosphoglycerates, lactate, ATP, ADP, AMP, NAD(+) and total nucleotides. Some results obtained with muscles stored at 37 degrees are included. 2. At the time the muscles were placed at controlled temperatures (about 1.5hr. post mortem) the phosphorus in the compounds measured accounted for 91+/-6% (s.d.) of the total acid-soluble phosphate. 3. The results indicated that at all temperatures the activities of the phosphorylase and phosphofructokinase steps limited the rate and the extent of post-mortem glycolysis. 4. The large variations in hexose monophosphate concentrations during storage indicated that the ratio of phosphorylase to phosphofructokinase activity varied considerably with time and temperature. 5. Between 3.5 and 7hr. post mortem the rates of glycolysis and of ATP turnover were not slower at 5 degrees that at 15 degrees , and were probably faster at 1 degrees . The significance of this finding is discussed.