Effect of Antemortem Environmental Temperatures on Postmortem Glycolysis and Tenderness in Excised Broiler Breast Muscle

Abstract

The effects of heat stress (38"C), cold stress (4OC) and extreme cold stress (-20°C) before slaughter on the tenderness and postmortem glycolysis of the excised chicken breast muscle were studied. Heat stress significantly (p < 0.05) increased the toughness of breast muscle. Though statistically not significant, cold stress also adversely affected the tenderness. The heat-stressed birds showed higher zero hr glycogen, higher zero hr pH and significantly (p < 0.05) lower ultimate pH than the controls. The cold-stressed birds showed intermediate values in these parameters. Highly significant correlations were observed between shear value and each of these three parameters. Glycolysis rate and final moisture content were minor factors which affected the muscle tenderness to a limited extent. The slightly elevated lactatedehydrogenase and creatine phosphokinase activities in serum and breast muscle of stressed birds failed to account for any variations in tenderness.

Glycogen debranching enzyme and some other factors relating to post‐mortem pH decrease in poultry muscles

“…kg −1 muscle, which corresponds closely with the glycolytic potential (mean) of 108.1 LA eq. kg −1 muscle reported Berri et al 31 and with the initial glycogen content of 52.8 mmol kg −1 muscle found Lee et al 32 In the present study, the initial glycogen content of chicken PS muscle was twice that of QF muscle, but Warriss et al 5 have reported as much as a three-fold difference between muscle types. A significant negative relationship existed between pH u and glycolytic potential in both muscles, but the correlations were lower than those Lee et al 32 found in chicken PS muscle (r = −0.78).…”

How climatic changes could affect meat quality

“…Drip loss from breast meat and cooking loss from leg meat can also be higher (Debut et al, 2003;Mujahid, Akiba, & Toyomizu, 2007;Northcutt et al, 1994;Petracci, Fletcher, & Northcutt, 2001). Some, but not all studies have shown that breast meat can be tougher following pre-slaughter heat stress, or that it may develop a stronger rigor (Lee et al, 1976;Wood & Richards, 1975). There has been no consistent effect on breast meat a à value when considering all the experiments, and no effect has been seen on heat-stable pinkness (Nagle, et al, 2000).…”

“…The other approach is to examine the effects of environmental conditions experimentally. In extreme situations both heat stress and exercise can influence muscle metabolism and meat quality (Lee, Hargus, Hagberg, & Forsythe, 1976;Ngoka & Froning, 1982). Quantitative relationships can then be used in models that apply to a sector of the industry.…”

The influence of defined ante-mortem stressors on the early post-mortem biochemical processes in the abdominal muscle of the Norway lobster,Nephrops norvegicus(Linnaeus, 1758)

“…Not only is the post-mortem biochemistry of these muscles changed, but consequently the overall quality, palatability and shelf life (use by date) of the meat is altered (Hendricks 1965;Fraser et al 1966;Lee et al 1976; Lewis et al 1981;Sikorski et al 1990;Lowe et al 1993;Sigholt et al 1997;Abdalla et al 1999;Diouf & Rioux 1999). There are numerous studies on spoilage and storage effects in the muscles of crustaceans (Sidhu et al 1974;Stroud et al 1982;Ashie et al 1996;Chinivasagam et al 1996;Shimada et al 2000;Mendes et al 2001;Aubourg et al 2007), but there is very little knowledge of the way in which ante-mortem stressors change the post-mortem biochemistry, and hence quality of related shellfisheries products.…”