Influence of high pre-rigor temperature and fast pH fall on muscle proteins and meat quality: a review

Abstract

Abstract. The impacts of accelerated pH decline combined with high muscle temperature on post-mortem muscle metabolism and subsequent meat quality attributes have been extensively studied. Traditionally, this phenomenon has been observed in pork muscles, primarily due to the relatively fast post-mortem glycolysis rate and its relationships to stress susceptibility of pigs before slaughter. However, the protein-denaturing condition of high temperature/rapid pH fall and subsequent PSE (pale, soft and exudative)-like abnormal meat quality characteristics have been observed in muscles from other species such as beef, lamb, venison and even poultry. Various pre-rigor conditions including the application of electrical stimulation, hot-boning, and/or pre-rigor carcass chilling temperatures in various muscles, in conjunction with carcass stretching/hanging methods, can also contribute to muscle-protein denaturation pre-rigor. This review considers the influence of a faster than normal pH fall at a higher than normal pre-rigor temperature on glycolysis, post-mortem muscle proteins and subsequently meat quality attributes. Gaps in current knowledge are identified and recommendations made for additional research.

Improving beef meat colour scores at carcass grading

“…Dark and light meat colours are associated with the unfavourable conditions known as darkcutting and heat-induced toughening, respectively. Both of these quality conditions negatively impact water-holding capacity, visual appearance, shelf-life and eating quality aspects such as tenderness (Purchas and Aungsupakorn 1993;Ferguson et al 1999;Kim et al 2014;Warner et al 2014b). It is well known that pre-slaughter stress in cattle depletes glycogen reserves and is associated with a high pH of the meat, particularly in animals on poor nutritional feeding regimes before slaughter (Lawrie 1958;Knee et al 2007).…”

Potential nutritional strategies for the amelioration or prevention of high rigor temperature in cattle – a review

“…Moreover, high rigor temperature may cause a loss in proteolytic potential due to inactivation of proteolytic enzymes (Kim et al 2014). Factors that contribute to elevated body temperature pre-slaughter would potentially predispose animals to higher carcass temperature immediately post slaughter.…”

“…One of the main causes of high rigor temperature appears to be a combination of rapid glycolysis and relatively slow cooling, which can lead to high rigor temperatures and potential toughening (Jacob and Hopkins 2014). Moreover, high rigor temperature may be exacerbated by loss of proteolytic potential due to inactivation of proteolytic enzymes (Kim et al 2014;Warner et al 2014a). The mechanisms of high rigor temperature in beef carcasses and the effects on meat quality are reviewed in Kim et al (2014) and Jacob and Hopkins (2014) in this issue of Animal Production Science.…”

“…Moreover, high rigor temperature may be exacerbated by loss of proteolytic potential due to inactivation of proteolytic enzymes (Kim et al 2014;Warner et al 2014a). The mechanisms of high rigor temperature in beef carcasses and the effects on meat quality are reviewed in Kim et al (2014) and Jacob and Hopkins (2014) in this issue of Animal Production Science. Factors that contribute to elevated body temperature pre-slaughter potentially predispose animals to higher carcass temperature immediately post slaughter (Jacob and Hopkins 2014).…”

Why is muscle metabolism important for red meat quality? An industry perspective

“…MSA has previously described this as 'heat-shortening' or 'heattoughening'. For reasons described in papers in this special issue (Jacob and Hopkins 2014;Kim et al 2014;Warner et al 2014), these terms are not recommended and the use of the term 'high rigor temperature' has been adopted in most of the papers in the special issue.…”