Post mortem glycolysis in meat pdf files

Sheep, rabbit and oxmuscle minces prepared soon after slaughter were diluted with 1 vol. Postmortem glycolysis is one of the most important factors determining the quality of meat. The effects of ante mortem stressors such as stunning, struggling, environmental temperature and feed withdrawal on the biochemical changes of broiler breast muscle are assessed in relation to postmortem biochemical changes and the subsequent tenderness of broiler breast meat. Main changes in post mortem glycolysis post mortem meat glycolysis occurs when o 2 supply to muscle tissue ceases, glycogen, main cho store of animals is no longer oxidized to co 2 and h 2 o but anaerobically broken down to lactic acid.

Effects of dietary energy sources on post mortem glycolysis. Consequently, muscle glycogen is metabolized via anaerobic glycolysis, which is less efficient at generating atp. Causes and contributing factors to dark cutting meat. The aim of this study was evaluation of the postmortem changes in bovine meat during aging, quantitative analysis of glycogen and lactic acid, as well. This paper details the postmortem changes that take place in the muscular tissue of poultry and the consequences of these on the resulting meat quality at the point of consumption. Postmortem changes that occur in the conversion of muscle to meat not only alter some of its biochemical and physical properties but also play an important role in improving its acceptability as food pearson, 1987. Pork with normal color and whc reaches an ultimate ph of 5. The inclusion of glycogen, atp, adp, nad or magnesium chloride in the diluent had little effect on the ultimate ph of the diluted mince. Understanding and utilizing postmortem events and processes eric pouliot1 with the collaboration of c. This includes muscle contraction and it also helps initiate relaxation.

Although many modifications are used, the methods may be divided into two classes, brine and drysalt cures. The postmortem changes that take place when muscle is converted into meat have a marked effect on the quality of the meat. Regulation of postmortem glycolysis in ruminant muscle d. Low salt pigmeat products and novel formulations slu. Steaks from more mature cows had an increased p meat using ante mortem enzyme injection and post mortem water injection 19610502. Brazilian archives of biology and technology scielo. Presumably, postmortem glycolysis and muscle ph decline is stopped, under normal carcass. Because of protein denaturation, there is exudation of moisture and discoloration. Effects of dietary energy sources on post mortem glycolysis, meat quality and muscle. In one reaction in the phosphagen system, the enzyme adenylate kinase catalyzes the. Both pse and dfd meat induce significant losses to the meat industry. No visible degradation of thick and thin filaments. Conversion of chicken muscle to meat and factors affecting. Generally the carcasses are stored for a few days after slaughter.

Empey found that bacteria grow and develop very slowly on meat during rigor, as a ph of approximately 5. Effects of early postmortem muscle ph and temperature on meat tenderness 6. Changes in specific myofibrillar proteins during the aging process a. The relationship between the degree of acceleration of post. No true crossover at f1,6p 2, hence regulation is not at pfk. Proteolysis is an important factor contributing to postmortem changes in skeletal muscle, including meat tenderness. Premortem glycolysis, occurring as a result of death struggle or epinephrine administration 1. The increased acidity of postmortem muscle results from the accumulation of lactic acid, which is formed as glycogen is degraded anaerobic glycolysis to produce atp. Request pdf characteristics of meat quality and the acceleration of postmortem glycolysis by electrical stimulation summarya brief period of electrical stimulation of freshly slaughtered lamb. Stimulated carcasses put into a blast freezer at 5 hr post. Postmortem changes in chicken muscle worlds poultry. Technology of meat, poultry, fish and seafood products module. Unlike mammalian and poultry meat, which shows strong postmortem drop in ph reaching ultimate peak values of about 5. As post mortem glycolysis proceeds, the muscle becomes inextensible.

Animals that are not handled optimally ante mortem will likely have faster running muscle biochemistry and. The post mortem pm glycolysis rate is influenced by many factors during the transformation of muscle to meat. If possible, a site for the post mortem remote from contact with other wild animals and domestic livestock should be selected. Start a free trial of quizlet plus by thanksgiving lock in 50% off all year try it free. Effect of some antemortem stressors on perimortem and. Meat tenderness may be improved by accelerating muscle metabolism or by damaging muscle structure and increasing the solubility of muscle proteins.

In the past it was assumed that the normal postmortem accumulation of lactic acid causes the. The importance and value of meat tenderness tenderness has been repeatedly reported as the most important quality attribute of meat hu. In experiment 1, longissimus dorsi ld steaks were stored at 3 c for 010 d. A file with the list of fatty acids in meat samples and their content were. While atp, adp and amp were rapidly broken down, the concentration of imp rose rapidly and remained high. Glycolysis and the associated ph decline are of primary importance for meat.

Changes in membrane permeability enhance the ion transport i. Dietary energy source can influence muscle glycogen storage at slaughter. The effect of nutrition on muscle ph decline and ultimate. Effects of earlypostmortem muscle ph and temperature on. Consumption of oxidized oil increases oxidative stress in. To study the effects of glycolysis on tenderness of poultry breast meat, premortem and postmortem glycolysis in muscle tissue was controlled either by epinephrine administration at suitable intervals of time before slaughtering or by allowing the birds to struggle freely just before and during slaughtering. Between lairage pens and the stunning area there was a 5 m single file. This study investigated the effect of early postmortem temperature on broiler protein characteristics and meat quality. Postmortem inspection food safety and inspection service. Seventytwo barrows with an average body weight of 65. Five intact korean bulls weighing about 550 kg were slaughtered to investigate postmortem glycolysis. The purpose of meat inspection is to certify whether or not meat is fit for human consumption. These deviations in postmortem ph decline can arise from a number of.

Principles of meat science 5th edition, chapter 5, pages 97 to 122. Bruce marsh for a number of reasons, the ph and temperature changes taking place in early postmortem muscle are of interest and importance to the meat investigator. Very rapid glycolysis due to excitement antemortem or due to holding on kill floor a long time before chilling postmortem. Expeditious prediction of postmortem changes in frozen fish. Regulation of postmortem glycolysis and meat quality. Request pdf characteristics of meat quality and the acceleration of postmortem glycolysis by electrical stimulation summarya brief period of electrical. These limitations likely occur because the term fish meat encompasses a vast number of species consumed for meat. Rapid post mortem glycolysis and high phu values suggest the occurrence of stress at and preslaughter. Meat and meat products encyclopedia of life support systems.

Proteolysis is an important factor contributing to post mortem changes in skeletal muscle, including meat tenderness. It is also important to note that anaerobic glycolysis is significantly less efficient. It is one of the recognizable signs of death, characterized by stiffening of the limbs of the corpse caused by chemical changes in the muscles postmortem. There is substantial evidence to show that consumers rate. Effect of cold stress during transportation on postmortem. The history of the development if the modern meat type chicken, the form and function of its muscles, the factors that determine muscle growth and their effects on. Greater change in concentration of glucose, g1p, g6p, f6p, lactate in es muscle 2. Sep 01, 2007 two experiments were conducted to investigate the influence of age of mature cows 24 yr, 68 yr, and 1012 yr cows. Both pse and dfd meat induce significant losses to the meat. Commonwealth scientific and industrial research organisation division of food preservation, meat research laboratory, cannon hill, queensl. In living tissue glycolysis helps generate adenosine triphosphate atp for cellular functions.

Two groups of twelve turkey carcasses with sirnilas ultimate ph values were sefected based on 15 min postmonem pm breast muscle ph rapid. While most of atp produced postmortem arises from glycolysis, muscle has a separate mechanism known as the phosphagen system to generate atp. In comparison to pigs and poultry, less information is available detailing the regulation of postmortem glycolysis of fish muscle. Muscle glycogen declined to about onethird of initial values. Presented at the 55th international congress of meat science and technology. The postmortem proteolysis is responsible for most of tenderization that occurs later during aging koohmaraie, 1996. Muscles were kept at different temperatures 0, 20 and 40 c until 4 h postmortem and then stored at 4 c. This is caused by preslaughter stress and, as the term suggests, results in a darker meat with undesirable meat quality characteristics. The aim of this study was evaluation of the postmortem changes in bovine meat during aging, quantitative analysis of glycogen and lactic acid, as well as examination of their impact on technological and sensory quality of selected muscles from.

Regulation of postmortem glycolysis in ruminant muscle. Pse meat immediately after slaughter due to accelerated glycolysis 23. These glycolytic and auto lytic changes are discussed in relation to the commercial handling of meat. Effect of postmortem changes on meat quality wismer. The objective of the current study was to investigate the effects of supplementing. Oxidised deactivated papain can be injected into the blood stream ante mortem or active papain can be applied to meat post mortem.

Rancidity of fat in meat is one of the precursors of flavor metabolites. Histochemical and meat quality characteristics of longissimus dorsi ld and psoas major pm muscles were made. Microorganisms may enter the meat by penetration from the surface, which is a slow process, and by following the cavities in meat, that is, the blood and lymph vessels. Postmortem changes in muscle electrical properties of. Request pdf characteristics of meat quality and the acceleration of post mortem glycolysis by electrical stimulation summarya brief period of electrical. Regulation of postmortem glycolysis in ruminant muscle 2014 ferguson, d. Food, wastes, hormones and metabolites supply stops. The aim of this study was to investigate the effects of sex, age and preslaughter conditioning of marketed indigenous south african goats on early post mortem and ultimate ph and temperature, colour and tenderness related properties. Smith this study was conducted to assess the regulation of glycolysis by 6phosphofructokinase pfk during the postmortem metabolism of beef muscle. Conditions behind the pse poultry meat are believed to be the same as observed in pork. Variation in the rate andor the extent of post mortem glycolysis is responsible for a major proportion of the variation in meat whc and color. Effect of sex, age, and length of preslaughter conditioning.

Glycolysis ceased at appreciably higher ph in the potassium chloride mince than in undiluted mince. Postmortem glycolysis in bovine longissimus muscle a. Annals of the new york academy of sciences 1987, 508 1 physiological, 516522. Contribution of postmortem muscle biochemistry to the. When an animal is harvested for meat, a series of biochemical reactions. Premortem glycolysis, occurring as a result of death struggle or epinephrine administration 12 hr before slaughtering, lowered the ph of the meat at the time of death and caused toughness. Immediately the neck is cut, blood circulation stops, 1. In both cases, abnormal physicochemicalproperties of meat color, waterholdingcapacity are.

Characteristics of meat quality and the acceleration of postmortem. The post mortem proteolysis is responsible for most of tenderization that occurs later during aging koohmaraie, 1996. Pdf regulation of postmortem glycolysis in ruminant muscle. Postmortem biochemistry of meat and fish journal of. In this way the postmortem changes are nearly inhibited. This study investigated the effects of dietary energy sources on meat quality, post mortem glycolysis and muscle fibre type. Glucose increases over 5fold, caused by debranching of glycogen.

Increases tenderness of meat unless the meat already is tender. Learn vocabulary, terms, and more with flashcards, games, and other study tools. In humans, rigor mortis can occur as soon as four hours after death. However, few studies have demonstrated whether the dietinduced change of muscle glycogen is achieved by the transformation of muscle fibre type. Influence of postmortem muscle glycogen content on the. A pit may have to be dug to dispose of the carcass, so. During oxygen debt, such as that occurring immediately following the death of animals, anaerobic metabolism is initiated in an attempt to restore homeostasis within the muscle. Further efforts to understand how the glycolytic enzyme kinetics are influenced by both pre and post slaughter factors will be beneficial in the ongoing quest to maximise fresh meat quality. The conversion of muscle to meat actually starts when someone decides to sell and market their pigs because this is when ante mortem stress occurs with the marketing and handling of animals. Effect of glycogen concentration and form on the response to electrical stimulation and rate of postmortem glycolysis in ovine muscle.

Understanding and utilizing postmortem events and processes. Post mortem procedures 11 if a cement floor is available which is rarely the case, this greatly facilitates subsequent disinfection. Effects of postmortem glycolysis on the quality of hotdeboned bovine muscle. How to use postmortem data it is difficult to identify when bruising occurs. Influence of post mortem glycolysis and cooling on colour. Postmortem regulation of glycolysis by 6phosphofructokinase in bovine muscle. May increase rate of glycogenolysis and thereby increase glycolysis.

Many workers associated with the meat industry were interested in this post mortem glycolysis process because on occasions something goes wrong. Effect of prerigor freezing and thawing on the intermediary metabolism. There are no clearly written guidelines covering all situations. Our study is in agreement with the results of hill5 hamilton. Influence of post mortem glycolysis and cooling on colour and colour stability in different muscles of belgian blue beef.

Minimization of postmortem glycolysis by epinephrine administration more than 5 hr before slaughtering increased the ultimate ph of meat and the tenderness. Effect of different ultimate ph range on meat quality of. High postmortem temperature combined with rapid glycolysis. In the past it was assumed that the normal post mortem accumulation of lactic acid causes the. Researchers have also used muscle glycolytic potential or glycogen. Irreversible crosslinking of actin and myosin occurs. No detectable breakdown products of thick and thin filaments. Postslaughter changes in atp metabolites, reducing and. The probable reason can be attributed to the fact that metabolic reactions continues after somatic death of an individual and glycolysis affects the postmortem blood glucose level in peripherally collected blood.

Postmortem changes in atp, glucose6phosphate and ph demonstrated that the rate of postmortem glycolysis in the pm was significantly faster than in the ld. As a tissue, muscle has the unique ability to switch its metabolic source of atp, the energy currency underpinning muscle function. The rate of post mortem glycolysis may be too fast, leading to a rapid drop in ph typical of pse meat, or too slow, resulting in too high ultimate ph typical of dfd meat knox et al. Glycolysis is one of the key metabolic pathways in the conversion of muscle to meat. Postmortem muscle glycolysis and meat quality characteristics. Temperature and the rate and extent of ph fall have a considerable effect on meat quality attributes in different animal species scheffler et al. This study investigated the effects of dietary energy sources on meat quality, post mortem glycolysis and muscle fibre type transformation of finishing pigs. Although the same ryanodine mutation found in pork was not. Rapid andor excessive glycolysis leads to pale, soft, and exudative pse meat, while insufficient glycolysis results in dark, firm, and dry dfd meat. The extent of post mortem glycolysis also has an effect on the tenderness of beef, pork, and lamb.

Effect of cold stress during transportation on post mortem metabolism and chicken meat quality a thesis submitted to the college of graduate studies and research in partial fulfillment of the requirements for the degree of doctor of philosophy in the department of food and bioproduct sciences university of saskatchewan. Glycolic changes which occur postmortem have an impact on the physical and sensory features of beef, which in turn determine the successive processes and influence such beef quality traits as colour, tenderness, and cooling loss. Atp consumed by noncontractile activity of amatpase and ion pumps. Other studies have also demonstrated the importance of temperature for the process of glycolysis, which affects meat quality. The explanation to this hitherto incongruent outcome can be attributed, in part, to the contribution of proteolysis. Postmortem changes in muscle electrical properties of bovine. The phu of pse pork is similar to that of normal pork. These results suggest that producing meat at a higher phu will result in acceptable quality by reducing the risk for pse and high drip losses. Over 10 million scientific documents at your fingertips. Characteristics of meat quality and the acceleration of post. Therefore, enhanced conductivity or impedance is an indirect measurement of enhanced drip loss or muscle softness which is a. Post mortem changes and conversion of muscle into meat death of the animal and consequences of circulatory failure. Post mortem alterations to the muscle proteome reflect the biological complexity of the process of muscle to meat conversion, a process that, despite decades of advancements, is all but fully understood.

All relevant data are within the paper and its supporting information files. Influence of postmortem aging in tenderness of chicken. Effects of dietary energy sources on post mortem glycolysis, meat. Added tenderisers augment the action of the muscle enzymes and usually contain the plant protease, papain. Also, few studies if any have reported on whether these oxidation conditions in the diet can regulate meat quality including post mortem ph changes and waterholding capacity in broiler breast meat. Pse pork shortterm glycogen depletion prior to death.