The effect of spray washing on calpain i autolysis, desmin and troponin t degradation during post mortem period was determined. Postmortem changes in atp, glucose6phosphate and ph demonstrated that the rate of postmortem glycolysis in the pm was. Meat and meat products encyclopedia of life support. Thus, this study was designed to determine meat quality, post mortem glycolysis and muscle fibre type transformation in pigs feeding different. Based on these results, the current study confirmed that the main factor influencing pork quality traits is the ultimate lactate content in muscle via postmortem glycolysis, and that levels of. Principles of meat science 5th edition, chapter 5, pages 97 to 122. Although many modifications are used, the methods may be divided into two classes, brine and drysalt cures.
Postmortem breakdown of atp and glycogen in ground muscle. Postmortem changes and meat quality questions and study. Anaerobic glycolysis generates lactate that accumulates. Electrical stimulation will hasten rigor by accelerating postmorten metabolism. 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. Glycolysis is the process in which one glucose molecule is broken down to form two molecules of pyruvic acid also called pyruvate. However, tissuespecific difference in glycogen metabolism between breast and thigh muscles of transported broilers has not been well studied. The aim of this study was evaluation of the post mortem changes in bovine meat during aging, quantitative analysis of glycogen and lactic. To elucidate the molecular mechanism underlying this fast glycolysis in muscle to become pse meat, post mortem atp metabolism, fructose2,6diphosphate content, and the activities of ampk. Glycolysis is supremely important in understanding how muscles are converted to meat. It is an anaerobic process as it can take place in both aerobic and anaerobic conditions, thus it does not require oxygen. 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. Consequently, there was a large variation in both the rate of glycolysis and temperature decline.
Amp activated protein kinase, glycolysis and pale, soft. Postmortem changes in atp, glucose6phosphate and ph demonstrated that the rate of postmortem glycolysis in the pm was significantly faster than in the ld. The major ratelimiting step of glycolysis in liver cells is a the conversion of glucose to glucose 6phosphate. Food, wastes, hormones and metabolites supply stops. At least six enzymes operate in the metabolic pathway. Pdf effects of dietary energy sources on post mortem.
Anaerobic glycolysis is normally present in muscles to provide atp when dioxygene is lacking. Variation in the response to manipulation of postmortem. Meat quality measurements values of muscle ph were measured with a ph meter orion research inc. Postmortem regulation of glycolysis by 6phosphofructokinase in bovine muscle. Effects of dietary energy sources on post mortem glycolysis. This study investigated the effects of dietary energy sources on meat quality, post mortem glycolysis and muscle fibre type transformation of finishing pigs. Muscle energy metabolism, growth, and meat quality in beef. Speeds up the postmortem processes this includes the speeding of rigor glycolysis accelerates proteolytic activity through enhanced calcium release prevents cold shortening an thaw rigor by accelerating glycolysis and onset of rigor weakens the structure of meat making it more tender physical disruption of muscle fibers. We thus investigated the differences in meat quality, adenosine phosphates, glycolysis, and bound key enzymes associated with glycolysis. Also, immediately post mortem, lactic acid will be produced as fibers attempt to keep the atp content at the normal level homeostasis. Post mortem changes and conversion of muscle into meat death of the animal and consequences of circulatory failure. They also mentioned that breast meat ph values appeared to be higher in the winter. However, few studies have demonstrated whether the dietinduced change of muscle glycogen is achieved by the transformation of muscle fibre type. The postmortem metabolism of atp and glycogen in ground bovine mttscle in some cases also in rabbit m,tscle was studied.
Favor anaerobic metabolism glycolysis by norepinephrine, epinephrine accumulation of lactic acid. Effects of dietary energy sources on post mortem glycolysis, meat quality and muscle fibre type transformation of finishing pigs article pdf available in plos one 106. Fluoride is a classic inhibitor of glycolysis discovered by otto warburg in 1941. Changes in key properties of the meat are outlined below. Muscle and meat biochemistry teaches the different concepts and topics under the eponymous subject. Low salt pigmeat products and novel formulations slu. Dransfield 1993 has presented a model which quantifies these changes and attempts to predict this increase in muscle tenderness post mortem. Mechanical and biochemical methods for rigor measurement.
The transformation of muscle in meat is a control point in the determinism of meat quality. It modifies the phosphate and magnesium in enolase, leading to controversy regarding the fluorination of drinking water. Mahabub alam ms student in animal science department of animal science and nutrition chittagong veterinary and animal sciences university, khulshi, chittagong 4202 cvasu 1 2. This study was conducted to assess the regulation of glycolysis by 6phosphofructokinase pfk during the postmortem metabolism of beef muscle.
Apr 07, 20 the first five reactions of glycolysis are what is referred to as the energy investment phase, since atp is invested into the reactions, the last five reactions are known as the energy payoff phase since it is here that the atp used is regenerated with two extra atp molecules, giving glycolysis a net gain of two atp per molecule of glucose used. Postmortem changes in pork muscle protein phosphorylation in relation to the rn genotype were investigated using onedimensional gel electrophoresis and a phosphor specific staining. However, many mechanisms of post mortem metabolic regulation have not been fully investigated in beef carcasses. These limitations likely occur because the term fish meat encompasses a vast number of species consumed for meat. The glycolysis process is a multistep metabolic pathway that occurs in the cytoplasm of animal cells, plant cells, and the cells of microorganisms. Pozzi bich411 lecture supplement notes 2 glycolysis glycolysis is a pathway that converts one glucose molecule to pyruvate, producing two molecules of atp and two molecules of nadh. Glycolic changes which occur post mortem 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. Strafuss, postmortem biochemical changes in canine blood, journal of forensic sciences, 1980, 25, 2, 122jcrossref. The relationship between the degree of acceleration of post. Glucose increases over 5fold, caused by debranching of glycogen. Smith this study was conducted to assess the regulation of glycolysis by 6phosphofructokinase pfk during the postmortem metabolism of beef muscle.
Generally the carcasses are stored for a few days after slaughter. Glycolysis is one of the key metabolic pathways in the conversion of muscle to meat. In comparison to pigs and poultry, less information is available detailing the regulation of postmortem glycolysis of fish muscle. Several and complex factors can affect poultry meat quality properties. In this way the post mortem changes are nearly inhibited. Histochemical and meat quality characteristics of longissimus dorsi ld and psoas major pm muscles were made. Beef the ancestor of the beef cattle was a type of wild ox domesticated in ancient greece and turkey during the stone age. Henrickson story in brief processing beef prior to the onset of rigor results in an unsatisfactory product. Glycolysis is the first stage out of a series of stages of cellular respiration. The prime function of glycolysis is the breakdown of sixcarbon sugars through enzymatic action, to produce threecarbon compounds pyruvate, nadh, which can then be utilized in the creation of atp, in the mitochondria or used in fat synthesis. The glycolytic pathway is also referred to as the embfenmeyerhof pathway in honor of the pioneers minus parnas who discovered it. Preslaughter transport effect on broiler meat quality and. Thus, glycolysis is also the decomposition of glycogen. Muscle glycogen declined to about onethird of initial values.
Irreversible crosslinking of actin and myosin occurs. This process occurs in all living cells regardless of the organism. The explanation to this hitherto incongruent outcome can be attributed, in part, to the contribution of proteolysis. Preslaughter transport effect on broiler meat quality and post mortem glycolysis metabolism of muscles with different fiber types. Changes in the concentrations of glycogen and lactate and the concentrations of some phosphoruscontaining. Mechanisms and strategies for improving meat tenderness. Stimulated carcasses put into a blast freezer at 5 hr post. Glycolysis is the process by which glucose is converted via fructose1,6bisphosphate to pyruvate with the generation of 2 mol atp per mol of glucose. As a tissue, muscle has the unique ability to switch its metabolic source of atp, the energy currency underpinning muscle function. Rapid ch n 8 wel1 own that temperature and rate of glycolysis are important determinants of meat quality. Postmortem changes in pork muscle protein phosphorylation. Regulation of postmortem glycolysis and meat quality.
Well its simple it is a metabolic process that converts a glucose 6 carbons molecule into 2 pyruvate molecules. 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. So in simple terms, glycolysis is the splitting of glucose. After several hours, post mortem meat reaches the ultimate ph, usually 5. This is caused by preslaughter stress and, as the term suggests, results in a darker meat with undesirable meat quality characteristics. After 24 h of chilling, additional samples were taken to evaluate and compare meat quality traits. Pdf on oct 14, 2019, s stajkovic and others published postmortem glycolysis and pork quality find, read and cite all the research you need on researchgate. Abstract the rates of ph fall and of changes in glycolytic intermediates and. Corry, possible sources of ethanol ante and post mortem. Effects of sugars on postmortem glycolysis in bovine muscle. There are ten enzymes that catalyze the glycolysis process from beginning to end.
Meat is the post mortem aspect of the 300 or so anatomically distinct muscles of the body, together with the connective tissue in which the muscle fibres are deposited and such intermuscular fat as cannot be removed without disrupting the muscle as a whole. Effects of muscle fiber type on glycolytic potential and meat. At ph 7 protons released during postmortem glycolysis are bound by the phos phorylation of adp to atp and are liberated during enzymic hydrohsis of atp. Sheep, rabbit and oxmuscle minces prepared soon after slaughter were diluted with 1 vol. An evaluation of slaughter procedures in the netherlands revealed puscl vare considerably. Atp consumed by noncontractile activity of amatpase and ion pumps. The potential of postmortem glycolysis to intensify twotoning severity in fresh hams is discussed. Rahuls noteblog notes on biochemistry notes on glycolysis. In the immediate postmortem period, as the muscle attempts to maintain homeostasis, muscle glycogen is metabolised via anaerobic glycolysis, thus phosphorylating adp to supply atp.
Thus, as postmortem metabolism continues, glycogen and atp levels. At 45 min postmortem, samples were taken from the eight muscles for meat quality measurements. Glucose is a 6 carbon molecule which is broken down into 2 three carbon molecules of pyruvate. Influence of postmortem muscle glycogen content on the. In this work, we studied the post mortem glycolytic behavior including lactate dehydrogenase and three dehydrogenase. Glycolysis normally causes an increase in acidity decrease in ph as muscles are converted to meat. The phosphorylation levels of several protein bands were found to be affected by the rn genotype and to change during postmortem development. Dehydrogenase enzymes associated to glycolysis in beef. Conversion of chicken muscle to meat and factors affecting. The characteristic conversion of muscle to meat that occurs post mortem arises due to a series of biochemical and biophysical changes that are initiated upon death. Regulation of postmortem glycolysis in ruminant muscle.
Postmortem muscle glycolysis and meat quality characteristics. Effects of sugars on post mortem glycolysis in bovine muscle mince 215 and the ph differences observed in the first 6 h were largely maintained for at least six days table 1. This work was supported in part by the australian meat research committee. The definition of quality can be described readily when the product is a simple. Up to 24 hours after slaughter, anaerobic glycolysis in muscle generates lactic acid and lowers the ph.
Post mortem changes in meat immediately after slaughter, changes occur in the muscle of an animal. Remote work advice from the largest allremote company. The effect of electrical stimulation on the rate of post mortem glycolysis in some bovine muscles p. Mar 16, 2014 glycolysis as the name suggests, is the breakdown of glucose. Effects of dietary energy sources on post mortem glycolysis, meat. Figure 2 shows some of the changes which occur after slaughter. Read variation in the response to manipulation of post mortem glycolysis in beef muscles by lowvoltage electrical stimulation and conditioning temperature, meat science on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Too much or too little acid and the meat is ruined. Emulsifying capacity binding properties cooking loss. Meat quality and storage characteristics depending on pse. Biochemical basis of the effect of preslaughter stress and post.
In order to fully understand the principles and mechanisms underpinning these methods, it is. Immediately the neck is cut, blood circulation stops, 1. Effects of ph early postmortem on meat quality in beef longissimus. The lowering of ph in muscle due to accumulation lactic acid is one of the most significant postmortem changes that occur due to postmortem glycolysis. At ph 7 protons released during postmortem glycolysis are bound by the. Preslaughter transport has been reported to decrease the quality of breast meat but not thigh meat of broilers. The effect of electrical stimulation on the rate of post. Acidity with the accumulation of lactic acid the ph falls from 7 to 5.
The post mortem oxygen depletion increases the glycolytic activity and lactate production. Learn vocabulary, terms, and more with flashcards, games, and other study tools. In broilers meat, simpson and goodwin 1975 reported that plant, sex and season had a significant effect on meat tenderness. Lactic acid in muscle and its effects on meat quality. Muscle metabolism, postmortem glycolysis, and meat quality.
Technology of meat, poultry, fish and seafood products module. This includes muscle contraction and it also helps initiate relaxation. These changes, like the changes in milk and eggs, can be retarded by method of handling and storage. 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. The gylco stands for glucose, and lysis stands for splitting. There was a tendency for meat from spraywashed animals to be tougher than meat from dry animals p 0. Dietary energy source can influence muscle glycogen storage at slaughter. In both cases, abnormal physicochemicalproperties of meat color, waterholdingcapacity are. Postmortem regulation of glycolysis by 6phosphofructokinase. The extent of glycolysis in diluted preparation of mammalian muscle. Glycolytic capacity and postmortem glycolysis in myopathied chicken skeletal muscle is evaluated. How to use post mortem data it is difficult to identify when bruising occurs.
Five intact korean bulls weighing about 550 kg were slaughtered to investigate postmortem glycolysis. Compound c, an inhibitor of ampactivated protein kinase, inhibits glycolysis in mouse longissimus dorsi postmortem. Of the monosaccharides glucose, fructose, mannose and galactose, each tested at 1. The book covers the gross and detailed composition and structure of muscles and the relationship of the nervous system with the muscular system.
Sep 01, 2007 read tenderness and oxidative stability of post mortem muscles from mature cows of various ages, meat science on deepdyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. Pork with normal color and whc reaches an ultimate ph of 5. The extent of post mortem glycolysis also has an effect on the tenderness of beef, pork, and lamb. Results showed that spray washing tended to cause an increase p 0. 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. Early postmortem changes as muscle is converted to meat a number of metabolic and structural changes occur. Energetics of glycolysis the free energy change, g. This process is promoted by insulin so that blood glucose levels are not exceededly high the oppositon to insulin is glucagon which is active during low levels of blood glucose. Effects of muscle fiber type on glycolytic potential and. This value varies within a large range and, in extreme cases, the ph may drop as low as 5. Abstract chicken meat results from overall biochemical and mechanical changes of the muscles after slaughtering process. Pdf regulation of postmortem glycolysis in ruminant muscle. Mar 17, 2012 after the death of an animal, cell metabolism is controlled locally. Postmortem glycolysis in bovine longissimus muscle a.
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