Glycolytic Intermediates and Co‐Factors in “Fast‐” and “Slow‐Glycolyzing” Muscles of the Pig

Abstract

SUMMARY— The Longissimus dorsi muscles from Chester White, Hampshire and Poland China animals were used to establish certain differences in metabolic intermediate patterns between muscles with “fast” and “slow” rates of post‐mortem glycolysis. Metabolic intermediate patterns were consistent with the concept that phosphorylase is the primary control site of postmortem glycolysis. Adenine nucleotide levels appeared to be the primary regulatory factors for phosphorylase. The phosphofructokinase and pyruvate kinase enzymes were also involved in post‐mortem glycolytic control. Levels of high‐energy intermediates (adenosine triphosphate, phosphocreatine and pyridine nucleotides) were much higher in the “O” hr samples of “slow‐glycolyzing” muscles than in similar samples from muscles having “fast” rates of post‐mortem glycolysis. No significant differences in levels of lactate or glucose were observed among these three groups in blood samples taken either at or 24 hr prior to the time of exsanguination.

A simple, reliable and reproductive method to obtain experimental pale, soft and exudative (PSE) pork

“…Failure to rapidly chill the pork carcass immediately postmortem can lead to PSE conditions. For example, it has long been recognized that when the temperature of pork muscle remains high postexanguination, it would activate glycogen phosphorylase and also phosphofructokinase, leading to a fast accumulation of lactic acid and pH decline (Kastenschmidt, Hoekstra, & Briskey, 1968). There are continuous efforts to diminish the occurrence of this phenomenon and to find reliable quality indicators (pH, color parameter, i.e., lightness at 24 h postmortem, electrical conductivity, etc.)…”

Phosphofructokinase and mitochondria partially explain the high ultimate pH of broiler pectoralis major muscle

“…The termination of postmortem metabolism in the presences of residual glycogen and glycolytic metabolites is a function of adenine nucleotides depletion or pH-495 mediated inactivation of PFK (Kastenschmidt et al, 1968;Greaser, 1986;England et al, 2014England et al, , 2016. To test whether adenine nucleotides disappearance is the reason for the cessation of postmortem metabolism in P. major muscle, we added 24 h P. major muscle to the in 500 vitro system with 3 mM ATP (pH 5.9).…”

Prediction of pork quality at the slaughter line using a portable Raman device

“…This may be explained by the different time frames in which the Raman spectra were obtained. The ATP concentration was shown to be nearly constant in the first hour after slaughter (Kastenschmidt et al, 1968). Thus, the ATP signals are less important in the early time frame for the prediction of the pH.…”

“…This peak is weighted as the second strongest signal in the VIP plot and, together with the peak at 1042 cm −1 , which indicates a stronger influence of creatine and sugar phosphates for the model in the present study. This can be explained by a higher conversion rate of phosphocreatine (PCr) to creatine in the earlier time frame (30 to 60 min) compared to the later time frame (60 to 120 min post mortem) Kastenschmidt et al, 1968;Schäfer et al, 2002). Raman peaks of PCr can be found at 849 and 978 cm −1 .…”