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The first aim of the study was to compare selected meat quality parameters in porkers without the gene RYR1T (ryanodine receptor gene). These were porkers slaughtered at 100 to 115 kg and 116 to 130 kg live weight. The second aim of the study was to determine the occurrence frequency of standard-quality meat (red, firm, nonexudative [RFN]) and the occurence frequency of defective meat (pale, soft, exudative [PSE] and acid, soft, exudative [ASE]). The analysis was conducted on the longissimus lumborum muscle in 114 crossbred porkers. The porkers were a cross of Camborough 22 sows and boars from lines 337PIC (Pig Improvement Company), Norsvin Landrace and Pietrain. All of the animals were provided with identical environmental and nutritional conditions. The average weight of the slaughtered animals in the light and heavy groups was 110 kg and 122 kg, respectively. Both groups had the same average post-slaughter meatiness (56.5%). A statistical analysis of selected meat-quality parameters did not show any significant differences between the weight groups. On the other hand, the classification based on carcass quality showed an occurence frequency of defective meat in heavier crossbred porkers (116 to 130 kg) that was three times higher than in those crossbred animals which weighed 100 to 115 kg when slaughtered. In porkers without the gene RYR1T, the defective meat types PSE and ASE occurred with a frequency of 17.54%.

The aim of this study was to compare the diagnostic values of two methods in pork meat quality evaluation, that is, Method I: pH1 and pH24 and Method II: electrical conductivity (EC2) and pH24, which included pH24, and their modifications, that is, Method III: pH1 and pH48 and Method IV: EC2 and pH48, which included pH48 measurement. Five meat quality classes, namely reddish-pink, firm and non-exudative (RFN), high quality (HQ), pale, soft and exudative (PSE), dark, firm and dry (DFD) and acid meat (AM) were assessed in four even-numbered genetic groups of 40 fatteners each, namely (LxY)xD-A, (LxY)xD-B, (LxY)xH and (LxY)x(DxP). The change of diagnostic method and therefore pH time measurement from 24 hours to 48 hours post mortem caused a major increase in the percentage of acid meat (AM) that was diagnosed. Most differences were observed in (LxY)xH fatteners, namely 77.5% between Methods I and III and 75% between Methods II and IV. This increase in AM frequency indicates that as a result of significant changes in the post-mortem metabolism that occur in the meat ageing process pH48 should be regarded as ultimate pH (pHu). [ABSTRACT FROM AUTHOR]

The experiment was conducted to identify the mitochondrial protein responsible for enhancing glycolytic flux. We hypothesized that mitochondrial F 1 -ATPase promotes ATP hydrolysis and thereby the flux through glycolysis. Porcine longissimus muscle mitochondria were incorporated into an in vitro system designed to recapitulate postmortem glycolysis with or without Na-azide to specifically inhibit the β-subunit of mitochondrial F 1 -ATPase that catalyzes ATP hydrolysis. Addition of mitochondria enhanced ATP hydrolysis, glycogen degradation, lactate accumulation, and pH decline in the in vitro system. However, the majority of mitochondria-mediated enhancement in glycolytic flux was abolished in the presence of Na-azide. To investigate further, myofibrillar and mitochondrial proteins were added to the in vitro system after 240 min from the initiation of the reaction. Greater pH decline and lactate accumulation were observed in system containing mitochondrial protein compared to their myofibrillar counterpart. In conclusion, mitochondrial F 1 -ATPase is capable of increasing glycolytic flux through promoting greater ATP hydrolysis at lower pH. [ABSTRACT FROM AUTHOR]

Postmortem lactate accumulation in skeletal muscle is linearly associated with the extent of pH decline. Yet, pigs harboring the AMPKγ3 R200Q mutation produce meat with similar lactate levels to that of wild-type pigs but have a lower ultimate pH. We hypothesized that lower initial lactate levels and (or) lower buffering capacity in muscle of these pigs may help explain this discrepancy. Longissimus lumborum muscle samples were harvested at 0 and 1440 min postmortem from AMPKγ3 R200Q and wild-type pigs. As expected, AMPKγ3 R200Q muscle exhibited a lower ultimate pH but similar lactate levels to that of wild-type pigs at 1440 min postmortem. However, the total net lactate produced postmortem was greater in the AMPKγ3 R200Q muscle due to lower initial lactate levels at 0 min postmortem. Buffering capacity measured over the pH range of 5.5–7.0 was also lower in AMPKγ3 R200Q muscle. Greater net lactate accumulation postmortem (i.e., glycolytic flux) coupled with a lower buffering capacity explains the lower ultimate pH of meat from AMPKγ3 R200Q pigs. [ABSTRACT FROM AUTHOR]

The first aim of the study was to compare selected meat quality parameters in porkers without the gene RYR1T (ryanodine receptor gene). These were porkers slaughtered at 100 to 115 kg and 116 to 130 kg live weight. The second aim of the study was to determine the occurrence frequency of standard-quality meat (red, firm, nonexudative [RFN]) and the occurence frequency of defective meat (pale, soft, exudative [PSE] and acid, soft, exudative [ASE]). The analysis was conducted on the longissimus lumborum muscle in 114 crossbred porkers. The porkers were a cross of Camborough 22 sows and boars from lines 337PIC (Pig Improvement Company), Norsvin Landrace and Pietrain. All of the animals were provided with identical environmental and nutritional conditions. The average weight of the slaughtered animals in the light and heavy groups was 110 kg and 122 kg, respectively. Both groups had the s ame average post-slaughter meatiness (56.5%). A statistical analysis of selected meat-quality parameters did not show any sign ificant differences between the weight groups. On the other hand, the classification based on carcass quality showed an occur ence frequency of defective meat in heavier crossbred porkers (116 to 130 kg) that was three times higher than in those cross bred animals which weighed 100 to 115 kg when slaughtered. In porkers without the gene RYR1T, the defective meat types PSE and ASE occurred with a frequency of 17.54%. [ABSTRACT FROM AUTHOR]

Fifteen meat samples collected from pigs (Neckar hybrid line) were selected from 75 animals on the basis of their technological quality traits, and the samples were classified as normal, PSE, and acid meat. Sensory analysis was performed on the three meat categories. Total meat protein and drip loss protein were analyzed by electrophoresis (SDS-PAGE), mass spectrometry, and image analysis. From a sensory point of view, PSE meat was characterized by lower color intensity, and acid meat was characterized by the lowest score of juiciness. Certain soluble proteins derived from the drip loss were associated with meat quality, especially phosphoglucomutase and the B chain of hemoglobin in the case of PSE and acid meat. Low quantities of myofibrillar proteins (myosin LC1, troponin T (TnT) and troponin C (TnC)) in meat with high glycogen levels and low pH levels resulted in a higher rate of proteolysis of myofibrillar proteins due to higher enzymatic proteolysis activity in the meat. The results of this study showed that the TnC/TnI ratio may be a pertinent marker of postmortem muscle metabolism and that this ratio is related to textural properties. [ABSTRACT FROM AUTHOR]

The first aim of the study was to compare selected meat quality parameters in porkers without the gene RYR1 (T) (ryanodine receptor gene). These were porkers slaughtered at 100 to 115 kg and 116 to 130 kg live weight. The second aim of the study was to determine the occurrence frequency of standard-quality meat (red, firm, nonexudative [RFN]) and the occurence frequency of defective meat (pale, soft, exudative [PSE] and acid, soft, exudative [ASE]). The analysis was conducted on the longissimus lumborum muscle in 114 crossbred porkers. The porkers were a cross of Camborough 22 sows and boars from lines 337PIC (Pig Improvement Company), Norsvin Landrace and Pietrain. All of the animals were provided with identical environmental and nutritional conditions. The average weight of the slaughtered animals in the light and heavy groups was 110 kg and 122 kg, respectively. Both groups had the same average post-slaughter meatiness (56.5%). A statistical analysis of selected meat-quality parameters did not show any significant differences between the weight groups. On the other hand, the classification based on carcass quality showed an occurence frequency of defective meat in heavier crossbred porkers (116 to 130 kg) that was three times higher than in those crossbred animals which weighed 100 to 115 kg when slaughtered. In porkers without the gene RYR1 (T) , the defective meat types PSE and ASE occurred with a frequency of 17.54%.