scholarly journals Relationship of glycogen and lactate concentrations as a pork quality indicator

2020 ◽  
Vol 50 (1) ◽  
pp. 26-37
Author(s):  
A Zybert ◽  
K Tarczyński ◽  
H Sieczkowska ◽  
E Krzęcio-Nieczyporuk ◽  
K Antosik
Keyword(s):  
Lactate Concentration ◽  
Muscle Metabolism ◽  
Pork Quality ◽  
Drip Loss ◽  
Post Mortem ◽  
Threshold Values ◽  
B Values ◽  
Muscle Ph ◽  
Longissimus Lumborum ◽  
Relationship Of

Muscle metabolites greatly determine pork quality. However, precise threshold values which indicate its deterioration or improvement are not fully known. This study aimed to determine the influences of pork Longissimus lumborum (LL) glycogen and lactate concentrations measured at 45 min post mortem on pH, colour (L*a*b*) and drip loss (DL) measured during 144 hours post mortem in order to prescribe appropriate threshold values. The investigation used 30 gilts and 30 barrows being fattened for slaughter. After slaughter, the carcasses were assigned to groups based on the observed levels of glycogen and lactate: low GlyL with glycogen ≤35 μmol/g, GlyM with glycogen between 35 and 55 μmol/g, GlyH with glycogen >55 μmol/g; LacL with lactate ≤40 μmol/g and LacH with lactate >40 μmol/g. Lower muscle pH was noted up to 24 h post mortem in the LacH group compared to LacL (P ≤0.01). 24 h post mortem higher pH was found in GlyL than in GlyM and GlyH (P ≤0.01), which were similar. Similarly no statistical differences were noted between The GlyM and GlyH groups were also similar in L*, DL96 and DL144, with lower values found for GlyL (P ≤0.01). Compared to LacH, LacL had lower L*, DL48, DL96 and DL144 (P ≤0.01) and higher a* and b* values. Muscle pH, drip loss, L* and a* values were more affected by lactate concentration if the glycogen concentration ≥35 μmol/g muscle tissue. Thus, metabolite concentration may be a useful and valuable indicator of pork quality. Keywords: drip loss, glycolytic resources, pork colour, post-mortem muscle metabolism

scholarly journals Comparing Gas and Electrical Stunning: Effects on Meat Quality of Pigs When Pre-Stunning Physical Activity Is Minimal

Foods ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 319
Author(s):  
E. M. Claudia Terlouw ◽  
Véronique Deiss ◽  
Thierry Astruc
Keyword(s):  
Physical Activity ◽  
Meat Quality ◽  
Muscle Metabolism ◽  
Carcass Characteristics ◽  
Muscle Contractions ◽  
Drip Loss ◽  
Post Mortem ◽  
Specific Effects ◽  
Longissimus Lumborum

A total of thirty pigs were experimentally slaughtered using gas (80% CO2 in air, 90 s; 30% CO2/70% N2O; 90 s) or electrical stunning (1.3 A, 10 s). Stunning may accelerate post-mortem muscle metabolism, due to psychological stress and/or muscle contractions. The specific effects of the stunning method were studied by limiting pre-stunning physical activity and stress: pigs were driven in a trolley from the rearing to the stunning site (6.5 m) and immediately slaughtered. Bleeding efficiency and carcass characteristics were similar and satisfactory for all stunning methods. Early post-mortem pH decline in the Longissimus lumborum was faster following gas compared to electrical stunning. The pH of other muscles was not influenced; color and drip loss showed minor effects. Hence, results are in contrast to current beliefs: compared to electrical stunning, following gas stunning, the stress and muscle contractions during the induction of unconsciousness have a slightly greater impact on Longissimus lumborum muscle metabolism; differences are minor and limited to certain muscles only.

scholarly journals Comparison of meat quality from Naïma and DanBred hybrid sows mated with P-76 boars

2022 ◽  
Vol 52 (1) ◽  
Author(s):  
Andrzej Zybert ◽  
Krystian Tarczyński ◽  
Halina Sieczkowska ◽  
Krzysztof Młynek
Keyword(s):  
Comparative Analysis ◽  
Meat Quality ◽  
Environmental Conditions ◽  
Lactate Concentration ◽  
Drip Loss ◽  
Post Mortem ◽  
Technological Quality ◽  
Imf Content

ABSTRACT: The objective of this study was the comparative analysis of selected attributes of nutritional and technological quality of pork from Naïma and DanBred gilts mated with P-76 boars. The research was carried on 50 pigs (25 in each group) reared under the same environmental conditions and slaughtered at about 115±5.0 kg. Both analyzed crossbreds populations were characterized by overall good nutritional and technological quality. However the loins from DanBred×P-76 compared with those from Naïma×P-76 had significantly greater glycogen and less lactate concentration in early post mortem period, higher pH at all measurement points (besides no statistical differences in pH measured 2 hours post mortem), lower thermal drip and drip loss measured 96 and 144 hours post mortem and lower lightness (except no differences measured 48 hours post mortem). Additionally loins from DanBred×P-76 contained more protein and less water. No statistical differences in IMF content between both analysed groups were noted (their average values were below 2%). Aforementioned may suggest that crossing both Naïma and DanBred hybrids with P-76 boars may not improve IMF content or increase marbling scores to the levels preferred for culinary purposes.

scholarly journals Post-mortem characterization of Dorper x Santa Inês lambs fed diets containing alternative foods

2021 ◽  
Vol 15 (4) ◽  
pp. 422-430
Author(s):  
Andrezza Miguel Silva ◽  
Cristiane Leal dos Santos-Cruz ◽  
Suely dos Santos Rocha ◽  
Márcio dos Santos Pedreira
Keyword(s):  
Castor Bean ◽  
Post Mortem ◽  
Sunflower Meal ◽  
Mineral Supplement ◽  
A Value ◽  
Muscle Ph ◽  
Longissimus Lumborum ◽  
Santa Inês ◽  
Cold Chamber

The objective of this study was to evaluate the post-mortem characteristics of lambs fed diets containing alternative foods. Twenty lambs, castrated Dorper x Santa Inês males, aged approximately 90 days and with mean weight of 20 kg were used. Experimental diets were composed of ground corn, soybean meal, mineral supplement, urea and Tifton-85 hay (forage). In addition to these ingredients, cottonseed, sunflower meal and castor bean cake were used as alternative foods in the proportions of 10, 8 and 8% of %DM, respectively. The experiment lasted 106 days, with 14 days for adaptation and 92 days for evaluation and data collection. At the end of the confinement period, the lambs were slaughtered, and the carcasses kept under cooling for a period of 24 hours. The measurements of pH, carcass temperature (internal and external) were measured in the Longissimus lumborum muscle, as well as the temperature and relative humidity of the cold chamber were measured. Muscle pH was altered as a function of diet and reached a value of 5.78 (lower pH) when lambs received the diet with castor bean cake. The internal carcass temperature was higher in the lambs that received the diet containing cottonseed (19.98°C), sunflower meal (19.71°C) and castor bean cake (19.87°C). The alternative foods can be used as ingredients in the formulation of diets for Dorper x Santa Inês lamb, for promoting the proper development of the post-mortem process, characteristic of good quality sheep meat.

scholarly journals Classification accuracy of different pork quality evaluation methods in assessment of meat with lowered drip loss

2021 ◽  
Vol 51 (10) ◽  
Author(s):  
Krystian Tarczyński ◽  
Andrzej Zybert ◽  
Halina Sieczkowska ◽  
Elżbieta Krzęcio-Nieczyporuk ◽  
Katarzyna Antosik
Keyword(s):  
Quality Evaluation ◽  
Threshold Value ◽  
Diagnostic Value ◽  
Evaluation Methods ◽  
Meat Sample ◽  
Pork Quality ◽  
Drip Loss ◽  
Threshold Values ◽  
Concentration Threshold

ABSTRACT: This study compared the diagnostic value of pork quality evaluation methods using different pH threshold values and time-points with muscle metabolites concentration threshold values measured 45 min. post mortem in assessment of meat with lowered drip loss. Samples of 100 longissimus dorsi (LD) (Landrace × Yorkshire) × Duroc fatteners were examined after slaughter for following parameters: muscle acidity in 35 min, 2 h, 3 h, 24 h and 48 h (pH1, pH2, pH3, pH24 and pH48), colour lightness (L*, a*, b*), meat yield after curing and thermal processing in 72 °C (technological yield), water-holding capacity (WHC) and drip loss in 48, 96 and 144 h (DL48, DL96, DL144). To verify the accuracy of analysed methods two groups were distinguished according to DL48, e.g. Low DL (DL48≤4%) and High DL (DL48>4%). In High DL pH1 to pH48 were statistically lower while L*, WHC, DL48, DL96, DL144 were statistically higher (P≤0.05). On the basis of pH-dependent methods classification to RFN (red, firm, normal), PSE (pale, soft, exudative), DFD (dark, firm, dry) and AM (acid meat) was performed and then the percentage share of Low DL and High DL among meat classified as RFN was evaluated. Despite most samples were classified as RFN Low DL share among them did not exceed 50%. If meat sample shows metabolites concentration below threshold value and was assigned to Low DL (or was assigned to High DL above threshold value) it was regarded as correctly classified. The most promising cut-off point (correct classification of 73%) was 45 µmol both for glycogen and lactate.

scholarly journals USEFULNESS OF SELECTED PARAMETERS DETERMINED 45 MINUTES POST MORTEM IN LONGISSIMUS LUMBORUM MUSCLE TO EVALUATE PORK QUALITY

2013 ◽  
Author(s):  
Halina Sieczkowska ◽  
Katarzyna Antosik ◽  
Elżbieta Krzęcio-Nieczyporuk ◽  
Andrzej Zybert ◽  
Maria Koćwin-Podsiadła
Keyword(s):  
Pork Quality ◽  
Post Mortem ◽  
Longissimus Lumborum

scholarly journals The effect of DanAvl Duroc and Pulawska boars in crossbred with DanAvl Hybrid on meat quality of finishing pigs

2018 ◽  
Vol 27 (3) ◽  
Author(s):  
Artur Rybarczyk ◽  
Robert Moroch ◽  
Daniel Polasik
Keyword(s):  
Meat Quality ◽  
Total Protein ◽  
Shear Force ◽  
Drip Loss ◽  
Finishing Pigs ◽  
Post Mortem ◽  
Lower Content ◽  
Lower Shear ◽  
Longissimus Lumborum

The research was aimed at determining the physicochemical and sensory properties of the m. longissimus lumborum at DanAvl Hybrid (Landrace – Yorkshire) fatteners and derived from DanAvl Hybrid sows and DanAvl Duroc and Pulawska boars. Fatteners derived from DanAvl Duroc boars were characterized by better meat quality compared to DanAvl Hybrids and their hybrids with Pulawska breed as evidenced by higher pH in 24–96 h post mortem (p.m.), higher sensory evaluation of juiciness, tenderness and flavor as well as lower shear force at lower content of total protein and higher content of intramuscular fat (IMF). However, DanAvl Hybrid fatteners were characterized by poorer meat quality, i.e. higher color lightness (L*) and higher drip loss both from fresh and thawed meat compared to those derived from DanAvl Duroc and Pulawska boars. Meat of fatteners after Pulawska breed was characterized by the highest redness (a*), and that after DanAvl Duroc breed, the lowest yellowness (b*) and saturation (C*).

scholarly journals Acute stress induced by the preslaughter use of electric prodders causes tougher beef meat

2007 ◽  
Vol 47 (7) ◽  
pp. 782 ◽  
Author(s):  
R. D. Warner ◽  
D. M. Ferguson ◽  
J. J. Cottrell ◽  
B. W. Knee
Keyword(s):  
Acute Stress ◽  
Muscle Metabolism ◽  
Water Holding Capacity ◽  
Eating Quality ◽  
Stress Treatment ◽  
Muscle Ph ◽  
Longissimus Lumborum ◽  
And Control ◽  
Water Holding ◽  
Adrenergic Activation

Adrenergic activation and hormone release preslaughter is an inevitable outcome of the systems used to move cattle to slaughter. The aim of this experiment was to investigate the effects of acute preslaughter stress in beef cattle on postmortem muscle metabolism and the meat quality, including consumer-assessed eating quality. Eighty-four cattle were used on three separate days, with ‘mobs’ of four cattle allocated to either a ‘control’ (no electric goads used preslaughter) or a ‘stress’ (six prods given with an electric goad over 5–10 min) treatment at 15 min preslaughter. Cattle undergoing the ‘stress’ treatment had higher plasma lactate at slaughter. The prerigor pH and temperature, ultimate pH and temperature at rigor of the longissimus thoracis muscle were similar between treatments (P > 0.05 for all). The water-holding capacity of the longissimus lumborum was reduced by the ‘stress’ treatment, as indicated by higher levels of water lost during suspension (drip loss), storage (purge) for 21 days and cooking (cooking loss at 1 day postslaughter) (P < 0.05 for all). ‘Stress’ cattle produced longissimus lumborum muscle with similar sarcomere lengths and Warner–Bratzler shear force at 2, 6 and 21 days, compared to ‘control’ cattle (P < 0.05 for all). The longissimus lumborum muscle of cattle undergoing the ‘stress’ treatment was rated less tender, less juicy, with a less acceptable flavour, a lower ‘liking’ and a lower MQ4 score (P < 0.05 for all). The ‘bloomed’ surface colour (CIE L*, a*, b*) of the longissimus lumborum muscle at 2, 6 and 21 days postslaughter was similar between the ‘stress’ and ‘control’ treatments (P > 0.05 for all). In conclusion, cattle subjected to acute preslaughter stress using electric goads produced meat which the consumer rated as tougher with inferior quality. The inferior quality induced by the acute stress treatment was associated with reduced water-holding capacity but was independent of muscle pH and temperature.

Effect of available dietary carbohydrate on glycolytic potential and meat quality of swine muscles

2002 ◽  
Vol 82 (3) ◽  
pp. 311-320 ◽  
Author(s):  
Giuseppe Bee
Keyword(s):  
Lactic Acid ◽  
Meat Quality ◽  
Dietary Treatment ◽  
Drip Loss ◽  
Post Mortem ◽  
Large White ◽  
Glycolytic Potential ◽  
Muscle Ph ◽  
Glycolytic Intermediates ◽  
Key Words Pig

The aim of this study was to determine whether glycolytic potential (GP) in pork muscle could be modified by the availability of carbohydrates in the diets and, if so, to what extent meat color and drip loss were affected. Biopsy samples of longissimus muscle (LM) from 48 Swiss Large White pigs (25 gilts, 23 barrows) weighing 70 kg were collected, and the GP was determined to vary from 111 to 187 μmol g-1 wet weight. At 90-kg body weight, pigs were moved into individual pens and assigned (blocked by GP and sex) to be fed 2.8 kg of a diet either high (H) or low (L) in available carbohydrate up to 104 kg. Pigs were fasted overnight (15 h) before slaughter. Glycogen, glucose, glucose-6-phosphate and lactic acid content were determined in samples of LM (predominantly glycolytic muscle) collected 30 min and 24 h post-mortem and in samples of the dark part of the semitendinosus (ST, oxidative part of the muscle) 24 h post-mortem. After slaughter, the decline in pH and temperature was recorded in the LM from 30 min to 24 h after bleeding. Regardless of the diet, content of glycolytic intermediates and lactic acid were higher in the LM compared to the ST. Diet did not alter the GP, and did not affect color or drip loss of the LM. However, in gilts fed the H diet muscle pH was lower by 0.2 units from 30 min until 6 h post-mortem than in gilts fed the L diet. These effects were not observed in barrows. ST of gilts fed the H diet had higher levels of glycolytic intermediates and lactic acid and, therefore, higher GP compared to gilts on the L diet, but no dietary effects occurred in barrows. Increased GP resulted in paler color and higher drip loss, whereas ultimate pH was not affected. The GP was positively correlated with L* (0.52), a* (0.49), b* (0.59) and drip loss (0.77) of the ST, whereas poor correlations were observed in the LM. In conclusion, dietary treatment only affected paleness and drip loss of the ST muscle and the effects were more pronounced in gilts than barrows. Increased GP resulted in paler meat with higher drip loss. Key words: Pig, glycolytic potential, meat quality, carbohydrate supply

scholarly journals Effect of ageing on the physicochemical properties of musculus longissimus lumborum of young bulls of five breeds

2017 ◽  
Vol 73 (12) ◽  
pp. 802-810 ◽  
Author(s):  
Piotr Domaradzki ◽  
Zygmunt Litwińczuk ◽  
Mariusz Florek ◽  
Paweł Żółkiewski
Keyword(s):  
Shear Force ◽  
Free Water ◽  
Cooking Loss ◽  
Water Holding Capacity ◽  
Drip Loss ◽  
Post Mortem ◽  
Black And White ◽  
Holstein Friesian ◽  
Longissimus Lumborum ◽  
Water Holding

Recent years have seen increasing interest in the conservation and use of native breeds of livestock raised in traditional farming systems. The experience of many European countries shows that promotion of raw materials and products derived from these breeds through a labelling system has a beneficial effect on the sustainable development of rural areas, contributes to preservation of the cultural heritage of the countryside, and increases the population of the breeds. As yet no beef produced in Poland has been included on the European list of traditional and regional products. For this reason we conducted a study to evaluate selected physicochemical properties of the meat of young bulls of three native breeds, Polish Red, White-Backed and Polish Black-and- White, compared with the meat of young Simmental and Polish Holstein-Friesian bulls, during a 14-day ageing of vacuum-packed meat. The following parameters were measured in m. longissimus lumborum (MLL) taken from half carcasses of 50 young bulls (10 from each breed): pH, electrical conductivity (45 min., 24 h, 2, 7 and 14 days post mortem), colour (according to CIE L*a*b*), shear force and energy. The water-holding capacity of the meat (drip loss, cooking loss and free water by the Grau-Hamm method), TBARS value (on days 2, 7 and 14) and content of haem pigments were determined as well. The physicochemical parameters of the MLL muscle obtained from the native Polish breeds of bulls (Polish Red, White-Backed and Polish Black-and-White) had intermediate values between those of Polish Holstein- Friesian (dairy type) and Simmental (dual-purpose) cattle. No qualitative deviations, such as those associated with DFD syndrome (pH 48 h in the range of 5.51-5.72), were found in any of the samples, which indicates that the raw material is well suited to the production of beef for culinary purposes. The breed of cattle was found to significantly influence the water-holding capacity parameters. The highest (P < 0.001) drip loss was reported on the 14th day post mortem for the MLL of young bulls of the Simmental (6.89%) and Polish Red breeds (6.47%). The highest cooking loss was found on the 7th day post mortem in the MLL of young bulls of the Polish Holstein-Friesian (30.66%) and Simmental breeds (30.92%). Significantly (P < 0.01) the least favourable water-holding capacity (the largest amount of free water) was shown by the muscle of young bulls of the Simmental breed on the 2nd day post mortem (75.31 mg) and the Polish Red breed on the 7th and 14th days post mortem (67.42 mg and 60.36 mg, respectively). On the 2nd and 7th days post mortem, the most tender MLL muscle was found (according to WBSF shear force) in the Polish Holstein-Friesian (76.8 N and 69.3 N) and Polish Black-and-White breeds (89.5 N and 59.1 N). On the last, 14th day of ageing, the instrumental WBSF shear force for the breeds evaluated was definitely more homogeneous and did not differ significantly (shear force in the range of 56.3-65.7 N; P > 0.05). Compared to the muscle of native breeds, that of the Polish Holstein-Friesians showed significantly lower haem pigments (on average 35 ppm less; P < 0.01) and a lower proportion of redness (a*) (P < 0.01) on the 2nd and 7th days post mortem. The MLL muscle of young bulls of the Polish Red breed had the lowest (P < 0.01) percentage content of yellowness (b*) during the whole ageing period. Significantly (P < 0.01) lower oxidative stability (higher TBARS value) was found in the meat from young bulls of the Polish Holstein-Friesian breed (on the 2nd and 7th days post mortem) and the White-Backed breed (on the 14th day) compared to all other breeds analysed. In general, the ageing time had a positive influence on the muscle quality, as the determinants of the visual and sensory attractiveness of the meat, which are also important in the meat industry, remained stable (pH), improved (colour and water-holding capacity G-H) or became more similar among the breeds (tenderness assessed on the basis of shear force, cooking loss)....

Dietary effects on exercising muscle metabolism and performance by 31P-MRS

1994 ◽  
Vol 77 (3) ◽  
pp. 1108-1115 ◽  
Author(s):  
D. E. Larson ◽  
R. L. Hesslink ◽  
M. I. Hrovat ◽  
R. S. Fishman ◽  
D. M. Systrom
Keyword(s):  
Minute Ventilation ◽  
Muscle Metabolism ◽  
Exercise Duration ◽  
Quadriceps Muscle ◽  
Peak Exercise ◽  
Crossover Fashion ◽  
Resonance Spectroscopy ◽  
Phosphorylation Potential ◽  
Beneficial Effects ◽  
Muscle Ph

To determine how diet modulates short-term exercise capacity, skeletal muscle pH and bioenergetic state were examined by 31P-magnetic resonance spectroscopy in nine healthy volunteers. Subjects performed incremental quadriceps exercise to exhaustion after 5 days of high-carbohydrate (HCHO) or high-fat (HFAT) diet randomly assigned in crossover fashion and separated by a 2.5-day period of ad libitum mixed diet. Simultaneous measurements were made of pulmonary gas exchange, minute ventilation, and quadriceps muscle pH and phosphorylation potential. At rest and peak exercise, respiratory exchange ratio and minute ventilation were higher after HCHO than after HFAT (P < 0.05), reflecting greater CHO utilization. Peak O2 consumption (VO2) was not increased after HCHO (P > 0.05), but exercise duration was (339 +/- 34 s for HCHO vs. 308 +/- 25 s for HFAT; P < 0.05). HCHO was associated with a blunted early fall of phosphocreatine (PCr)/Pi vs. VO2 (-4.1 +/- 0.7 x 10(-2) min/ml for HCHO vs. -5.6 +/- 1.2 x 10(-2) min/ml for HFAT; P < 0.05). On both study days, the slope of PCr/Pi vs. VO2, before and after the PCr threshold, was correlated with exercise time. The results suggest that a diet rich in CHO improves exercise efficiency through beneficial effects on intracellular phosphorylation potential.

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