• Journal of Animal Science and Technology
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• v.65 no.1
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• pp.160-174
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• 2023

The purpose of this study was to compare marbling score, meat quality, juiciness, sarcomere length, and skeletal muscle satellite cell (SMSC) growth and related gene expression between Woori black pig (WB) and the Landrace, Yorkshire, and Duroc (LYD) crossbreed at different body weights (b.w.). WB was developed to improve meat quality and growth efficiency by crossbreeding Duroc with Korean native black pig. A total of 24 pigs were sacrificed when their b.w. reached about 50, 75, 100, and 120 kg. SMSC were isolated from the femoris muscles, and muscle and adipose tissues were sampled from the middle and the subcutaneous part of the femoris of hind legs, respectively. Expression levels of genes including Myoblast determination protein 1 (MyoD), Paired box gene 3 (Pax3), Myosin heavy chain (MyHC), and Myogenin, which are responsible for the growth and development of SMSC, were higher in LYD than the WB. Muscle growth inhibitor myostatin (MSTN), however, was expressed more in WB compared to LYD (p < 0.01). Numbers of SMSC extracted from femoris muscle of LYD at 50, 75, 100, and 120 kg b.w. were 8.5 ± 0.223, 8.6 ± 0.245, 7.2 ± 0.249, and 10.9 ± 0.795, and those from WB were 6.2 ± 0.32, 6.2 ± 0.374, 5.3 ± 0.423, and 17.1 ± 0.315, respectively. Expression of adipogenic genes in adipose tissue including CCAAT/enhancer-binding protein (CEBP)-β, peroxisome proliferator activated receptor (PPAR)-γ, and fatty acid synthase (FASN), were greater in WB when compared with LYD (p < 0.01). Results from the current study suggest that different muscle cell numbers between 2 different breeds might be affected by related gene expression and this warrants further investigation on other growth factors regulating animal growth and development.

• Journal of Animal Science and Technology
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• v.46 no.1
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• pp.97-106
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• 2004

The study was conducted to investigate the effects of practical variations in feed restriction, pre-slaughter handing and chilling regime on pork quality during ageing. A total of twenty male landraces were allocated into three treatments(i.e., pre-slaughter feeding, stress and chilling regime) in a factorial arrangement. pH, temperature, free calcium ions, WB-shear force, sarcomere length, cooking loss, drip loss and objective color were determined during rigor development and/or 1, 3, 7 d postmortem. Pre-slaughter chasing stress for approximately 15 min had no effects on pH/temperature profile and objective meat quality. There was an interaction(P < 0.05) between the fasting treatment and chi1ling regime for muscle temperature at pH 6.2. Sarcomere length indicated that the current experiment conditions did not induce muscle shortening, with 1.7 to 1.8 ${\mu}m$, in spite of a significant effect of the fasting treatment (P<0.01). Pigs fed until the morning of slaughter showed a low WB-shear force(P < 0.05) until 3 d at I "C. The treatment also resulted in a higher Hunter L* and a*(P < 0.05) at 24 h and 7 d. Fasted pigs showed a significantly(P < 0.05) reduced cooking loss. The current results indicated that feeding upon the morning of slaughter became detrimental on meat color and the negative effect on cooking loss were linearly elevated with increased ageing time. On the other hand, WB-shear force did not distinguishable after 3 d. Collectively, it appeared that feed restriction from a day before slaughter could produce more a desirable meat quality at the time of consuming. However, the limited effect of animal handling and chilling rate on meat quality is not necessarily to extend to that these do not affect pork quality, as that largely depends on experimental design.

• Korean Journal of Food Science and Technology
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• v.26 no.1
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• pp.88-92
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• 1994

The influence of the storage temperature between $0^{\circ}C$ and $30^{\circ}C$ on the biochemical, physical changes and meat qualities in the red muscle(M. sternomandibularis and M. mastoideus) of Korean native cattle postmortem were studied. The results obtained were summarized as follows; The pH-value during the first hours post mortem was dropped faster in storage temperature $0^{\circ}C$ than in $10^{\circ}C$, but the final pH-value reached after about 30 hrs. post mortem. The muscle which was stored in $30^{\circ}C$ reached the final pH within 10 hrs. The muscle which was stored in $0^{\circ}C$ showed the increased R-value at fast speed from the beginning. It reached maximum R-value after 20 hrs as it gradually increase showing low R-value by 10 hrs. in $10^{\circ}C$. The muscle which was stored in $0^{\circ}C$ shortened to about 46% after 10 hrs. It was contracted about 17% after 15 hrs in $10{\sim}20^{\circ}C$. The sarcomere length of Korean native cattle had the least contraction in $10^{\circ}C$ and it was contracted $18{\sim}20%\;(1.60{\sim}1.63\;{\mu}m)$ after 5 hrs., $45{\sim}46%$after 24 hrs in $0^{\circ}C$ and $30^{\circ}C$ which was generated cold shortening and rigor shortening. The meat that was stored in $0^{\circ}C$ and $30^{\circ}C$ showed about 2-fold higher shear force than it that was stored in $10^{\circ}C$ at postmortem 24 hrs. The meat that was stored in $10^{\circ}C$ at postmortem 24 hrs. showed drip loss less than 3% during the 9 days ripening period. The meat with cold shortening and rigor shortening showed the high drip loss.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.2
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• pp.114-120
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• 1994

To clarify the effect of storage temperature on the morphological and histological changes of plaice, Paralichthys olivaceus muscle at early stages after killing, the changes in breaking strength of muscle, morphological observation of myofibrils and histological observation of extracellular spaces during storage at $0^{\circ}C\;and\;10^{\circ}C$ were studied. The maximum breaking strength of samples stored at $0^{\circ}C$ was reached within 10hrs and then it dropped significantly (p<0.05) from 10hrs to 25hrs of storage. However, breaking strength was not increased in fresh muscle stored at $10^{\circ}C$ and gradually decreased after 10hrs storage. In myofibrils prepared from dorsal muscle immediately after death, A-band, I-band, H-band and Z-line in sarcomere were clearly distinguishable from each other. Due to muscle contraction, it was not easy to distinguish H-band from I-band observed in sarcomere stored at $0^{\circ}C$ after 10hrs storage. But, in the case of samples stored at $10^{\circ}C$, H-band could be observed dimly until 15hrs of storage. The changes in morphological myofibrils were closely related to increase of breaking strength. No extracellular space was observed among muscle cells immediately after killing. Stored samples at $0^{\circ}C$ showed extracellular spaces after 15hrs storage. On the other hand, samples stored at $10^{\circ}C$ didn't show any extracellular spaces until 15hrs storage and showed extracellular spaces after 24hrs storage. It was thought that the post-mortem tenderization of plaice muscle was closely related to the gradually disintegration of the extracellular matrix structure after killing.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.4
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• pp.327-334
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• 1994

This study was undertaken to clarify the effect of killing methods on the morphological and histological changes of plaice, Paralichthys olivaceus muscle at early stage after killing. Killed samples by the three different methods were stored at $5^{\circ}$, and the changes in breaking strength of muscle, morphological observation of myofibrils and histological observation of extracellular spaces through storage were monitored. Samples killed by electrifying in sea water showed the maximum value of breakin strength immediately after killing and then it dropped significantly(p<0.05) until 2.5hrs passed. Breaking strength of samples killed by spiking at the head instantly and dipping in sea water including anesthetic rose steadily over 10hrs and 15hrs after killing, respectively. In myofibrills prepared from dorsal muscles immediately after spiking at the head instantly, A-band, H-band, I-band, and Z-line in sarcomere were clearly distinguishable each other. Due to muscle contraction by electrical stimulation, it was impossible to distinguish H-band from I-band observed in sarcomere immediately after killing for samples killed by electrifying. But, in the cases of samples killed by spiking and dipping, H-band could be observed dimly until 10hrs and 15hrs storage. No extracellular space was observed among muscle cells immediately after spiking at the head instantly. Samples killed by spiking at the head instantly and dipping in sea water including anesthetic showed extracellular spaces among all muscle cells after 15hrs and 25hrs storage, respectively. The other hand, samples killed by electrifying in sea water (110V, 30sec.) showed a few extracellular spaces immediately after killing and then it showed extracellular spaces among all muscle cells after 2.5hrs storage.

• Journal of Animal Science and Technology
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• v.46 no.5
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• pp.821-832
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• 2004

A total of 80 pigs were used to investigate the effect of dietary glycine betaine(N,N,N-trimethylglycine) on pork quality during cold storage. About 70 kg pigs were randomly a1loted into one of four experimental diet groups(0%, 0.2%, 0.4% and 0.6% glycine betaine). Pigs were slaughtered at approximately 110 kg live weight, and pH, color(CIE $L^* a^* b^*$), shear force, sarcomere length, lipid oxidation and composition of fatty acid were measured in pork loin for 13 days of cold storage. The concentration of glycine betaine in pork loin was significantly increased(P<0.05) with increasing of glycine betaine level in diet. Pork loins from dietary betaine groups showed significantly higher muscle pH and lower CIE $b^*$ values compared to control group after 13 days of storage. There were significant differences in shear force values among pork loins from diet groups at 24 hrs postmortem. However, pork loins from control diet showed longer sarcomere length than those of dietary betaine groups. Dietary glycine betaine increased the ratio of saturated fatty acids and decreased unsaturated fatty acids in pork loins. Especially the ratios of linoleic and myristic acid were decreased with increasing dietary betaine level. However, dietary glycine betaine did not affect lipid oxidation (TSARS) and sensory evaluation during cold storage.

• Applied Microscopy
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• v.19 no.1
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• pp.1-18
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• 1989

It has been debated whether postischemic reperfusion is necessarily beneficial to salvage the myocardium after ischemic insult or not. Therefore, this study was undertaken to compare the ultrastructural changes as well as the distribution of $Ca^{2+}$ in the ventricular myocardial cells after transient ischemia and after postischemic reperfusion, and to suspect to what extent the postischemic reperfusion is beneficial. After 10 minutes of ischemia, the heart developed wide I bands, glycogen depletion, intramyofibrillar edema, mitochondrial swelling, clumping and migration of chromatin, ghosts of lipid droplets, disintegration of cell junctions, sarcolemmal disruption, and loss of $Ca^{2+}$ binding capacity of the sarcolemma and the mitochondria. In spite of reperfusion, in a large number of cells, the ultrastructure was more severely damaged, however, $Ca^{2+}$ binding capacity of the sarcolemma and the mitochondria restored. These results suggest that postischemic reperfusion may help the myocardial cells to restore their function to control $Ca^{2+}$ to a certain extent, but that it could aggravate the ischemic insult.

• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.921-932
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• 2006

Management to improve beef tenderness is always been a historical idea, but during the recent past it has become an issue of prime importance to the meat scientists and the industries as well. Variation in tenderness is the prime explanation for consumer’s dissatisfaction for the concern meat. It has been well documented that both postmortem proteolysis and sarcomere length have significant effect on meat tenderness and its consistency. Electrical stimulation and tenderstretch techniques have been used by a number of countries to underpin carcass quality assurance schemes focused on eating quality. The mechanism(s) by which the postmortem interventions improve tenderness (or prevent toughness) has not been fully elucidated. However, it is evident that electrical stimulation accelerates the development of rigor mortis so that prevention of cold shortening is possible and ageing commences at higher temperatures. On the other hand, tendersretch appears to prevent meat toughness via placing tension of the myofibrils and connective matrix during rigor development. Previous findings indicated that electrical stimulation and tenderstretch improved beef tenderness even for fattened cattle under moderate chilling conditions. Recent studies demonstrate beef tenderness to be one of the most important factors determining satisfaction levels of Korean beef consumers. There are number of studies which reported that electrical stimulation and tenderstretch techniques improved Hanwoo tenderness and color. It is believed that the techniques are mostly useful wherein controls of carcass size, fatness and/or chilling regimes are not easy such as Korean beef industry. However, Korean beef industry is one such area where postmortem intervention techniques have not been adopted so far. Taking into consideration of the Korean beef industry, wherein carcass size and fatness varies the post-slaughter intervention technique could be the most feasible measurement to ensure eating quality. The manuscript attempts to highlight the current knowledge aiming primarily towards the assurance of beef tenderness.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.3
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• pp.424-431
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• 2007

The aim of this study was to determine the effects of short road transportation in an open truck during hot season on live weight shrink, physiological responses, and carcass and meat quality of Omani sheep at 6 and 12 months of age. Thirty-six male sheep, 18 of each age group, were used. Age groups were assigned randomly to transported and not-transported groups. The transported group was transported to the slaughterhouse the day of slaughter in an open truck covering a distance of approximately 100 km. The average temperature during transportation was $37^{\circ}C$. The not-transported group was kept in a lairage of a commercial slaughterhouse with ad libitum feed and water for 48 h prior to slaughter. Blood samples were collected from sheep before loading and prior to slaughter via jugular venipuncture to assess their physiological response to transport in relation to hormonal levels. Animals were weighed just before loading onto a truck and after transport to assess shrinkage. Muscle ultimate pH, expressed juice, cooking loss percentage, WB-shear force value, sarcomere length and colour L*, a*, b* were measured on samples from longissimus dorsi, biceps femoris and semitendinosus muscles collected at 24 h postmortem at $1-3^{\circ}C$. Live weight shrinkage losses were 1.09 and 1.52 kg for 6 and 12 month transported sheep, respectively. The transported sheep had significantly (p<0.05) higher cortisol, adrenaline, noradrenaline, and dopamine concentration levels prior to slaughter at both ages than the not-transported sheep. Transportation significantly influenced meat quality characteristics of three muscles. Muscle ultimate pH and shear force values were significantly higher, while CIE L*, a*, b*, expressed juice and cooking loss were lower in transported than not-transported sheep. Age had a significant effect on meat quality characteristics of Omani sheep. These results indicated that short-term pre-slaughter transport at high ambient temperatures can cause noticeable changes in physiological and muscle metabolism responses in sheep.

• Food Science of Animal Resources
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• v.26 no.1
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• pp.43-48
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• 2006

To investigate the effect of boning time and storage temperature on meat quality of duck breast, a total of thirty duck breasts were designed in frozen-thawed, chilled-storage, and cold-boning samples. No significant differences were found among pH of all samples. However, cold-boning samples showed significantly (p<0.05) lower cooking loss than the other samples. Frozen-thawed samples showed significantly (p<0.05) higher lightness ($L^*$) and yellowness($b^*$), shorter sarcomere length and higher shear force values compared to the other samples. The result speculated that muscle shortening was affected by lower temperature (frozen) hence tenderness was decreased. Sarcoplasmic protein solubility showed no significant differences among samples, whereas cold-boning samples showed significantly (p<0.05) higher myofibrillar and total protein solubility than the other samples. The result of sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) patterns, chilled-storage and cold-boning samples showed degradation at high molecular protein (nebulin), which was not observed in frozen-thawed samples. Therefore, this data suggested that muscle shortening, tenderness and protein degradation are not affected by boning time rather affected by rapid change of temperature in frozen-thawed samples.