• Asian-Australasian Journal of Animal Sciences
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• v.20 no.8
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• pp.1285-1291
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• 2007

This research investigated variation in the improvement of the texture of chicken and pork sausages induced by microbial transglutaminase (MTG). The extractability of myofibrillar proteins from these sausages as well as the ${\varepsilon}-({\gamma}-glutamyl)$lysine (G-L)　content were also investigated. MTG treatment of sausages significantly increased the breaking strength values in both meat types, especially for samples incubated at $40^{\circ}C$. However, values of the breaking strength in both meat types were increased differently. The variation in protein extractability of samples incubated at $40^{\circ}C$ for both meat types could lead to some consideration of the mechanisms and the high accessions of myosin heavy chain (MHC) to MTG. SDS-PAGE analysis showed significant changes in the density of the bands after adding MTG, especially for the pork samples in which the bands disappeared totally. The G-L content in the presence of MTG was double that in control samples of both meat types. This study suggests that the binding ability of myofibrillar proteins with MTG is strong. This leads us to suggest that MTG functions positively with different improvements in the texture of chicken and pork products that are treated mechanically, such as sausages. Variability in gel improvement level between chicken and pork sausages was observed; this resulted from the variation in meat proteins in response to MTG, as well as to the original glutamyl and lysine content.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.4
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• pp.333-338
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• 1986

Compositions of protein and amino acid in the muscle of crucian carp, Carassius carassius, and snakehead, Channa argus, were determined by amino acid autoanalyzer, and the protein subunits composed of sarcoplasmic and myofibrillar proteins were also analyzed by sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis. The crucian carp muscle contained about $14.7\%$ of protein, and the protein was composed of $32.6\%$ in sarcoplasmic, $62.0\%$ in myofibrillar, $4.9%$ in alkali soluble and $0.6\%$ in stroma protein. The snakehead muscle, on the other hand, contained about $16.1\%$ of protein, and $30.7\%,\;64.1\%,\;4.7\%\;and\;0.4\%$ in the above order. The sarcoplasmic and myofibrillar proteins were composed of 10 and 19 subunits respectively, in the crucian carp, and 12 and 18 subunits in the snakehead. The total amino acid compositions in the muscle of the crucian carp and snakehead were found to be very similar except lysine and glutamic acid. The major amino acids of their muscle protein were lysine, glutamic acid, arginine and aspartic acid in order. In free amino acid content of the crucian carp, histidine occupied $52\%$ of the total free amino acid, and glutamic acid, glycine and taurine did $85\%$ in case of snakehead.

• Journal of Fisheries and Marine Sciences Education
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• v.3 no.2
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• pp.47-72
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• 1991

To obtain the principal data for useful treatment and processing of Korean geoduck (Panope japonica A. ADAMS) which inhabit mostly at Dong-Hae coastal area in Korea, changes of $NH_2$-N, TMAO, TMA, total creatinine, protein composition and fatty acid composition in raw and blanched geoduck muscle during storage at $-20^{\circ}C$ were investigated. In addition, its chemical composition variation in the whole year was elucidated. The moisture content in geoduck muscle meat was 78.1% to 82% in the whole year. Particularly, in July its moisture content was maximum as 82% and in September minimum as 78.1%. Crude protein was in the range of 12.3-16.4%, crude lipid the average was 1.5%, crude ash on the average was 1.4%. The abundant fatty acids in geoduck muscle oil were $C_{16}$ : 0, $C_{16}$ : 1, $C_{18}$ : 0, $C_{18}$ : 1, $C_{20}$ : 5, and $C_{22}$ : 6 acids. During storage at $-20^{\circ}C$, content of unsaturated fatty acid such as eicosapentaenoic acid (EPA, $C_{20}$ : 5) and docosahexaenoic acid (DHA, $C_{22}$ : 6)in raw geoduck muscle decreased somewhat and the raw geoduck was slightly oxidized. Trimethylamine (TMA), volatile basic nitrogen (VBN)and $NH_2$-N of raw muscle increased compared to blanched muscle. Trimethylamine oxide (TMAO) was slightly decreased during the storage period. The muscle protein was approximately composed of 37% sarcoplasmic, 29% myofibrillar, 22% alkali soluble, and 12% stroma protein. Among several proteins, myofibrillar protein content decreased mostly, while the alkali-soluble and stroma protein content increased slightly during storage at $-20^{\circ}C$.

• Perspectives in Nursing Science
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• v.2 no.1
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• pp.19-36
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• 2005

Muscle atrophy is defined as a decrease in muscle mass, cross-sectional area, and myofibrillar protein content. Causes inducing muscle atrophy may be inactivity, denervation, undernutrition and steroid. Inactivity may decrease protein synthesis and increase protein breakdown of skeletal muscle. The muscle atrophy due to inactivity was induced by bed rest, hindlimb suspension, cast, total hip replacement arthroplasty, anterior cruciate ligament reconstruction. Denervated atrophy may be induced by the loss of innervation from lower motor neuron. The atrophy was apparent in the lower limb of hemiplegic patients following ischemic stroke and in the hindlimb of ischemic stroke rats. Protein breakdown of skeletal muscle in the undernourished state results in muscle atrophy. The atrophy due to undernutrition was evident in cancer and leukemia patients and in the undernourished rats. Steroids have been used to treat allergies, inflammatory diseases, autoimmune diseases and to inhibit immune function following transplantation. Steroids may induce muscle atrophy by protein breakdown of skeletal muscle. Muscle Physiology Laboratoryat College of Nursing, Seoul National University proved that dexamethasone may induce hindlimb muscle atrophy in rats and exercise and DHEA may attenuate hindlimb muscle atrophy induced by the steroid in rats. Nurses working with patients undergoing steroid treatment need to be cognizant of steroid induced muscle atrophy. They need to assess whether muscle atrophy is being occurred during and after the steroid treatment. Moreover, they need to apply exercise and DHEA to the patients undergoing steroid treatment in order to attenuate the steroid induced muscle atrophy.

• Journal of Animal Science and Technology
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• v.62 no.4
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• pp.533-542
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• 2020

The objective of this study was to observe the interactions between salt-soluble proteins extracted from beef and elephant foot yam (Amorphophallus campanulatus) flour in heat-induced gel matrix development. The effect of salt concentration; 0.5%, 1.0%, 1.5%, and 2.0% in weight/weight basis (w/w), during protein extraction on pH, salt-soluble protein concentration and myofibril fractions of beef extract was determined firstly, and no significant effect was found. The beef salt-soluble proteins extracted using salt solution at different concentrations were then added with elephant foot yam flour at 5%, 10%, and 15% w/w, gelatinized at 90℃ for 20 min, and cooled down at 4℃ for 12 h. The interactions between beef salt-soluble proteins and elephant foot yam flour resulted in an improved gel strength (p < 0.01) and the addition level of elephant foot yam flour affected the pH, instrumental color, moisture, crude protein, and ash content significantly. The addition of elephant foot yam flour also reduced the size of the pores in the gel matrix as shown by scanning electron microscope (SEM) photographs. These suggest that elephant foot yam flour well interacts with beef salt-soluble proteins to form gel matrix.

• Food Science of Animal Resources
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• v.44 no.4
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• pp.779-789
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• 2024

The effects of irradiation on meat constituents including water, proteins, and lipids are multifaceted. Irradiation leads to the decomposition of water molecules, resulting in the formation of free radicals that can have both positive and negative effects on meat quality and storage. Although irradiation reduces the number of microorganisms and extends the shelf life of meat by damaging microbial DNA and cell membranes, it can also accelerate the oxidation of lipids and proteins, particularly sulfur-containing amino acids and unsaturated fatty acids. With regard to proteins, irradiation affects both myofibrillar and sarcoplasmic proteins. Myofibrillar proteins, such as actin and myosin, can undergo depolymerization and fragmentation, thereby altering protein solubility and structure. Sarcoplasmic proteins, including myoglobin, undergo structural changes that can alter meat color. Collagen, which is crucial for meat toughness, can undergo an increase in solubility owing to irradiation-induced degradation. The lipid content and composition are also influenced by irradiation, with unsaturated fatty acids being particularly vulnerable to oxidation. This process can lead to changes in the lipid quality and the production of off-odors. However, the effects of irradiation on lipid oxidation may vary depending on factors such as irradiation dose and packaging method. In summary, while irradiation can have beneficial effects, such as microbial reduction and shelf-life extension, it can also lead to changes in meat properties that need to be carefully managed to maintain quality and consumer acceptability.

• Food Science of Animal Resources
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• v.43 no.2
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• pp.269-281
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• 2023

In this study, we evaluate the effect of gelatin coating and sonication of wet-aged pork loin on quality. The moisture content of wet-aged pork loin with sonication and gelatin coating was the highest in the G5S sample (5% gelatin coating and sonication), while the moisture content of wet-aged pork loin with sonication was higher than that without sonication. The pH of wet-aged pork loin with sonication was lower than that without sonication. The aging loss of 5% gelatin coating with sonication was significantly lower than that of G0 (control), while the cooking loss was the lowest in G0 wet-aged pork loin. The water holding capacity of the wet-aged pork loin was the highest in G1. The thiobarbituric acid reactive substances value of wet-aged pork loin was significantly decreased with coating and not affected by sonication. The gelatin coating and sonication treatment significantly increased the myofibrillar fragmentation index of the samples. Shear force of wet-aged pork loin significantly decreased as the samples were gelatin-coated and sonicated. The myofibrillar and total protein solubilities were not significantly different between samples. In conclusion, the 1% gelatin coating with sonication can enhance the quality of wet-aged pork loin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.6
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• pp.1288-1292
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• 1999

The physicochemical properties and palatability of Hanwoo(cow, steer, and bull) beef loin(1＋ carcass grade) were studied. pH(5.56~5.69), moisture content(67.6~69.0%), crude protein content(17.8~18.7%), and crude fat content(11.9~13.8%) of Hanwoo beef loin did not show significant difference between the types of Hanwoo. L(44.5~46.9), a(19.9~20.6), and b(10.3~11.6) color parameters, water holding capacity (69.4~70.5%), volatile basic nitrogen content(9.86~11.28mg%), thiobarbituric acid value(0.148~0.158 mg malonaldehyde/kg), and cooking loss(26.3~27.9%) of beef loin did not show significant difference between the types of Hanwoo either. Hardness, myofibrillar fragmentation index(MFI), and chewiness of beef loin were 6.1~6.9 dyne/cm2, 50.3~54.9, and 39.5~ 52.0g, respectively. No differences were found in hardness and MFI between the types of Hanwoo, while chewiness of cow was much lower than that of steer and bull(p<0.05). Cow was the best in palatability.

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.728-734
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• 2007

In this study, we prepared surimi from pork leg and chicken breast by pH adjustments of 3.0 and 11.0. The content of crude protein, yield, water-holding capacity, redness, yellowness, myoglobin(Mb) and metmyoglobin(metMb) were significantly higher in the surimi manufactured from pork leg at adjustment pH 3.0 compared to the other surimi samples; whereas whiteness, myofibrillar protein, breaking force, deformation and gel strength were lower than other samples(P<0.05). The textural attributes were significantly higher in the surimi manufactured from pork leg at adjustment pH 11.0 compared to the other surimi samples; whereas Mb, metMb, cooking loss, breaking force, deformation and gel strength were lower than other samples(P<0.05). Again, the content of crude protein, yield, pH, breaking force, deformation, gel strength and lightness were significantly higher in the surimi manufactured from chicken breast at adjustment pH 3.0 compared to the other surimi samples; whereas myofibrillar protein, redness and metMb were higher than other samples(P<0.05). The content of myofibrillar protein, deformation, lightness and cohesiveness were significantly higher in the suriml manufactured from chicken breast at adjustment pH 11.0 compared to the other surimi samples; whereas Mb, cooking loss, yield and breaking force were higher than other samples(P<0.05). The chicken breast surimi had superior color and gel characteristics than manufactured from pork leg, and adjustment pH 11.0 had superior whiteness and cohesiveness than the pH 3.0 adjusted sample, however, there were no significant differences in sensory attributes among the surimi samples.

• Korean Journal of Food Science and Technology
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• v.7 no.4
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• pp.221-228
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• 1975

Meat tenderness is one of the most important factors in meat products because it plays a major role in the palatability of meat. To get information on the role of commercial meat tenderizer, the tenderizing ability of commercial meat tenderizer was measured with various substrates. The results obtained are as follows. 1. Content of crude protein in a commercial meat tenderizer was 4.9%. 2. Optimum temperature for proteolytic activity of meat tenderizer was $60{\sim}70^{\circ}C$. 3. Maximal activity of proteinase was obtained at pH $6{\sim}7$. 4. Proteolytic enzyme was activated by KCN, NaCN, EDTA. Thus, it was concluded that protease system of commercial meat tenderizer composed of plant origin proteinases. 5. Proteinase activity was completely inhibited by 10mM of N-Ethylmaleimide. 6. Commercial meat tenderizer showed stronger proteolytic activity on casein than on the water soluble fraction of meat protein, whereas it hydrolyzed the myofibrillar protein less efficiently.