• Food Science of Animal Resources
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• v.34 no.6
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• pp.808-814
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• 2014

This study investigated the effect of gum arabic (GA) combined with microbial transglutaminase (TG) on the functional properties of porcine myofibrillar protein (MP). As an indicator of functional property, heat-set gel and emulsion characteristics of MP treated with GA and/or TG were explored under varying NaCl concentrations (0.1-0.6 M). The GA improved thermal gelling ability of MP during thermal processing and after cooling, and concomitantly added TG assisted the formation of viscoelastic MP gel formation. Meanwhile, the addition of GA decreased cooking yield of MP gel at 0.6 M NaCl concentration, and the yield was further decreased by TG addition, mainly attributed by enhancement of protein-protein interactions. Emulsion characteristics indicated that GA had emulsifying ability and the addition of GA increased the emulsification activity index (EAI) of MP-stabilized emulsion. However, GA showed a negative effect on emulsion stability, particularly great drop in the emulsion stability index (ESI) was found in GA treatment at 0.6 M NaCl. Consequently, the results indicated that GA had a potential advantage to form a viscoelastic MP gel. For the practical aspect, the application of GA in meat processing had to be limited to the purposes of texture enhancer such as restructured products, but not low-salt products and emulsion-type meat products.

• Food Science of Animal Resources
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• v.39 no.4
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• pp.576-584
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• 2019

This study was performed to evaluate the physicochemical properties of myofibrillar protein (MP) gels containing pork skin gelatin at different salt concentrations. MP gels were prepared to the different salt levels (0.15, 0.30, and 0.45 M) with or without 1.0% of pork skin gelatin. Cooking yield (CY), gel strength, shear stress were measured to determine the physical properties, and SDS-polyacrylamide gel electrophoresis, scanning electron microscopy, fourier transform infrared spectroscopy, sulfhydryl group and protein surface hydrophobicity was performed to figure out the structural changes among the proteins. The addition of gelatin into MP increased CYs and shear stress. MP at 0.45 M salt level had the highest CY and shear stress, as compared to MPs at lower salt concentrations. As the salt concentration of MP gels increased, the microstructure became the compact and wet structures, and decreased the amount of ${\alpha}-helix$/unordered structures and ${\beta}-sheet$. MP with gelatin showed a decreased amount of ${\alpha}-helix$/unordered structures and ${\beta}-sheet$ compared to MP without gelatin. The addition of gelatin to MP did not affect the sulfhydryl group, but the sulfhydryl group decreased as increased salt levels. MP mixtures containing gelatin showed a higher hydrophobicity value than those without gelatin, regardless of salt concentration. Based on these results, the addition of gelatin increased viscosity of raw meat batter and CY of MP gels for the application to low salt meat products.

• Fisheries and Aquatic Sciences
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• v.25 no.1
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• pp.31-39
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• 2022

To clarify the factors influencing the physical properties of fish after heat treatments, we investigated changes in the properties of proteins in the dorsal ordinary and dark muscle of yellowtail (Seriola quinqueradiata) heated under different conditions commonly used for the purposes of food hygiene. High-temperature/short-time heating (85℃ for 90 s and 75℃ for 60 s) affected the protein solubility more than low-temperature/long-time heating (63℃ for 30 min). Sodium dodecyl sulphate-polyacrylamide gel electrophoresis and differential scanning calorimetry showed that low-temperature/long-time heating reduced the degree of actin denaturation in fish compared with that by other heating conditions. In addition, collagen solubility was enhanced with low-temperature/long-time heating. Therefore, these results suggest that differences in the degree of actin and collagen denaturation are responsible for the enhanced meat tenderness and diminished meat shrinkage, resulting from low-temperature/long-time heating.

• Food Science of Animal Resources
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• v.42 no.5
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• pp.723-743
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• 2022

Beef muscles from mature cows and bulls, especially those originating from the extremities of the carcass, are considered as underutilized due to unsatisfactory palatability. However, beef from culled animals comprises a substantial proportion of the total slaughter in the US and globally. Modern consumers typically favor cuts suitable for fast, dry-heat cookery, thereby creating challenges for the industry to market inherently tough muscles. In general, cull cow beef would be categorized as having a lower extent of postmortem proteolysis compared to youthful carcasses, coupled with a high amount of background toughness. The extent of cross-linking and resulting insolubility of intramuscular connective tissues typically serves as the limiting factor for tenderness development of mature beef. Thus, numerous post-harvest strategies have been developed to improve the quality and palatability attributes, often aimed at overcoming deficiencies in tenderness through enhancing the degradation of myofibrillar and stromal proteins or physically disrupting the tissue structure. The aim of this review is to highlight existing and recent innovations in the field that have been demonstrated as effective to enhance the tenderness and palatability traits of mature beef during the chilling and postmortem aging processes, as well as the use of physical interventions and enhancement.

• Korean Journal of Food Science and Technology
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• v.22 no.6
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• pp.640-645
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• 1990

Changes of the electrophoretic patterns of myofibrillar proteins by sugar audition and heat treatment was studied. In the electrophoretic patterns of myofibrills prepared from no sugar added meat, as the intensity of higher molecular weight band such as myosin heavy chain showed a remarkable decrease by heating, that of lower molecular weight band such as actin showed no change. That from sugar added meat showed more remarkable decrease in the intensity of higher molecular weight band than that from no sugar added meat and this tendency was most noticeable in case of glucose addition. The effect of digestion with proteases after sugar addition and heat treatment on the electrophoretic patterns exhibited the descending order of trypsin >chymotrypsin >peptidase. By digestion with these three enzymes at one time myosin produced 27.000 dalton and 32.000 dalton components, and actin showed 16,000 dalton component. in the case of heat treatment, a part of actin was not digested. And in the case of glucose addition the myosin aggregates was not digested with these three enzymes at a time.

• Food Science of Animal Resources
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• v.38 no.5
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• pp.950-958
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• 2018

The physicochemical characteristics and oxidative stability of wet-aged and dry-aged pork cuts were investigated at different aging periods (1, 7, 14 and 21 d). Samples were assigned into four groups in terms of shoulder blade-wet aging (SW), shoulder blade-dry aging (SD), belly-wet aging (BW), and belly-dry aging (BD). SD showed significantly higher pH at 21 d of aging than the other samples. Wet-aged cuts had significantly higher released water (RW) %, lightness ($L^*$) and shear force compared to the dry-aged meats. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed greater degradation of proteins for dry-aged cuts than the wet-aged cuts. At the end of aging, wet-aged cuts showed significantly lower thiobarbituric acid-reactive substances (TBARS) value than the dry-aged samples, indicating higher oxidative stability for wet-aged pork cuts. However, dry-aging led to higher degradation of proteins resulting in increased water-holding capacity (WHC) and decreased shear force value.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.8
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• pp.1083-1088
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• 2012

The breeding value of marbling score in skeletal muscle is an important factor for evaluating beef quality. In the present study, we investigated proteins associated with the breeding value of the marbling score for bovine sirloin to select potential biomarkers to improve meat quality through comparative proteomic analysis. Proteins isolated from muscle were separated by two-dimensional gel electrophoresis. After analyzing images of the stained gel, seven protein spots for the high marbling score group were identified corresponding to changes in expression that were at least two-fold compared to the low marbling score group. Four spots with increased intensities in the high marbling score group were identified as phosphoglycerate kinase 1, triosephophate isomerase, acidic ribosomal phosphoprotein PO, and capping protein (actin filament) Z-line alpha 2. Spots with decreased intensities in the high marbling score group compared to the low score group were identified as 14-3-3 epsilon, carbonic anhydrase II, and myosin light chain 1. Expression of myosin light chain 1 and carbonic anhydrase 2 was confirmed by Western blotting. Taken together, these data could help improve the economic performance of cattle and provide useful information about the underlying the function of bovine skeletal muscle.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.3
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• pp.55-61
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• 1987

This study was carried out to investigate the changes in the pH, extractability of protein, ATPase activity of myofibrillar protein, myofibrillar fragmentation, freezing loss and drip loss during storage at $4^{\circ}C$ and $-20^{\circ}C$ in breast and leg muscle of spent-hen meat. pH values ill pectoral and leg muscle were lowest ell tile 1st day and 1st week during cold and frozen storage, respectively. The extractabilities of myofibrillar proteins were increased graduall during cold storage and were highest on the 1st week during frozen storage, The $Mg^{2+}-ATPase$ activities of myofibrillar proteins were highest on the 1st day and 1st week during cold and frozen storage, respectively. The myofibrillar fragmentations were greatly changed on the 1st day during cold storage and 1st week during frozen storage. Freezing losses and drip losses were increased gradually during frozen storage. pH values in breast muscle were lower than those of leg muscle, and the extractabilities, $Mg^{2+}-ATPase$ activities, fragmentations of myofibrillar proteins, and drip losses in breast muscle were higher than those of leg muscle during storage, but the patterns of the changes in both muscles were similar during storage.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.11
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• pp.1662-1669
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• 2007

The high mobility group AT-hook1 (HMGA1) proteins are known to be related to the regulation of gene transcription, replication and promotion of metastatic progression in cancer cells. The loss of expression by disrupting the HMGA1 gene affects insulin signaling and causes diabetes in the mouse. Previously identified single nucleotide polymorphism (SNP) of HMGA1 was significantly associated with fat deposition traits in the pig. In this study, we identified 3,935 bp nucleotide sequences from exon 5 to exon 8 of the bovine HMGA1 gene and its mRNA expression was observed by quantitative real-time PCR. Six single nucleotide polymorphisms in the bovine HMGA1 gene were detected and the allele frequencies of these SNPs were investigated using the PCR-RFLP method in nine cattle breeds including Limousin, Simmental, Brown Swiss, Hereford, Angus, Charolais, Hanwoo, Brahman and Red Chittagong cattle. The map location showed that the bovine HMGA1 gene was also closely located with a previously identified meat quality QTL region indicating this gene is the most likely positional candidate for meat quality traits in cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.33 no.5
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• pp.778-787
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• 2020

Objective: This study was conducted to investigate the effects of normal and heat stress environments on growth performance and, selected physiological and immunological parameters, caecal microflora and meat quality in Cobb 500 and Ross 308 broilers. Methods: One-hundred-and-twenty male broiler chicks from each strain (one-day-old) were randomly assigned in groups of 10 to 24 battery cages. Ambient temperature on day (d) 1 was set at 32℃ and gradually reduced to 23℃ on d 21. From d 22 to 35, equal numbers of birds from each strain were exposed to a temperature of either 23℃ throughout (normal) or 34℃ for 6 h (heat stress). Results: From d 1 to 21, strain had no effect (p>0.05) on feed intake (FI), body weight gain (BWG), or the feed conversion ratio (FCR). Except for creatine kinase, no strain×temperature interactions were observed for all the parameters measured. Regardless of strain, heat exposure significantly (p<0.05) reduced FI and BWG (d 22 to 35 and 1 to 35), immunoglobulin Y (IgY) and IgM, while increased FCR (d 22 to 35 and 1 to 35) and serum levels of glucose and acute phase proteins (APPs). Regardless of temperature, the Ross 308 birds had significantly (p<0.05) lower IgA and higher finisher and overall BWG compared to Cobb 500. Conclusion: The present study suggests that the detrimental effects of heat stress are consistent across commercial broiler strains because there were no significant strain×temperature interactions for growth performance, serum APPs and immunoglobulin responses, meat quality, and ceacal microflora population.