• Food Science of Animal Resources
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• v.39 no.6
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• pp.934-942
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• 2019

Previous studies on dry aged beef, which substantially increases the value of low-grade raw beef and non-preferred cuts, are currently limited to the observation of aged beef changes in laboratory settings or under particular aging conditions, whereas the factors influencing aging have so far been underexplored. Herein, we attempt to establish a technique for distinguishing between fresh and aged beef by observing changes in quality during beef aging. Specifically, we analyzed the effect of time on the quality of aged beef sourced from three Korean manufacturers and identified quality indicators that can be used to distinguish between fresh and aged beef, regardless of supplier. Storage/trimming/aging/cooking losses, moisture/fat/protein/collagen contents, and water holding capacity were tested as potential indicators, among other parameters. As a result, the quality of dry aged beef was shown to be supplier-dependent, which made the identification of factors for the above origin-independent discrimination difficult. Nevertheless, as storage loss, water holding capacity, and cooking loss significantly changed with dry aging time in all cases, these parameters were concluded to be potentially suited for discrimination purposes. The insights gained in this work may help promoting further research in this field and contribute to the development of a standard for consistent aged beef production.

• Food Science of Animal Resources
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• v.39 no.6
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• pp.888-902
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• 2019

Our aim was to investigate the effects of bromelain embedded in double emulsion (DE) on physicochemical properties of pork loin. We evaluated DE characteristics such as size, zeta potential, and microscopy after fabrication. We marinated meat with distilled water (DW), 1% (w/v) bromelain solution, blank DE, and 1% (w/v) bromelain loaded in double emulsion (DE E) for 0, 24, 48, and 72 h at 4℃, and prepared raw meat for control. The marinated samples were assessed for color, water holding capacity, cooking loss, moisture content, pH, protein solubility, Warner-Bratzler shear force (WBSF) and gel electrophoresis. The droplet size of 1% (w/v) bromelain embedded in DE was increased compared with blank DE (p<0.05) and values of zeta potential decreased. The increase in lightness and color difference range of the DE-treated group was lower than that of the DW-treated group (p<0.05). Moreover, treatment by immersion in 1% (w/v) DE E resulted in the highest water holding capacity values (p<0.05) and lower cooking loss values than water base treatment (p<0.05). Results for myofibrillar protein solubility and WBSF showed a similar trend. 1% (w/v) DE E showed degradation of myosin heavy chain after 48 h in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Thus, bromelain-loaded DE is useful for controlling and handling enzyme activity in food industry.

• Korean Journal of Agricultural Science
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• v.42 no.2
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• pp.125-129
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• 2015

This study was conducted to investigate the incidence of bone-fracture from pig carcass slaughtered in eight processing plants located in Daejeon and Chungnam area, Korea, during the year 2013 and 2014, and to evaluate the quality of semimembranous muscle from bone-fractured carcasses. Twenty semimembranous muscles were collected from bone-fractured carcasses and none bone-fractured (control) ones, respectively, after storage of pig carcass at $5^{\circ}C$ for 24 h. The pH, cooking loss, and color of semimembranous muscle were measured as quality parameters. In total 4,865,502 of pig carcasses, the occurrence of bone fracture was 0.328% (15,975 heads) and scored the highest defect (26.31%) in total abnormal carcasses. The pH and cooking loss of semimembranous muscle from bone-fractured carcasses were significantly lower than those of control (p<0.05). $L^*$ and $a^*$ values of semimembranous muscle were not significantly different between bone-fractured carcass and control whereas that of $b^*$ values was significantly higher in bone-fractured carcass than control (p<0.05). Eight out of twenty semimembranous muscle collected from bone-fractured carcasses were confirmed as PSE whereas only one in control. In conclusion, the incidence of bone-fracture pre- and during slaughter of pig may cause serious defects in final meat quality. Therefore, the proper handling and treatment should be implicated to avoid and/or decrease the incidence of bone-fracture of pigs.

• Korean Journal of Poultry Science
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• v.43 no.2
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• pp.55-61
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• 2016

With the aim of investigating the differences in the quality traits of breast meat between spent hen and broiler chicken, the physicochemical characteristics, fatty acid profile and sensory attributes of breast meat from the two chicken types were assessed. A higher protein content and a lower moisture content were found in breast of spent hen compared to that of commercial broilers (P<0.05). No significant differences in crude fat and ash contents were detected between commercial broilers and the older spent hens (P>0.05). Spent hens showed a significantly lower pH value than did commercial broilers. Spent hen meat had a higher $L^*$ value than broiler chicken meat did (P<0.05). However, $a^*$ and $b^*$ values of breast meat were similar between spent hens and commercial broilers. Water holding capacity values measured in the breast meat were comparable between the two types of chicken used in this study (P>0.05). However, spent hen meat showed a higher cooking loss value than did broiler meat (P<0.05). Total polyunsaturated fatty acid content was significantly higher in spent hen meat compared to broiler meat, in particular eicosapentaenoic acid and docosahexaenoic acid. Nevertheless, sensory characteristics of breast meat were comparable between spent hen and broiler chicken. This information can help consumers to understand better the nutritive value and important quality traits of breast meat from commercial broilers and spent hens.

• Animal Bioscience
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• v.34 no.11
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• pp.1849-1858
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• 2021

Objective: Tenderness is a very complex feature, and the process of its formation is very complicated and not fully understood. Its diversification is one of the most important problems of beef production, as a result beef aging is widely used to improve tenderness as it is believed to provide a homogeneous product to consumers. While few studies have evaluated the muscle structure properties in relation to tenderness from early post-mortem, there little to no information available on how the muscle nanostructure of beef carcasses changes during post-mortem ageing to determine the appropriate aging time for acceptable tenderness. Methods: Muscle nanostructure (myofibril diameter [MYD], myofibril spacing [MYS], muscle fibre diameter [MFD], muscle fibre spacing [MFS], and sarcomere length [SL]), meat tenderness and cooking loss [CL]) were measured on 20 A2 longissimus muscles of Bonsmara, Beefmaster, Hereford, and Simbra at 45_mins, 1, 3, and 7 days post-slaughter. Muscle nanostructure was measured using a scanning electron microscope, while tenderness was measured using Warner Bratzler shear force. Results: At 45 minutes post-slaughter, breed affected MYD and MYS only, while at 24_hrs it also affected MFD and MFS. On day 3 breed effected MFS and SL, while on day 7 breed effected tenderness only. As the muscles matured, both MYD and MYS decreased while CL increased, and the muscles became tender. There was no uniformity on muscle texture features (surface structure, fibre separation, muscle contraction, and relaxation) throughout the ageing period. Conclusion: Meat tenderness can be directly linked to breed related myofibril structure changes during aging in particular the MYD, spacing between myofibrils and their interaction; while the MFD, spacing between muscle fibres, SL, and CL explain the non-uniformity in beef tenderness.

• Korean Journal of Agricultural Science
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• v.48 no.3
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• pp.455-464
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• 2021

This study was conducted to evaluate meat quality traits, proximate composition, fatty acid profile and sensory attributes of pork produced under free-range and semi-intensive pig rearing systems. Longissimus dorsi muscles from pork carcasses were taken just after the slaughtering of finishing pigs reared under semi-intensive and free-range systems to test the meat quality parameters (pH, color, water holding capacity, and cooking loss), proximate composition (moisture, protein, fat, and ash) and fatty acid profile. Furthermore, the organoleptic properties were evaluated using 30 untrained panelists. The results revealed that the system of rearing did not affect (p > 0.05) the proximate composition, water holding capacity, color, pH and cooking loss of pork along with the fatty acid composition except for vaccenic acid (p < 0.05). The monounsaturated fatty acid (MUFA) content was affected (p < 0.05) by the rearing system while no effects were observed on the unsaturated fatty acid: saturated fatty acid ratio and omega-six to omega-three fatty acids ratios (p > 0.05). No difference was observed (p > 0.05) concerning the sensory attributes although pork obtained from the free-range system had the highest scores. In conclusion, the system of rearing did not show a significant effect on the meat quality parameters, composition and sensory attributes of pork obtained from cross-bred pigs.

• Food Science of Animal Resources
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• v.39 no.1
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• pp.54-64
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• 2019

Wet and dry aging methods were applied to improve the quality of three different beef cuts (butt, rump, and sirloin) from Hanwoo cows (quality grade 2, approximately 50-mon-old). After 28 d of wet aging (vacuum packaged; temperature, $2{\pm}1^{\circ}C$) and dry aging (air velocity, 2-7 m/s; temperature, $1{\pm}1^{\circ}C$; humidity, $85{\pm}10%$), proximate composition, cooking loss, water holding capacity, shear force, color, nucleotides content, and sensory properties were compared with a non-aged control (2 d postmortem). Both wet and dry aging significantly increased the water holding capacity of the butt cuts. Dry aging in all beef cuts induced lower cooking loss than that in wet-aged cuts. Shear force of all beef cuts was decreased after both wet and dry aging and CIE $L^*$, $a^*$, and $b^*$ color values in butt and sirloin cuts were higher in both wet and dry aging (p<0.05) groups than those in the non-aged control. Regardless of the aging method used, inosine-5'-monophosphate content among beef cuts was the same. The sensory panel scored significantly higher values in tenderness, flavor, and overall acceptability for dry-aged beef regardless of the beef cuts tested compared to non- and wet-aged cuts. In addition, dry-aged beef resulted in similar overall acceptability among the different beef cuts, whereas that in wet-aged meat was significantly different by different beef cuts. In conclusion, both wet and dry aging improved the quality of different beef cuts; however, dry aging was more suitable for improving the quality of less preferred beef cuts.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.10
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• pp.1611-1620
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• 2019

Objective: The aim was to investigate the influence of ultrasound and adenosine 5'-monophosphate (AMP) marination (UAMP) on tenderness and structure of myofibrillar proteins of beef. Methods: Five groups, the untreated meat (Control), deionized water marination (DW), ultrasound followed by DW (UDW), AMP marination (AMP), and ultrasound followed by AMP (UAMP) were studied. Myofibrillar fragmentation, cooking loss, shear force, thermograms, histological observation of meats and myofibrillar proteins properties were investigated in these different treatments. Results: The results showed that UAMP significantly increased myofibrillar fragmentation index from 152 (Control), 231 (AMP), and 307 (UDW) to 355 (p<0.05), respectively. The lowest cooking loss, shear force and peak denaturation temperature were observed in UAMP. In histological observation, UDW and UAMP had more fragmented muscular bundles than the others. Furthermore, a drastic increase in ${\alpha}$-helix and decrease in ${\beta}$-sheet of myofibrillar proteins was observed in UAMP, implying the disaggregation of protein samples. The synchronous fluorescence spectra of myofibrillar proteins in UAMP suggested the combination of ultrasound and AMP could accelerate the unfolding molecular structure and destroying hydrophobic interactions. The results of circular dichroism and synchronous fluorescence spectra for myofibrillar proteins coincided with the microstructures of beef. Conclusion: The results indicate that ultrasound combined with AMP improved meat tenderness not only by disruption in muscle integrity, increasing water retention, but also altering their spatial structure of myofibrillar proteins.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.3
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• pp.413-420
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• 2019

Objective: This study investigated the effects of dry radish leaf and root on the quality of pork patties during refrigeration storage. Methods: The patties were divided into the following three groups: the control containing 0% dry radish leaf root powder, RL1 containing 0.5% dry radish leaf root powder, and RL2 and RL3 containing 1% and 2% dry radish leaf root powder, respectively. Proximate composition, pH, cooking loss, microbial analysis, lipid oxidation analysis, color, texture profile analysis and sensory test were performed. Results: Moisture, crude protein, and crude ash contents in RL2 and RL3 were significantly higher than those in other groups (p<0.05), whereas crude fat contents in RL2 and RL3 were significantly lower than other groups (p<0.05). Lightness was significantly lower in RL2 and RL3 than in CON (p<0.05). Cooking loss for RL2 and RL3 were significantly lower than those for the other groups (p<0.05). The pH, thiobarbituric acid levels, and total plate counts of RL2 and RL3 were significantly lower than those of CON at days 7 and 14 (p<0.05). Hardness values of RL2 and RL3 were significantly lower than those of CON, whereas chewiness values were higher than those of CON (p<0.05). In addition, the juiciness of RL2 were significantly greater (p<0.05) than those of the other groups. Conclusion: Dried radish leaves and roots improved the proximate composition and quality characteristics of pork patties, providing a basis to produce high-quality patties with extended expiration dates. Thus, dried radish leaves and roots are effective ingredients for health or functional foods.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.8
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• pp.1195-1204
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• 2019

Objective: The purpose of this study was to investigate whether addition of konjac gel with three different vegetable powders can increase quality of low-fat frankfurter-type sausage. Methods: Low-fat frankfurter-type sausages were manufactured with formulations containing konjac gel and three vegetable powders (aloe vera, cactus pear, or wheat sprout) as pork fat replacers. The formulations of frankfurters were as follows: NF (normal-fat; 20% pork fat), LF (low-fat; 10% pork fat), KG (low-fat; 10% pork fat+10% konjac gel), and konjac gel with three vegetable powders (KV), such as KV-AV (10% pork fat+10% konjac gel with aloe vera), KV-CP (10% pork fat+10% konjac gel with cactus pear), and KV-WS (10% pork fat+10% konjac gel with wheat sprout). Proximate analysis, pH value, color evaluation, cooking loss, water-holding capacity, emulsion stability, apparent viscosity, texture profile analysis, and sensory evaluation were determined. Results: The konjac gel containing groups showed lower fat content (p<0.05) and higher moisture content than NF group (p<0.05). The pH value of frankfurters was decreased in three KV groups (p<0.05). The three KV groups had increased dark color (p<0.05) compared with KG, and KV-CP had the highest redness (p<0.05). The water-holding capacity and emulsion stability were higher in the three KV groups than KG and LF (p<0.05). Cooking loss was generally decreased in the three KV groups, compared with KG (p<0.05). The apparent viscosity of KV groups was similar with NF group and overall texture properties were improved in KV-CP. In the sensory evaluation, the highest overall acceptability was found in KV-CP groups (p<0.05). Conclusion: The four fat replacers improved physicochemical properties of low-fat frankfurters. Particularly, konjac gel with cactus pear powder seems more acceptable as a pork fat replacer.