• Food Science of Animal Resources
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• v.31 no.5
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• pp.676-683
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• 2011

The aim of this study was to compare the physicochemical changes of hot-boned chicken breast and leg muscles. Chicken breast and leg muscles from 56 broilers were excised within a 15 min post-mortem (PM) and stored at $20^{\circ}C$. Physicochemical traits were determined at 0.5, 6, 12, and 24 h PM. The ultimate pH of leg muscle was higher than that of breast muscle (p<0.05). The content of glycogen in the breast muscle was relatively higher than that in the leg muscle until 6 h PM (p<0.05). R-values showing rigor mortis of breast and leg muscles were completed after or before 6 h PM. Breast muscle had less cooking loss than leg muscle (p<0.05). Drip loss did not significantly differ between breast and leg muscles with the exception of that at 6 h PM. The sarcomere length of leg muscle was relatively longer than that of breast muscle (p<0.05). The MFI of leg muscle was significantly lower than that of breast muscle (p<0.05). The shear force of leg muscle was lower than that of breast muscle at 6 and 12 h PM (p<0.05); however, that of both muscles did not significantly differ at 24 h PM.

• Food Science of Animal Resources
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• v.29 no.1
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• pp.55-61
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• 2009

The objective of this study was to examine the effects of high and low chilling temperature on the water-holding capacity (WHC) and tenderness of hot-boned breast meat of broiler chickens. Breast meat was obtained from 32 broiler chickens within 15 min post-mortem (PM), and then divided into two groups. One group was chilled at $-1^{\circ}C$ and the other group was stored at $30^{\circ}C$ for 3 hr, and then all the samples were chilled at $2^{\circ}C$ until 24 hr PM. During the storage, their physicochemical characteristics were tested at 15 min, 3 hr and 24 hr PM. These included pH, R-values, cooking losses, sarcomere length, MFI, and shear force of the breast meat, none of which was different (p>0.05) between the two temperature treatments at $-1^{\circ}C$ and $30^{\circ}C$. However, sarcomere length was shortened more at $-1^{\circ}C$ than at $30^{\circ}C$, MFI was larger at $30^{\circ}C$ than at $-1^{\circ}C$, drip loss was greater at $30^{\circ}C$ than at $-1^{\circ}C$, and WHC was lower at $30^{\circ}C$ than at $-1^{\circ}C$(p<0.05). In brief, in terms of yield and tenderness, broiler breast meat stored at $-1^{\circ}C$ was superior to that stored at $30^{\circ}C$.

• Journal of Welding and Joining
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• v.34 no.1
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• pp.21-25
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• 2016

The automotive vehicle is made through the following processes such as press shop, welding shop, paint shop, and general assembly. Among them, the most important process to determine the quality of the car body is the welding process. Generally, more than 400 pressed panels are welded to make BIW (Body In White) by using the RSW (Resistance Spot Welding) and GMAW (Gas Metal Arc Welding). Recently, as the needs of light-weight material due to the $CO_2$ emission issue and fuel efficiency, new joining technologies for aluminum, CFRP (Carbon Fiber Reinforced Plastic) and etc. are needed. Aluminum parts are assembled by the spot welding, clinching, and SPR (Self Piercing Rivet) and friction stir welding process. Structural adhesive boning is another main joining method for light-weight materials. For example, one piece aluminum shock absorber housing part is made by die casting process and is assembled with conventional steel part by SPR and adhesive bond. Another way to reduce the amount of the car body weight is to use AHSS (Advanced High Strength Steel) panel including hot stamping boron alloyed steel. As the new materials are introduced to car body joining, productivity and quality have become more critical. Productivity improvement technology and adaptive welding control are essential technology for the future manufacturing environment.

• Food Science of Animal Resources
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• v.31 no.1
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• pp.19-26
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• 2011

In this study, we evaluated the physicochemical and sensorial properties of frozen Hanwoo beef patties prepared from prerigor and post-rigor muscle with soybean sauce or sodium chloride. The pH of the soybean sauce treatments was lower than the sodium chloride treatments (p<0.05); however, the Hanwoo patty prepared from pre-rigor muscle with soybean sauce had a lower cooking loss and smaller diameter than the Hanwoo patty prepared under the same conditions from post-rigor muscle (p<0.05). The addition of the soybean sauce inhibited lipid oxidation due to the antioxidative materials in soybean sauce such as melanoidin. The hardness of patties prepared from pre-rigor treatment was lower relative to those prepared from post-rigor muscle (p<0.05); however, there was no significant difference between springiness, cohesiveness, and chewiness (p>0.05). In the sensory evaluation, patties prepared from pre-rigor muscle with soybean sauce had a significantly high score in all traits (p<0.05); thus, pre-rigor muscle with soybean had the highest overall acceptability. Furthermore, the addition of soybean sauce to pre-rigor muscle produced similar effects as those observed for the addition of sodium chloride in regards to psychochemical properties. Moreover, meat products produced from pre-rigor muscle will have better antioxidative and sensorial properties.