• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.10
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• pp.195-202
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• 2019

This study was undertaken to investigate whether the local Woori black pigs could replace Duroc as the terminal sire in order to reduce foreign currency outgoings. This study compared the physicochemical properties of pork loins in two cultivars of three-way crossbred pigs: Landrace ${\times}$ Yorkshire ${\times}$ Duroc (LYD) and Landrace ${\times}$ Yorkshire ${\times}$ Woori black pig (LYW). A total of 119 pigs (59 LYD and 60 LYW) aged 180 days were used in the experiment. After 24 hours of cooling, pork loins were assessed for their physicochemical traits, meat color, fatty acid and sensory evaluation. The moisture content and water holding capacity showed no significant difference between the two cultivars. Fat content and cooking loss were significantly higher in LYW than in LYD (p<0.05), whereas shear force and pH were significantly lower in LYW than LYD (p<0.05). Redness ($a^*$), yellowness ($b^*$), and stearic acid (C18: 0) content were also significantly higher in LYW than in LYD (p<0.05). Sensory evaluation revealed significantly higher meat color and flavor in LYW than LYD (p<0.05). Taken together, these results indicate that certain physicochemical qualities are improved in the LYW cultivar, as compared to LYD. Therefore, Woori black pig (W) has the potential to be substituted for Duroc, a breeding pig used currently.

• Korean Journal of Poultry Science
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• v.45 no.4
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• pp.261-272
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• 2018

This study was conducted to evaluate the difference in the quality of chicken thigh meat from conventional and animal welfare farms during refrigeration storage over 9 days. Chicken thigh meat from conventional (CTC, n = 30) and animal welfare farms (CTW, n = 30) was tested. The pH value was significantly lower in CTW (6.28) than in CTC (6.37) on day 1; however, no significant differences were found on subsequent days. The yellowness of CTW was higher than that of CTC on day 1, but CTW showed lower yellowness than did CTC on day 7 and 9. The cooking loss, water holding capacity, lightness, redness, and coliform levels of CTC did not show any significant difference when compared with CTW during storage. The shear force of CTW was significantly higher than that of CTC on day 1, 3, 7, and 9. Total microorganism and coliform in CTC and CTW increased with increasing storage days. On day 7 and 9, the total microorganism level of CTW was lower than that of CTC. The thiobarbituric acid value of CTW was lower than that of CTC on day 9. The volatile basic nitrogen (VBN) of CTW was lower than that of CTC during storage. Anserine content and 1,1-diphenyl-2-picryl-hydrazyl(DPPH) scavenging activity of CTW was significantly higher than CTC on day 1. These results suggest that CTW stayed fresher for longer than did CTC because of low total microorganism level on day 7 and 9, and VBN during refrigerated storage.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.116-125
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• 2018

This study was carried out physicochemical and sensory evaluation to compare the quality characteristics of pork loins from Yorkshire, Duroc, Pietrain, and Duroc ${\times}$ Pietrain (DP). A total of 79 pigs from Yorkshire(22), Duroc(22), Pietrain(17), and DP(18) was used for the experiment. After 24 hours of cooling, pork loins were gathered and vacuum-packed from left carcasses and then the physicochemical traits and sensory evaluation were conducted. The pH of the loins from breed Pietrain was lower than those of the other breeds (p<0.01). While the moisture content of loins was higher in Pietrain than in the other breeds (p<0.01). The fat content of loins was higher in Duroc and DP than in the other breeds and lower in Pietrain than in the other breeds (p<0.01). Pietrain loins had the lowest drip loss (p<0.01) and the highest water holding capacity (p<0.01). There were no significant differences in the cooking loss and shear force of the loins among 4 breeds (p>0.05). There was a significant difference in the CIE color L*, a* and b* values of the loins from 4 breeds (p<0.01). Sensory scores of the loins were ranked lower in Pietrain in overall. The results of this study indicate that meat quality could be altered according to the breeds.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.47 no.4
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• pp.361-368
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• 2021

The objective of this study was to establish technology for removing bacteria with human- and eco-friendly material. Staphylococcus aureus as an important component for balanced equilibrium among microbiomes, was cultured under various concentrations of phosphate. Experimental observation relating to physical properties was performed in an addition of phosphate buffer. Statistically minimum value of size and hardness using atomic force microscope was observed on the matured biofilm at 5 mM concentration of phosphate. As a result of absorbance for the biofilm tagged with dye, concentration of biofilm was reduced with phophate, too. To identify whether this reduction by phosphate at the 5 mM is caused by counter ion or not, sodium chloride was treated to the biofilm under the same condition. To elucidate components of the biofilm counting analysis of the biofilm using time-of-flight secondary ion mass spectrometry was employed. The secondary ions from the biofilm revealed that alteration of physical properties is consistent to the change of extracellular polymeric substrate (EPS) for the biofilm. Viscoelastic characterization of the biofilm using a controlled shear stress rheometer, where internal change of physical properties could be detected, exhibited a static viscosity and a reduction of elastic modulus at the 5 mM concentration of phosphate. Accordingly, bacteria at the 5 mM concentration of phosphate are attributed to removing the EPS through a reduction of elastic modulus for bacteria. We suggest that the reduction of concentration of biofilm induces dispersion which assists to easily spread its dormitory. In conclusion, it is elucidated that an addition of phosphate causes removal of EPS, and that causes a function of antibiotic.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.1
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• pp.73-80
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• 2022

In this study, details of NRC beam-column connections were developed in which beam and columns pre-assembled in factories using steel angles were bolted on site. The developed joint details are NRC-J type and NRC-JD type. NRC-J type is a method of tensile joining with TS bolts to the side and lower surfaces of the side plate of the NRC column and the end plate of the NRC beam. NRC-JD type has a rigid joint with high-strength bolts between the NRC beam and the side of the NRC column for shear, and with lap splices of reinforcing bar penetrating the joint and the beam main reinforcement for bending. For the seismic performance evaluation of the joint, three specimens were tested: an NRC-J specimen and NRC-JD specimen with NRC beam-column joint details, and an RC-J specimen with RC beam-column joint detail. As a result of the repeated lateral load test, the final failure mode of all specimens was the bending fracture of the beam at the beam-column interface. Compared to the RC-J specimen, the maximum strength of the specimen by the positive force was 10.1% and 29.6% higher in the NRC-J specimen and the NRC-JD specimen, respectively. Both NRC joint details were evaluated to secure ductility of 0.03 rad or more, the minimum total inter-story displacement angle required for the composite intermediate moment frame according to the KDS standard (KDS 41 31 00). At the slope by relative storey displacemet of 5.7%, the NRC-J specimen and the NRC-JD specimen had about 34.8% and 61.1% greater cumulative energy dissipation capacity than the RC specimen. The experimental strength of the NRC beam-column connection was evaluated to be 30% to 53% greater than the theoretical strength according to the KDS standard formula, and the standard formula evaluated the joint performance as a safety side.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.277-285
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• 2021

This study was conducted to compare performance, carcass yield, and meat quality of 4 Korean indigenous commercial chickens (Hanhyup 3: G, Sorae 1: V, Woorimatdak 1: S, Woorimatdak 2: W). A total of 384 chickens were divided into 4 treatments with 4 Korean indigenous commercial chickens, 6 repetitions per treatment, and 16 birds per treatment (♀ 8 birds, ♂ 8 birds). For 12 weeks, body weight was significantly higher in G and V breeds than S and W breeds (P<0.01), but body weight gain lower in S breed (P<0.05). Feed conversion ratio was significantly higher in W breed at 8~10 wk of age (P<0.05). There was no significant difference on livability among four treatments. Carcass yield and fresh meat ratio were highest in V breed at 12 wk of age (P<0.05). On breast meat, shear force was lower in G breed (P<0.05), and higher in male than in female (P<0.05). Lightness (L^*) of breast meat was higher in female except V breed, and redness (a^*) was significantly higher in breed G (P<0.05). Yellowness (b^*) of breast meat was higher in G and V breeds, and higher in male than in female except breed G. In conclusion, G and V breeds showed superior performance, and S and W breeds showed superior meat quality.

• Korean Journal of Poultry Science
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• v.48 no.4
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• pp.227-238
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• 2021

This study investigates the effect of perch type and height on the growth performance, footpad dermatitis (FPD), blood parameters, behavioral characteristics, and meat quality of broilers. A total of 912 one-day-old male Ross 308 broilers (48.23±0.264 g) were subjected to a three x two factorial design of three types of perch (wood, steel, plastic) and two levels of perch height (10→30 cm change, 10 cm fixed) over a five-week experiment. Growth performance, perch availability, litter quality, FPD incidence, serum biochemical parameters, and meat quality of the broilers were evaluated. There were no significant differences in the body weight, feed conversion ratio, and biochemical parameters (except for aspartate aminotransferase), pH, color, and water holding capacity. The incidence of FPD was significantly higher in the plastic perch group than in the wood and steel perch groups (P<0.05) at five weeks of age. Perch use was high in the order of wood, steel, and plastic groups in the daytime and nighttime at one, three, and five weeks of age (P<0.05). Perch use was higher in the 10 cm fixed group than the 10→30 cm group (P<0.05). The shear force of the breast significantly increased in the order of wood, steel, and plastic groups (P<0.05). In conclusion, the group with a fixed perch height of 10 cm had high perch usage. Additionally, the use of wooden perches was higher than that of other materials, and it lowered the incidence of FPD in broilers.

• Food Engineering Progress
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• v.23 no.1
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• pp.7-15
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• 2019

The impregnation of solid foods into the surrounding hypotonic or hypertonic solution was explored as a method to infuse NaCl in pork loin cube without altering its matrix. Mass transfer kinetics using a diffusive model as the mathematical model for moisture gain/loss and salt gain and the resulting textural properties were studied for the surrounding solutions of NaCl 2.5, 5.0, 10.0 and 15% (w/w). It was possible to access the effects of brine concentration on the direction of the resulting water flow, quantify water and salt transfer, and confirm tenderization effect by salt infusion. For brine concentrations up to 10% it was verified that meat samples gained water, while for processes with 15% concentration, pork loin cubes lost water. The effective diffusion coefficients of salt ranged from 2.43×10^-9 to 3.53×10^-9 m²/s, while for the values of water ranged from 1.22×10^-9 to 1.88×10^-9 m²/s. The diffusive model was able to represent well salt gain rates using a single parameter, i.e. an effective diffusion coefficient of salt through the meat. However, it was not possible to find a characteristic effective diffusion coefficient for water transfer. Within the range of experimental conditions studied, salt-impregnated samples by 5% (w/w) brine were shown with minimum hardness, chewiness and shear force.

• Korean Journal of Poultry Science
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• v.50 no.4
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• pp.325-336
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• 2023

This study used leaves and stems of 'Tongchaeru', one of the sweet potato varieties, to investigate broiler productivity, meat quality, blood properties, growth hormones, and immune factor levels according to drying method and amount added to feed. For this experiment, a total of 720 1-day-old male Ross 308 broilers were used. Treatments were assigned with 3 replicates per treatment and 20 birds were assigned to each replicate. The treatment group was designed into 12 treatments according to the type of natural product (leaves (L), stems (S)), drying type (natural (N), hot air (H), freeze (F)) and amount added (0.1%, 0.3%). The test was conducted for a total of 5 weeks. In this study, there was no significant difference in productivity depending on the type and amount of additives added (P>0.05). The FS 0.3% group showed high pH and WHC levels, and the shear force was lowest at HL 0.1% group (P<0.05). Blood cell and serum biochemical components were similar in all treatments, and growth hormone IGF-1 was highest in FS 0.1% group (P<0.05). There was no significant difference in IFN-γ, but the highest level of IL-6 was seen in the HS 0.1% group (P<0.05). In conclusion, the meat quality and the level of growth hormone and immune factors in the body were different depending on the type and amount of dried leaves and stems of sweet potato 'Tongchaeru', further study is needed to compare the selected additives and amounts added with those without additions.

• Journal of Animal Science and Technology
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• v.54 no.2
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• pp.111-124
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• 2012

Feeding trial was conducted with 80 Hanwoo steers (7.5 months of age, 204.4 kg body weight) for 680 days from growing period to late fattening period to examine the feeding value of whole crop barley silage TMR (BS-TMR) and whole crop rye silage TMR (RS-TMR) on body gain, feed cost, slaughter characteristics and quality characteristics of $longissimus$ $dorsi$ muscle. Dietary treatments were conventional separate feeding of concentrate and rice straw (control), feeding BS TMR up to middle fattening period and same diet as for control during late fattening period (BS-TMR I), feeding BS-TMR for whole experimental period (BS-TMR II), feeding RS TMR up to middle fattening period and same diet as for control during late fattening period (RS-TMR I) and RS TMR for whole experimental period (RS-TMR II). Sixteen castrated calves were assigned to each treatment (4 pens, 4 heads per pen). Pens in each treatment were randomly distributed. Feeding both BS silage TMR and RS silage TMR slightly increased body gain of Hanwoo steers at the stages of growing and early fattening, and increased (P<0.0001) at middle fattening compared to feeding control diet while control diet tended to increase body gain at late fattening stage compared to feeding BS-TMR I, BS-TMR II and RS-TMR I diets. Total body gain was slightly increased in Hanwoo steers fed both I and II for BS and RS TMR compared to that in control diet. Feed cost per kg gain per head was relatively low in the Hanwoo steers fed silage TMRs to that fed control diet. Carcass weight, back fat thickness and $longissimus$ $dorsi$ area of Hanwoo steers tended to increase but lowered (P<0.047) yield index by feeding silage TMRs. Feeding BS TMR slightly decreased marbling score but no difference was found in the number of head over grade 1 between diets. Control diet tended to improve yield grade compared to silage TMRs. Chemical composition, water holding capacity, drip loss, cooking loss and pH, color and fatty acid composition of $longissimus$ $dorsi$ were not affected by experimental diets and feeding duration of silage TMRs. Shear force, however, was increased (P<0.046) by silage TMRs without difference between them compared to control diet. Based on the results of the current study, BS TMR and RS TMR could improve body gain and reduce feed cost without deteriorating meat quality compared to separate feeding of concentrate and rice straw. Overall feeding value was similar between BS TMR and RS TMR.