• Journal of Environmental Health Sciences
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• v.36 no.5
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• pp.383-390
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• 2010

Exposure to fugitive dust can contribute to several respiratory health problems, and proper sampling of fugitive dust is necessary to assess exposure. However, field sampling of soil dust encounters problems from spatial and temporal differences in soil properties, field operations, and meteorological conditions. To minimize these problems, we designed a dust generator that simulates dust generation from soil. The dust generator consisted of a rotating chamber where soil samples were loaded and tumbled, and a settling chamber, where airborne soil dust samples were collected. As standard operating conditions, we decided on 2 g soil mass, 10 min sampling time, and 20 rpm rotating speed, with a flow rate of 30 l/min, based on three common soil textures of loam, sandy loam and silt loam. To evaluate optimal operating conditions, we used mixtures of Joomoonjin silica sand and clay. Although the average $PM_{10}$ concentration of Joomoonjin silica sand was low, dust concentrations were increased by an increased content of clay. The dust concentrations were consistent across repeated experiments, and showed similar concentration profiles during the sampling time with mixtures of clay and sand (coefficient of variation was $13.6{\pm}w;7.1%$). The results demonstrated that these standard operating conditions were suitable for the dust generator, which can be used to investigate variations in soil properties that affect dust production and potential potency of fugitive dust exposure.

• Korean Journal of Food Science and Technology
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• v.32 no.5
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• pp.1068-1072
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• 2000

Strawberry jams were prepared with addition of 1.0 and 2.0% dietary fiber isolated from ascidian (Halocynthia roretzi) tunic for recycling wastes of seafood source and developing new food products. The texture of the jams examined were using a back extrusion rig. All of the rheological parameters decreased in the fiber-enhanced jams. Viscosity profiles were also decreased in the fiber-enhanced jam samples. Hunter L' and a' values increased in the fiber-enhanced jams, accordingly revealing reddish color. As a result of sensory evaluations, the result of taste tests and overall acceptability were significantly acceptable. In the list of acceptability factors, except spreadibility, jam where 1% fiber was added, high sensory scores and preferable acceptability were noted.

• Journal of the Korean earth science society
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• v.40 no.1
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• pp.9-23
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• 2019

Super-refraction of radar beams tends to occur primarily under a particular vertical structure of temperature and water vapor pressure profiles. A quality control process for the removal of anomalous propagation (AP) ehcoes are required because APs are easily misidentified as precipitation echoes. For this purpose, we collected X-band polarimetric radar parameters (differential reflectivity, cross-correlation coefficient, and differential phase) only including non-precipitation echoes (super-refraction and clear-sky ground echoes) and precipitation echoes, and compared the echo types regarding the relationships among radar reflectivities, polarimetric parameters, and the membership functions. We developed a removal algorithm for the non-precipitation echoes using the texture approach for the polarimetric parameters. The presented algorithm is qualitatively validated using the S-band Jindo radar in Jeollanam-do. Our algorithm shows the successful identification and removal of AP echoes.

• Journal of the Korean Society of Food Culture
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• v.36 no.1
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• pp.84-91
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• 2021

The oriental plum (Prunus salicina) is one of the most popular fruits in Korea due to its sweet taste and pleasant aroma. The objective of this study was to analyze the quality characteristics and antioxidant activities of a puree made using plums stored at low-temperatures. The quality characteristics were determined by estimating total soluble solids (TSS, °Brix), titratable acidity (TA, % citric acid), TSS/TA ratio, pH, colors, sugar content, and sensory profiles. The antioxidant effects were estimated by total polyphenol and flavonoid content and radical scavenging activity. The results showed that the plum puree containing both the flesh and the peel had markedly higher red coloration (a⁎ value) than the puree without the peel, while yellow coloration (b⁎ value) and lightness (L⁎ value) were lower in the puree without the peel than with the peel. The sensory qualities including the plum taste and flavor, texture as well as overall acceptance showed no significant variation between the samples. Meanwhile, the total polyphenol/flavonoid content and radical scavenging activities were significantly improved by the presence of fruit peel and by frozen storage. These findings suggest that frozen plums could be a suitable ingredient for making a puree and concentrate for the food manufacturing industry.

• Food Science of Animal Resources
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• v.42 no.3
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• pp.398-410
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• 2022

We studied effects of aging methods and temperature on the physical, chemical, and amino acid composition of pork belly from Berkshire and Landrace×Yorkshire×Duroc (LYD) swine. Pork belly samples were assigned randomly to breed groups (Berkshire and LYD), aging temperature groups (0℃ and 9℃), and aging method groups. One samples of vacuum-packaged hanging pork bellies were hung in a refrigerated cooler with 83±2.0% humidity, while the other samples were immersed in a 3.5% salt solution in a vacuum package and subsequently stored in the same cooler for 2 weeks. LYD pork had lower pH and purge loss and higher lightness values than those of Berkshire pork (p<0.05). Moreover, thiobarbituric acid reactive substances and hardness values of LYD pork were lower than those of Berkshire pork after aging (p<0.05). Berkshire pork had a higher level of flavorful amino acids than LYD pork did during aging (p<0.05). Bellies aged at elevated temperatures for two weeks had higher volatile basic nitrogen. However, significantly higher percentages of flavorful and sweet taste amino acids were observed in bellies aged at 9℃ compared to those aged at 0℃ for 2 weeks. Moisture content was higher in immersed samples than hanging samples after two weeks of aging (p<0.05). Hanging pork bellies exhibited higher texture profiles than immersed pork bellies at two weeks (p<0.05). We concluded that breeds, aging temperature, and methods affected most quality attributes of pork belly.

• Food Science and Preservation
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• v.20 no.6
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• pp.775-783
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• 2013

Changes in the various quality characteristics of hamburg steak depending on the packaging methods were investigated during storage at $5{\pm}1^{\circ}C$ for up to 15 days. Three packaging treatments including vacuum packaging (VAP), air-containing packaging (AC), and oxygen scavenger packaging (OS) were applied in this experiment. The initial total aerobe bacteria counts were identical at 2.3 log CFU/g in all treatments, but the growth rate of total aerobe bacteria in the AC samples was significantly faster than the VAP and OS samples during storage. The changes in the TBA and VBN values over the storage time showed that lipid oxidation and protein spoilage developed fastest in the AC sample, followed by OS and then VAP samples. The instrumental color and texture profiles were not significantly differ between treatments during storage (p>0.05). After 12 days of storage at $5^{\circ}C$, evaluation of the samples' sensory attributes showed that the AC samples had become unmarketable with a score of less than 5.0 points for all sensory properties, whereas the VAP and OS samples were still marketable.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.2
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• pp.180-187
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• 2015

This study was conducted to determine the effects of feeding by-product feed (BF)-based silage on the performance, blood metabolite parameters, and carcass characteristics of Hanwoo steers. The BF-based silage was composed of 50% spent mushroom substrate, 21% recycled poultry bedding, 15% cut ryegrass straw, 10.8% rice bran, 2% molasses, 0.6% bentonite, and 0.6% microbial additive (on a wet basis), and ensiled for over 5 d. Fifteen steers were allocated to three diets during the growing and fattening periods (3.1 and 9.8 months, respectively): a control diet (concentrate mix and free access to rice straw), a 50% BF-based silage diet (control diet+50% of maximum BF-based silage intake), and a 100% BF-based silage diet (the same amount of concentrate mix and ad libitum BF-based silage). The BF-based silage was fed during the growing and fattening periods, and was replaced with larger particles of rice straw during the finishing period. After 19.6 months of the whole period all the steers were slaughtered. Compared with feeding rice straw, feeding BF-based silage tended (p = 0.10) to increase the average daily gain (27%) and feed efficiency (18%) of the growing steers, caused by increased voluntary feed intake. Feeding BF-based silage had little effect on serum constituents, electrolytes, enzymes, or the blood cell profiles of fattening steers, except for low serum Ca and high blood urea concentrations (p<0.05). Feeding BF-based silage did not affect cold carcass weight, yield traits such as back fat thickness, longissimus muscle area, yield index or yield grade, or quality traits such as meat color, fat color, texture, maturity, marbling score, or quality grade. However, it improved good quality grade (1+ and 1++) appearance rates (60% for the control group vs 100% for the BF-based silage-fed groups). In conclusion, cheap BF-based silage could be successfully used as a good quality roughage source for beef cattle.

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.38-43
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• 2004

Effects of heat treatment on functional properties of soy protein were examined. Soy protein isolate (SPI) was prepared from Korean soybean varieties, Manli and Taekwang, subjected to heat treatment at $60^{\circ}C$ for 30, 60, 90, and 120 min. pH-solubility results of SPI showed typical U-shape profiles with minimum solubility at pH 4-5 of isoelectric points of soy proteins, longer heat treatments showing slightly higher solubility. Water absorption, emulsifying activity, emulsion stability, and emulsion capacity of SPI increased, while oil absorption decreased, with heating time in Manli variety. Manli and Taekwang showed the highest emulsion capacities after 90-and 60-min heat treatments, respectively. Foam expansion of all SPIs increased with heating time up to 90 min. Texture profile analysis showed heat treatment up to 90 min significantly increased hardness, adhesiveness, springiness, gumminess, and chewiness, whereas significantly decreased cohesiveness of SPI gels (p<0.05).

• Korean Journal of Food Science and Technology
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• v.39 no.3
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• pp.260-265
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• 2007

In this study, the quality characteristics of retort Tteok (Korean rice cake) prepared with various dextrinization times were investigated during storage. The moisture content of the retort Tteok made with dextrinized rice was 43.19-43.34% at 0 day and there were no differences in the samples during storage. As dextrinization time increased, the L value of the retort Tteok decreased, and the a and b values increased. Again there were no differences in the samples during storage. In the texture profiles, the hardness, gumminess and chewiness of the retort Tteok increased with increasing dextrinization time for all the samples, except the ones that were dextrinized for 32 minutes. The adhesiveness of the retort Tteok increased with decreasing dextrinization time, and springiness and cohesiveness did not differ among the samples. Also, the quality characteristics showed no differences after 15 days of storage. In the sensory evaluation, color, smell and delicate taste were significantly different between the retort Tteok made with rice dextrinized over 16 minutes and that made with no dextrinized rice. The retort Tteok with rice dextrinized for 16 minutes showed the highest score in the softness. Storage times up to 120 days made no differences in the sensory evaluation measurements. These results indicate that a dextrinization time of 16 minutes seems to give the best quality to retort Tteok made with dextrinized rice.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.2
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• pp.159-169
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• 2004

Sedimentation and depositional pattern of the fine-grained sediments in the southeastern inner shelf of Korea were studied using a very high-resolution seismic profiles and sediment data. The recent mud deposits up to 45 m thick are distributed in the inner shelf forming a nearshore belt from the eastern part of Geoje Island to off the Pohang along the coast. The sediment in this area consists of homogeneous mud with mean grain size between $8.6\;to\;5.3\phi$ and does not show any distinct variability It gradually becomes finer and well sorted northeastward along the coast. Sediments normally appear as structureless massive mud but X-radiographs show that some bioturbation and faint lamination are present. The sediments accumulate at a rate of 0.18-0.44 cm/yr and the rate coincides well with the long-term (a 1000-year scale) accumulation based on very high-resolution seismic data. Distribution of wet bulk density and velocity shows a gradual increase from the southeastern part of Ulsan to off Pohang, whereas porosity shows a reverse pattern. Correlations between velocity and porosity/mean grain size are different from other regions compared, due to the difference of sediment texture and sedimentary environment. The recent shelf deposits are seismically characterized by three distinct facies: 1) well-stratified (near the river mouth), 2) semi-transparent (eastern part of Geoje Island), and 3) transparent (off Ulsan). The results suggest that fine-grained sediment derived from rivers, forming a nearshore mud belt, have been transported northeastward by the northeastward-flowing coastal current.