• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.2
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• pp.54-60
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• 2023

In this study, microstructure and basic property analysis of DG (Desulfurization gypsum) and CCMs (Carbondioxide conversion capture materials) made by reacting CO₂ with DG were conducted to analyze applicability as a cement admixture. The main crystalline phases of DG were CaO and CaSO₄, and CCMs were CaSO₄, CaCO₃, Ca(OH)₂ and CaSO₄·H₂O. As a result of particle size analysis, the difference in average particle sizes between the two materials was about 7 ㎛. No major heavy metals were detected in the CCMs, and as a result o f TGA, the CO₂ decomposition of CCMs was more than twice as high as that of DG. Therefore, it was judged that CCMs could be used as a cement admixture through optimization of manufacturing conditions. As a results of measuring the strength behavior of DG and CCMs mixture ratios, the long-term strength of CCMs-mixed mortar was higher, and this is due to the filler effect of CaCO₃ in CCMs.

• Microbiology and Biotechnology Letters
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• v.43 no.3
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• pp.195-203
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• 2015

Two bacterial strains, Bacillus licheniformis YB-1413 and YB-1414, producing extracellular α-galactosidase, were obtained from homemade Doenjang. On the basis of their biochemical properties, 16S rRNA sequences and random amplified polymorphic DNA patterns by polymerase chain reaction, they were found to be somewhat different from one another. α-Galactosidase productivities of the two isolates were increased by wheat bran, but drastically decreased by melibiose, raffinose and sucrose which were used as carbon sources. The enzyme productivities were increased by yeast extract as a nitrogen source with maximum levels of 1.87 U/ml for YB-1413 and 1.69 U/ml for YB-1414, respectively. The enzymes of both isolates exhibited maximum activity for hydrolysis of para-nitrophenyl-α-D-galactopyranoside (pNP-αGal) under reaction conditions of pH 6.0 and 45℃. Their hydrolyzing activities for pNP-αGal were drastically decreased by the addition of low concentrations of ribose and galactose. They were capable of hydrolyzing completely α-1,6 linked galactosyl residue in melibiose, raffinose and stachyose, which are known to be anti-nutritional factors in products of soybean and legume. In relation to the latter, the isolates YB-1413 and YB-1414 have potential applicability in improving soybean-fermented foods and the nutritional value of soybean feed.

• The Journal of Engineering Geology
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• v.23 no.4
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• pp.435-445
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• 2013

Since design response spectrum does not reflect local soil characteristics, site specific response spectrum of observed ground motions appears relatively higher than design response spectrum at high frequency range. These problems have been pointed out from the domestic seismic design industry. Among various estimation methods, this study used the method H/V ratio of ground motion for estimating site amplification. This method has been extended to background noise, Coda waves and S waves recently for estimating site amplification. This study applied this method to the background noise and Coda wave energy. This study analysed more than 267 background noises from 15 macro earthquakes including main Fukuoka earthquake (2005/03/20, M=6.5) and then compared to results from S waves, at 8 main domestic seismic stations. The results showed that most of the domestic seismic stations gave similar results to those from S waves. Each station showed its own characteristics of site amplification property in low, high and specific resonance frequency ranges. Comparison of this study to other studies using different method can give us much information about dynamic amplification of domestic sites characteristics and site classification.

• Korean Journal of Medicinal Crop Science
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• v.16 no.5
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• pp.371-375
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• 2008

This study was conducted to evaluate geographical distribution patterns of natural habitats, soil properties, and plant species grown with native Boehmeria platanifolia in South Korea. The relative density and coverage of Boehmeria platanifolia were 7.0% and 25.6% respectively. Most Boehmeria platanifolia were growing below 200 m of altitude, and they were rarely found at the higher altitude. Over 80% of Boehmeria platanifolia's habitats were found at below $20^{\circ}$ and their habitats were concentrated at the west and the north face slope rather than the south face slope. Nearly 90% of Boehmeria platanifolia were grown at little and middle light condition's area, and 69.1% of them were natively growing in humid soil in their natural habitats. Soil texture of their habitats were mostly clay loam and the soil pH was 6.2. The contents of soil organic matter was $24\;g\;kg^{?1}$ and $P_2O_5$ was $31\;mg\;kg^{?1}$. Plant species grown with native Boehmeria platanifolia were 60 family, 125 genus and 171 species. Clematis apiifolia showed the highest relative density and coverage among plant species grown with native Boehmeria platanifolia.

• The Korean Journal of Mycology
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• v.38 no.2
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• pp.152-159
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• 2010

The influence of urushiol, as an allergen on laccase property of Fomitella fraxinea was investigated. The enzyme production was reached to the highest level after 10 days, cultivation and the activity and mycelial biomass were increased by 2.5 and 1.5 folds, respectively, by adding urushiol in the culture medium. In liquid cultures using a Cu Mn-free medium, laccase lactivity was decreased by 3.8-9.2 folds, with similar dry cell weight. Two isoenzymes, were purified using anion exchange, hydrophobic interaction and size-exclusion chromatographies. Both isoenzymes are monomeric proteins, with $M_W$ around 67 kDa(Lac1) and 66 kDa(Lac2), and isoelectric points of 3.67 and 3.81. The optimal conditions for purified isoenzymes were found to be pH 4.5-5.0 and $30-35^{\circ}C$. Activity decreased by the addition of $Fe^{2+}$, $Mg^{2+}$, $Na^+$, and strongly inhibited by EDTA and sodium azide.

• Food Science of Animal Resources
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• v.32 no.4
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• pp.504-511
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• 2012

The effects of the addition of wheat fiber on physico-chemical properties and sensory characteristics of pork loin cutlets were investigated to develop pork loin cutlets formulated with different concentrations of wheat fiber (0, 1, 2, 3, and 4%). The moisture content, ash content, pH, and lightness of pork loin cutlets increased with increasing wheat fiber levels (p<0.05). However, the fat content, calorie, redness, hardness, cohesiveness, gumminess, and chewiness decreased with increasing wheat fiber levels (p<0.05). The protein content, yellowness, and springiness of pork loin cutlets did not show significant difference (p>0.05). The sensory evaluation shows the greatest overall acceptability was ranked at the pork loin cutlets added with wheat fiber at 3%. Pork loin cutlets with added wheat fiber could be commercially acceptable meat products, and can be improved quality characteristics. The best results were obtained for pork loin cutlets with addition of 3% wheat fiber.

• Korean Journal of Food Science and Technology
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• v.51 no.4
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• pp.348-355
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• 2019

This study investigated the impact of cellulase treatment on the extraction yield of potato starch (PS), and compared the physicochemical properties of PS by conventional (CSE) and enzymatic (ESE) starch extraction. In ESE, the PS extraction yield was predominantly influenced by reaction temperature, time and their interaction, compared to the cellulase concentration. When potatoes were treated for 8 h at $40^{\circ}C$ with 1.5% cellulase, the PS extraction yield was about 3.4-fold higher than that by CSE. Compared to CSE-PS, ESE-PS showed lower total starch contents and higher amylose contents, resulting in lower swelling factors and distorted pasting viscosity profiles accompanied by absence of peak and breakdown viscosities. However, ESE did not affect the gelatinization characteristics of PS. Overall results suggested that ESE can provide the highest yield of PS, and ESE-PS can be a potential starch source for extending the utilization of PS in food industries.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.5
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• pp.860-866
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• 2015

Three types of Korean style fried rice sauce, 'Kimchi-tomato sauce', 'Doenjang butter sauce', and 'Seafood sauce' were developed in this study. Physicochemical properties such as pH, soluble solid content, acidity, salinity, and texture of sauces were analyzed after application of three different sterilization conditions ($110^{\circ}C/50min$, $115^{\circ}C/30min$, and $121^{\circ}C/20min$). However, no trend was observed in physicochemical properties of each sauce by sterilization conditions. The lightness (L-value) of doenjang butter sauce was higher than the other two sauces. Redness (a-value) and yellowness (b-value) of doenjang butter sauce and seafood sauce were greater than those of kimchi-tomato sauce due to different ingredients. Total viable cells were not detected under all sterilization conditions of the three types of sauce. The sensory evaluation results showed that $121^{\circ}C/20min$ of sterilization scored better than $110^{\circ}C/50min$ or $115^{\circ}C/30min$ sterilization in terms of overall preference of kimchi-tomato sauce and doenjang butter sauce. Overall, the preference of the three types of sauce showed that seafood sauce was best, followed by doenjang butter sauce and kimchi-tomato sauce.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.440-448
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• 1993

To utilize effectively fish skin wasted from fish processing, a dover sole skin gelatin was prepared by alkaline extraction method and the physico-chemical properties were examined. Conditions for the suitable pretreatment, extraction and decolorization for gelatin preparation from dover sole skin are as follows: the skin is limed with 1.0% calcium hydroxide solution at $5^{\circ}C$ for 4 days, washed thoroughly for 2 days with tap water, extracted with 5 volumes of water $(pH\;5.0{\sim}7.0)$ to dehydrated skin for 3 hours at $50^{\circ}C$, and then bleached with 3% activated carbon. Though dover sole skin gelatin was prepared under above conditions, physico-chemical property values such the melting point and gelling point of that were lower than those of yellowfin sole skin gelatin as well as the commercial pork skin gelatin. Therefore, the purified dover sole skin gelatin requires a suitable modification operation for better quality gelatin manufacture.

• Food Science of Animal Resources
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• v.35 no.1
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• pp.143-148
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• 2015

Yogurt powder is fermented milk processed in the form of dry yogurt, and has advantages such as stability, storability, convenience, and portability. China and Vietnam are important export target countries because of the increased demand for dairy products. Therefore, we surveyed dairy product standardization in order to establish an export strategy. Lactic acid bacteria counts are unregulated in Korea and Vietnam. In China, lactic acid bacteria counts are regulated at $1{\times}10^6$ colonyforming units (CFU)/mL and detected at $6.24{\pm}0.33\;Log\;CFU/mL$. All three countries have regulated standards for total bacterial counts. In China, total bacterial counts of milk powder are regulated to n=5, c=2, m=50,000, M=200,000 and detected at $6.02{\pm}0.12\;Log\;CFU/mL$, exceeding the acceptable level. Lactic acid bacterial counts appeared to exceed total bacterial counts. Coliform group counts, Staphylococcus aureus, Listeria monocytogenes, and Salmonella species were not detected. Acidity is not regulated in Korea and Vietnam. In China, acidity was regulated to over $70^{\circ}T$ and detected $352.38{\pm}10.24^{\circ}T$. pH is unregulated in all three countries. pH was compared to that of general fermented milk, which is 4.2, and that of the sample was $4.28{\pm}0.01$. Aflatoxin levels are not regulated in Korea and China. In Vietnam, aflatoxin level is regulated at 0.05 ppb. Therefore, all ingredients of the yogurt powder met the safety standards. This data obtained in this study can be used as the basic data in assessing the export quality of yogurt powder.