• The Korean Journal of Food And Nutrition
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• v.29 no.4
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• pp.499-505
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• 2016

To improve the shelf-life of mushrooms, Lentinula edodes GNA01 mushrooms were treated with gel packs containing slow-released chlorine dioxide ($ClO_2$) gas at 5~10 ppm for 5 days at $20^{\circ}C$ and the weight loss rate as well as the changes in pH, color and texture properties of the treated samples were investigated. The weight of the control and $ClO_2$ gas treated samples were decreased slightly, and there were no differences during the storage period. However, the weight of the control changed faster than those of the $ClO_2$ gas treated samples during storage period. The pH in the control and in the $ClO_2$ gas treated samples were decreased during storage period, but the samples treated with 5 and 7 ppm $ClO_2$ gas were the least changed. On the other hand, the samples treated with 10 ppm $ClO_2$ gas showed no difference from the other treatments during 4 days, but the pH was lower than that of the control on the fifth day. The lightness of inside and outside in mushroom were decreased whereas redness and yellowness were increased during storage period. However, color changes in the $ClO_2$ gas treated samples were lower than those of the control. Especially, the samples treated with 5 and 7 ppm $ClO_2$ gas were the least changed. The texture of the mushroom were decreased consistently during storage period. The texture of the control changed faster than those of the $ClO_2$ gas treatments during 5 days. Especially, the samples treated 5 ppm $ClO_2$ gas were the least changed.

• The Korean Journal of Food And Nutrition
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• v.30 no.3
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• pp.591-598
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• 2017

To prolong the shelf-life of strawberry, samples were treated with gel packs containing slow-released chlorine dioxide($ClO_2$) gas at 3~7 ppm for 6 days at room temperature. The weight loss and decay ratio as well as changes in pH, color and texture properties of the treated samples were investigated. The weight of the control and $ClO_2$ gas treated samples decreased slightly, but the weight of the control changed faster than those of the $ClO_2$ gas treated samples during the storage period. The decay ratio of control was higher than those of the $ClO_2$ gas treatments since 4 days of storage. The pH and acidity in the control and in the $ClO_2$ gas treated samples were no differences during storage period. The lightness of strawberry decreased during storage, but there was no difference in lightness among the treatments even when storage time was extended. The redness and yellowness of the control showed higher change than those of the $ClO_2$ gas treatments during 6 days. The firmness of the control changed more rapidly than those of the $ClO_2$ gas treatments during 6 days. Especially, the samples treated 3 and 5 ppm $ClO_2$ gas were the least changed. And the scores for appearance, firmness and overall acceptance control and 7 ppm $ClO_2$ gas treatment decreased more rapidly than those of 3 and 5 ppm treatment.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.488-492
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• 2012

Two strains, traditionally referred to as rock flower (Bawhi-kot) and buckwheat flower (Memil-kot or Chile-Kot), were isolated from stored traditional soy sauce and were identified by using the 18S ITS1/4 region sequences. The rock flower strain showed 99% of similarity with Cladosporium sp. and buckwheat flower strain was 99% identical with yeast Sterigmatomyces halophilus. Both strains were tentatively named Cladosporium sp. NK1 and Sterigmatomyces halophilus NK2, respectively. The optimal growth pHs and temperatures of both strains in a YPD broth medium were in the range of pH 5.0 to 7.0 and 22 to $27^{\circ}C$. Both strains were able to grow in more than 20% of NaCl. In the enzyme activity assay, high protease activity of Cladosporium sp. NK1 and S. halophilus NK2 were obtained in YPD containing 10% of NaCl. High amylase activities of both stains were in 15% and 5% of NaCl, respectively. Lipase activity was, however, not detected in both strains.

• Food Science of Animal Resources
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• v.38 no.3
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• pp.515-529
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• 2018

The present study was designed to investigate the effects of calpain system on the formation of volatile flavor compounds in Hanwoo beef. In the first experiment (exp.1), Longissimus lumborum (LL) muscle samples were injected with solutions containing 50 mM $CaCl_2$ or 50 mM $ZnCl_2$ and 154 mM NaCl respectively, and aged for 7 d at $4^{\circ}C$. In the second experiment (exp.2), the ground LL muscle was incubated with the aforementioned solutions containing cathepsin inhibitor. The injection with $CaCl_2$ solution greatly elevated the calpain activity and concomitantly, significantly decreased the Warner-Bratzler shear force (p<0.05). The pH, meat color and cooking loss did not differ (p>0.05) between the treatment groups. A total of 51 volatile compounds were identified using the solid phase microextraction with gas chromatography (SPME-GC). Results on volatile analyses from the both experiments showed that the injection with calcium ions led to significant increase (p<0.05) concentrations of pyrazines and sulfuric compounds. These results coincide with a higher rate of protein degradation due to the $CaCl_2$ injection as compared to the control group. Significantly (p<0.05) higher levels of lipid oxidation derived-aldehydes were found in the samples with $ZnCl_2$. The exp.1 showed that cathepsin inhibitors had no effect on the formation of volatile flavor components after 7 d of aging. These results imply that the proteolytic activity of the calpain system is associated with generation of volatile compounds of chiller-aged beef, while the role of cathepsins is likely very limited.

• Korean Journal of Poultry Science
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• v.24 no.4
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• pp.169-177
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• 1997

Four experiments were conducted to investigate the association of yolk cholesterol level with egg trails, serum cholesterol level, body weight (BW) and breed differences and other variations. Athens Canadian Randombred (ACRB), a commercial layer breed (CL) and two commercial broiler breeds (BR1 and BR2) were used for this studies. Egg weight of CL was heavier by 8.7g per egg than that of ACRB, but the yolk percentage and yolk cholesterol were lower by 7.8％ per egg and 5.5mg per g yolk than those of ACRB, respectively. Yolk cholesterol content had no significant relation with the average egg weight or yolk weight in ACRB, but was significantly related with yolk fat level. However, yolk cholesterol level in CL showed inverse relationship with other egg traits compared to that of ACRB. In the CL female group, the association of yolk cholesterol level with BW was significant(P$\leq$0.05) at 25 weeks of age, but was not significant different at 26 wks of age. The relationship of yolk cholesterol with serum was not significantly different at 25 weeks of age, whereas it showed significant negative(-) correlation coefficient(P$\leq$0.01) at 26 wks of age. The association of yolk cholesterol level with egg age in CL population was not high comared to that of other treatments. The serum cholesterol content of CL was not significantly different with BR1 and BR2 populations at 25 weeks of age, but was significantly(P$\leq$0.05) higher than that of BR1 or BR2 at 26 weeks old.

• Journal of the East Asian Society of Dietary Life
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• v.18 no.1
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• pp.72-79
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• 2008

This study investigated the changes in textural characteristics that occurred by adding maltose syrup, dextrin, and sucrose to whole egg gels, by assessing coagulation after cooling. It also examined the optimal NaCl and sucrose concentrations for whole egg gels sensory evaluations, and then studied how the addition of sucrose effected gel formation and textural characteristics under optimal NaCl concentration. The additions of maltose syrup, dextrin, and sucrose, presented some color changes. The greater the addition of maltose syrup or dextrin, the lower the L, a, and b values of the whole egg gel and whole egg liquid, and ultimately the color turned dark bluish green. With increasing additions of sucrose, maltose syrup, and dextrin, the viscosity of the whole egg liquid increased slightly. In terms of the mechanical texture characteristic of the gel, the texture was most elastic with the 0.8% addition of sucrose, and hardness decreased by increasing the ratio of added sucrose. Increasing amounts of maltose syrup resulted in less hardness and SF. And for dextrin, the SF increased up to 2.5 and then decreased, and hardness decreased with increasing amounts of dextrin. Based on sensory evaluations, the 0.8% addition of NaCl was significantly preferred(p<0.05), in terms of salty taste. The overall preference scores indicated that the whole egg gel made with 0.3% sucrose and the optimal NaCl concentration(0.8%) was most preferred, and each sample was significant(p<0.05). Under the optimal 0.8% NaCl concentration increasing the sucrose concentration resulted in a darker egg gel color, in terms the L value. SF, NF, and hardness, which are mechanical texture parameters, were when 0.8% sucrose and the optimal NaCl concentration of 0.8% were added to whole egg liquid, in preparing the whole egg gel.

• Food Science and Preservation
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• v.22 no.6
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• pp.893-900
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• 2015

In this study, we evaluated the antidiabetic effect of a submerged culture of Ceriporia lacerata mycelium (CL01) on hematological indices, as well as protein and mRNA expression of the insulin-signaling pathway, in db/db mice. After CL01 was administrated for 4 weeks, blood glucose levels decreased consistently, and plasma insulin and c-peptide levels each decreased by roughly 55.8%, 40% of those in the negative control (p<0.05). With regard to HOMA-IR, an insulin resistance index, insulin resistance of the CL01-fed group improved over that of the negative control group by about 62% (p<0.05). In addition, we demonstrated that the protein expression levels of pIR, pAkt, pAMPK, and GLUT4 and the mRNA expression levels of Akt2, IRS1, and GLUT4 in the muscle cells of db/db mice increased in the CL01-fed group compared to the corresponding levels in the control group. These results demonstrate that CL01 affects glucose metabolism, upregulates protein and gene expression in the insulin-signaling pathway, and decreases blood glucose levels effectively by improving insulin sensitivity. More than 90% of those who suffer from type 2 diabetes are more likely to suffer from hyperinsulinemia, hypertension, obesity, and other comorbidities because of insulin resistance. Therefore, it is possible that CL01 intake could be used as a fundamental treatment for type 2 diabetes by lowering insulin resistance, and these results may prove be useful as basic evidence for further research into the mechanisms of a cure for type 2 diabetes.

• Korean Journal of Soil Science and Fertilizer
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• v.2 no.1
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• pp.27-30
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• 1969

The present notes summarize the results obtained from the effect of soil-solution ratio on pH values of soils having widely different physico-chemical characteristics. The pH was determined in deionized water N-KCl and 0.01 M $CaCl_2$ solution The results obtained are: 1. With deionized water, the pH values increase with the increase in soil-solution ratio. The increase is more in upland soils than in paddy soils. 2. With N-KCl solution, there is also an increase in pH values with the increase in soil-solution ratio but the increase is less than the corresponding increase with deionized water. 3. With 0.01 M $CaCl_2$ solution, there is practically no change in pH values with the increase in soil-solution ratio except for saline soils. 4. In case of saline soils, the pH increase even in case of 0.01 M $CaCl_2$ solution with increase in soil-solution ratio, the reason for increase may be due to decrease of electric potential by high concentration of salts.

• Proceedings of the Korean Vacuum Society Conference
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• 1999.07a
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• pp.249-249
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• 1999

GaN과 같은 III-nitride 반도체 관한 식각 기술의 연구는 blue-emitting laser diode(LD)를 위한 경면(mirror facet)의 형성뿐만아니라 새로운 display 용도의 light emitting diodes (LED), 고온에서 작동되는 광전소자 제조 등에도 그 중요성이 증대되고 있다. 최근에는 III-nitride 물질의 높은 식각속도와 미려하고 수직한 식각형상을 이루기 위하여 ECR(Electron Cyclotron Resonance)이나 ICP(Inductively Coupled Plasma)와 같은 고밀도 플라즈마 식각과 CAIBE(Chemically assisted ion beam etching)를 이용한 연구가 진행되고 있다. 현재 제조되어 지고 있는 LED 및 LD와 같은 광소자의 구조의 대부분은 p-GaN/AlGaN/InGaN(Q.W)/AlGaN/n-GaN 와 같은 여러 층의 형태로 이루어져 있다. 이중 InGaN는 광소자나 전자소자의 특성에 영향을 주는 가장 중요한 부분으로써 현재까지 보고된 식각연구는 undoped GaN에 대부분 집중되고 있고 이에 비해 소자 특성에 핵심을 이루는 InGaN의 식각특성에 관한 연구는 미흡한 상황이다. 본 연구에서는 고밀도 플라즈마원인 ICP 장비를 이용하여 InGaN를 식각하였고, 식각에는 Cl2/CH4, Cl2/Ar 플라즈마를 사용하였다. InGaN의 식각특성에 영향을 미치는 플라즈마의 특성을 관찰하기 위하여 quadrupole mass spectrometry(QMS)와 optical emission spectroscopy(PES)를 사용하였다. 기판 온도는 5$0^{\circ}C$, 공정 압력은 5,Torr에서 30mTorr로 변화시켰고 inductive power는 200~800watt, bias voltage는 0~-200voltage로 변화시켰으며 식각마스크로는 SiO2를 patterning 하여 사용하였다. n-GaN, p-GaN 층 이외에 광소자 제조시 필수적인 InGaN 층을 100% Cl2로 식각한 경우에 InGaN의 식각속도가 GaN에 비해 매우 낮은 식각속도를 보였다. Cl2 gas에 소량의 CH4나 Ar gas를 첨가하는 경우와 공정압력을 감소시키는 경우 식각속도는 증가하였고, Cl2/10%Ar 플라즈마에서 공정 압력을 감소시키는 경우 식각속도는 증가하였고, Cl2/10%CHF3 와 Cl2/10%Ar 플라즈마에서 공정압력을 15mTorr로 감소시키는 경우 InGaN과 GaNrks의 선택적인 식각이 가능하였다. InGaN의 식각속도는 Cl2/Ar 플라즈마의 이온에 의한 Cl2/CHF3(CH4) 플라즈마에서의 CHx radical 형성에 의하여 증가하는 것으로 사료되어 진다.

• Bulletin of the Korean Chemical Society
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• v.29 no.3
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• pp.627-640
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• 2008

The geometrical structures, atomic charges, and relative energies of tetracoordinated Pd complexes [PdCl3Z (Z = Cl-, Br-, OH?-, H2O, NH3, PH3), PdCl2Z2 (Z = Br-, OH?-, H2O, NH3, PH3), PdZ?2X (Z = Cl-, OH?-, H2O, NH3, PH3; X = oxalate, O2-?CCO2-), and PdZ2Y (Z = Cl?-, OH?-, H2O, NH3, PH3; Y = succinate, CO2-?CHCHCO2-?)] and the ligand exchange reactions of the Pd complexes were investigated using the ab initio second order Mller-Plesset perturbation (MP2) and Density Functional Theory (DFT) methods. The geometrical characteristics of the tetracoordinated Pd(II) complexes with mono- and bidentate ligands, the effects of the atomic charges for the charged and uncharged ligands, the (dz2-p ) interactions between the dz2-orbital of Pd(II) and the p -orbital of bidentates, and the relative stabilities between the isomers of PdCl2Z2 and PdZ2Y were investigated in detail. The potential energy surfaces for the ligand exchange reactions used for the conversions of {[PdCl2(NH3)2] + H2O} to {[PdCl(NH3)2(H2O)]+ + Cl?-?} and {[PdCl2(PH3)2] + H2O} to {[PdCl(PH3)2(H2O)]+ + Cl?-?]} were investigated. The geometrical structure variations, molecular orbital variations (HOMO and LUMO), and relative stabilities for the ligand exchange processes were also examined quantitatively.