• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.248-254
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• 2015

Uptake of the triazole fungicides, fluquinconazole and tetraconazole from shoot part of onion was assessed by determining residual amounts of applied fungicides in edible and shoot parts of onion after the foliar application. Combined product of fluquinconazole and tetraconazole (14:7, v/v) as a 21% active ingredient of suspended emulsion formulation was diluted at ratio of 500 and 200 times and sprayed on the shoot part of onion after sealing its root part with absorbent paper. At 10 days after the pesticide application, fluquinconazole residue in the shoot part was the greatest as 5.2 mg/kg at 200 times-dilution treatment, while tetraconazole residue in this part was the smallest as 1.2 mg/kg at 500 times-dilution treatment. On the other hand, the pesticide residues in edible parts of onion at all the treatments were less than limits of detection, 0.01 mg/kg. However, fluquinconazole residues in the edible part of onion divided into three groups such as 1st, 2nd, and 3rd layers were detected at concentrations of 0.04 or 0.24 mg/kg, and these results show the different distribution of pesticides in onion depending on divided layers. In addition, chopped onions were soaked in pesticide solutions prepared with dilution of 1,000 times, cooked using three food processing types such as boiling, stir frying, and pickling, and the pesticide residues in them were analyzed. The analyzed results showed the largest pesticide dissipation in onion followed boiling process (76.9~92.6%).

• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.606-613
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• 2016

The purpose of this study is to analyze the possibility of a residual product of coffee (RC). RC oil extracted with n-hexane at $60({\pm}10)^{\circ}C$ for 24 hours. In this study, the cytotoxicity of RC oil was observed against B16F10 melanoma cells and RAW 264.7 macrophage cells by water solubletetrazolium salt-1 assay, and The RC oil measured by methods of DPPH radical scavenging and antimicrobial activities in Staphylococcus aureus, Staphylococcus epidermidis, Escherichia coli, Candida albicans. As a result, the RC oil treatment-related cytotoxic effects appeared on B16F10 melanoma cells from 0.125 to $2{\mu}{\ell}/m{\ell}$ and RAW 264.7 macrophage cells from 0.125 to $0.5{\mu}{\ell}/m{\ell}$ concentrations in this study. RC oil is radical scavenging activity concentrations on dependent. The antimicrobial activity of RC oil ($150{\mu}l/{\ell}$) was determined by clear zone method. Straphylococcus epidermidis, Straphylococcus aureus, Escherichia coli, Candida albicans showed clear zone by each $11.3{\pm}0.4$, $12.{\pm}0.7$, $12.0{\pm}0.0$, $0.0{\pm}0.0mm$. It is suggested that RC oil have effects on the cytotoxicity, antioxidant and antimicrobial that could be applicable to cosmetics as a new material.

• Journal of Dairy Science and Biotechnology
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• v.33 no.3
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• pp.203-207
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• 2015

The majority of food drying processes are based on the use of thermal energy. However, such methods may deteriorate the quality of the final product. Freeze-drying is one of the most useful processes for drying thermosensitive substances. Food that contains beneficial bacteria, for example, is susceptible to heat treatment, but during freeze-drying beneficial bacteria are preserved in these food items. The primary goals of this study were to develop yogurt snacks and to compare the viability of lactic acid bacteria (LAB) in yogurt snacks under different freeze-drying temperatures. In addition, the survival of LAB during storage was investigated. Survival of LAB in freeze-dried yogurt snacks gradually decreased over 16 weeks of storage. LAB had a residual viability of 25.5% after 16 weeks of storage at room temperature. LAB survived better in freeze-dried plain yogurt snacks than in freeze-dried strawberry yogurt snacks during storage. Freeze-dried yogurt snacks contained 11.9% fat, 57.1% carbohydrate, and 18.7% protein. In conclusion, the viability of LAB in freeze-dried yogurt snacks depends on the temperature during freeze-drying: the higher the freeze-drying temperature, the lower the viability of LAB in yogurt snacks. The viability of LAB in yogurt snacks was also dependent on the moisture content and nutritional value.

• Journal of Life Science
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• v.12 no.4
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• pp.433-441
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• 2002

There has been an increasing public concern about environmental safety and human health of field crops while customer consumes more and more field crops, to which overdose and residual chemicals were applied. As a solution for the problems, construction of sustainable agroecosystem is spreading out to pursuit the economic value of agricultural management as well as to meet environment concern. Public has extended their understanding on the preservation of environment and safeness of agricultural products, and governmental policy toward sustainable agriculture drives rapid increase of the production of sustainable agricultural products. Under this circumstances, it is time to encourage more consumption and to activate market system for the sustainable agricultural products. This study was initiated to diagnose the problems and future direction of domestic sustainable agriculture by analyzing the overall opinions of consumer on the sustainable agriculture. The results are as follows: The pursuit of low input management is a prerequisite to creat high valued agricultural products, and serious consideration should be taken to produce clean crops using natural products. Consummers are willing to pay 10∼50% more prices if the products get certified by official eco-label programs. It is believed that practice of sustainable agriculture using biopesticide and natural pesticide would accelerate the rapid extension of this pro-environmental agricultural management. To activate production and consumption of sustainable agricultural products correct informations on safety should be addressed to customer, and confidence has to be brought about from customer. This could be done by obtaining various and efficient distribution route, product competency for quality, upgraded sales strategy, maximum utilization of certificate system, and practice of recall system, so on.

• Journal of the Korean Ceramic Society
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• v.39 no.10
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• pp.955-962
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• 2002

The microstructure change of brazed $Si_3N_4$/Stainless steel 316 joint with Cu buffer layer were examined to clarify the effects of brazing process conditions such as brazing time and temperature on the mechanical properties and reliability of brazed joints. For the brazed joint above 900${\circ}C$, the Cu buffer layer was completely dissolved into brazing alloy and the thickness of reaction product formed at $Si_3N_4$/brazing alloy joint interface was abruptly increased, which could increase the amounts of residual stress developed in the joint. The fracture strength of brazed $Si_3N_4$/Stainless steel 316 joint with Cu buffer layer at 950${\circ}C$ was much reduced comparing to those of joints brazed at the lower temperature. But, it was found that the effects of brazing time was not critical on the mechanical properties as well as the reliability of $Si_3N_4$/Stainless steel 316 joint with Cu buffer layer brazed at the temperature below 900${\circ}C$.

• Journal of Dairy Science and Biotechnology
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• v.35 no.1
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• pp.39-45
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• 2017

The market for lactose-hydrolyzed milk is growing due to an increased awareness of lactose intolerance, and increased market interest for modified milk with health claims. The aim of this study was to compare the quality characteristics of 2% lactose-hydrolyzed milk with its lactose hydrolysis rate, with the goal of applying the method to dairy product monitoring in the future. We observed that the freezing point of milk significantly decreased with increasing lactose hydrolysis rate. A linear relationship was found between lactose concentration and freezing point, following the equation (y=-50.416x + 767.91). However, no significant changes were observed in other physicochemical properties of the milk (pH, titratable acidity, total solids and color) (p<0.05). In conclusion, we could predict the residual lactose content quickly and easily in 2% low fat milk by measuring its freezing point. This could represent an easy means for assessing the lactose hydrolysis rate of dairy products.

• Journal of Sericultural and Entomological Science
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• v.29 no.2
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• pp.51-57
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• 1987

The intent of this research is to acquire some basic informations about formulation of the viral pesticide, Hyphantria cunea nuclear polyhedrosis virus and its virulence under field condition. The nuclear polyhedrosis virus was formulated as wettable powder using spreader, sticker and U.V. protector. The formulated product and aqueous virus were diluted with water at the concentration of 1${\times}$106PIB/ml and sprayed on mulberry leaves in the field. The leaves were fed with 3rd instar larvae of H. cunea to determine the inactivation period of the viral pesticides. The aqueous virus was completely inactivated on 5th day after spray, while the formulated one showed a spare mortality to the larvae even on 20th day after spray. In field application test, The fromulated and aqueous virus were sprayed on individual mulberry tree and 3rd instar laevae of H. cunea were fed on the trees. The mortality of the larvae one day after spray of the formulated and aqueous virus were about 50% and 40%, respectively. The formulated virus exhibited a persistent virulence to the larvae up to 9th day after spray, which the mortality was approximately 30%. The residual virulence of the formulated and aqueous virus was extended up to 4th day and 2nd day after spray, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.1
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• pp.52-57
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• 2005

Previous studies showed that shell meal fertilizer from the oyster farming industry could be a potential inorganic soil amendment to increase Chinese cabbage productivity and to restore the soil nutrient balance in upland soil (Lee et al., 2004). Herein, shell meal fertilizer was applied at rates of 0, 4, 8, 12, and $16Mg\;ha^{-1}$ to upland soil (Pyeontaeg series, Fine silty, Typic Endoaquepts) for Chinese cabbage cultivation. We found available phosphate increased significantly with shell meal fertilizer application, due to high content of phosphate ($1.5g\;P_2O_5\;kg^{-1}$) in the applied shell meal fertilizer. In addition, high pH of shell meal fertilizer contributed to increase available phosphate content by neutralization of acidic soil. Total and residual P contents increased significantly with increasing shell meal fertilizer application, but we could not find any tendency in organic and inorganic P fraction. Of extractable P fraction, water-soluble phosphorus (W-P) and calcium-bound P (Ca-P) contents increased significantly with increasing application level. By contrast, aluminum and iron-bound P (Al-P and Fe-P) decreased slightly with shell meal application. The present experiment indicated that shell meal fertilizer had a positive benefit on increasing available phosphate content in arable soil. And so the increased available phosphate by shell meal fertilizer may decrease phosphate application level and then reduce phosphorus loss in arable soil.

• Journal of Applied Biological Chemistry
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• v.61 no.2
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• pp.191-194
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• 2018

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are emerging pollutants in agricultural product, and the residual patterns and the uptake potentials were only studied on several crops, not on rice. The residue level and bioconcentration factor (BCF) of PFOA and PFOS were investigated on the low ($1mg\;kg^{-1}$) and the high contaminated soil ($5mg\;kg^{-1}$) groups. The residue levels in brown rice in the low group and in the high group were 0.002-0.004 and $0.008-0.030mg\;kg^{-1}$ of the each perfluorinated compounds (PFCs), and in the rice husk were $0.035-0.074mg\;kg^{-1}$ and $0.125-0.376mg\;kg^{-1}$ of the each PFCs, respectively. Furthermore, the residues in rice straw were the highest level in the all rice parts both in the groups. The PFOA and PFOS were reached to $3.723mg\;kg^{-1}$ and $7.641mg\;kg^{-1}$, respectively, and the BCF (1.474 and 4.700) as well.

• Korean Journal of Environmental Agriculture
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• v.13 no.2
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• pp.199-208
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• 1994

Analytical methods for the determination of the derivatives of the herbicide (${\pm}$)-2-(4-chloro-2-methylphenoxy)propionic acid (MCPP) by capillary column gas chromatography with mass spectrometer (GC-MS) and electron-capture detection (GC-ECD) were studied. A successful procedure was introduced for the ester preparation using $H_2SO_4$, as the catalyst and the alcohol 2,2,2-trichloroethanol (TCE) or 2,2,2-trifluoroethanol (TFE). The identificaiton and elucidation of MCPP by GC-MS spectrometry following the esterification with diazomethane, $BF_3$/methanol, $H_2SO_4$/methanol, TCE, TFE, or pentafluorobenzyl bromide (PFB) were carried out. A comparison of the response-sensitivities among those MCPP esters was made with GC-ECD. Although the methylation product of MCPP was confirmed by GC-MS, its low sensitivity to the ECD limited the detection of MCPP. TCE, TFE, and PFB derivatization methods resulted in a high rate of MCPP esterifications and very sensitive ECD molecular responses. Based on efficiency, convenience, worker safety, and least sample contamination, TFE esterificaiton was considered as the superior method for MCPP analysis to the other methods of derivatization. An accurate method is described for quantifying MCPP in soil leachates by GC-ECD at very low concentrations without the requirement of a complicated clean-up process. As a result, MCPP residues at concentrations of less than $0.1{\mu}g$ in 100ml soil leachate were detected.