• The Korean Journal of Pesticide Science
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• v.8 no.4
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• pp.338-346
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• 2004

The methanol extract of Chloranthus japonicus roots effectively controlled the development of rice blast(Magnaporthe grisea), rice sheath blight(Corticium sasaki), tomato pay mold(Btrytis cinerea), tomato late blight(Phytophthora infestans), and wheat leaf rust(Puccinia recondita). From the methanol extract of C. japonicus roots, three antifungal substances were isolated. Their chemical structures were determined to be shizukanols B, C, and D mainly by mass and NMR spectral data. Among the three substances, shizukanol C showed the strongest inhibitory activity against mycelial growth of the plant pathogenic fungi tested; it completely inhibited mycelial growth of M. grisea. Colletotrichum gloeosporioides, and C. acutatum at concentrations of more than $12.5{\mu}g$/ and P. infestans at concentrations of more than $3.13{\mu}g/m\ell$. They also controlled effectively the development of rice blast and wheat leaf rust. On the other hand, they caused phytotoxic symptoms on barley leaves and inhibited the growth of duckweed (Lemna paucicostata) with $EC_{50}$ values of $30.0{\mu}g/m\ell$ for shizukanol B, $49.9{\mu}g/m\ell$ for shizukanol C, and $154{\mu}g/m\ell$ for shizukanol D. In addition, shizukanol C showed an insecticidal activity against brown planthopper (Nilaparavata lugens), peen peach aphid (Myzus persicae), diamond-back moth (Plutella xylostella), and tobacco cutworm (Spodoptera litura) of the 5 arthropod pests tested with mortality values of more than 60% at a concentration of $1,000{\mu}g/m\ell$.

• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.109-120
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• 2012

This study was conducted to monitor 284 pesticides residue level in 2,914 commercial agricultural products in the northern area of Seoul in 2011 by the multi class pesticide multiresidue analysis methods in Korea Food Code using GC, HPLC, GC-MSD and, LC-MSD. The detection rate of pesticide residues were 14.8% (431/2,914). The order of agricultural products in which the pesticide residues were detected was perilla leaves 40.0% (28/70), chamnamul 35.5% (11/31), amaranth 30.0% (3/10) and spinach 27.7% (38/137) etc. The percentage of products that exceeded the MRLs (maximum residue limits) were 1.0% (31/431). Those products that exceeded MRLs were ginseng (6), perilla leaves (4), leek (4), welsh onion (3) and sedeum (3) etc. The 59 kinds of the pesticides were detected on this study, 21 pesticides of them were detected over MRLs. Detection rate of fungicides (56.4%) was higher than that of insecticides (42.1%). And procymidone was detected with considerable high frequency. Additionally, residual residual violates pesticides were in the order of tolclofos-methyl, endosulfan, dimethomorph, diniconazole and fludioxonil. According to the agricultural marketing channels, detection and excess rate of them were monitored. Detection and excess rate of samples circulated in agricultural traditional market were highest. The estimated daily intakes (EDI) of the pesticides were compared to personal acceptable daily intakes (PADI) in order to risk assessment by food consumption. Diazinon in Korean cabbage showed the highest %ADI, 2.9901 and others showed below 3.0 %ADI. Overall, these results indicate that residue levels of pesticides detected were evaluated as safe.

• The Korean Journal of Pesticide Science
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• v.16 no.3
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• pp.202-208
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• 2012

A high-performance liquid chromatographic (HPLC) method was developed to determine residues of cyromazine, a triazine insecticide, in agricultural commodities. Cyromazine was extracted with 90% aqueous methanol from representative crops which comprised brown rice, oyster mushroom, oriental melon, watermelon, and Chinese cabbage. Following to evaporation of methanol in the extract, the aqueous concentrate was acidified to form the protonated cyromazine. Dichloromethane partition was then applied to remove nonpolar co-extractives in the aqueous phase. Strong cation-exchange chromatography using Dowex 50W-X4 resin was employed for final purification of the extract. Cyromazine was successfully separated on a Zorbax SB-Aq $C_{18}$ column showing high retention for polar compounds. Cyromazine was sensitively quantitated by ultraviolet absorption at 214 nm. Limit of quantitation (LOQ) of the method was 0.04 mg/kg irrespective of sample types. Each crops were fortified at 3 different concentrations of cyromazine for recovery test. Mean recoveries from samples fortified at LOQ~2.0 mg/kg in triplicate ranged 80.2~103.3% in five agricultural commodities. Relative standard deviations in recoveries were all less than 6%. A selected-ion monitoring LC/MS method with electrospray ionization in positive-ion mode was also provided to confirm the suspected residue. The proposed method was reproducible and sensitive enough to routinely determine and inspect the residue of cyromazine in agricultural commodities.

• Korean Journal of Plant Tissue Culture
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• v.28 no.5
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• pp.289-296
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• 2001

The main objective of this topic is to establish strategies and to plan biotechnology researches which are related to the agricultural improvements especially focusing on the crop breeding in Korea. From 1960's to 1980's government policy had been emphasized to develope high yielding cultivars for the self sufficient supply of the staple food crops. As a result, considerable increase of rice production has been made with accumulating technology and man's powers. Recently genetically modified crops harboring useful characteristics have been developed using biotechnology and released in the developed countries. National research institutes and private companies have been developed biotechnology researches to establish competitive capabilities, however they have not been successfully used in commercialization. Therefore it is necessary to promote the practical. application by connecting molecular technology with conventional breeding. Proposed research projects are; (1) basic researches including plant genome studies, (2) developing new cultivars through gene transformation, (3) screening and producing antioxidants, secondary metabolite substances and edible vaccines. To set a government policy, both domestic and international research trends were reviewed and possibility of success based on the economic view point were discussed. The intellectual property and preservation of environment play a key role to decide the research priority. It is also necessary for us to make one step system for the distribution of research resources such as microorganisms, genes cloned, plant seeds and research informations for promoting research activities.

• Korean Journal of Food Science and Technology
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• v.31 no.3
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• pp.619-624
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• 1999

This work was to study the potential health food use of germinated colored rice after germinating and drying using microwave under vacuum. Colored rice was soaked in water at $15^{\circ}C$ for 2 days and then germinated at $25^{\circ}C$ for $3{\sim}4\;days$. The germinated colored rice was dried by different drying methods: microwave vacuum drying 1, microwave vacuum drying $2\;(drying{\rightarrow}crushing{\rightarrow}drying)$, hot air drying, vacuum drying and freeze drying. Each drier except freeze drier was set to maintain the sample temperature at $60^{\circ}C$. During microwave vacuum drying 1 or 2, the sample reached $60^{\circ}C$ much faster (within 5 min) and was dried much faster ($2{\sim}3\;hrs$ than the other drying methods. The initial drying rate of microwave vacuum drying was ten times faster than that of hot air drying. The microwave vacuum drying 2 retained the highest ${\alpha}-amylase$ activity, followed by microwave vacuum drying 1, freeze drying, vacuum drying, and hot air drying.

• Korean journal of food and cookery science
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• v.31 no.3
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• pp.344-351
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• 2015

The purpose of this study is to improve Korean food market competitiveness in China, and to develop product diversity. Therefore, the paper will discuss and analyze the feasibility of combining Korean and Chinese cuisines. The paper is based on a SPSS-analyzed survey of 255 Jiangsu residents focusing on the concept of breakfast, and the recognition of and preference for Korean food. The result showed a high level of eating out for breakfast in Jiangsu province and the expectation of many options. The respondents generally preferred porridge, steamed stuffed dumplings, noodles and other options that are relatively convenient. Korean foods such as bulgogi, samgyeopsal, tteokbokki and bibimbap generally enjoyed a high degree of recognition and preference. This study selected bulgogi, jeyukbokkeum, dakgalbi and japchae as the stuffings for steamed dumplings and an evaluation of sensory attributes including saltiness, sweetness, spiciness, and gravy was conducted using 30 professionals. Relatively high scores were recorded in all aspects. Compared with the reference product, the dumplings with Korean food stuffing achieved higher scores. As a new development and attempt, the steamed dumplings with Korean food filling evaluated during this test demonstrated feasibility and enormous market potential. The study provides a new direction and reference value for the Chinese breakfast market and for the penetration of Korean food into the Chinese market.

• Korean journal of food and cookery science
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• v.28 no.2
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• pp.207-214
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• 2012

In this study, cabbage ($Brassica$ $oleracea$ var. $capitata$) Kimchi was made packed into four kinds of packaging materials, PET vessel, PP tray, OPP/AL/PE film and Nylon/PE/LLDP film, and the effects of these packaging materials on Kimchi quality characteristics, such as lactic acid bacteria counts, salinity, sugar contents, pH, total acidity, electron donating ability were examine as well as their effects on the sensory qualities after storage at a temperature of $4^{\circ}C$. The pH change ranged from pH 6.24 to 6.43 shortly after manufacture, and did not significantly change until 7 days of storage. However, it began to decrease rapidly after 14 days. On the 35th day of storage, the acidity was 0.79% in the PET vessel and 0.83% in OPP/AL/PE. Therefore, the PET vessel and OPP/AL/PE were considered appropriate packaging materials for Kimchi storage. The salinity did not change significantly during the storage period, and the sugar content generally increased in the four kinds of packaging materials, but decreasing after the 7th day of storage. After 14 days of storage, the Kimchi stored in the OPP/AL/PE film showed the highest lactic acid bacteria counts. Although the electron donating ability was the highest after proper time for fermentation, it decreased in all the packaging materials after the proper time for fermentation. However, the OPP/AL/PE film had an antioxidant potential of up to 93.18%. In the sensory evaluation, fermented Kimchi was found to be superior unfermented Kimchi. In addition, the Kimchi stored in the OPP/AL/PE film for 14 days showed the high score of 6.70 and 6.60 in overall preference. Therefore, the results of this study provide basic knowledge on the fermentation level and packaging material's condition for commercialization of small packed cabbage Kimchi. Henceforth, industrialization must include a variety of studies under these conditions to increase the merchantability.

• Korean Journal of Soil Science and Fertilizer
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• v.11 no.2
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• pp.67-73
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• 1979

The effect of liming on the potassium equilibrium activity ratio ($AR^k_e$) of Chinese cabbage cultivated soil and on the potassium uptake by the plant summarize as follows: 1. $AR^k_e$ is raised by the application of 1.6 ton of $Ca(OH)_2$ per hectare that required amount to adjust pH 6 for the soil. Generally, it could be confirmed that both liming and potassium placement to the soil show the combined effects to raise $AR^k_e$. 2. The exchangeable potassium and the electrical conductivity increase by liming. The mean value of the exchangeable potassium is 0.71 m. equ. per 100g of limed soils while the control give 0.64 m. equ. per 100g. For the electrical conductivity, limed soil show $766{\mu}mho$ and $750{\mu}mho$ is for the control. 3. The reason $AR^k_e$ value increase by liming could be considered that concentrations of $K^+$ and $Ca^{{+}{+}}+Mg^{{+}{+}}$ in the equilibrium solution are increased owing to release both K and $Ca^+$ Mg into the liquid from solid phase in the potassium equilibrium system of the soil. 4. For considering that the energies of exchange of calcium by potassium in the limed soils at different potassium treatment, that is without K, 200 kg $K_2O/ha$ and 350 kg $K_2O/ha$, give -3887 and -3778 and -3737 calories per chemical equivalent respectively. On the other hand in case of the controls which received the same amounts of potassium as mentioned above, energy values are -3983, -4392 and -4228 calories respectively. 5. The absorbed amount of potassium and weights of dry matters of the plant which grown in the limed soils show little higher values than the controls.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.3
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• pp.199-204
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• 1987

This study was conducted to verify the identity and the effects on soil improvements by the application of Barley stone which has been recently named as miraculous mineral on account of being propagandized as health stone because of several special effect of medicine, the supplement of micronutrients for agriculture, prevention against diseases and insects of plant, and the increase of nutrient holding capacity of soil. The results were summarized as follows; 1. Barley stone is considered as Diabase Porphyrite by the analysis of X-ray Diffraction, chemical composition and microspore's observation. This mineral stone called as Barley stone has been deducted because of being seen as if the feature was attatched with cooked barley and appearently scattered about feldspar's phenocryst on the dark-green stone base. 2. In chemical characteristics of barley stone, the pH 8.7 was higher but C.E.C. 9.0 me/100g was lower then those of other clay minerals such as Bentonite and Zeolite, and so barley stone material was not considered suitable for improvement of sandy loam soil. 3. Effects of Bentonite and Zeolite application on yield of paddy rice were 108-109% compare to non-treated plot, but Barley stone has not increased rice yield. Notwithstanding the increase of application of barely stone to 5 ton per 10a, the yield increase was not significantly showing only 102-103% and the effects of Peanut, hot pepper and chinese cabbage were not recognized either.

• Journal of the Mineralogical Society of Korea
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• v.19 no.3 s.49
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• pp.171-187
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• 2006

The status of heavy metal contamination was investigated using chemical analyses of stream waters and sediments obtained from Samsanjeil and Sambong Cu mining area in Goseong-gun, Gyeongsangnam-do. In addition, the degree and the environmental risk of heavy metal contamination in stream sediments was assessed through pollution index (Pl) and danger index (DI) based on total digestion by aqua regia and fractionation of heavy metal contaminants by sequential extraction, respectively. Not only the degree of heavy metal contamination was significantly higher in Samsanjeil area than in Sambong area, but its environmental risk was also revealed much more serious in Samsanjeil area than in Sambong area. The differences in status and level of contamination and environmental risk between both two mining areas may be attributed to existence of contamination source and geology. Acid mine drainage is continuously discharged and flows into the stream in Samsanjeil mining area, and it makes the heavy metal contamination in the stream more deteriorated than in Sambong mining area in which acid mine drainage is not produced. In addition, the geology of Samsanjeil mining area is mainly comprised of andesitic rocks including a small amount of calcite and having lower pH buffering capacity fer acid mine drainage, and it is likely that the heavy metal contamination cannot be naturally attenuated in streams. On the contrary, the main geology of Sambong mining area consists of pyroclastic sedimentary Goseong formation containing a high content of carbonates, particularly calcite, and it seems that these carbonates of high pH buffering capacity prevent the heavy metal contamination from proceeding downstream in stream within that area.