• Horticultural Science & Technology
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• v.30 no.4
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• pp.442-448
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• 2012

Many outbreaks of food-borne illnesses have been associated with the consumption of fresh vegetables and fruits contaminated with food-borne pathogens. Contaminated medium, manure and irrigation water are probable vehicles for the pathogen in many outbreaks. The aim of this study was to determine the potential transfer of Escherichia coli and Bacillus cereus from medium and soil fertilized with contaminated compost or irrigation with contaminated water to the edible parts of lettuce. Moreover, survivals of the two pathogens on lettuce contaminated medium, soil and irrigation water were estimated. Lettuce seeds were planted in medium contaminated with 7.5 log colony forming unit (CFU)/g of E. coli and B. cereus. Seedlings grown in the contaminated medium were transplanted in soil fertilized with contaminated pig manure compost or uncontaminated soil. Contaminated irrigation water with E. coli and B. cereus at 8.0 log CFU/mL was applied only once on the plant by sprinkle irrigation and surface irrigation. Although E. coli and B. cereus in medium and sprouted lettuce after planting seeds were reduced as time passed, these pathogens survived in seedling raising stage for extended periods. The numbers of E. coli and B. cereus in lettuce grown on contaminated soil were detected over 4.0 log CFU/g for 21 days. The numbers of E. coli and B. cereus in lettuce applied by sprinkle irrigation were higher than those of surface irrigation by 5.0 log CFU/g. Our results indicated that contaminated medium, soil and irrigation water can play an important role in the presence of food-borne pathogens on vegetables.

• Korean Journal of Food Science and Technology
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• v.47 no.5
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• pp.586-592
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• 2015

This study was performed to determine optimum approaches for control of microorganisms in school refectories and kitchens. A reduction of more than 5.0 log CFU/mL was noted for Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, Staphylococcus aureus, and Streptococcus mutans after treatment with 5 ppm ozone water for 60 s. Treatment of different vegetables with ozone water for 5 min showed bactericidal effects with 2-4 log reduction of viable cell number; the bactericidal effects differed according to the kinds of vegetables. The viable cell number on kitchen apparatus and tableware was not detected by ozone water treatment for 60 s. In addition, the count of the bacteria floating in the air in refectories and kitchens decreased 2.0 log CFU/1,000 L air to 0-1 CFU/1,000 L air on treatment with 45 ppm ozone gas for 12 hr. Therefore, ozone water and ozone gas may be good candidates as antimicrobial agents that can be used to improve sanitary conditions in school refectories and kitchens.

• Reproductive and Developmental Biology
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• v.33 no.3
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• pp.119-123
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• 2009

The two dimensional quantitative structure-activity relationships (2D-QSARs) models concerning the binding affinity constants ($p[Od.]_{50}$) between 2-cyclohexyltetrahydropyrane and 2-cyclohexyltetrahydrofurane analogues as substrates, and bovine odorant binding protein (bOBP) as receptor were derived by multiple regression analyses method and discussed. The statistical quality of the optimized 2D-QSAR model (5) was good (r=0.907). From the model, the binding affinity constants ($p[Od.]_{50}$) were dependent upon the optimal value ($(TL)_{opt.}$=2.737) of total lipole (TL) of substrate molecules. Based on these findings, the high active compounds predicted by optimized 2D-QSAR model (5) were 2-(dimethylcyclohexyl)tetrahydropyrane molecule and their isomer molecules. The binding affinity constants regarding bOBP of the tetrahydrofuryl-2-yl family compounds were dependent upon the hydrophobicity (logP) of whole substrate molecules. In any case of porcine odorant-binding proteins (pOBP), the constants were dependent upon the hydrophobicity (${\pi}x={\log}P_X-{\log}P_H$) of substituents (R) in substrate molecules. Also, from the optimal values of hydrophobic constant, the hydrophobicity for bOBP influenced ca. twice time bigger (bOBP>pOBP) than that for pOBP.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.5
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• pp.445-453
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• 2012

This study examined microbial contamination during seasoned and dried squid Dosidicus gigas processing, including the apparatus, machines, and employee's gloves at each step in processing at two companies. The numbers of bacteria floating in air in each processing area were also examined. The numbers of Staphylococcus aureus (3.6-6.0 log CFU/g) and Escherichia coli (1.3-1.4 log MPN/100 g) in domestic and imported daruma (a semi-processed product of seasoned and dried squid) at companies A and B exceeded the regulatory limits of the Food Sanitary Law of Korea (S. aureus, ${\leq}2.0$ log CFU/g; E. coli, negative). S. aureus in both daruma was reduced to below the detection limit or 3.6 log CFU/g after the roasting step, but increased again to 3.3 and 5.5 log CFU/g after the mechanical tearing step at companies A and B, respectively. E. coli showed similar tendencies at both companies. The surfaces of the apparatus, machines, and employee's gloves that contacted daruma were also contaminated with S. aureus (1.0-5.5 log CFU/$m^2$) and E. coli (negative-to 3.5 log MPN/$m^2$). The numbers of bacteria floating in air were high (1.7-5.1 log CFU/$m^3$) at both companies. These results suggest that sanitation standard operating procedures (SSOP) must be developed to control of microbial cintamination in seasoned and dried squid.

• The Korean Journal of Food And Nutrition
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• v.14 no.1
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• pp.59-64
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• 2001

Treating pork loins with lactic acid cultures (Lactococcus lactis subsp. ATCC 11454 grown in 10% milk solids) during storage at 4$^{\circ}C$ were studied. 2-Thiobarbituric acid (TBA), color. and drip loss evaluations of refrigerated pork loins were assessed. Pork loins were immersed in solutions containing 0∼10% individual lactic acid cultures for 0∼5 min. Pork loins treated with 3.96 log units of lactic acid cultures after storage of 1 days as 4$^{\circ}C$ had no significant difference (P > 0.05) TBA values compared to those of controls. Pork loins treated with 3.96 log unitss of lactic acid cultures during storage of 9 days at 4$^{\circ}C$ had no significant difference (P > 0.05). Hunter color L* and b* values compared to those of controls. However, pork loins treated with 4.10 and 4.23 log unitss of lactic acid cultures after storage of 1 and days at 4$^{\circ}C$ had a significant difference (P < 0.05) Hunter color a* values compared to those of controls. Pork loins treated with 4.10 and 4.23 log unitss of lactic acid cultures after storage of 4 days at 4$^{\circ}C$ had a significant difference (P < 0.05) drip loss values compared to those of controls.

• Korean Journal of Food Science and Technology
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• v.44 no.4
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• pp.478-483
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• 2012

In order to evaluate the microbial safety of the foodstuffs and manus in regards to foodservice operations, the total of 1,051 samples of drinking waters, vegetables, and cooked foods were collected. Total viable count (TVC), coliform group, and pathogens were analyzed. Twenty five percent samples of 441 drinking waters showed high contamination of above 2 log CFU/g TVC. Twenty percent of the waters were contaminated by above one log CFU/g coliform. Forty percent of non-heated food, Moochim, were contaminated by above 5 log CFU/g TVC and 26% of Moochim were contaminated by above 2 log CFU/g coliform. Bacillus cereus and Eschericia coli were detected on boiled rice and kimchi, and B. cereus was detected with a high ratio. Therefore, the foodstuffs and manus regarding foodservice operations appear to be generally safe. However, efficient microbial control for drinking water and Moochim-style food is necessary and in particular, careful management to reduce microbial contamination should be applied to drinking water.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.5
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• pp.800-807
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• 2013

This study investigated the quality characteristics and microbial hazards of commercial garlic available in supermarkets, traditional markets, and online shopping malls. Total bacterial counts were 2.55 log CFU/g in whole garlic and 5.20~7.40 log CFU/g in processed garlic, possibly due to contamination during processing. The total bacterial count from garlic purchased in supermarkets was below 5 log CFU/g, while garlic purchased in traditional markets and online shopping malls had counts of 3.87~6.34 and 3.73~6.11 log CFU/g, respectively. Thus garlic purchased at supermarkets appears to be more hygienic than garlic from traditional markets or online shopping malls. Some garlic purchased from supermarkets also had a lower pH (4.96~5.17) compared to fresh chopped garlic (7.4~7.5), likely due to the addition of citric acid and ascorbic acid, to reduce microbes and prevent browning. The moisture content of chopped garlic was 61.92~89.32%, with moisture content in imported garlic from China above 75%. The L, a, and b color values were 52.63~64.47, -3.74~8.75, and 10.67~17.88, respectively. The a and b values of supermarket garlic (-3.74~-3.20 and 10.67~13.90) were lower due to the addition of citric acid.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.3
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• pp.321-328
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• 2008

In this paper, a novel log-periodic cantor dipole antenna(LPCDA), which is composed of the cantor-dipole elements instead of the existing dipole elements, is proposed. The proposed antenna makes possible the antenna miniaturization by using the cantor-dipole elements. To investigate the reliability of the proposed antenna, LPCDA is designed and analyzed at $1{\sim}4GHz$ band and compared with LPDA(Log-Periodic Dipole Antenna) characteristics. It is shown that although the elements of LPCDA are 13.3% shorter than LPDA, the gain increases about 2dB and VSWR is less than 2 in at the upper band.

• Journal of the Korean Mathematical Society
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• v.45 no.4
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• pp.993-1005
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• 2008

Let {$X,\;X_n;n{\geq}1$} be a sequence of i.i.d. random variables. Set $S_n=X_1+X_2+{\cdots}+X_n,\;M_n=\max_{k{\leq}n}|S_k|,\;n{\geq}1$. Then we obtain that for any -1$\lim\limits_{{\varepsilon}{\searrow}0}\;{\varepsilon}^{2b+2}\sum\limits_{n=1}^\infty\;{\frac {(log\;n)^b}{n^{3/2}}\;E\{M_n-{\varepsilon}{\sigma}\sqrt{n\;log\;n\}+=\frac{2\sigma}{(b+1)(2b+3)}\;E|N|^{2b+3}\sum\limits_{k=0}^\infty\;{\frac{(-1)^k}{(2k+1)^{2b+3}$ if and only if EX=0 and $EX^2={\sigma}^2<{\infty}$.

• Korean journal of food and cookery science
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• v.21 no.5
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• pp.575-584
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• 2005

The objective of this study was to develop bioactive ginseng yogurt, fermented by B. minimum KK-1 and B. cholerium KK-2, which showed transforming activity of ginseng extract to compound K. Among older people, 3% ginseng yogurt fermented by B. minimum KK-1 and mixed with Bifidobacterium KK-1, KK-2 showed the highest overall acceptability(6.80, 6.80) among 1%(3.87, 3.67), 2%(4.40, 4.53) and 3% ginseng yogurt. The pH of ginseng yogurt was lower than that of plain yogurt. During 9 days of storage, the pH of each yogurt slightly decreased and then increased until 15 days of storage. The 3 8.25 log CFU/g and B. cholerium KK-2; 7.78 log CFU/g). Therefore, ginseng might be used as a growth factor during the fermentation of yogurt. The L value of ginseng yogurt decreased, and the a and b values increased, with increasing ginseng concentration.