• Mycobiology
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• v.45 no.3
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• pp.139-149
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• 2017

The genus Hyaloperonospora (Peronosporaceae; Oomycota) is an obligate biotrophic group that causes downy mildew disease on the Brassicaceae and allied families of Brassicales, including many economically relevant crops, such as broccoli, cabbage, radish, rape, and wasabi. To investigate the diversity of Hyaloperonospora species in northeast Asia, we performed a morphological analysis for the dried herbarium specimens collected in Korea, along with molecular phylogenetic inferences based on internal transcribed spacer rDNA and cox2 mtDNA sequences. It was confirmed that 14 species of Hyaloperonospora exist in Korea. Of these, three species, previously classified under the genus Peronospora, were combined to Hyaloperonospora: H. arabidis-glabrae comb. nov. (ex Arabis glabra), H. nasturtii-montani comb. nov. (ex Rorippa indica), and H. nasturtii-palustris comb. nov. (ex Rorippa palustris). In addition, finding two potentially new species specific to northeast Asian plants is noteworthy in support of the view that the species abundance of Hyaloperonospora has been underestimated hitherto.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.6
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• pp.849-855
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• 1996

Processing condition and pigment maintenance of cockle, Fulvia mutica were studied. Proximate composition of whole meat was $82.3\%$ moisture, $10.8\%$ crude protein, $0.8\%$ crude lipid, $2.5\%$ carbohydrate and $3.1\%$ crude ash, and that of foot muscle was $80.6\%,\;12.3\%,\;0.3\%,\;2.9\%\;and\;3.3\%$ respectively. When the living cockle was soaked in $2\%$ NaCl solutions, about $90\%$ of silt and mud was removed after 10 hours soaking, and over $92\%$ was removed when the pH was adjusted to 7.5. When the pigment destruction was tested by 40 seconds at $75^{\circ}C,\;80^{\circ}C,\;85^{\circ}C,\;90^{\circ}C\;and\;95^{\circ}C$, retention ratios of pigment in cockle were above $95\%$ at all temperature. Soaking in ethanol for 5 minutes resulted in strong adhesion of pigment to meat. Soaking in seasoning liquid containing $10\%$ soy sauce, $5\%$ wasabi, $5\%$ sugar, $2\%$ vinegar, $2\%$ powdered garlic for 3 minutes was effective for instant processing of cooked and frozen cockle after thawing. After 60 days storage at $-20^{\circ}C$, the contents of moisture, crude lipid, carbohydrate, ash and salinity were not changed so much, and pH and TBA values increased to 6.6 and 0.3 compared with 6.2 and 0.2, respectively, while pigment absorbance at 226 nm was decreased from 2.7 to 2.3. However, in case of 60 days storage at $-45^{\circ}C$, there was no change in these compositions.

• Journal of fish pathology
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• v.30 no.1
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• pp.63-66
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• 2017

Twenty nine edible plants were selected in order to study their exfoliation effect on abalone Haliotis discus hannai from its substrate. Exfoliation was observed in spearmint Mentha spicata, lemon balm Melissa officinalis, rose flower, onion Allium cepa, wasabi powder, mustard powder, omija Schizandra Chinensis, and hibiscus Hibiscus sabdariffa solutions. In particular, both the omija and hibiscus solutions exfoliated over 90% of the abalone. In field tests, 3% and 4% omija solutions exfoliated 93.6% (850/908) and 97.1% (810/834) of abalone, respectively, whereas 3% and 4% hibiscus solutions exfoliated 96.1% (780/812) and 97.4% (700/719), respectively. The detached abalone were recovered within 1 min 39 seconds. These results indicate that the omija and hibiscus solutions (3% and 4%) may be useful in the exfoliation of abalone.

• Korean Journal of Medicinal Crop Science
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• v.5 no.1
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• pp.36-42
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• 1997

This study was investigated on the effects of colchicine and EMS. induced mutation, plant on the germination and polypeptide pattern and peroxidase activity monitored by two dimensional gel analysis in Wasabia japonica Matsum (wasabi). Germination rate of Muju was higher than that of Ulrung-Do and optimum concentration for germination was appeared 100 ppm GA3 containing with 10 ppm BAP in these cultivars. Survived plants rate of Muju was higher than that of Ulrung-Do after colchicine and EMS treatment. Peroxidase activity and plant height were decreased by mutagen treatments, while incresed in root and stem thickness. The number of protein spots and pattern showed difference between Muju and Ulrung-Do . The plants treated mutagen increased polypeptide spots, especially EMS treatment showed more different polypeptide pattern compared to control.

• Horticultural Science & Technology
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• v.29 no.4
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• pp.311-316
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• 2011

This study aimed to determine the effect of EC (electrical conductivity) levels of nutrient solution in hydroponic culture on allyl-isothiocyanate (AITC) content within plant tissues, Vitamin C content and physiological responses in wasabi plant (Wasabia japonica M. 'Darma'). The 'Darma' was grown for 5 weeks with a deep flow technique (DFT) system controlled at 5 different EC levels, including 0.5, 1, 2, 3, and $5dS{\cdot}m^{-1}$. In result, the highest total content of AITC showed at EC level 5 and $3dS{\cdot}m^{-1}$ for 1 or 5- week, respectively. The total content of AITC increased about 1.2-1.4 times when the plants were grown in the EC levels between 0.5 and $2dS{\cdot}m^{-1}$, whereas the content decreased about 6 and 56 % in the EC level 3 and $5dS{\cdot}m^{-1}$, respectively. The content of AITC was relatively higher in petiole tissue, about 53 %, taken from 1 week-grown plants when the EC was controlled between 0.5 and $2dS{\cdot}m^{-1}$. Root tissue also had relatively higher content of AITC, about 45.1 %, when the EC was controlled at 3 and $5dS{\cdot}m^{-1}$. However, a 5-fold decrease in the AITC content was found in blade tissue and a 6.8-fold decrease in root when the EC was controlled at $5dS{\cdot}m^{-1}$ for 5 weeks. There was no significant difference in the vitamin C content in 1-week grown leaf tissues under the different EC level treatments; but, the content increased about 27% in 5-week grown plants at the EC level between 0.5 and $2dS{\cdot}m^{-1}$, compared to the 1 week-grown leaf tissue. Electrolyte leakage of leaf tissue taken from 3-week grown plant was 3-fold higher at the EC level $5dS{\cdot}m^{-1}$, compared to the EC level between 0.5 and $2dS{\cdot}m^{-1}$. Chlorophyll content, photosynthesis rate and transpiration rate were decreased when the EC was controlled at higher than $2dS{\cdot}m^{-1}$. Leaf water content, specific leaf area and growth were decreased when the EC was controlled at $5dS{\cdot}m^{-1}$ for 5 weeks. All the integrated results in this study suggest that the EC level of nutrient solution should be maintained at lower than $3dS{\cdot}m^{-1}$ in order to improve nutritional value and quantity required for hydroponically grown wasabi as functional vegetable.

• The Korean Journal of Food And Nutrition
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• v.14 no.6
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• pp.548-561
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• 2001

Listeria spp. from sea water, fishes and shellfishes have been troubled in many countries. So we exam ined its distribution rates, biochemical characteristics of a separated strain, growth curve of pH at set times to 4 species of standard strain, and yes or no of growth inhibition for precautionary measure of food poisoning by L. monocytogenes, garlic, mustard, wasabi, and green tea extracts including sensitivity of antibiotics 10 species. As its results, check numbers of its positivity to Listeria spp. were 32 species in total examination body 200 species, and its isolation rates were 16%, L. innocua was 14.0%, L. monocytogenes 1.0%, and L. seeligeri 1.0% by the strain species. All the standard strain of 4 species showed growth inhibition bellow pH 3.0, its pH conditions of the optimum growth at 7.0∼8.0, and its growth was more active in alkali co]tuition than in acid condition. Its growth inhibition examination by garlic extracts had an the worst effects with O.D values of 0.078∼0.210. But the case of mustard and wasabi had weakened effect, and the case of green tea had some effect as the time went by. The results of sensitivity examination of antibiotics 10 species were as fellows. L. innocua of the 16 cases showed sensitivity of 100% in all 5 species, Ampicillin, etc, and Ciprofloxacin showed sensitivity of 43.7% and gentamicin, 93.7%. But tetracycline showed tolerance of 31.3% , cefotaxine. 75%, nalidixic acid, 100%. L. monocytogenes of the 6 cases showed sensitivity of 100% in all 6 species, ciprofloxacin, etc.

• Journal of Food Hygiene and Safety
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• v.23 no.3
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• pp.227-232
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• 2008

The purpose of this study was to investigate the antibacterial effect of films on shelf-life and microbiological Safety of pork meat. Effects of antimicrobial films against total aerobic bacteria, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Typhimurium, Staphylococcus aureus in pork meat were evaluated during storage of 14 days at $5^{\circ}C,\;10^{\circ}C\;and\;15^{\circ}C$. Antimicrobial films were developed with addition of a natural substance, wasabi extracts(Wasabia japonica). At $5^{\circ}C$ storage, growth of total aerobic bacteria, E. coli O157:H7, L. monocytogenes were inhibited higher than at 10 and $15^{\circ}C$. Especially, the numbers of S. Typhimurium and S. aureus were increased gradually at $5^{\circ}C$ even in the control sample, and it takes more than 14 days to increase in every sample upto 6 $log_{10}cfu/g$. The higher antimicrobial effects of the films were observed at storage of $5^{\circ}C$ than at $10^{\circ}C$ and $15^{\circ}C$. There was a limit of a single treatment of antimicrobial film to prolong shelf-life of pork meat. The synergistic effect of antimicrobial film were observed with addition of refrigeration at $5^{\circ}C$.

• Korean Journal of Plant Tissue Culture
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• v.25 no.4
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• pp.257-261
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• 1998

The repeated subcultures of in vitro plant materials in wasabi became highly vitrified and the capacity for multiple shoot formation from the vitrified plant materials was very low. In order to improve the quality of in vitro propagated planting materials, the experiments were carried out using culture vessels capped with membrane filter(MF). When vitrified shoots were cultured on MS medium with 0.2mg/L BA in the vessels with MF or without MF for 60 days, the shoots in the vessels with MF did not vitrified. In contrast, the shoots grown in the vessels without MF vitrified at 65%. The stomates of vitrified leaves were circular and inflated, whereas those of normal leaves acclimatizated in the vessels with MF were ovate in shape. The hardened shoots were also cultured on MS media without sucrose containing 0.01mg/L IBA in vessels with(photoautotrophic culture) or without(control) MF. Sucrose was necessary for survival of the in vitro plantlets in the vessels without MF. After 20 days of culture, the shoots in the vessels without MF on the sucrose-free media turned yellow and died. But the shoots in the vessels with MF in the sucrose-free media produced a lot of roots. When shoots were cultured on MS medium with 2% sucrose containing 0.01mg/L IBA in the vessels with(photomixotrophic culture) or without(heterotrophic culture) MF, best growth occured in photomixotrophic culture.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.415-422
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• 2013

This study was conducted to establish the optimum LED light source and quality for growth of Wasabia japonica seedlings in the LED chamber plant factory system. The light treatments were combined with four colors LED (red, blue, white, far-red), irradiation time ratio of the red and blue LED per minute(1:1, 2:1, 5:1, 10:1), and duty ratio of mixed light (100%, 99%, 97%). The growth response of W. japonica was the greatest in the R + B mixed light treatment, and seedlings grown in the red LED alone was higher than blue LED alone in the monochromic radiation treatments. In the R + B mixed LED, 1:1 ratio of R and B was the best for total biomass and tiller production. In mixed light treatments, the growth response of W. japonica was highest in the 100% duty ratio with R + B mixed light, while that was highest in the 97% duty ratio with R + B + W mixed light. Leaf area and dry weight were increased in the red light treatment alone, while specific leaf area was increased in the blue light alone. With the increasing red LED light ratio, leaf area and dry weight of W. japonica was significantly increased under the R + B mixed light treatment. In mixed light treatments, the leaf growth responses of W. japonica was highest in the 97% duty ratio with R+B mixed light, while that was highest in the 100% duty ratio with R + B + W mixed light. For cultivating W. japonica in a plant factory, treating red LED supplemented with a blue light or higher ratio of the red to blue LED was benefit to promote the growth of W. japonica.

• Journal of Food Hygiene and Safety
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• v.31 no.1
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• pp.8-14
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• 2016

The purposes of this study are to confirm ways to reduce bacteria of minimally processed agricultural products, using antibacterial foods that are easily available in home and to improve bacterial hygienic condition of them. We chose garlic-allicin, ginger-gingerol, green tea-catechin, cinnamon-cinnamic aldehyde, wasabi-allyl isothiocyanate as antibacterial foods and their unique antibiotic materials. We confirmed the better washing effect when these antibiotic extracts were used, compared to washing effect by only distilled water. Their antibiosis was proved by statistical processing. PFGE (Pulsed Field Gel Electrophoresis) of Bacillus cereus shows continuous contamination probability of minimally processed vegetables by same product suppliers and the necessity of systematic measures against bacterial contamination.