• Journal of Animal Science and Technology
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• v.48 no.6
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• pp.797-804
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• 2006

The present study was undertaken to investigate the post-thawed survivability of bovine embryo depending on different dose of ethylene glycol and sucrose. Ovaries were collected at local slaughterhouse and the cumulus-oocyte-complexes aspirated from ovaries were in vitro matured, fertilized and cultured at 39°C in an atmosphere of 5% CO2 incubator. For conventional slow-freezing, d 7 or 8 expanded blastocysts were collected. Embryos were equilibrated in 1.5 M and 1.8 M ethylene glycol(EG) with 0.1 M and 0.3 M sucrose in Dulbecco's phosphate-buffered saline(D-PBS) supplemented with 0.5% bovine serum albumin. Embryos were then loaded individually into 0.25ml-straw and placed directly into cooling chamber of programmable freezer precooled to 󰠏7°C, after 2 min, the straw was seeded, maintained at 󰠏7°C for 8 min, and then cooled to 󰠏35°C at 0.3°C/min, plunged and stored in liquid nitrogen for at least 3 days. For thawing, the straw containing embryos were warmed in air for 10 sec and exposed to 37°C water for 20 sec. Straws were then removed from 37°C water. Rates of blastocyst survive and hatching were evaluated at 24 to 72 h post-warming. No difference of the survivability was shown between 1.5 M and 1.8 M EG (71 and 70%, respectively). Addition of 0.1 M sucrose to 1.5 M and 1.8 M ethylene glycol in the freezing solution did not differ significantly embryo survival (74 and 77%, respectively), whereas survival rates was higher(89%) in freezing solution contained 0.3M sucrose to 1.8M EG compared with 0.3M sucrose to 1.5M EG group(71%). However, there was no difference in the overall total cell number between the two groups (122±1.8 vs 131±1.4, respectively). In conclusion, the results suggest that 0.3 M sucrose in 1.8 M EG may be optimal condition for freezing and thawing methods with in vitro produced embryos and may be applied to on-farm conditions for embryo transfer.

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.106-116
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• 2005

This experiment was conducted to investigate available extraction capacity and potential mobility of heavy metal according to the distribution property and contamination level of heavy metals in soils and to suggest a reform measure of soil environment assessment methodology applied with soil quality and the official soil heavy metal test methods in domestic and foreign countries. The soils were collected from the natural forest paddy with long-term application of same type fertilizer, and paddies near metal mine and industrial complex. The post-treatment methods of soil were partial extraction, acid digestion and sequential extraction methods. For the heavy metal contents with different soil properties, it was shown that their natural forest and paddy soil were slightly low and similar to the general paddy soil, while their paddies near metal mine and industrial complex were higher than the standard level of Soil Environment Protection Act. Heavy metal concentrations in the soils with different soil properties had difference between $HNO_3\;and\;HNO_3+HCl$ extractant by US-EPA 3051a method. There were highly significant positive relationships in both two methods. It was appeared that the higher extractable concentration ratio with 0.1N-HCl to total heavy metal content with $HNO_3+HCl$ extractant the greater total heavy metal content. There were highly significant positive correlationship between total heavy metal content and extractable content with 0.1N-HCl. For extractable capacity of soil extractable solution compared to the total heavy metal content it was appeared that it extractable method with 0.1N-HCl was higher than those with EDTA and DTPA. In extractable ratio with 0.1N-HCl in the contaminated paddy soils near mine and industrial complex, it was shown that the lower soil pH, the higher total heavy metal content. The order of a potential mobility coefficient by distribution of heavy metal content with ie different typies in the soil was Cd>Ni>Zn>Cu>Pb. It could be known that contamination characteristics of heavy metals with different types of soils were affected by different heavy metal components, contamination degree and soil chemical properties, and heavy metal concentration with different extractable methods had great variations with adjacent environment. To be compared with assessment methodology of soil environment impact at domestic and foreign countries with our results, it might be considered that there was necessary to make a single analysis method based on total heavy metal content with environmental overloading concept because of various analysis methods for total heavy metal content and present analysis method with great variation according to soil environment. In spite of showing higher concentration of heavy metal with acidic digestion than the extractable method, it might be considered that there is need to be adjusted the national standard of soil heavy metal contamination.

• Journal of Food Hygiene and Safety
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• v.27 no.2
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• pp.161-168
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• 2012

This study was conducted to evaluate microbial contamination levels of Korea traditional rice cakes such as Sirutteok, Garaetteok and Gyeongdan in the manufacturing process and environment. The microbial contamination levels such as total aerobic bacteria, fungi, coliforms, Escherichia coli, Staphylococcus aureus, Bacillus cereus and Clostridium perfringens of rice cake products were analyzed. The contamination levels of total aerobic bacteria, coliforms, fungi and B. cereus in raw materials were in the range of 2.4~4.5, ND~1.9, 1.2~2.1 and 1.0~2.1 log CFU/g, respectively. The microbial contamination levels of total aerobic bacteria, coliforms, fungi and B. cereus in manufacturing process of rice cakes were increased in the soaking and grinding steps and were decreased in steaming step. E. coli, S. aureus and C. perfringens were not detected in any manufacturing process and environment. The microbial contamination levels of raw materials and final products of rice cake were suitable for microbial safety standard in Korea. However, the manufacturing environment such as equipments and employee's sanitation were in trouble for microbial safety. The results of this study suggest that safety educatio n for personal hygiene and safetymanagement in processing environment are continuously required to assure safety in working environment and employee's individual hygiene.

• Journal of Food Hygiene and Safety
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• v.27 no.2
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• pp.127-132
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• 2012

This study was conducted to investigate of changes for organic acids in takju during storage conditions. Two types of takju, unsterilized and sterilized, were used. Acetic acid, citric acid, lactic acid, malic acid and succinic acid were detected in sample. Residues of malic acid was not detected after 7 days storage in room temperature($25^{\circ}C$). In contrast to lactic acid was increased by times after storage. Acetic acid concentrations was gradually increased in room temperature but was not changed in cold temperature($4^{\circ}C$). After storage for 10 days, the organic acid residues lactic acid > citric acid > succinic acid > malic acid > acetic acid in unsterilized takju. Compared to unsterilized sample, organic acid residues in sterilized sample was not significantly changed. Consequently, organic acids residues mainly affected by sterilization.

• Journal of Food Hygiene and Safety
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• v.31 no.6
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• pp.458-464
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• 2016

Mulberry is considered a healthy food for antioxidants and many other beneficial nutrients. However, food safety concerns exist as this commodity scarcely passes through a sanitizing step due to the fragile nature of mulberry fruits. Fermented mulberry wort is one traditional way to utilize and preserve mulberries by mixing with sugars although hygienic practices are not often implemented. The purpose of this study was to investigate the fate of foodborne pathogens in fermented mulberry wort. Microbial population of inoculated E. coli in mulberry wort showed a decreasing pattern as the fermentation progressed. A quicker decrease was observed in the mulberry wort mixed with sugar at 1 to 0.8 ratio (w/w, mulberry: sugar) compared to 1 to 1 ratio, which could be due to the amount of acids generated during the fermentation process. When fully-fermented mulberry wort was contaminated with foodborne pathogens, they all decreased in population although their deceasing patterns varied depending on the species of tested bacteria. Steep deceases in population of inoculated foodborne pathogens were observed when the fermented wort was stored at $30^{\circ}C$ in comparisons to the other storage temperature, 5 and $20^{\circ}C$, regardless of bacterial species. This study necessitates the optimization of a sanitizing process during fermentation and storage of mulberry wort.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.2
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• pp.159-166
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• 1999

This study was conducted to investigate the effects of application of the dolomite particle and the shell powder on soil characteristics, dry matter yield and nutritive value of forages in loam soil at the experimental field of National Livestock Research Institute, Suwon, from 1994 to 1996. Application treatments were control, lime, dolomite 0.5, 2.0, 4.0mm, and shell powder in mixed pasture. Rate of dust occurrence was greatly decreased according to dolomite application and the dissolving rate in soil was highest in shell powder application among treatments. Although there was no significant difference, average dry matter yield of forages for 3 years was slightly increased with the application of lime, shell powder, dolomite 0.5mm, 4.0mm, 2.0mm and control in order. Both Ca and Mg contents of forages were no differences among treatments in 1994. However, all treatments were higher than those of control in 1995. And K and Na contents of forages were no differences among treatments. Lime requirement was greatly increased from 2,630 to 6,150kg per ha with the lapse of time. Although soil hardness was optimum level at first, it was likely to become hard little by little after treatments. Solid phase of soil was lowered a little except for control. Organic matter and available $P_2O_5$ contents of soil were highest in shell powder application among treatments, and K, Ca and Mg contents of soil were no differences among treatments. Ca content was increased a little in 1995, but decreased a little in 1996 compared to that of soil before treatments in 1994. AIso, Mg content was lowered than that of soil before experiment in 1995 and 1996. The results demonstrated that use of dolomite and shell powder as lime substitutes could be reduced dust problem and coast pollution as well as soil improvement. Therefore, it is desirable to apply the dolomite and the shell powder every 3 years in loam soil.

• Horticultural Science & Technology
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• v.19 no.3
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• pp.378-383
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• 2001

Embryo culture, ovule culture and ovary slice culture were tested to find optimum method for overcoming post fertilization barrier in interspecific crosses between L. longiflorum 'Gelria' and L. cernuum. Although reciprocal crosses between the species were carried out by cut-style pollination method, fruits developed only in crosses of L. longiflorum${\times}$L. cernuum. On the 40 days after pollination, ovaries were sliced into 2-4mm thickness and cultured on a hormone-free Murashige-Skoog (MS) medium, supplemented with 2%, 4%, 6%, 8% and 10% sucrose. For the L. longiflorum Gelria'${\times}$L. cernuum cross, ovule development was found to be best at 6% sucrose and a lot of hybrid plant lets established directly from the ovary slice culture and subsequent ovule culture. High concentration of sucrose above 8% made ovules abort or vitrificate from 40 days after culture. In contrast, ovules from the L. cernuum${\times}$L. longiflorum 'Gelria' cross swelled well in ovary slice culture, however, they did not germinated in subsequent ovule culture. On the 60 days after pollination, ovules thicker than 0.6mm was interpreted as one containing embryo. The embryo size ranged from 1.2 mm to 1.7 mm, and in vitro development of the excised embryos was found to be best with the MS medium (pH 5.8), supplemented with $0.1-1 mg{\cdot}L^{-1}$ NAA and 6% sucrose. Thick ovules excised 60 days after pollination germinated about 60% as normal seeds in MS medium supplemented with 6% sucrose and free hormone. The ovule culture 60 days after pollination was concluded to be most recommendable to produce interspecific hybrids in large scale crosses between L. longiflorum 'Gelria' and L. cernuum by the reason of easy procedure.

• Ocean and Polar Research
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• v.26 no.4
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• pp.581-594
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• 2004

CREAHS II carried out an intensive hydrographic survey covering almost entire East Sea in 1999. Hydrographic data from total 203 stations were released to public on the internee. This paper summarized the results of water mass analysis by OHP (Optimum Multiparameter) method that utilizes temperature, salinity, dissolved oxygen, pH, alkalinity, silicate, nitrate, phosphate and location data as an input data-matrix. A total of eight source water types are identified in the East Sea: four in surface waters(North Korea Surface Water, Tatar Surface Cold Water, East Korean Coastal Water, Modified Tsushima Surface Water), two intermediate water types (Tsushima Middle Water, Liman Cold Water), two deep water types (East Sea Intermediate Water, East Sea Proper Water). Of these NKSW, MTSW and TSCW are the newly reported as the source water type. Distribution of each water types reveals several few interesting hydrographic features. A few noteworthy are summarized as follows: The Tsushima Warm Current enter the East Sea as three branches; East Korea Coastal Water propagates north along the coast around $38^{\circ}N$ then turns to northeastward to $42^{\circ}N$ and moves eastward. Cold waters of northern origin move southward along the coast at the subsurface, which existence the existence of a circulation cell at the intermediate depth of the East Sea. The estimated volume of each water types inferred from the OMP results show that the deep waters (ESIW + ESPW) fill up ca. 90% of the East Sea basins. Consequently the formation and circulation of deep waters are the key factors controlling environmental condition of the East Sea.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.3
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• pp.75-86
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• 2003

In the near future, the capacity of conventional anaerobic digester is thought to be insufficient because of the increase of the total solids from expansion of intercepting sewer, sewage quantity and direct input of night soil from near apartment districts. The objectives of this study was to investigate the improvement of digestion efficiency using microbial agent(Bio-dh). The system was a pilot-scale, two-staged, anaerobic sludge digestion system. The first-stage digester was heated and mixed. The agitation velocity of the first-stage digester was 120rpm. The second-stage digester was neither heated nor mixed. The Digestion temperature was kept at $35{\pm}1^{\circ}C$ The detention time of digester was 19 days. The dosage of sewage sludge and microbial agent were $0.65m^3/day$ and $0.5{\ell}/day$, respectively. The experiments was run for 25days. Three times a week, $COD_{Mn}$ and SS of effluent, TS, VS, and biogas production rate were measured. Temperature, pH, and alkalinity were measured daily. The results were as follows ; Without microbial agent, digestion efficiencies ranged 46.0%~50.9%(mean=48.6%), with microbial agent(Bio-dh), digestion efficiencies ranged 52.8%~57.3%(mean=54.2%). Consequently, microbial agent(Bio-dh) increased the sludge digestion efficiency about 12%. Also, Without microbial agent, the mean concentration of $COD_{Mn}$ and SS of second-stage digester effluent were 1,639mg/L, 4,888mg/L respectively. With microbial agent, the mean concentration of $COD_{Mn}$ and SS of second-stage digester effluent were 859mg/L, 2,405mg/L respectively. Consequently, microbial agent(Bio-dh) increased the removal efficiency of $COD_{Mn}$ and SS about 47.6% and 50.8%, respectively.

• Microbiology and Biotechnology Letters
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• v.41 no.2
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• pp.168-175
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• 2013

In this study we investigated the possibility of preparing brewed brown rice makgeolli, a traditional Korean rice wine, under diverse conditions. For this purpose the physicochemical characteristics of makgeolli brewed at different temperatures, utilizing a variety of nuruks, the traditional Korean fermentation agent, were studied. The alcohol content was seen to be highest when brewing occurred at $30^{\circ}C$, with the nuruk TN producing 16.2%. At $20^{\circ}C$TN produced 14.1% alcohol content. The alcohol content was therefore higher, by about 2%, for $30^{\circ}C$ fermentations than $20^{\circ}C$ fermentations. Similarly, saccharifying activity was influenced by temperature and sugar content, with a higher activity seen at $30^{\circ}C$ than at $20^{\circ}C$. As the fermentations progressed acidification petered out, with titratable acidity being 0.50-0.67% in all end samples. On the Hunter L, a, b scale; the a value decreased slightly, while the b value increased steadily during the fermentation process. Measurements of total organic acids were highest at $30^{\circ}C$, with the nuruk AK, at about 550 mg%. The content of citric acid was the highest at $30^{\circ}C$, being 230-310 mg% in all samples. However, more lactic acid was detected at $20^{\circ}C$ than at $30^{\circ}C$. Total free amino acid was highest at $30^{\circ}C$, with TN at $8,605{\mu}g/ml$, AK at $6,083{\mu}g/ml$, and RJ at $2,381{\mu}g/ml$. Total free amino acid and essential amino acid was shown to be higher at $30^{\circ}C$ than at $20^{\circ}C$. The bioactive substance ${\gamma}$-aminobutyric acid was also higher at $30^{\circ}C$, with TN at $223{\mu}g/ml$. From all of these results, we surmise that brown rice makgeolli manufacturing conditions are optimal at $30^{\circ}C$ fermentation temperatures and using the nuruk TN for brewing vinegar. In addition, the nuruk used clearly affects the quality of brown rice makgeolli and an appropriate method to determine the best nuruk for various purposes should be pursued.