• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2000.11a
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• pp.76-100
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• 2000

A brief general discussion of the nature and function of biosensors is presented. While the primary motivator for biosensor development has been the health-care industries, recent research efforts have spread to problems in agriculture and biological production systems. To illustrate some of the research from our laboratory, three example biosensors and their corresponding applications are presented. The first of these is an immunosensor for measurement of the hormone progesterone during milking as a method to improve reproductive management of dairy herds. The second example is an enzyme sensor for measurement of urea in milk as a menas to determine the efficiency of conversion of input protein to milk protein and, thus, improve nutritional management of dairy herds. The third example is a DNA sensor using polymerase chain reaction to detect pathogenic bacteria in the wash water of fresh and minimally processed fruits and vegetables. The potential for application of biosensors in agriculture, agrobiotechnology, food processing, and environmental monitoring has barely been realized.

• Journal of the Korean Dietetic Association
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• v.19 no.2
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• pp.124-139
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• 2013

Unlike studies of Europeans and Americans, many epidemiological studies of the Korean population have indicated that their risk for cardiovascular disease does not decrease with a vegetable-rich diet. The different dietary practices of Koreans, who consume salted vegetables instead of fresh vegetables (common in the Western diet), has been suggested as a reason for this observation. Korea is in a period of rapid epidemiologic transition, which includes dietary and disease patterns; therefore, this study investigated differences in the food consumption pattern and blood lipid profiles of Koreans compared to Europeans and Americans. The identification of dietary patterns related to blood lipid abnormalities was carried out using the 2007~2009 Korean National Health and Nutrition Survey data from 14,056 subjects. Dietary patterns were analyzed according to food group and nutrient intake. Blood lipid abnormalities were classified into three groups: hypercholesterolemia, hypertriglyceridemia, and low HDL cholesterolemia (hypo-HDL-cholesterolemia). The prevalence of hypercholesterolemia, hypertriglyceridemia, and hypo-HDL-cholesterolemia was 12.4%, 16.2%, and 27.7% respectively. In our analysis, the low consumption of all food groups was related to hypercholesterolemia. The high consumption of vegetable-containing foods, alcoholic beverages, and the low consumption of milk products were associated with hypertriglyceridemia and hypo-HDL-cholesterolemia. Thus, unlike Europeans and Americans, the low consumption of all food groups is related to hypercholesterolemia and a low consumption of milk products is related to hypertriglyceridemia and hypo-HDL-cholesterolemia. Dietary pattern might play a role in epidemiologic transition of Korean. Also, this study implies necessity of further research using longitudinal data.

• Food Science of Animal Resources
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• v.34 no.5
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• pp.665-673
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• 2014

We compared standard culture methods as well as conventional PCR and real-time PCR for the detection of Listeria monocytogenes (L. monocytogenes) in milk, cheese, fresh-cut vegetables, and raw beef that have different levels of background microflora. No statistical differences were observed in sensitivity between the two selective media in all foods. In total, real-time PCR assay exhibited statistically excellent detection sensitivity (p<0.05) and was less time consuming and laborious as compared with standard culture methods. Conventional culture methods showed poor performance in detecting L. monocytogenes in food with high levels of background microflora, generating numerous false negative results. While the detection of L. monocytogenes in fresh cut vegetable by culture methods was hindered only by L. innocua, various background microflora, such as L. innocua, L. welshimeri, L. grayi, and Enterococcus faecalis appeared on the two selective media as presumptive positive colonies in raw beef indicating the necessity of improvement of current selective media. It appears that real-time PCR is an effective and sensitive presumptive screening tool for L. monocytogenes in various types of foods, especially foods samples with high levels of background microflora, thus complementing standard culture methodologies.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.4
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• pp.373-381
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• 1994

This experiment was conducted to investigate the effects of nitrogen fertilizer level on forage yield and feed value, and to clarify the optimum nitrogen fertilizer level of rye in middle west area when cultured in paddy field. The field experiment treated 5 levels of nitrogen fertilization was carried out at Yesan from Oct. 1990 to June 1991. The fresh and dry weight increased with increased nitrogen fertilizer level by 30kg /10a, but dry matter ratio decreased. The ratio of leaf blade and leaf sheath in rye plant increased with increased nitrogen fertilizer level, but the ratio of stem and inflorescence decreased. The content and yield per unit area for protein, total digestible nutrient(TDN). Minerals, and energy increased with increased nitrogen fertilizer level, while acid detergent fiber(ADF) and neutral detergent fiber(NDF) decreased. The ratio of available protein among crude protein became higher with increased nitrogen fertilizer level. The optimum clipping time for net energy gain(NEG) and net energy maintenance(NEM) were 10 days earlier than milk stage for conventional items including TDN and proteins.

• Journal of Plant Biotechnology
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• v.45 no.1
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• pp.55-62
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• 2018

In the present study in vitro mutagenesis was used to study the effect of gamma irradiation and EMS on callus induction, morphogenesis and production of multiple shoots from different explants of Citrullus colocynthis (L.) Schrad. Gamma radiations (5 kR to 20 kR) and certain chemicals have been effected on plant growth developments and changes of biochemical metabolisms in plants. Murashige and Skoog (MS) medium containing with auxins such as NAA, IAA, 2,4-D (0.5 ~ 2.0 mg/l), cytokinines BAP, kn TDZ, (0.5 ~ 2.5 mg/l), L-Glutamic acid (1 ~ 2 mg/l) and Coconut milk (10 ~ 20%). After 5 weeks on induction media, explants and callus (EC) were exposed to 5 kR, 10 kR, 15 kR and 20kR, of gamma radiation and treated with 1, 2, 3, 4 and 5 mM ethyl methane sulphonate (EMS) for 30 min. The highest percentage of callusing was observed (70%) stem irradiated with 5 kR and significantly decrease in fresh and dry weight of callus in the below 4 kR doses and above 20 kR doses, there was a progressive decrease in the fresh weight and dry weights when compared to control callus. Maximum percentage of plantlet regeneration (59%) was induced from callus exposed to 15 kR gamma irradiation on MS media fortified with 2.0 mg/l 2,4-D + 2.0 mg/l BAP + 2.0 mg/l L-glutamic acid. Increase in gamma irradiation dose above 15 kR and 5 mM EMS reduced regeneration capacity of callus. Doses higher than 20 kR and 7 mM EMS was lethal to micropropagated plants of Citurullus colocynthis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.1
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• pp.98-105
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• 1989

The examination to find out how the activity of glutamine synthetase (GSA) develop in each wheat leaves during the growth period was carried out. GSA/g FW/leaf were very low at leaf differentiation stage and increased highly several times by unfolding and development of leaf, and declined deeply with the advance of senescence in each leaves. GSA/g FW/leaf were risen gradually from the every lower leaves to the every upper leaves, in consequence activity level and maximum peak per g fresh weight of 7th-flag leaves were two or three times higher than those at the 1st-4th leaves in all of 12 applied nitrogen treatments, thereupon. the highest activities per g fresh weight showed in the 8th leaves. GSA/g FW/leaf was shown two peaks in the 6th-flag leaves and one peak in 1st-4th leaves, respectively. GSA/g FW/leaf (except for senescence leaves) and GSA/plant were increased gradually to the infloresscence emerging stage and were shown the first maximum peak at 13 days before anthesis, then were declined rapidly. to the milk ripe stage (7 days after anthesis). and were shown the second maximum peak at the early dough ripe stage (22 days after anthesis) .

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.1
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• pp.63-74
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• 1999

This experiment was carried out to determine voluntary intake according to growth stage of sorghum $\times$ sudangrass hybrid in mono and intercropping. The results obtained from these experiments are as follows; Crude protein content of intercropping cultivation(sorghum $\times$ sudangrass hybrid + soybean) was higher than monocropping(sorghum $\times$ sudangrass hybrid), while ADF content was not different. Intake rates of leaf and stem showed highly at the intercropping comparing with monocropping(180cm~milk stage), but there was no difference at dough and yellow stage. Also, voluntary intake of fresh and dry matter showed same tendency. Voluntary intake of dry matter was the highest value of $98.4g/kg^{0.75}$ at milk stage treatment of intercropping. The intakes of crude protein were 9.6, 8.5, 7.2 and $7.2g/kg^{0.75}$ at 180cm, 250cm, boot stage and milk stage of intercropping treatment, respectively. These were higher than those for monocropping treatment. As mentioned above the results, intercropping cultivation could be recommended as increasing method of sorghum $\times$ sudangrass hybrid utilization when intake of dry matter and crude protein were considered.

• Food Science of Animal Resources
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• v.23 no.1
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• pp.70-74
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• 2003

Cheese consumption in Korea has continuously increased far the last decades by industrialization and globalization. In addition, import of fresh cheese has increased from 2 tons, and 30 thousand dollars in 1991 to 20 thousand tons, and 49 million dollars in 2001. However, Korea standard for cheese differs from CODEX, and is not consistent. To investigate more proper standards for cheese, 20 natural cheeses and 17 process cheeses were obtained from market and analysed. All the cheeses except 1 soft cheese met the standard, but 'unripened cheese' was not different from 'soft cheese' in milk solid content. Natural cheese firmness showed exponential inverse relationship(R=0.8226) to moisture on a fat-free basis(MFFB) which is used for the natural cheese standard in CODEX. Therefore, it was thought appropriate to refer to CODEX standard for using textural terminology in Korea standard for natural cheese. For process cheese, milk solid cant be estimated by the analysis, and there are no merits and penalties by the classification. It was thought proper to classify the process cheese by types, such as 'Powder', 'Slice', 'Spread', and 'Portion'. Rule for 15∼34% milk solid content of products should be prepared in standard for animal products as 'Process cheese products' for the promotion of development and consumption of cheese.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.8
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• pp.1068-1075
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• 2000

A study involving nutrient balances and radioisotope labeling techniques was undertaken to study energy and protein metabolism, and glucose kinetics of female crossbred Etawah goats, using 12 weaned (BW $14.0{\pm}2.0kg$), 12 late pregnant (BW $27.8{\pm}1.8kg$) and 12 first lactation does (BW $25.0{\pm}5.0kg$). Each class of animal was randomly allotted into 3 dietary treatment groups R1, R2 and R3, that received 100%, 85%, and 70% of ad libitum feed. The rations offered were pellets containing 21.8% CP and 19.3 MJ GE/kg, except for the lactating does who received pellets (17.2% CP and 18.9 MJ GE/kg) and fresh Penisetum purpureum grass. Energy and nitrogen balance studies were conducted during a two-week trial. Daily heat production (HP, estimated by the carbon dioxide entry rate technique), glucose pool and flux were measured. Equations were found for metabolizable energy (ME) and protein intake (IP) requirements for growing goats: ME (MJ/d)=1.87+0.55 RE-0.001 ADG+0.044 RP $(R^2=0.89)$ and IP (g/d)=48.47+2.99 RE+0.029 ADG+0.79 RP $(R^2=0.90)$; for pregnant does: ME (MJ/d)=5.92+0.96 RE-0.002 ADG+0.003 RP $(R^2=0.99)$ and IP (g/d)=58.34+5.41 RE+0.625 ADG-0.30 RP $(R^2=0.98)$; and for lactating does: ME (MJ/d)=4.23+0.713 RE+0.003 ADG+0.006 RP+0.002 MY $(R^2=0.86)$; IP (g/d)=84.05-5.36 RE+0.055 ADG-0.16 RP+0.068 MY $(R^2=0.45)$, where RE is retained energy (MJ/d), ADG is average daily gain in weight (g/d), RP is retained protein (g/d) and MY is milk yield (ml/d). ME and IP requirements for maintenance for growing goats were 0.46 MJ/d.kg $BW^{0.75}$ and 7.43 g/d.kg $BW^{0.75}$, respectively. Values for the pregnant and lactating does were in the same order, 0.55 MJ/d.kg $BW^{0.75}$ and 11.7 g/d.kg $BW^{0.75}$, and 0.50 MJ/d.kg $BW^{0.75}$ and 10.8 g/d.kg $BW^{0.75}$, respectively. Milk protein ranged from 3.06 to 3.5% and milk fat averaged 5.2%. Glucose metabolism in Etawah crossbred female goat is active, but glucose flux is low compared to temperate ruminant breeds which may implicate its role to support production.

• Korean Journal of Food Science and Technology
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• v.45 no.3
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• pp.267-273
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• 2013

We aimed to improve the flavor quality of plain yogurt, which is known to be sour and less desirable in flavor, varying concentrations of a buckwheat saccharification solution (BSS) were added to milk, followed by fermentation with commercially available mixed strains of lactic acid bacteria. Volatile compounds were analyzed using the gas chromatography-headspace-solid phase microextraction (GC-HS-SPME) method. Fermentation properties, including pH, titratable acidity, viable cells, viscosity, and color value were also measured. Eleven volatile compounds were identified with GC-MS. Of which, diacetyl, butanoic acid, and 2-heptanone proportionally increased as the levels of BSS increased. Undesirable compounds such as acetic acid and 2-butanone, decreased as BSS concentration increased. Fermentation properties were significantly altered with the addition of BSS. Our findings indicate that the flavor quality of plain yogurt can be improved by adding BSS for fermentation, with an additional health benefit from buckwheat.