• Journal of Biosystems Engineering
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• v.6 no.1
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• pp.15-27
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• 1981

In order to investigate on the field performance of 3.5PS power tiller and to obtain the optimum using conditions of it, this experiment has been carried on the plowing operation, the rotary harrowing operation and the ridging operation that compared 3.5PS power tiller(KC-450) with the existing 5PS(DT-40) and 8PS(DT-85) power tiller. It has been performed at Suck Jung-Dong, Ansung Country, from March to October in 1980. The results of this field test were obtained as follows; 1. The plowing performance of KC-450 tiller was found to be 125min/10a that was lower than that of DT-85 tiller by 26min/10a in the effective plowing speed 0.9m/sec. 2. The field efficiency of KC-450 tiller was the highest among the power tillers as to be 82 persent that was higher than that of DT-85 tiller by 5 persent in the effective plowing speed 1m/sec. 3. The rotary harrowing performances of DT-40 tiller and DT-85 tiller were higher than that of KC-450 tiller in the rotary harrowing operation of the same speed, and the field efficiency of KC-450 tiller and DT-40 tiller were higher than that of DT-85 tiller in the rotary harrowing operation. 4. The ridging Performance of testing power tillers were nearly equality in the ridging operation of the same speed, and the field efficiency of testing tillers were higher KC-450 tiller than DT-40 tiller, DT-40 tiller than DT-85 tiller. 5. The work performance of power tiller increased with increase in the size of field area. Work performance and field efficiency of KC-450 tiller were higher than other tillers below 8a in field size 6. DT -85 tiller was more useful in deep plowing depth. But below 8a in field size KC-450 tiller was more easily operated and its field efficiency was higher 7. KC-450 tiller should be more useful to operate in the small size field or in the small scale farming and for the cultivation of vegetables, gardening plants, medicinal herb and tobacco plants, or for the cultivation in vinyl house.

• Journal of Nutrition and Health
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• v.41 no.1
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• pp.100-110
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• 2008

The present study estimates intake levels of dietary fiber (DF) in Korean adults aged 20 and over, using a newly established dietary fiber database for 3,149 food items, as well as 24-hour recall method data from the 2001 Korean National Health and Nutrition Survey. Dietary fiber intake and food groups are analyzed by gender, age, and region. The average dietary fiber intake, per capita of Korea was estimated to be 12.24g/1,000kcal or 23.58g/day. Calorie-based dietary fiber intake for 20-49 year-old-Korean males, 20-29 year-old females, and the adults who resided in metropolitan areas was under the Adequate Intake for DF, 12 g/1,000 kcal. Further, the dietary fiber intake after adjusting energy intake in people over 75 year-old was estimated to be 75% of AI. Vegetables, cereals and fruits were three major sources of DF for Korean, making up approximately 75% of DF. Regarding the subjects of this study, major sources of dietary fiber were Kimchi and well-polished rice, which supplied 13.98% and 9.16% of total dietary fiber intake, respectively. The result of this study could contribute to the establishment of DRIs for dietary fiber, after adjusting energy intake for Korean aged 75 years and over. The beneficial health effects of DF and the necessity of nutritional education in this area should be continuously emphasized concerning 20-29 year-old people and metropolitan adults.

• The Korean Journal of Pesticide Science
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• v.16 no.2
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• pp.121-130
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• 2012

In analyzing pesticide residue, LLE (liquid liquid extraction) is generally applied as one of the existing methods, but needed quite a lot of organic solvents and analytical apparatuses for the sample pre-treatment. In addition to its long analysis time and complex analytical processes, it is required to develop a more rapid and efficient method at present. In order to establish an economic and simple pesticide residue analytical method, this study carried out a comparative experiment on the existing analytical method with a new sample pre-treatment method named QuEChERS (quick, easy, cheap, effective, rugged and safe), which extracts and refines pesticide components by directly adding solid powder into the sample. Both the two analytical methods showed favorable values of correlation coefficient ($R^2$ > 0.99) of calibration curves. In terms of the detection limit (identification limit), imidacloprid showed 0.02 mg/kg, while the rest of pesticides showed a level around 0.05 mg/kg. The results of this experiment revealed that the recovery of LLE was 92.8-100.9% and the RSD was below 2.5%. On the other hand, the recovery of QuEChERS was 92.2-101.6% and RSD was below 1.9%. As a result of comparing the amount of pesticide residue by the time between the two analytical methods by using Paired t-Test, there was no significant difference between the two analytical methods as the p-value ranged from 0.3148-0.9890. Considering the results of the two methods, the QuEChERS method had similar recovery, compared to the analytical method using the existing LLE, and the analytical time was shortened by about one fourth of that of the existing method. Moreover, since it excludes the use of harmful organic solvents like dichloromethane during the process of extraction, thus leading to protecting experimenters health and remarkably reducing the amount of disused solvents, it is judged as an echo-friendly and economic analytical method.

• Korean Journal of Organic Agriculture
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• v.13 no.4
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• pp.389-400
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• 2005

This study was conducted to investigate into the ecological environments and the soil microflora of purple-bracted plantain lily (Hosta longipes Matsumura) for wild vgetables. Native soil textures of purple-bracted plantain lily were in the order of sandy loam (SL) > loam (L) > clay loam (CL). pH in soil was relatively acid by 4.8, electric conductivity was 0.08mS/cm, and organic matter content was 0.08g/kg. CEC was measured by $100.8cmol^{(+)}kg^{-1}$ and available phosphate was 103.4mg/kg. Contents of exchangeable cations in terms of potassium, calcium, and magnesium were measured by $0.33cmol^{(+)}kg^{-1},\;2.26cmol^{(+)}kg^{-1},\;and\;0.87cmol^{(+)}kg^{-1}$, etc. Diurnal changes in the air temperature of the natives were 15 to $20^{\circ}C$, that temperature differential was relatively little compared with that in open field by 15 to $30^{\circ}C$. Relative humidity in the natives were much more humid by 60 to 80% compared with that in open feld by 35 to 85%. Light intensity in the natives and the open field at ten o'clock were $2,300{\mu}mol/m^2/sec.\;and\;1,750{\mu}mol/m^2/sec.$ Total number of soil microorganisms were $8.4{\times}10^7\;c.f.u./g$. Mycorrhizal spore densities over $500{\mu}m,\;355{\sim}500{\mu}m,\;251{\sim}354{\mu}m,\;107{\sim}250{\mu}m\;and\;45{\sim}106{\mu}m$ were 0.8, 1.3, 2.1, 38.1, and 110.0 respectively. Mycorrhizal root infections by vesicle and hyphae were 17% and 6%. However, arbuscules in the roots were not shown.

• Korean journal of food and cookery science
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• v.7 no.1
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• pp.67-80
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• 1991

This study researched the dietary habit of boy's and girl's high school students, and into low it was connected with the state of health between the group of having the right dietary habit and the group of having the wrong habit. Results were as follows: 1. The age about the object person of research was the most numerous in 79% at 16~17 years old, the average weight was $55.67\pm9.08$kg, the average height was $165.47\pm7.56$cm. 2. In the parent's school career of the object person of research, persons who graduated high school were many. The mother's educational level was lower than the father's school career. The parent's school career in the district south of a river was higher than the parent's school career in the district north of a river. And the parent's school career of cultural students was high. 3. The frequency of food intake in the district north of a river and in the district south of a river was a meaningful difference in the vegetables blended in green and yellow things (p<.01), fruit (p<.05), rice, flour, potatoes (p<.05), and so the district north of a river took less than the district south of a river. 4. The most regular diet in a day was lunch. The appetite of the students was generally good. 5. The general environment and state of health were a meaningful difference about melancholia (p<.05) in the district of north and south of river, and so melancholia in students of the north of a river was high. 6. The state of health according to regular diet was a meaningful difference, so regular student was better than irregular student in state of health, and was the same in study. 7. Eating habit correlated much to each state of health, Especially in physical health, the muscular frame correlated to fruit (p<.001), seaweeds (p<.05), fried food, jun, panbroiled food (p<.05), salty taste (p<.05), sour taste(p<.001).

• Korean journal of food and cookery science
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• v.31 no.4
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• pp.477-484
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• 2015

The objective of this study was to investigate the awareness of the meaning of a low-sodium diet as well as the self-reported preference of saltiness and sodium-intake related dietary behaviors for university students in Busan. A survey was conducted with 977 students (male: 512, female: 465). For the self-reported preference of saltiness, 45.8% of the participants reported 'moderate' preference, 35.3% reported 'salty' preference, and 18.8% reported 'unsalty' preference. Males had significantly higher scores than females (p<0.01). Regarding awareness of the meaning of a low-sodium diet, 20.8 % of the students did not recognize the phraseand, males had significantly lower awareness than females (p<0.01). The 'salty' group had a significantly lower rate than others (p<0.01). Males had significant higher sodium-related dietary behaviors scores than females for the following questions 'I often eat dried seafood and salted seafood', 'I usually eat all the broth in soups or stews' (p<0.01), 'I usually eat a lot of kimchi and salt-pickled vegetables', 'I usually eat soy dip or hot pepper dip with sushi and fritters' (p<0.05). Mean scores for sodium-related dietary behaviors by self-reported preference of saltiness were 2.49/5.00 (unsalty), 2.87/5.00 (moderate), and 3.19/5.00 (salty), respectively. There was a statistically significant difference between the groups (p<0.01). The lower the scores for the self-reported preference of saltiness, the lower the scores for sodium intake-related dietary behaviors (p<0.01). The average score for sodium-related dietary behaviors in the group familiar with the meaning of a low-sodium diet was significantly lower than that of the group that 'did not know' (p<0.01).

• Korean journal of food and cookery science
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• v.26 no.3
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• pp.335-345
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• 2010

The objective of this study was to model the kinetics of S. aureus survival on high risk foods in school foodservice operations. After inoculating S. aureus ATCC25923 onto the various high risk foods, the effects of competitive microorganism, storage temperatures($25^{\circ}C$, $35^{\circ}C$), and initial contamination levels ($1.0{\times}10^2\;CFU/g$, $1.0{\times}10^5\;CFU/g$) on the growth of S. aureus were investigated. Lag time decreased and specific growth rate increased with a storage temperature ($25^{\circ}C$<$35^{\circ}C$) and with a higher initial inoculation level ($1.0{\times}10^2\;CFU/g$<$1.0{\times}10^5\;CFU/g$). Previously it was shown that S. aureus is a weaker competitor than other organisms, but it proliferates aggressively in a noncompetitive environment. However, in our study, when S. aureus was used to inoculate japchae (glass noodles with sauteed vegetables) and meat ball, the growth of S. aureus was similar and more active with competitive organisms than that without competitive organisms. Regardless of other factors, the initial level of S. aureus was a more significant factor of the growth. High inoculation levels of S. aureus were reached at 6 log CFU/g within 3 hours. An incubation temperature of $35^{\circ}C$ and the animal protein component of menu items also were identified as significant factors influencing the growth of S. aureus. Therefore, the duration of time meals are stored before serving should be considered a critical control point. Food service providers must control time and temperature to insure the safety of cooked foods.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.337-342
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• 2008

In this study, HPLC was used to determine the total sugar contents of processed foods as well as main and side dishes that were acquired from noncommercial foodservices. The total sugar content was identified as the total amount of both mono- and di-saccharides according to the nutritional information standard defined by the Korea Food and Drug Administration. The results for the processed foods were as follows: $25.3{\pm}9.5%$ for biscuits, $11.7{\pm}10.6%$ for snacks, $29.9{\pm}17.7%$ for chocolate, $35.5{\pm}9.3%$ for processed chocolate products, $11.0{\pm}2.7%$ for fruit juice, $10.0{\pm}3.6%$ for carbonated beverages, $23.0{\pm}3.2%$ for ice cream, $24.5{\pm}3.2%$ for ice milk, and $11.4{\pm}2.6%$ for stirred yogurt. Overall, candy items had relatively higher total sugar contents ($71.1{\pm}19.3%$ ) than any other items. Foods in the school zone had $52.3{\pm}24.4%$ total sugars. The noncommercial foodservice foods were classified into 5 main dish categories and 12 side dish categories. The total sugar contents of the main dishes were $2.6{\pm}1.9%$ for cooked rice with seasoning, and $4.7{\pm}0.1%$ for spaghetti. Among the side dishes, hard boiled foods and stir-fried foods contained the highest amounts of sugar, which were dependent on the main ingredients in the foods. Other side dishes with high sugar contents included seasoned vegetables/dried fish/seaweed ($5.5{\pm}5.3%$), salads ($5.6{\pm}3.1%$), and kimchies ($5.7{\pm}4.1%$). The total sugar contents of the side dishes ranged widely, and were significantly different according to main ingredients, cooking method, and amount of spice.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.3
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• pp.303-310
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• 2007

Sweetpotato shoot tops (leaves, tips and petioles) are known to be very useful parts as vegetables because of their high nutritive values and great biomass yield. In this study, the phenolic compound contents, antibacterial activity, mutagenic activity, and antimutagenic activity were investigated in sweetpotato tips that were 10-15cm of shoot top including stems, petioles and tender leaves after sprout of storage roots. The study was done by extracting sweetpotato tips with 80% ethanol and the ethanol fraction was re-extracted with hexane, chloroform, ethyl acetate, butanol and water. In ethyl acetate and butanol fractions, total phenolic compounds contained 95. 6mg/g extract and 69.3 mg/g extract, respectively, The antibacterial activity was measured using the paper disk method with concentrations of 1, 2, 5 and 10 mg/disk of butanol and ethyl acetate fractions against L. monocytogenes and S. Typhimurium strains. Higher doses of solvent extracts showed the higher antibacterial activities. In addition, 5, 10 and 20 mg/mL of the extracts were tested to determine the antibacterial activity in liquid culture. The sweetpotato leaf extract by ethyl acetate showed 1 log reduction compared to control after 24 hrs on Listeria monocytogenes, but 20 mg/ml of butanol extract completely inhibited the growth of the pathogen after 12 hrs. The extracts from ethyl acetate or butanol on Salmonella Typhimurium did less than 1 log reduction during cultivation compared to control. The numbers of S. Typhimirium TA98 and TA100 revertant colonies were 29-33 and 159-188 CFU/plate, respectively, indicating that solvent extracts were no mutagenic activity. The antimutagenic test was performed by adding direct mutagen 2-NF and MMS, and butanol and ethyl acetate showed antimutagenic effect. Thus, this study showed that sweetpotato tips had high phenolic contents and both antimicrobiol and antimutagenic properties. Sweetpotato tips would be good nutritive source because of their high nutrient content without any toxicity in consuming.

• Korean Journal of Environmental Agriculture
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• v.36 no.1
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• pp.43-49
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• 2017

BACKGROUND: Greenhouse crops are one of agricultural products consumed largely in Korea. Cucumber is a typical example as main vegetables of greenhouse crops. Thus, pesticide residue analysis is an important requirement to guarantee pesticide safety of cucumber. This work was aim to investigate the residues of penthiopyrad and pyriofenone in cucumber after harvest. METHODS AND RESULTS: Cucumber was subjected to treat with penthiopyrad and pyriofenone at a level of recommended dose 0, 1, 2, 3, 5, 7 and 10 days before harvest under greenhouse conditions. The samples were extracted with organic solvent by using a homogenizer and purified on solid phase cartridge column followed by LC-MS/MS analysis. The recovery levels of penthiopyrad and pyriofenoneranged from approximately 81 to 93% with the method limit of 0.005 mg/kg and coefficient of variation less than 10%. Penthiopyrad and pyriofenone were detected at a level less than maximum residue limit in cucumber at 10 days before. The half-lives of penthiopyrad and pyriofenone were determined to 2.4 ~ 2.6 days. CONCLUSION: Penthiopyrad and pyriofenone are suggested to use in cucumber 10 days before harvest to reach their levels less than maximum residue limit.