• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.3
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• pp.294-298
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• 2009

A glasshous experiment was carried out in 2002 to evaluate growth differences between two wick types, and to determine the optimum number of wicks in a wick-based hydroponics for production of 'Dejima' seed potatoes (Solanum tuberosum L.). The six minitubers ($7.0{\pm}0.2g$/tuber) produced through aeroponics were planted in a polystyrene box (51 cm long $\times$ 31 cm wide $\times$ 20 cm high) containing growth medium (perlite+peatmoss 1:2, v/v mixtures). Before the boxes were filled with the medium, 6 wicks per box were vertically and 2 to 10 wicks were horizontally installed, respectively, at the bottom of the boxes through holes. Comparing with 6 vertical wick treatment, 6 horizontal wick treatment increased the number of tubers per plant, but decreased average tuber weight. Yield of tubers greater than 5 g (seed potatoes) was not significantly affected by wick type. As the number of the horizontal wicks per box was increased from 2 to 6, the number of seed potatoes increased from 2.8 to 8.0/plant and then leveled off. Average tuber weight increased with increasing the number of the wicks up to 8 and then leveled off. As the number of the wicks per box was increased from 2 to 6, seed potato yield increased from 1.81 to 6.59 kg/$m^2$ and then slowly increased up to 10 wicks per box, reaching 12.9 kg/$m^2$. The results indicate that installing 8 wicks per box ($0.16m^2$) horizontally for the wick culture system in production of 'Dejima' seed potatoes is beneficial considering seed potato yield, cost of wicks, and convenient filling with medium.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.3
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• pp.260-264
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• 2009

Sufficient seedling establishment of Chinese milk vetch (CMV) is the most important factor in the CMV cultivation. In order to obtain sufficient seedling stand, CMV seed should be planted at right seed planting date. An optimum CMV seed planting time for stable seedling establishment was determined based on the final water drainage time for rice harvest in fall. Five planting times from 10 days before water drainage (DBWD) to 15 days after water drainage (DAWD) at five day interval were evaluated during the period of 2006-2007 and 2007-2008 and the optimum CMV seed planting time was determined based on seedling stand, winter survival rate, and dry matter production. CMV seedling stand before winter was high with $575{\sim}1,050\;plants/m^2$ regardless of seed planting times but after overwintering, it was greater in seed planting date between 5 DBWD to 5 DAWD than that of 10 to 15 DAWD treatments. Winter survival rate, dry matter production and seed production yield also showed similar trend to the seedling establishment. On the other hand, when CMV seeds were sowed early at 10 DBWD, seedling stand and winter survival rate were lower than that of 5 DBWD to 5 DAWD. This result indicates that an optimum CMV seed planting time based on the final water drainage could be between 5 DBWD (September 20) to 5 DAWD (September 30).

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.193-193
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• 2017

The black heart in potato is a physiological disorder that occurs when potatoes suffer from breathing problems. When storing potatoes at a low temperature around $0^{\circ}C$, there is a high possibility that the respiration rate of potato will rise and black heart will occur. Also, respiration can occur easily and briefly in a state where high temperature and ventilation is insufficient. Recently, as black heart has been occurred continuously and severely in South Korea, here we tried to identify the causes of black heart in potato and to develop the control strategy of this disorder. Firstly, we analyzed the influence on the black heart on the basis of preservation containers (breathable plastic box, burlap bag, paper box, sealed plastic box). After harvesting the potato which is cv. Superior, it preserved for 6 months under conditions of temperature $3.5^{\circ}C{\pm}0.2$ and humidity 85%, after then we surveyed the incidence of emergence rate, rate of weight loss and occurrence rate of black heart. Secondly, in order to investigate the time point of black heart initiation under the oxygen concentration condition of 1% or less, The potatoes were used for this experiment stored for 6 months in a aerated plastic box under conditions of temperature $3.5^{\circ}C{\pm}0.2$ and humidity 85% under sufficient oxygen condition. After stored for 6 month, those were stored at $15^{\circ}C$ and below 1% of oxygen for 25 days, and then the incidence of black heart was surveyed. Thirdly, to investigate the effects of the number of days after harvest on the occurrence of black heart, it was examined the occurrence of black heart stored on 40 days and 100 days after harvesting under sealed condition and vacuum condition. The temperature condition of potato storage was stored was at $4^{\circ}C$ and $25^{\circ}C$ in humidity 85%. As a result of investigating the occurrence of black heart depending on the storage containers, all of the potatoes stored in the sealed plastic box had been occurred black heart. However, black heart of the potatoes in the other treatments did not. Potato preserved under the condition of below 1% of oxygen was found to occur 32% black heart after 25 days of storage. The potatoes corresponding to the required number of days after harvesting were stored for 31 days and the black heart was examined on the occurred. As a result, the potatoes which were 40 days after the harvest did not have black heart under sealed condition and vacuum condition. But potatoes harvested 100 days after harvesting had a black heart incidence of 95.7% under sealed condition at $4^{\circ}C$. The potato placed in the vacuum condition and a sealed state at $25^{\circ}C$ was transformed into anaerobic respiration, the inner tissue of tuber collapsed. Therefore, it is considered that black heart is caused by the breathing trouble in the central part when the oxygen is almost consumed after the aerobic respiration which gradually consumes the oxygen. We conclude that the black heart occurred in the central part where exchange of oxygen and carbon dioxide is the slowest is sensitive to respiration disorder. It is thought that research to investigate black heart generation time according to storage conditions and post-harvest state of potatoes is further necessary.

• Korean Journal of Food Science and Technology
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• v.45 no.6
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• pp.693-699
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• 2013

A simple, sensitive, and specific method for quantifying the nicotine content of synthetic favoring substances (SFS) was developed using high performance liquid chromatography (HPLC) with a photo-diode array detector (PDA). Nicotine was extracted from SFS samples by using an acid-base liquid-liquid extraction method with dichloromethane and distilled water. The nicotine content was quantified by HPLC/PDA (261.9 nm) with a $C_{18}$ column under a gradient of 10% acetonitrile with 20 mM ammonium formate (ammonia solution adjusted to pH 8.7) to 100% acetonitrile. The calibration curve, analyzed from concentration standards between 0.1 to 2 mg/L, presented linearity with a correlation coefficient ($r^2$)>0.9999. The limit of quantitation (LOQ) of nicotine in SFS was 0.4 mg/kg, and the average recoveries ranged from 76.4% to 96.3%. The repeatability of measurements, expressed as the coefficient of variation (CV%), ranged from 1.74 to 5.12%. This newly developed method for nicotine quantification in SFS can be considered an analytical method with an acceptable level of sensitivity and repeatability.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.67-74
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• 2020

In this study, various constituents and biological activities of different parts of asparagus were analyzed and compared. The Ca content was high in the leaves, K was significantly high in the top 25 cm of the spear, and Fe and Na were significantly high in the roots. The ascorbic acid, rutin, total polyphenol, and total flavonoid contents were high in the leaves, and the asparagine and glutathione contents were significantly high in the top 25 cm of the spear and roots, respectively. The bottom 5 cm of the spear had the highest saponin content compared with all other parts. The DPPH and ABTS radical scavenging activities were the highest in the leaves. The bottom 5 cm of the spear had the highest α-amylase inhibitory activity, whereas the stem showed the highest anti-inflammatory activity. These results suggest that the usually inedible parts of asparagus may be highly valuable as high-quality functional components owing to their antioxidative and anti-inflammatory activities.

• Childhood Kidney Diseases
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• v.11 no.1
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• pp.24-31
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• 2007

Purpose : Nitric oxide(NO) is a very potent vasodilator synthesized from L-arginine by endothelial cells. We investigated whether urinary NO excretion was altered in various renal diseases in children and whether urinary NO excretion could be used in predicting pathologic causes and fibrosis in renal diseases in children. Methods : We recruited 48 patients(32 minimal change nephrotic syndrome[MCNS] and 16 vesicoureteral reflux[VUR] patients from the pediatric renal clinic in Korea University Guro Hospital. We measured the concentration of nitrite$(NO_2)$ and nitrate$(NO_3)$ by Griess reaction and that of creatinine(Cr) by Jaffe method in randomized spot urines. We then analyzed the urinary$(NO_2+NO_3)/Cr$ ratios and compared the values between each patient group. Urinary $(NO_2+NO_3)/Cr$ ratios were also evaluated according to the recurrence and the degree of proteinuria at sampling in the MCNS group and compared according to the presence of renal scarring and the grade of reflux in the VUR group. Results : The ratios of urinary$(NO_2+NO_3)/Cr$ were significantly increased in the VUR and MCNS groups, as compared to the control group. In the MCNS group, a higher level of urine $(NO_2+NO_3)/Cr$ was observed In frequent relapse patients(relapse over four times within one year after first diagnosis) and the patients with severe proteinuria at sampling, respectively. The VUR group with renal scars also showed a higher level of urinary$(NO_2+NO_3)/Cr$ compared to that without scars. Conclusions : In summary, VUR may play a role in the pathogenesis of VUR and MCNS. NO also seems to affect proteinuria and renal scar formation. (J Korean Soc Pediatr Nephrol 2007;11:24-31)

• Korean Journal of Poultry Science
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• v.41 no.4
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• pp.241-247
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• 2014

The objective of this experimental was to investigate the effect of dietary Cu-sulfate and Cu-soy proteinate on productive performance and small intestinal microflora. A total 1,000 Hy-Line Brown laying hens (35 weeks old) were randomly allotted to 1 of 5 dietary treatments: Control, Cu-sulfate 50, 100 (50, 100 ppm Cu supplementation as Cu-sulfate) and Cu-SP 50, 100 (50, 100 ppm Cu supplementation as Cu-soy proteinate). Each treatment was replicated 4 times with fifty birds per replication, housed in 2 birds cages. Fifty birds units were arranged according to randomized block design. Feeding trial lasted 5 weeks under 16L : 8D lighting regimen. Hen day egg production was significantly (P<0.05) higher in Cu treated groups than control. Feed intake, broken and shell-less egg production was not significantly influenced by treatment. Eggshell color, eggyolk color, haugh unit, and eggshell thickness were not significantly influenced by treatment. However, eggshell strength was significantly (P<0.05) greater in Cu treated groups than control. Concentration of copper of liver was significantly (P<0.05) greater in Cu treated groups than control. Concentration of zinc and iron of liver were not influenced by treatments. Population of Cl. perfrigens and Lactobacilli in the small intestinal content were significantly (P<0.05) influenced by treatments. Population of Cl. perfrigens decreased and that of Lactobacilli increased in the Cu supplement groups. In conclusion, dietary Cu sulfate and Cu-soy proteinate similarly improves egg production, eggshell strength, and favors intestinal microbial population of laying hens.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.829-846
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• 2015

This study was conducted to determine the effects of organic fertilization rates on the nutrient accumulation and recovery in radish (Raphanus sativus L.) as well as growth and yield of radish in Jeju island. An understanding the relationships between organic fertilization rate, crop nutrient recovery and crop yield can assist in making organic fertilizer recommendation which balances crop value and environmental risk in organic cultivation. Nitrogen (T-N), phosphate ($P_2O_5$) and potassium ($K_2O$) were applied at 0, 115-35-40, 230-70-80 (standard application rate), 460-140-160, 230-200-100 (recommended application rate) and 158-53-35 kg/ha (customary application rate), respectively as the broadcast application of mixed organic fertilizer (N 4.5% - $P_2O_5$ 1.5% - $K_2O$ 1%) in combination with langbeinite ($K_2O$ 22%), 100% at sowing period. The organic fertilizer was made of organic materials like oil cakes. Total yield of radish, as fresh weight of roots, increased with increasing organic fertilizer doses to a maximum at rate of standard or soil-testing application. Nitrogen, phosphate and potassium accumulations of radish increased curvilinearly with increasing organic fertilization rate to a maximum at rate of N 460 - $P_2O_5$ 140 - $K_2O$ 160 kg/ha. However, nitrogen, phosphate and potassium use efficiency of applied organic fertilizer decreased curvilinearly or linearly with increasing organic fertilization rate. Application of organic fertilizer in combination with langbeinite (as a potassium source) had significant effect on the yield of radish. Organic fertilization on a basis of standard or soil-testing application rate is recommended for maximun radish yield in organic cultivation.

• Korean journal of food and cookery science
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• v.17 no.3
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• pp.195-203
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• 2001

The purpose of study was to improve the storage time of breads with spices. The quality of breads with garlic, ginger and cinnamon powder containing 1 % concentration were investigated using sensory and mechanical evaluation. For 14 days, total microbial count and chemical properties were analyzed at 18$^{\circ}C$. The result of sensory evaluation was not significantly different between control and breads with spices powder. But breads with spices powder were significantly higher than control in texture and acceptability. Especially, bread with cinnamon powder was most favorable in acceptability. The result of total microbial count showed that breads with spices powder were reduced with storing time passed and bread with cinnamon powder was most reduced in breads with spices powder. ks storing time passed, moisture contents and pH range were decreased and L, a and b value were decreased in all breads. Hardness, gumminess and brittleness of torture analysis were increased as storing time passed, but springiness and cohesiveness were decreased. A negative correlation was observed between the sensory and mechanical properties in general. Sensory Properties of springiness and swelling were positively correlated with the acceptability. In the analysis of correlation between the chemical and mechanical properties showed that lightness of mechanical properties had positive correlation with pH range and moisture contents. Moisture contents of chemical properties had negative correlation with hardness, but had positive correlation with cohesiveness of mechanical properties.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.1
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• pp.55-60
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• 2006

This study was conducted to investigate the effects of water extract from enzymic-treated Salicornia herbacea (Hamcho) on lipid metabolism in rats fed high cholesterol diet. Experimental rats were divided into six groups which were composed of normal diet group, normal and $2\%$ Hamcho extract diet group, high cholesterol diet group, high cholesterol and $1\%,\;2\%\;and\;4\%$ Hamcho extracts diet groups. Body weight gain and food efficiency ratio (FER) of the high cholesterol diet group were significantly increased compared to the normal diet group, while those of the high cholesterol and Hamcho extracts diet groups were decreased compared to the high cholesterol diet group. Food intake was not significantly different among all experimental groups, The serum TG content of the high cholesterol diet group was significantly increased compared to the normal diet group, but that of the high cholesterol and extracts diet group was significantly decreased in dose-dependent concentration. The liver TG, total lipid and total cholesterol contents of the high cholesterol diet group were significantly increased compared to the normal diet group, while those of the high cholesterol and $2\%\;or\;4\%$ Hamcho extracts diet groups were significantly decreased compared to the high cholesterol diet group. The serum total cholesterol and LDL-cholesterol contents, and AI of the high cholesterol diet group were significantly increased compared to the normal diet group, while those of the high cholesterol and Hamcho extracts diet groups were decreased, and especially the high cholesterol and $4\%$ Hamcho extract diet group was significantly decreased compared to the high cholesterol diet group. Serum HDL-cholesterol contents of the high cholesterol diet group were significantly increased compared to the normal diet group. These results suggest that supplementation of water extract from enzymic-treated Salicornia herbacea may have a pronounced impact on lipid metabolism of serum and liver in the rats fed high cholesterol diet.