• Korean Journal of Organic Agriculture
• /
• v.6 no.1
• /
• pp.63-75
• /
• 1997

This study aims to find out the devices to minimize the amount of nitrate ingested from kimchi, the main way of vegetable intake for Koreans, and the basic data to deliver to calculate the total daily intake for Korean, investigating the year-round changes of nitrate content in vegetables for Kimche raw material, and changes of nitrate content by salting of chinese cabbage, and stewed kimchi through the use of different cooking methods. The results obtained were summarized as follow: over between 205-6655mg/kg f.w. in chinese cabbage, 480-3970mg/kg f.w. in chinese radish, 157-5820mg/kg f.w. in lettuce and 29-520mg/kg f.w. in cucumber respectively. Therefore it was strongly adviced to introduce the nitrate limit value of vegetables in Korea if the nitrate content in Kimchi should be reduced to meet the nitrate ADI(Acceptable Daily Intake, 219mg60kg b.w) of FAO.WHO, because the nitrate content in Kimchi reflects the nitrate content in vegetables. In order to keep the low nitrate content in Kimchi. it was adviced to remove the outer leaf which contains 2-3 times higher nitrate content compare to the inner leaf at the time of preparation, i.e. chinese cabbage, before the soaking treatment in salt solution for Kimchi making process. The dehydration by soaking treatment in salt solution occurred at 0.9%~4.7% in leaf midrib and more than 13%~24% in leaf blade. The nitrate content after soaking in salt solution was increased 107%~123% compared with before soaking, increasing rates of nitrate content in the outer and inner leaf midrib were higher than those in leaf blade. The increase of nitrate content in salt solution after soaking due to the dehydration of chinese cabbage by soaking treatment. The Kimchi stew(Kimchi JJige) was processed with and without animal oil, but the amount of nitrate in kimchi stew did not decrease both treatments, but it increased after the processing since the water in Kimchi stew has got low by boiling.

• Journal of Life Science
• /
• v.20 no.11
• /
• pp.1667-1674
• /
• 2010

Influence of nitrate on growth, chlorophyll content, content and activity of rubisco and rubisco activase of tobacco plant cultured on MS medium treated with cadmium in vitro was studied. In vitro growth and chlorophyll content reduced at 0.2 mM Cd was recovered by nitrate and this recovery was most significant at 80 mM nitrate. Rubisco content at 80 mM nitrate was more increased compared to that at other concentrations. A similar change was also shown in rubisco activity. These resultsindicate that the activation and induction of rubisco reduced by Cd were recovered by nitrate. The degree of intensity of 55 and 15 kD polypeptides identified as the large and small subunits of rubisco by SDS-PAGE analysis at 80 mM nitrate was significantly higher than that at other concentrations. The content and activity of rubisco activase at 80 mM nitrate was significantly increased than that at other concentrations. These data suggest that the recovery effects of rubisco by nitrate may be associated with rubisco activase.

• Korean Journal of Environmental Agriculture
• /
• v.15 no.3
• /
• pp.383-390
• /
• 1996

This experiment was conducted to investigate the influence of nitrogen fertilizer forms, fertilizer and herbicide application rates on growth of radish. The nitrate content and nitrate reductase activity of radish were analyzed along with the growing stage. Nitrate nitrogen was more efficient than ammonium nitrogen for radish. With increasing the fertilizer application rate, accumulated of nitrate content was increased. The amount of nitrate nitrogen was highest at 25days after seeding in petioles, and $32{\sim}39days$ after seeding in root. Nitrate content was decreased as sampling date was delayed, whereas the content increased in the root at early growing stage and then decreased. The nitrate cotent increased in the order of petioles, roots, and leaf blades and nitrate reductase activity increased petioles, leaf blades, and roots. The higher nitrogen fertilizer and herbicide application increased nitrate nitrogen accumulation in radish as compaired with control treatment and nitrate reductase activity showed similar trend.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.47 no.6
• /
• pp.139-146
• /
• 2015

We manufactured natural dyed Korean traditional paper (Hanji) for cultural properties conservation and storage with goldthread (Coptis chinensis) and silver nitrate ($AgNO_3$). Goldthread and silver nitrate are known to be an excellent antimicrobial activity. The effect of content of goldthread and silver nitrate on properties of dyed Hanji was investigated. Color strength of dyed Hanji decreased with increasing content of silver nitrate. After-mordanting with 3% silver nitrate improved lightfastness of dyed Hanji. Tannic acid treatment increased K/S value of dyed Hanji. As the amount of the increase in goldthread content was reduced silver nitrate content. Sim-mordanting method was used for simplifying manufacture process. Silver nitrate sim-mordanting method increased K/S value of goldthread than after-mordanting method.

• Plant Resources
• /
• v.2 no.1
• /
• pp.26-30
• /
• 1999

Nitrate in edible vegetables is converted to nitrite by nitrate reductase(NR) and/or bacteria in intestines. Nitrite and amino, in the intestine of some animals and human, bind to form nitrosamine, which is toxic and known as carcinogen. This study was carried out to examine the effect of added chlorides and their concentrations on growth, yield and nitrate content in leaf lettuce plants in hydroponics. Seeds of lettuce cv, "Samsunjokchukmyon" were planted on April 29, and seedlings were planted on June 2, and were cultured until July 5 in 1998. KCI and CaCl₂ were used as chloride source and their concentrations were 1, 2 and 4 me/L, respectively, in the lettuce standard nutrient solution for National Horticultural Research Institute(NHRI). Completely randomized design with 3 replications was used. Nitrate content and NR activity were measured 2 and 5 weeks after planting(WAP). The obtained results were summarized as the follows : Leaf weight per plant was difference from harvest dates and treatments, but total leaf weight was not significantly different among treatments. Number of leaves was higher in KCI 2 me/L, CaCl₂1 me/L and control at 2 WAP than the others, and was higher in KCI 1 me/L, and control at 3 WAP than others, and was higher in control at 5 WAP. Total number of harvested leaves was the highest in control with 14, which followed by KCI 2 me/L and CaCl₂1 me/L. Nitrate content was decreased by addition of chloride in nutrient solution. Nitrate content in the 3rd and 9th leaves was significantly decreased. NR activity was higher in control and CaCl₂ addition treatments, while KCI addition treatments reduced NR activity. However, no direct relationship with nitrate was observed. Growth characteristics such leaf length and leaf width were not significantly influenced by chloride addition.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.12 no.4
• /
• pp.239-245
• /
• 1992

Aspects of nitrate accumulation of forages growing on grasslands in Chonbuk Province, and the effects of different rates of N fertilizer on the total nitrogen and nitrate contents of sudangrass-hybrid and corn were studied through the 1991 growing season. The results obtained are summarized as follows: I . Thc nitrate content of the forages was increased by N application and decreased as the plants matured. 2. Nitrate concentration was high throughout the growing season in samples collected at Namweon-gun 1, which was considered as potentially unsafe. 3. Total nitrogen and nitrate content of plants generally increased with the increasing rates of N fertilizer, but not statistically significant among treatments except the plot of 25 kg N/lOa. 4. The annual crops had a greater tendency to accumulate nitrate than the perennial forage species. 5. It is suggested that high level of N fertilizer and manure may result in toxic levels of nitrate, and special attention must be given in feeding them.

• Journal of Life Science
• /
• v.17 no.5 s.85
• /
• pp.646-651
• /
• 2007

This investigation was performed to study the influence of Cd and nitrate on growth, and chlorophyll and photosynthetic enzymes in seedling of tobacco. Growth inhibition by Cd was not recovered by nitrate. Chlorophyll levels were reduced by Cd. The combination of Cd and low concentration of nitrate decreased the chlorophyll content compared to that in plants exposed only to Cd. Activity and content of rubisco at Cd treatment was significantly lesser than in plants receiving no treatment, These data suggest that rubisco activity was associated with an amount of rubisco protein, and that the activation and synthesis of rubisco is inhibited by Cd. Both the activity and content of rubisco decreased by Cd were more decreased by nitrate. A similar change pattern was also observed in activity and content of rubisco activase. These results suggest that Cd- and nitrate-induced changes of rubisco could be correlated with rubisco activase, and that nitrate was concerned in not only the activation and synthesis of rubisco directly, but also rubisco activase leading to a large change in rubisco.

• Korean Journal of Organic Agriculture
• /
• v.7 no.2
• /
• pp.125-151
• /
• 1999

After the release of facts that the high nitrate contents in vegetables by Korean organic farming, organic farmers were recommended by Korean Organic Farmer Association to apply 20t/ha compost while they applied before as much as they could, sometimes even more than 100t/ha. This study was aimed to check the safety of Korean organic product in terms of nitrate content. Current nitrate content in leaf and root vegetables by 3 different farming systems(organic farming, conventional farming, greenhouse farming) were monitored and furthermore it was compared with previously published another data in Korea to find out any changes among the monitored years(1993-1999). Current nitrate content in chinese cabbage, lettuce and kale became less compare to those of the beginning of monitoring, and especially those cultivated organic farming got the lowest value while previous organic vegetables at beginning of 90's showed the higher value than those cultivated in greenhouse. This decrease in organic vegetables was affected by less application rate of organic fertilizer than before at 20t/ha. But the nitrate level by organic farming was still higher compare to those cultivated by conventional farming in open field, since currently monitored organic vegetables were cultivated basically in greenhouse condition. It shows the organic farmer the necessity of transfer their farming site and condition from greenhouse to open field in order to decrease of its high level of nitrate caused long-term application and slow release characteristics of organic fertilizer. It was concluded the adoption of soil nitrate test to recommend a organic farmer the exact application rate for need of crop growth. Additionally the mechanism of lower nitrate accumulation in rice and fruit vegetables were also discussed in the paper.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.14 no.4
• /
• pp.329-338
• /
• 1985

This study was undertaken in order to research formation of nitrosamine and its related compounds by salt concentration and nitrate content during Korean native soysauce fermentation. The results from measuring the changes of nitrite and dimethylamine content can be summerized as follows. As the nitrate content in used water was getting higher and the salt concentration was getting lower, the soysauce fermentation was abnormal. As the salt concentration was getting higher, the reduction of nitrate and formation of nitrite were delayed. But whether the nitrate content in used water was higher or not, the nitrite was continuously remained. An addition of ascorbic acid restrained the reduction of nitrate, and simultaneously, it could eliminate the nitrite effectively. As the nitrate content in used water, was getting higher, the content of dimethylamine was getting lower. Nitrosodimethylamine was detected from 0 to 261.34 ppb.

• Korean Journal of Soil Science and Fertilizer
• /
• v.33 no.6
• /
• pp.384-392
• /
• 2000

To establish N fertilizer recommended scheme for the Chinese cabbage cultivation in green house based on the soil test of nitrate nitrogen, relationship among the content of soil nitrate and fertilizer effects and fertilizer N use efficiency were investigated from nine soils which differed amount of nitrate nitrogen from $14mg\;kg^{-1}$ to$226mg\;kg^{-1}$. The amount of nitrate nitrogen in soil showed a positive correlation with the dry weight of chinese cabbage in the plot of no fertilization. When the fertilizer effects were calculated by difference between the plots of fertilization and no fertilization in the dry weight and the amount of N uptake, a negative correlation was obtained between the amount of nitrate nitrogen in soils and the fertilizer effects. There was also a negative correlation between the amount of nitrate nitrogen in soils and fertilizer use efficiency. Recommendation of application rate of nitrogen fertilizer based on content of $NO_3-N$ in soils was evaluated by the regression equation among the content of soil nitrate, fertilizer effects and fertilizer N use efficiency. Incase the content of $NO_3-N$ nitrogen in soil is more than $200mg\;kg^{-1}$, No N fertilization is recommended; However, The standard N fertilization($320kg\;ha^{-1}$) is recommended for the soils with less than $50mg\;kg^{-1}$. For the soils ranged from $50mg\;kg^{-1}$ to $200mg\;kg^{-1}$ in the amount of nitrate nitrogen, an equation has been developed in order to calculate the recommended amount of fertilizer N.