• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.942-947
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• 2005

This study was investigated to analyze the effect of extracts from the Lepista nuda, on the antioxidant activity to form a part of studies on the functional materials of L. nuda. Antioxidant activity of L. nuda extracts was evaluated by measuring the electron-donating ability (EDA), the superoxide dismutase (SOD)-like activity, and the nitrite-scavenging ability. The EDAs of water and ethanol extracts at the concentration of 1,000 ppm by the rotary heating method from L. nuda were $60.47\%$ and $60.13\%$, respectively and those of water and ethanol extracts by microwave-assisted method were $87.73\%$ and $84.84\%$, respectively. The measurements of SOD-like activity were in the range of $24.58\%\~42.03\%$ at 1,000 ppm. EDA and SOD were increased with the concentrations of extracts. The nitrite-scavenging ability at the concentration of 1,000 ppm was the highest and $29.77\%$ at pH 1.2, and was decreased with an increment of pH value. These results indicated that microwave­assisted water extract from L. nuda showed the highest activities on the EDA and nitrate-scavenging ability, while the rotary heating ethanol extract had the highest effect on the SOD-like activity.

• Korean Journal of Microbiology
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• v.10 no.3
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• pp.97-104
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• 1972

The extent of water pollution was investigated at 4 stations in Kyonggi Bay during the summer seasons in 1970 and 1971. The concentrations of dissolved oxygen, total hardness, ammonia, nitrate, nitrite, phosphate, chemical oxygen demand, salinity, biochemical oxygen demand, coliform bacteria and facel coli were examined together with the measurement of pH and transparency. The relationship between the extent of pollution and the distance from the Inchon Bay also was examined. The concentrations of biochemical oxygen demand, chemical oxygen demand, ammonia, nitrate, nitrite, phosphate, coliform bacteria nad fecal coli were all highest at station 1, and lowest at station 4. Values were somewhat higher at low tide level in general. On the contrary, dissolved oxygen concentration was highest at station 4 and lowest at station 1. The highest and lowest values of biochemical oxygen demand were 10.88 ppm at station 1 and 0.27 ppm at station 4. The chemical oxygen demand concentrations at station 1 and 4 were 1.90 ppm and 0.63 ppm. Ammonia concnetration at station 1 was 0.43 pp, and was nearly 5 times as much as that at station 4. The values were $2.45{\times}10^{-4}$ ppm at station 1, and $6{\times}10^{-4}$ ppm at station 4. Nitrite concnetration at station 1 was $3{\times}10^{-4}$ppm and was the highest, while the lowest was $9.45{\times}10^{-5}$ ppm at station 4. Phosphate value at station 1 too was the highest and was about 4 times as much as that at station 4. Coliform bacteria were most abundant at station 1, and were counted to be 1.$1.7{\times}10^{-5}$cells/ml. At station 4, the number greatly reduced to 8 * 10$^{2}$ cells/ml. The number of fecal coli at station 1 was $2{\times}10^{-4}$ cells/ml. But at station 4, no fecal coli was detected at high tide level. At low tide level, 3 cells/ml were counted at station 4. In all of these, the highest data were obtained at low tide level, while most of the lowest value, at high tide level. Generally, values at statio 1 were 3-5 times as much as those at station 4. Concentration of dissolved oxygen at station 1 was 0.366 mg-atoms/1 and was the lowest. The highest value was 0.420 mg-atoms/1 and was recorded at station 4. The highest at station 4, which certainly were believed to be the result of the dilution by the fresh water of the Han river flowing into the Inchon Bay. As we can see from the data above, the extent of pollution was highest at station 1, the nearest from Inchon harbor, and lowest at station 4, where is the farthest, Station 1 and 2 were proved to be much polluted, but station 3 and 4, not.

• Korean Journal of Plant Resources
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• v.27 no.1
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• pp.29-34
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• 2014

The aim of the study was to examine the cosmetic and biological activity of Lagerstroemia indica L. and it is possible that can be used as a cosmetic ingredient for application of cosmetic industries. Lagerstroemia indica L. branch was extracted with 70% acetone in water. In the result of DPPH (1,1-diphenyl-2-picryl-hydrazyl) scavenging radical activity, acetone extract of Lagerstroemia indica L. branch were higher than 73% at the 50 ppm concentration. ABTS radical cation decolorization activity by acetone extract were higher than 78% at the 50 ppm. Both examine of DPPH and ABTS showed high antioxidative activities at the 50 ppm. In the result of nitrite scavenging ability, acetone extract were higher than 63% at the 50 ppm. Collagenase inhibition activity by extract were higher than 85% at the 50 ppm. Extract is showed high collagenase inhibition more than comparison group EGCG at all concentration. These results suggest that Lagerstroemia indica L. has a great potential as a cosmeceutical raw material as well as anti-oxidant and anti-inflammatory and collagenase inhibition activity.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.1
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• pp.105-110
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• 1985

A incubation study was conducted to find out the effects of rice straw and gypsum as soil ameriolite on urease, nitrate and nitrite reductase activities in newly reclaimed saline sandy soil. The results obtained were summarized as follows: 1. Very low urease activities were observed in saline soil if contrast to high productive paddy soil. Urease activities were lower at 5 days than that of 25 and 50 days after incubation. Remarkably high urease activities were obtained by the application of rice straw and gypsum. 2. Comparing with NPK treatment, application of rice straw and gypsum were enhanced the activities of nitrate and nitraite reductase. 3. Positive correlation (r=0.5501 p=0.05) was obtained between urease activities and ammonium nitrogen concentration in soil. 4. Cyclic oxidation and reduction of nitrate and nitrite in soil were obtained in terms of first order microbial kinetics reaction in case of application of rice straw and gypsum, respectively. 5. Positive correlation (r=0.6296 p=0.05) was obtained between the activitie of nitrite reductase and nitrate reductase in soil.

• Korean Journal of Ecology and Environment
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• v.38 no.4 s.114
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• pp.439-444
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• 2005

The environmental quality of the middle-reach of the Yahagi River has deteriorated in recent years. The nutrient dynamics within the reach were investigated to explain the changes. Seasonal pattern of $NO_3\;^--N$ concentration tended to stay low from April or May through July or August and then increased till winter or early spring, although there were peaks during high flow periods in mid-September, 2000 and late-August, 2001. No clear seasonal changes were observed in $PO_4\;^{3-}-P$ concentration. In the bimonthly records from 1980-2002, the DIN concentrations on January and March were higher than other months whereas the average daily flows on January and March were lower than they were in other months. The mean DIN concentration showed a high negative correlation with the median of average daily flow. In the past 50 years, the average concentration of DIN (excluding nitrite) was 0.21 mg $L^{-1}$ in 1952-1953. The concentration was about twice this high around 1980, and it is about three times this high at present. On the other hand, the average concentration of $PO_4\;^{3-}-P$ was below the limit of detection in 1952-53. However, it increased to almost 0.03 mg $L^{-1}$ around 1980, then decreased to approximately 0.016mg $L^{-1}$ at present. Our results suggest that the increasing DIN concentration is one of the causes of environmental change in the Yahagi River. We conclude that controlling the DIN concentration is essential for improving the river environment.

• Journal of Soil and Groundwater Environment
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• v.19 no.4
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• pp.62-69
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• 2014

In the results of monitoring nitrate concentration in more than 8,000 groundwater wells around agro-livestock, the average and maximum nitrate concentration was 9.4 mg/L and 101.2 mg/L, respectively. Since about 31% of the monitoring wells was exceed the quality standard for drinking water, nitrate control such as remediation or source regulation is required to conserve safe-groundwater in South Korea. Typical nitrate-treatment technologies include ion exchange, reverse osmosis, and biological denitrification. Among the treatment methods, biological denitrification by indigenous microorganism has environmental and economic advantages for the complete elimination of nitrate because of lower operating costs compared to other methods. Major mechanism of the process is microbial reduction of nitrate to nitrite and nitrogen gas. Three functional genes (nosZ, nirK, nirS) that encode for the enzyme involved in the pathway. In this work, we tried to develop simple process to determine possibility of natural denitrification reaction by monitoring the functional gene. For the work, the functional genes in nitrate-contaminated groundwater were monitored by using PCR with specific target primers. In the result, functional genes (nosZ and nirK) encoding denitrification enzymes were detected in the groundwater samples. This method can help to determine the possibility of natural-nitrate degradation in target groundwater wells without multiplex experimental process. In addition, for field-remediation application we selected nitrate-contaminated site where 200~600 mg/L of nitrate is continuously detected. To determine the possibility of nitrate-degradation by stimulated-natural attenuation, groundwater was sampled in two different wells of the site and nitrate concentration of the samples was 300 mg/L and 616 mg/L, respectively. Fumarate for different C/N ratio was added into microcosm bottles containing the groundwater to examine denitrification rate depending on carbon concentration. In the result, once 1.5 times more than amount of fumarate stoichiometry required was added, the 616 mg/L of nitrate and 300 mg/L of nitrate were completely degraded in 8 days and 30 days. The nitrite, byproduct of denitrification process, was also completely degraded during the experimental period.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.11
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• pp.1580-1586
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• 2010

This study was conducted to examine antioxidative and physiological activities of water extracts from different parts (flower, leaf, root, and the whole plant) of Taraxacum officinale. The water extracts from different parts were measured to obtain total flavonoids content, total polyphenol content, electron donating ability, SOD-like activity, nitrite-scavenging ability and tyrosinase inhibition effects. Total flavonoids and total polyphenol contents in flower extract were 32.91 mg/g and 49.31 mg/g, respectively, which were much higher than those of any other parts. The electron donating abilities of flower, leaf, the whole plant, and root extracts were 87.07%, 87.66%, 81.06% and 66.20%, respectively at a concentration of 1 mg/mL. The activities increased in a dose-dependent manner. The SOD-like activity of water extracts from different parts showed 9.07~10.97% at a concentration of 1 mg/mL. The nitrite-scavenging abilities of flower and leaf extracts measured at pH 1.2 were 36.34% and 38.16%, respectively at a concentration of 1 mg/mL. Tyrosinase inhibition activity of the leaf extract at a concentration of 1 mg/mL was the highest (34.19%) and that of the whole plant and root extracts was shown to be more than 20%. These results suggest that water extracts from different parts of Taraxacum officinale could be used as an antioxidative functional food source.

• Journal of Life Science
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• v.28 no.10
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• pp.1193-1200
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• 2018

This study investigated the physiochemical properties, antioxidative, nitrite-scavenging, and alcohol metabolism enzyme activities of nectarine vinegar prepared by a traditional fermentation method. The pH of nectarine vinegar was 3.70, the sugar content was $8.87^{\circ}Brix$, and the total acidity was 6.29%. Among organic acids detected, acetic acid was highest at 32.42 mg/ml, followed by lactic acid, malic acid, and succinic acid. Total phenol content of the nectarine vinegar was $121.84{\mu}g$ tannic acid equivalents (TAE)/100 ml. The antioxidative effects of muskmelon vinegar were measured using 1,1-Diphenyl2-picrylhydrazy (DPPH) radical-scavenging activity and superoxide dismutase (SOD) assay. DPPH of nectarine vinegar was increased in a dose-dependent manner, which was 84.47% at 40% concentration. SOD activity was increased in a dose-dependent manner, which was 89.06% at 60% concentration. Nitric scavenging activities of nectarine vinegar were 94.17%, 76.91%, and 20.21% at pH values 1.2, 3.0, and 6.0 at 100% concentration, respectively. The effects of nectarine vinegar on alcohol-metabolism were determined by measuring the generation of reduced nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH). ADH and ALDH activities of nectarine vinegar were increased in a dose-dependent manner, which were 153.61% and 178.20 % at 60% concentration, respectively. These results suggest that nectarine vinegar has great potential as a resource for high quality functional health beverages.

• Korean journal of food and cookery science
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• v.28 no.3
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• pp.275-283
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• 2012

This study was conducted to monitor the quality characteristics of Lespedeza cuneata ethanolic extracts, by a response surface methodology. The independent variables were the extraction temperature ($35{\sim}95^{\circ}C}$), extraction time (2~10 hr), and ethanol concentration (10~90%). The coefficients of the determinations (R2) were 0.8562 (p<0.1), 0.9787 (p<0.01), and 0.8344 (p<0.1) in total polyphenol, total flavonoid, and electron donating ability, respectively. The electron donating ability and nitrite scavenging effect were improved with an increase of ethanol concentration, rather than the extraction temperature. ORAC (Oxygen Radical Absorbance Capacity) with extraction conditions was 1,636.47~2,696.99 ${\mu}moles$ TE/g, and was increased with the increase of extraction temperature and 40~60% of ethanol concentration. Estimated conditions for the maximized extraction including the yield, total polyphenol, electron donating ability, nitrite scavenging effect, and ORAC, were $60{\sim}68^{\circ}C$ in extraction temperature, 6~7 hr in extraction time, and 38~60% in ethanol concentration.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.53-59
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• 2009

This study was performed to investigate the taste composition and antioxidant properties of cheonggukjang containing Korean red ginseng (RGC), as compared to either general cheonggukjang (GC) or non-fermented boiled soybeans (BS). Amylase activity was the highest (576.7 unit/g) in RGC, whereas protease activity was the highest (326.0 unit/g) in GC. The total soluble sugar contents of BS, GC, and RGC were 2,027.5, 905.5, and 837.5 mg/100 g, respectively. RGC had the highest amount of total amino acids (2,127.4 mg/100 g) and essential amino acid (50.9%) among the samples. The ratio of sweet to bitter components was higher in RGC than in GC. Although the extracts of RGC had higher radical scavenging activity for 1,1-diphenyl-2-picrylhydrazyl (DPPH) than BS or GC, regardless of the extract concentration, the ethanol extract of RGC showed the highest scavenging ability (92.4%) at 2.0 mg/mL. The chloroform extracts from GC and RGC showed their greatest superoxide dimutase-like activities at 17.2 and 19.7% at a concentration of 2 mg/mL, respectively. Regardless of the samples, the nitrite scavenging ability was positively correlated to the extract concentration, and RGC had highest ability among samples under the same extract concentrations.