• Culinary science and hospitality research
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• v.16 no.4
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• pp.297-304
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• 2010

This study examines the physicochemical property and antioxidant activity of wild grape juice, and the result is as follows. Total anthocyanin and color intensity contents of wild grape juice were $17.0{\pm}0.1%$ and $33.9{\pm}1.4%$, respectively. The contents of total phenols and flavonoid in wild grape juice were $25.4{\pm}3.1$ mg/100g, $4.4{\pm}1.4$ mg/100 g, respectively. Total mineral content in wild grape juice was $28.5{\pm}8.4$ mg/l00 g and the potassium content($11.3{\pm}0.3$ mg/100 g) was the highest Electron donating abilities of wild grape juice at concentration of $1,000\;{\mu}L$/mL were $94.8{\pm}1.2%$ Reducing power of wild grape juice at concentration of $1,000\;{\mu}L$/mL was 1.134. The electron donating abilities and reducing power were increased significantly with the sample concentration in the reaction mixture increased The nitrite scavenging ability was dependent on pH of the reaction mixture and sample concentration. The nitrite scavenging ability of wild grape juice was $77.1{\pm}1.1%$ at concentration of $1,000\;{\mu}L$/mL under pH 1.2.

• Journal of environmental and Sanitary engineering
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• v.9 no.1
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• pp.76-88
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• 1994

This study was carried out to investigate contents of nitrosamine precursors such as trite and dimethylamine( DMA ) in some foods. The diazo and Cu- dithiocarbamate melt were used for determination, respectively. The major affecting factors of Nnitrosodimethylamine( NDMA ) formation such as pH, contents of DMA and NaNO$_{2}$, other chemicals, and UV- ray in beverage were investigated in vitro. The contents of nitrite in meat sausage and meat ham were 6.44 ∼ 18.66ppm and 12.85- 39.95pp% respectively, And extremely low level was detected in a certain kind of fish sausage. The contents of DMA in meat sausage meat ham and fish sausage were 3.34∼15. 85ppm, 1.20∼7.10ppm and 7.38∼12.28ppm, respectively. The optimum pH for NDMA formation in vitro was 3.0. NDMA formation was rapidly occurred at high temperature and formed above 80% within 1 hour reaction. The formation of NDMA was increased in proportion to the concentration of DMA and the square of the nitrite concentration. 0.1 M of sodium citrate, sodium tartarated and sodium taiocyanate enhanced NDMA formation. But sodium chloride did not affect. However, 0.3M of ascorbic acid, erythroid acid, ascorbic, palmitate and propy, gallate inhibited NDMA formalion approximately 78%,81%,86% and 85%, respectively. Cow milk and soybean milk inhibited 35 ∼47% of NDMA formation but orange juice and apple juice enhanced 15 ∼64% of NDMA formation. The peak in HPLC for NDMA disappeared by irradiation of UV to prior formed NDMA This result suggest that NDMA was destroyed by UV irradiation.

• The Korean Journal of Community Living Science
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• v.16 no.2
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• pp.11-16
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• 2005

The purpose of this study was to investigate the antioxidant properties of unripened apple extracts. The amount of total flavonoids in the peel and 5/30 samples were 2.7times and 5.0 times higher than the flesh and 6/30 samples, respectively. The degree of angintensin I converting enzyme (ACE) inhibition activity in hot water extracts was higher than the other extracts. In the 5/30 sample, a $0.1\%$ concentration of unripened apple powder showed almost the same electron-donating ability with a $0.5\%$ concentration of the 6/30 sample. More than $90\%$ of the electron-donating ability was observed from the peel extracts regardless of solvents used for extraction. The nitrite-scavenging effects of acetone and methanol extracts of the 5/30 sample were the strongest at pH 1.2, and especially the $80\%$ methanol extracts exhibited a powerful scavenging effect of more than $90\%$ at pH 3.0.

• Journal of Korean Society of Water and Wastewater
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• v.35 no.2
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• pp.135-142
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• 2021

The activity of anaerobic ammonium oxidation (ANAMMOX) immobilized in synthetic media (Poly Ethylene Glycol, PEG) and granular form was evaluated comparatively to investigate the effect of influent nitrogen concentration and exposure of oxygen. In ANAMMOX granule reactor, when concentration of influent total nitrogen increased to 500mg/L, removal efficiency of ammonium, nitrite and nitrate were shown to 90.5±6.5, 96.6±4.9, and 93.2±6.1%, respectively. In the case of the PEG gel, it showed lower nitrogen removal performance, resulting in that the removal efficiency of ammonium, nitrite and nitrate were shown to 83.3±13.0, 96.4±6.1, and 90.3±7.5%, respectively. In second step, when exposed to oxygen, the nitrogen removal performance in the ANAMMOX granule reactor also remained stable, but the activity of PEG gel ANAMMOX was found to be inhibited. Consequently, the PEG gel ANAMMOX was a higher sensitivity than that of granular ANAMMOX with two variables applied in this study.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.37 no.1
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• pp.13-17
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• 2004

The effects of temperature on nitrification of enriched nitrifiers were investigated by using kinetics and thermodynamics method through the batch test. Aquaculture recirculating water, which was sampled at Chung Cheong Buk-Do Inland Fisheries Research Institute, was analized to observe the characteristics of nitrification. Temporal variation of ammonium, nitrite and nitrate concentration was measured at batch experiments. Activation energy was calculated using Arrhenius equation with the oxidation rates of specific ammonium or nitrite ion. These oxidation rates were measured at temperature range of $6-35^{\circ}C$ and ammonium concentration range of 0.2-1.8 mg/L. Two distinct activation energy of Nitrosomonas sp. at temperature $6-15^{\circ}C\;and\;15-35^{\circ}C$ was 93.1 and 25.0 KJ/mol, respectively. Nitrate accumulation was observed at temperature over $15^{\circ}C.$

• Microbiology and Biotechnology Letters
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• v.47 no.2
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• pp.296-302
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• 2019

In this study, the effects of ammonium concentration ($117.5-1155.0mg-N{\cdot}l^{-1}$), nitrite concentration ($0-50.0mg-N{\cdot}l^{-1}$), and temperature ($15-35^{\circ}C$) on nitrification performance and its functional genes (amoA-arc, amoA-bac, hao) in an enriched consortium inoculated with humic acid were determined. Notably, the maximum nitrification rate value was observed at $315mg-N{\cdot}l^{-1}$ of ammonium, but the highest functional gene copy numbers were obtained at $630mg-N{\cdot}l^{-1}$ of ammonium. No inhibition of the nitrification rate and functional gene copy numbers was observed via the added nitrites. The optimum temperature for maximum nitrification performance was observed to be $30^{\circ}C$. The amoA-bac copy numbers were also greater than those of amoA-arc under all test conditions. Notably, amoA-arc copy numbers and nitrification efficiency showed a positive relationship in network analysis. These results indicate that ammonium-oxidizing archaea and bacteria play important roles in the nitrification process.

• Food Science and Biotechnology
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• v.17 no.4
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• pp.687-691
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• 2008

This study was performed to investigate the taste composition and biological activities of cheonggukjang containing Rubus coreanum to improve cheonggukjangs' flavor and consumption. In R. corenum cheonggukjang (RCC), the total content of soluble sugars, including glucose, fructose, maltose, and sucrose, was 1,052.1 mg/100 g. Glutamic acid, phenlylalanine, leucine, cystine, and tyrosine were the major amino acids, and the ratio of sweet to bitter components was higher in RCC than in general cheonggukjang (GC). The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities of the extracts, in decreasing order, were found to be: ethanol extract> water extract> chloroform extract, at all concentrations. The water extract had the highest SOD-like activity (10.2%) at a concentration of 0.5 mg/mL, whereas the chloroform extract showed the highest SOD-like activity (19.1%) at a concentration of 2 mg/mL. The nitrite scavenging ability was higher at pH 1.2 than at pH 3.0 or 6.0, and had a positive correlation with the extract concentration. The chloroform extract had the highest nitrite scavenging ability (84.6%) at a concentration of 2 mg/mL and pH 2.0.

• Food Science of Animal Resources
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• v.38 no.2
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• pp.417-430
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• 2018

This study was conducted to determine the effects of NaCl concentration and cooking temperature on the color and pigment characteristics of presalted ground chicken breasts. Four treatments with different salt concentrations (0%, 1%, 2%, and 3%) were prepared and stored for 7 d prior to cooking. Each sample was cooked to four endpoint temperatures ($70^{\circ}C$, $75^{\circ}C$, $80^{\circ}C$, and $85^{\circ}C$). The salt concentration affected the color and pigment properties of the cooked ground chicken breasts. As the salt concentration increased, the cooking yield and residual nitrite content also increased. However, the samples with 1%, 2%, and 3% NaCl showed similar nitrosyl hemochrome and total pigment contents. Among the products containing salt, the samples with 3% NaCl showed the lowest percentage myoglobin denaturation (PMD) and the lowest CIE $a^*$ values. The cooking temperature had limited effects on the pigment properties of cooked ground chicken breasts. The oxidation-reduction potential and residual nitrite contents increased with cooking temperature, while the PMD, nitrosyl hemochrome, total pigment contents and CIE $a^*$ values were similar in the samples cooked at different temperatures. These results indicated that the addition of up to 2% salt to ground chicken breasts and storage for 7 d could cause the pink color defect of cooked products. However, the addition of 3% NaCl could reduce the redness of the cooked products.

• Journal of Microbiology and Biotechnology
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• v.27 no.10
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• pp.1798-1807
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• 2017

The differentiations in nitrogen-converting activity and microbial community structure between granular size fractions in a continuous completely autotrophic nitrogen removal over nitrite (CANON) reactor, having a superior specific nitrogen removal rate of $0.24g/(g\;VSS{\cdot}h)$, were investigated by batch tests and high-throughput pyrosequencing analysis, respectively. Results revealed that a high dissolved oxygen concentration (>1.8 mg/l) could result in efficient nitrite accumulation with small granules (0.2-0.6 mm in diameter), because aerobic ammonium-oxidizing bacteria (genus Nitrosomonas) predominated therein. Meanwhile, intermediate size granules (1.4-2.0 mm in diameter) showed the highest nitrogen removal activity of $40.4mg/(g\;VSS{\cdot}h)$ under sufficient oxygen supply, corresponding to the relative abundance ratio of aerobic to anaerobic ammonium-oxidizing bacteria (genus Candidatus Kuenenia) of 5.7. Additionally, a dual substrate competition for oxygen and nitrite would be considered as the main mechanism for repression of nitrite-oxidizing bacteria, and the few Nitrospira spp. did not remarkably affect the overall performance of the reactor. Because all the granular size fractions could accomplish the CANON process independently under oxygen limiting conditions, maintaining a diversity of granular size would facilitate the stability of the suspended growth CANON system.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.590-593
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• 2001

The effect of salinity on the nitrification efficiency of the nitrifier consortium was evaluated for the nitrification of saline wastewater. The nitrifier consortium, which was the activated sludge acclimated with ammonium as the only energy source, was used as the nitrifier for the salt acclimation. Airlift reactors for the nitrification of ammonia with increasing concentration in saline synthetic wastewater (35 g/I NaCD, and synthetic wastewater without salt as a control, were continuously operated with the nitrifier consortium for 43 days. The ammonia removal rate was about 23g ammonia-N/$m^3$/day in both the absence and presence of the salt. An accumulation of nitrite was observed in the saline nitrification reactor at an early period. However, the nitrite decreased to less than 1 mg/l after 39 days of operation. The salinity increased the acclimation time of the nitrifier consortium to obtain a stable marine nitrification system. However, the salt acclimated system showed the efficient removal of ammonia which was same as that without salt.