• Korean Journal of Food Science and Technology
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• v.35 no.4
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• pp.690-695
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• 2003

Physiological activities of 40% ethanol extracts of Phellinus ribis were studied by employing several biological and biochemical assays. The extracts of Phellinus ribis displayed nitrate-scavenging activities (NSA) at pH 1.2 as with 64% NSA with 1.0 mg/mL of the extracts. They also had 91% 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities at the concentration of 1.0 mg/mL. Antioxidant activities of the extracts (at 0.5 mg/mL) on the autoxidation of linoleic acid (p<0.001) were also observed.. The inhibitory effect of the extracts on angiotensin converting enzyme was 11%. Cytotoxic effects of Phellinus ribis extracts against human cancer cell tines were also examined using MTT assay. The extracts (at 50 mg/mL) had severe growth inhibitory effects on A549, Hela, AGS, and SK-Hep-1, which were 8, 44, 76 and 42%, respectively. Ames test indicated that the extracts had no mutating effects on Salmonella typhimurium TA98 and TA100.

• Food Science and Preservation
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• v.17 no.4
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• pp.563-570
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• 2010

We sought to ferment wine from mulberry (Morus alba) juice. The soluble solid content was $9.5{\sim}14.5^{\circ}brix$ on day 6 of fermentation, and gradually fell later; sugar was not further consumed when $3^{\circ}brix$ was attained. Alcohol content rose dramatically on day 6 of fermentation, being 4.5% (v/v) at fermentation temperatures of 16C and 18C, 6.5% (v/v) at 20C, and 8.0% (v/v) at 25C, rising further to 10.5~11.5% (v/v) on day 48, at higher culture temperatures. Citric acid, malic acid, and oxalic acid were present in mulberries. The levels of both citric and oxalic acid fell after fermentation, whereas malic acid concentration increased. All of fructose, glucose, maltose, and sucrose were fermented. Electron-donating ability (EDA) was elevated to over 90% of the control value in mulberry juice diluted to 40% (v/v). SOD-like activities in juice and wine were 80.1% and 72.1% of the control value. Nitrite-scavenging abilities (NSAs) were 86.2% and 85.2% of control in undiluted juice and wine, respectively. Mulberry juice had an activation level higher than that of mulberry wine, but functionality neither rose nor fell after fermentation. Insensory evaluation, the overall wine score was better than average, at 5.00, demonstrating the commercial potential of mulberry wine.

• Korean Journal of Environmental Biology
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• v.37 no.2
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• pp.136-143
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• 2019

This study investigates the effect of denitrified biofloc water on changes in the water quality parameters and the physiological characteristics of shrimps. Biofloc rearing water contains a large number of microorganisms and can rapidly stabilize the water quality and energy saving if reusable due to high water temperatures. Rearing water contain floating bacteria with both aerobic and anaerobic bacteria. Therefore, when the carbon source is added in limited air supply, the anaerobic state is activated and the denitrification process is possible. In this study, the denitrification water had the following properties: ammonia (6.9 mg L^-1), nitrite (0.3 mg L^-1), nitrate concentration (9.2 mg L^-1), high pH (8.42) and alkalinity (590 mg L^-1). The experimental group consisted of seawater (SW, control), a mixture of Seawater and denitrified biofloc water (DNW) in the ratio of 3:1, 1:1 and DNW only. All experiments were done in triplicate. As a result, the survival rate never changed even when 100% of the denitrification water was utilized. However, a body fluid analysis showed that creatine and BUN were increased due to index of stress and the tissue damage resulting from the high denitrified water content. Body fluid ions (Na⁺, K⁺, and Cl^-) significantly decreased as the denitrified water content increased. It was recommended that the denitrification water be mixed with a certain ratio (less than 50%) in the future as it may affect the osmotic pressure control in shrimps.

• 한국해양학회지
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• v.23 no.3
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• pp.130-145
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• 1988

Spatial distribution and temporal variations of phytoplankton population were investigated in Ch$\check{o}$nsu Bay, the Korean western coast. Diurnal fluctuations of phytoplankton standing crop are associated with semidiurnal tidal cycle, as high concentration at low tide and low at high tide. In monthly variations of phytopolankton standing crop, the 1st peak occurrs in March and the 2nd one in August. The study area could be divided into two parts, outer bay and inner bay according to the physical and biological factors such as water temperature and salinity, and phytoplankton distribution patterns. The northern waters of the bay, however, may be affected by irregular fresh water influx through the lock of the dike. Because of the hydrographical differences among the surveyed stations, phytoplankton species succession patterns of each station have some differences. On the whole in this study area, Paralia sulcata and Skeletonema costatum are dominant species all the year round. However, except June, Paralia sulcata, a tychopelagic diatom is not dominant species at Station 6 (northern end of the bay). This seems to be caused by the fact that the waters of northern part of the bay is less turbulent than that of the outer bay. The result of principal component analysis (PCA) indicates that Ch$\check{o}$nsu Bay is normal coastal ecosystem where the environmental conditions are cycled in a year, and water temperature and nitrogenous nutrients such as nitrate, nitrite and ammonia are major factors to influence the annual cycle of environmental conditions.

• Food Science and Preservation
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• v.14 no.6
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• pp.655-661
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• 2007

The biological activities of methanol extracts of Angelica gigas Nakai, such as antioxidation, anticancer and immuno-activity, were investigated in relation to development of functional foods. Anti-oxidation activity in the methanol extracts were assessed by hydrogen donating activity, reducing power and hydroxyl radical scavenging activity. Activities were dose-dependent over concentrations of 0.1, 0.5 and 1 mg/mL, with thehydrogen donating activity being over 50% at 1 mg/mL concentration. The methanol extracts inhibited the proliferation of SW480 cells in a dose-dependent manner, and chromatin condensation and apoptotic bodies were observed by fluorescence microcopy in the cells treated with the extracts for 24 hr. Caspase-3 activity was also increased in a dose-dependent manner in cells treated with the extracts relative to control cells. The extracts did not induce the proliferation of mouse spleen cells or NO production in macrophage cells (RAW 264.7). These results show that the methanol extract had slight anti-oxidative activity and did not increase immuno-activity, but inhibited proliferation of SW480 through apoptosis via a caspase dependent pathway.

• Journal of Applied Biological Chemistry
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• v.63 no.3
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• pp.259-265
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• 2020

Antioxidative activities of 50% ethanolic extracts from Du-zhong (Eucommia ulmoides Oliver) leaf and bark were investigated. Yields of the leaf and bark extract were 8.1±0.31 and 17.4±0.89%, respectively. Polyphenol contents of the leaf and bark extract were 64.1±3.35 and 42.4±2.38 ㎍ gallic acid equivalents/mg, respectively. Flavonoid contents of the leaf and bark extract were 24.0±3.15 and 36.7±3.18 ㎍ quercetin equivalents/mg, respectively. As concentration of the leaf and bark extract increased, their antioxidative activities proportionally increased. EC₅₀ values of the leaf and bark extract for cation radical scavenging were 560.6±17.65 and 1,357.4±8.45 ㎍/mL, respectively. EC₅₀ values of the leaf and bark extract for free radical scavenging were 574.2±14.70 and 2,103.1±108.59 ㎍/mL, respectively. EC₅₀ values of the leaf and bark extract for ferric reducing antioxidant power were 319.9±13.42 and 705.9±26.08 ㎍/mL, respectively. EC₅₀ values of the leaf and bark extract for nitrite scavenging were 2,329.2±35.11 and 5,467.6±243.92 ㎍/mL, respectively. In the presence of 74.8 ㎍/mL of the leaf extract and 177.2 ㎍/mL of the bark extract, linoleic acid peroxidation was inhibited by 70.0 and 79.1%, respectively. The Du-zhong leaf extract possessed higher antioxidative activities than its bark extract.

• Food Science and Preservation
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• v.14 no.5
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• pp.474-480
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• 2007

Response surface methodology (RSM) was employed to optimize extraction conditions preserving valuable functional properties of fluid Cheonggukjang obtained from red ginseng. Based on a central composite design, the study plan was established using variations in microwave power, ethanol concentration, and extraction time. Regression analysis was applied to obtain a mathematical model. A maximum electron donating ability (EDA) of 99.09% was obtained under the specific extraction conditions of microwave power 135.62 W, ratio of solvent to sample contents. 3.60 g/mL, and an extraction time of 11.79 min. The maximum inhibitory effect on tyrosinase activity was 10.02% at 119.16 W, 4.02 g/mL, and 5.57 min. The maximum superoxide dismutase (SOD)-like activity was 63.83% under the extraction conditions of 125.29 W, 4.04 g/mL, and 11.02 min. Based on superposition of four-dimensional RSM data obtained to optimize electron donating ability, nitrite-scavenging ability, inhibitory effect on tyrosinase activity, and SOD-like activity, the optimum ranges of extraction conditions were found to be a microwave power of $l{\sim}85 W$, a ratio of solvent to sample content of $1.4{\sim}2.8\;g/mL$, and an extraction time of $6.5{\sim}11\;min$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.2
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• pp.141-147
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• 2008

This study investigated the isoflavone contents and physiological properties of non-fermented soybean (NF) and the fermented soybeans prepared with Asp. oryzae (AO) and B. natto (BN). The total isoflavone contents (daidzin, genistin, daidzein and genistein) of NF, AO and BN were 81.8 mg/100 g, 130.7 mg/100 g and 139.5 mg/100 g, respectively. Especially, the total phenol contents of NF, AO and BN were 2.1%, 4.3% and 7.6%, and the total flavonoid contents were 1.3%, 1.6% and 2.7%, respectively. The nitrite-scavenging abilities of NF, AO and BN were 34.4%, 55.2% and 92.5%, respectively. Antimicrobial activity of BN was shown to be the strongest to Bacillus cereus, Staphylococcus aureus and Escherichia coli. The SOD-like activity was the strongest in AO, whereas the electron donating ability was the strongest in BN. Antioxidant activity of AO at concentration of 0.02% was stronger than BN or NF.

• Journal of the Korean Chemical Society
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• v.17 no.4
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• pp.262-268
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• 1973

p-Phenylenediamine was tetrazotized with sodium nitrite in an excess amount of concentrated hydrochloric acid media at -10$^{\circ}$C. It was also tetrazotized almost completely in 45% perchloric acid media. The two diazo groups in the tetrazonium salt were substituted by halogen, and the degree of tetrazotization reaction was observed by dihalobenzene yielded. The result of the tetrazotization was dependent upon the stability of the tetrazonium salt, and the stability was determined by concentration and quantity of the acid media. In dilute acid media the tetrazonium salt was unstable and completely decomposed. In concentrated acid media, though the tetrazonium salt was stable, tetrazotization reaction was retarded. To harmonize the two opposing tendencies it was advisable to find the optimum acidity of media at which the salt was fairly stable. About $40{\sim}45$% of the acid media was suitable. The fact that the $H^+$ ion behaved as a negative catalyst supported the assumption that the diazotization reaction is primarily a reaction between the free amine and a nitroso group. The reaction of tetrazotization is expressed with respect to the kinetics and mechanism of diazotization.

• Korean Journal of Ecology and Environment
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• v.57 no.2
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• pp.61-74
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• 2024

Daemadeung, located in the estuary of the Nakdong River, is formed by sand dunes and possesses well-developed intertidal flats. This study aimed to investigate the habitat of benthic microalgae, photosynthetic pigments, and photosynthetic efficiency in the intertidal flats of Daemadeung from January to December 2011. The inorganic nitrogen content in the sediment pore water was primarily composed of ammonium, while nitrate + nitrite was dominant in the upper layer water. The concentration of chlorophyll a and fucoxanthin in the sediment surface was significantly higher than the mean of all the sediment layer. The average Fv/Fm of benthic microalgae during the entire survey period was 0.52±0.03, with the highest value (0.61±0.08) observed in February. The rETR_max showed a seasonal trend, being high from spring to early autumn (April to October) and low from winter to early spring (January to March, November, December), with the highest value (153.05±2.30 µmol electrons m^-2 s^-1) in July and the lowest (38.49±5.17 µmol electrons m^-2 s^-1) in January. The average Fv/Fm of diurnal microalgae was 0.48±0.03, with the highest value (0.61±0.08) observed at noon. The rETR_max showed a highest peak at noon (54.24±11.35 µmol electrons m^-2 s^-1) and reached its lowest point at 16:00 (26.17±4.75 µmol electrons m^-2 s^-1). These findings suggest that the productivity of benthic microalgae varies significantly depending on the survey time and sediment depth. Therefore, to quantify the productivity of benthic microalgae using Diving-PAM, surveys should be conducted based on tidal conditions, and simultaneous pigment analysis of sediment layers should also be performed.