• Applied Biological Chemistry
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• v.37 no.4
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• pp.266-271
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• 1994

In order to investigate the effects of the mixing ratio of rice on Doenjang, Meju Doenjang and Koji Doenjang were prepared respectively with oaring mix ratio of raw materials. The following results were obtained, after fermentation of up to 3 months. Significant differences between the kinds of Doenjang were not found in moisture and salt contents. Protein solubility $(water\;soluble\;nitrogen/total\;nitrogen{\times}100)$ was $32{\sim}50%$ and $14{\sim}24%$ in Koji Doenjang and Meju Doenjang, respectively. Protein digestibility $(formol\;nitrogen/total\;nitrogen{\times}100)$ was similar to the tendency of protein solubility. Reducing sugar content was $5{\sim}6%$ in Meju Doenjang, while $19{\sim}21%$ in Koji Doenjang. As the mixing ratio of rice increased, reducing sugar content also increased. Sensory evaluation showed that Koji Doenjang was desirable than Meju Doenjang and the mixing ratio of 20% rice was recommened for Koji Doenjang.

• Journal of the Korean Society for Marine Environment & Energy
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• v.2 no.1
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• pp.63-73
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• 1999

The results of residual currents simulation by a three-dimensional hydrodynamic model showed the water volume transport and the residence time to be about 4km³ per tidal cycle and about 6 years through the line of latitude, 34° 25' N in the Yellow Sea, and to be about 13km³ per tidal cycle and about 2.5 years through the southeastern boundary line of the Yellow Sea, respectively. On the bases of the entire seawater volume of the Yellow Sea and dissolved oxygen (DO) in summer, the environmental capacity of the Yellow Sea for reception of the maximum pollution load without reducing DO concentration below 5.0mg/ℓ in seawater may be estimated to be about 58×10/sup 6/tons of chemical oxygen demand (COD), which is equivalent to the load about 8 times as high as the annual organic pollution load from 14 major rivers. On the bases of DO transports by residual currents calculated on the line of 34° 25' N latitude and on the southeastern boundary line of the Yellow Sea being about 57×10³tons and about 203×10³tons of DO per day, respectively, the environmental capacities of the Yellow Sea for reception of the maximum pollution loads without reducing DO concentration in seawater nay be equivalent to COD loads about 3 times and 10 times, respectively, as high as the existing organic pollution loads from 14 major rivers.

• Journal of the Korean Applied Science and Technology
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• v.37 no.4
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• pp.906-914
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• 2020

To investigate the usefulness of natural plants, physicochemical characteristics, functional components and physiological activities of dodder(Cuscuta australis R.Brown) were experimented. The extraction of dodder was carried out at 60℃ in shaking bath with 10 times of distilled water for three hours. Harmful metals such as lead, cadmium and arsenic were not detected, but the content of mercury from dodder was 0.0004ppm in acceptable standards. The extraction yield was 23.45%, total content of phenolics equivalent to gallic acid was 699.8 mg/100g and total content of flavonoid equivalent to naringin was 373.8 mg/100g. 28 kinds of free amino acids were detected with the contents of 252mg/100g in the dodder extract, and the contents of anserine and sarcosine were analysed highest in all amino acids. From the comparison of physiological activities of dodder extract with those of ascorbic acid, total reducing power, electron donating ability based on DPPH radical scavenging and ferric reducing antioxidant power was equivalent to 88%, 56% and 40%, respectively, of ascorbic acid. The nitrite scavenging activity of dodder extract was 78% of ascorbic acid on pH 1.5, but the antioxidant index of dodder on perilla oil was about 4 times greater than that of ascorbic acid.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.2
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• pp.689-696
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• 2017

The practical applications of ordinary high-fluidity concrete have been limited due to several drawbacks, such as high hydration heat, high amount of shrinkage, and non-economic strength development. On the other hand, due to its advantages, such as improvement of construction quality, reduction of construction cost and period, the development of high-fluidity concrete is a pressing need. This study examined the properties of high-fluidity concrete, which can be manufactured on the low binders using a viscosity agent to prevent the segregation of materials. The optimal viscosity agent was selected by an evaluation of the mechanical properties of high-fluidity concrete among six viscosity agents. The acrylic type and urethane type viscosity agents showed the best performance within the range where no material separation occurred. The mechanical properties were evaluated to examine the optimal amount of AC and UT viscosity agent added by mixing two viscosity agents according to the adding ratio and blending them together with high performance water reducing agent. When the ratio of the AC : UT viscosity agents was 5:5, it was most suited for high-fluidity concrete with low binders by increasing the workability and effect of the reducing viscosity.

• Food Science and Preservation
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• v.23 no.2
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• pp.267-274
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• 2016

This study was conducted to examine the physicochemical properties and antioxidant activities of medicinal fruit extracts (Corni fructus, Schizandra chinensis, Rubus coreanus Miquel and Lycii folium) with different extraction mixing ratios (MS, an equal ratio of the medicinal fruit = 1.25:1.25:1.25:1.25; M1, 2:1:1:1; M2, 1:2:1:1; M3, 1:1:2:1 and M4, 1:1:1:2) from medicinal fruit. pH, sugar content and acidity of the extracts were 3.22~3.52, $3.20{\sim}4.20^{\circ}Brix$ and 3.60~5.85%, respectively. The extraction yield of M2 (42.33%) was higher than those of MS (36.03%), M1 (40.40%), M3 (32.53%) and M4 (35.90%). The total polyphenol and flavonoid contents of M3 were 14.54 g/100 g and 5.65 g/100 g, respectively. The DPPH and ABTS radical scavenging activities of M3 at $1,000{\mu}g/mL$ were 86.09% and 90.49%, respectively. The ferric-reducing antioxidant power and the reducing power of M3 at $250{\sim}1,000{\mu}g/mL$ were $0.36{\sim}0.86{\mu}M$ and 0.21~0.96, respectively. The antioxidant activities of M3 were significantly higher than those of the other extracts. In conclusion, this study demonstrated that medicinal fruit extracts had potential as a functional material.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.10
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• pp.1331-1337
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• 2012

The study analyzed the total polyphenolic contents, DPPH radical scavenging activities, ABTS radical scavenging activities, reducing power levels, SOD-like activities, and tyrosinase inhibition activities of fractions from Campanula takesimana Nakai extract. Total polyphenolic content of the ethyl acetate fraction from Campanula takesimana Nakai extract was the highest. The ethyl acetate fraction of Campanula takesimana Nakai extract showed the lowest $IC_{50}$ value (0.13 mg/mL) as well as greater than 98% ABTS radical scavenging activity, which was similar to ascorbic acid. Further, reducing power was significantly higher in the ethyl acetate fraction. The SOD-like activity of edible plant was 70.56% (n-butanol fraction) and 62.27% (ethyl acetate fraction) at 1 mg/mL. Tyrosinase inhibition activity of Campanula takesimana Nakai extract was reduced to 34.77% in the n-butanol fraction and 30.85% in the ethyl acetate fraction at 5 mg/mL. These results suggest that the ethyl acetate and n-butanol fractions of Campanula takesimana Nakai extract could be applicable as food additives or cosmeceutical ingredients.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.11
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• pp.1487-1492
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• 2012

Antioxidant activity and neuroprotective effects of extracts from Cichorium endivia L. (CEL) on hydrogen peroxide-induced oxidative damage in neuronal cells were investigated. The total polyphenol and flavonoid contents of the water and ethanolic extracts from CEL were $36.2{\pm}0.99$, $37.2{\pm}3.76$ mg gallic acid equivalent/g extract, and $46.9{\pm}5.22$, $53.86{\pm}5.09$ mg catechin equivalent/g extract, respectively. In addition, antioxidant activities of the extracts were also determined by ferric reducing antioxidant power (FRAP), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity and reducing power. In an MTT assay on the neuronal cells, the extracts showed a protective effect by increasing cell viability on hydrogen peroxide-induced oxidative damage in neuronal cells. Antioxidative enzyme (superoxide dismutase: SOD, catalase: CAT) levels in cultured neuronal cells were increased in the presence of extracts from CEL. It was found that CEL extracts inhibited hydrogen peroxide-induced Bcl-2 and Bax expression in neuronal cells. These results indicate that the CEL extracts possess an antioxidant activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1201-1206
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• 2010

As a means to increase the production and consumption of the brown colored rice with high content of GABA ($\gamma$-aminobutyric acid), this study was conducted to develop brown colored rice tea. After roasting at various temperatures and times, color values and GABA content of the brown colored rice were analyzed. Physicochemical properties such as browning, turbidity, reducing sugar, soluble solid, total polyphenol and pH of brown colored rice tea were determined after the rice powder was put into tea bags and leached in hot water. Sensory characteristics were investigated for three kinds of tea roasted at $170^{\circ}C$ for 10, 20 and 30 min. As the roasting temperature and time increased, L, a and b values decreased as well as GABA content. The brown colored rice roasted at $170^{\circ}C$ for 10 min contained the highest content of GABA. Browning, turbidity, reducing sugar, soluble solid and total polyphenol of the brown colored rice tea increased as the roasting temperature and time increased, on the contrary, pH decreased. The brown colored rice tea roasted for 30 min was preferred the most in color, flavor, taste and overall acceptance. From this result, the brown colored rice tea needs to be manufactured by a combination of the brown colored rice roasted at $170^{\circ}C$ for 10 min and 30 min to satisfy the consumer's preference and high content of GABA.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.3
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• pp.381-388
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• 2014

The antioxidant activities of extracts from Rubus coreanus Miquel (black raspberry) and Morus alba L. (mulberry) fruits were investigated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, 2,2-azino-bis-(3-ethylbenzo-thiazoline-6-sulfonic acid) (ABTS) assay, and reducing power assay. Aqueous mixtures of ethanol, methanol, and acetone were analyzed in order to determine the most effective extraction solvent for the two fruits. Black raspberry and mulberry extracts with the 60:40 acetone-water mixtures (v/v) showed the highest DPPH radical scavenging activities (56.2 and 85.2%, respectively) compared to the other extraction solvents. The 60% acetone extract was finally selected as an extraction solvent and then sequentially fractionated according to solvent polarity. Among the fractions of the two fruits, the ethyl acetate fraction showed the highest antioxidant activity as well as total phenolic and total flavonoid contents. In addition, there were high correlation coefficients between antioxidant activities and their contents. The $EC_{50}$ value of the ethyl acetate fraction from mulberry fruit was 2.2 times lower than that of butylated hydroxytoluene (BHT) in DPPH assay. The major phenolic acid and anthocyanin of the two fruits were protocatechuic acid and cyanidin-3-glucoside, respectively.

• Korean Journal of Materials Research
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• v.25 no.2
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• pp.75-80
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• 2015

The carbon dioxide($CO_2$) released while producing building materials is substantial and has been targeted as a leading contributor to global climate change. One of the most typical method to reducing $CO_2$ for building materials is the addition of slag and fly ash, like pozzolan material, while another method is reducing $CO_2$ production by carbon negative cement development. The MgO-based cement was from the low-temperature calcination of magnesite required less energy and emitted less $CO_2$ than the manufacturing of Portland cements. It is also believed that adding reactive MgO to Portland-pozzolan cements could improve their performance and also increase their capacity to absorb atmospheric $CO_2$. In this study, the basic research for magnesia cement using $MgCO_3$ and magnesium silicate ore (serpentine) as main starting materials, as well as silica fume, fly ash and blast furnace slag for the mineral admixture, were carried out for industrial waste material recycling. In order to increase the hydration activity, $MgCl_2$ was also added. To improve hydration activity, $MgCO_3$ and serpentinite were fired at $700^{\circ}C$ and autoclave treatment was conducted. In the case of $MgCO_3$ as starting material, hydration activity was the highest at firing temperature of $700^{\circ}C$. This $MgCO_3$ was completely transferred to MgO after firing. This occurred after the hydration reaction with water MgO was transferred completely to $Mg(OH)_2$ as a hydration product. In the case of using only $MgCO_3$, the compressive strength was 3.5MPa at 28 days. The addition of silica fume enhanced compressive strength to 5.5 MPa. In the composition of $MgCO_3$-serpentine, the addition of pozzolanic materials such as silica fume increased the compression strength. In particular, the addition of $MgCl_2$ compressive strength was increased to 80 MPa.