• Food Science and Preservation
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• v.22 no.6
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• pp.915-919
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• 2015

This study was performed in order to provide basic data for predicting the usefulness of Jicama (Pachyrhizus erosus) as a food raw material. The changes in the physicochemical properties of freeze-dried and hot air-dried Jicama were investigated and analyzed. The moisture content of raw Jicama was 81.84%. The crude protein, crude fat, crude ash and carbohydrate content of hot air-dried Jicama powder were 2.85, 0.79, 7.93 and 88.44%, while those of freeze-dried Jicama powder were 3.93, 0.83, 7.92 and 87.32%, respectively on dry basis. Regarding the color values, the lightness of freeze-dried Jicama (92.86) was higher than that of the hot air-dried Jicama (88.01), whereas the redness (-0.67) and yellowness (3.21) of freeze-dried Jicama were lower than those of the hot air-dried Jicama (0.43) and (11.96), respectively. The brown index was lower in the freeze-dried Jicama (0.029) than in hot air-dried Jicama (0.107). The total sugar content showed no significant differences between freeze (46.49 mg/g) and hot air-dried Jicama (45.11 mg/g). Finally, the amylose content was higher in freeze-dried Jicama (5.66%) than in hot air-dried Jicama (6.63%).

• The Korean Journal of Food And Nutrition
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• v.28 no.4
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• pp.602-611
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• 2015

Aronia melanocarpa (Rosaceae family), black chokeberry, has significantly higher anthocyanin, phenolic compounds, and antioxidant activity than other berries. The aim of this study is to characterize the content of aronia makgeolli prepared with the additive method such as fresh-type and crushed-type and to investigate the effect of aronia on the quality of makgeolli at $25^{\circ}C$ for 8 days. The changes in pH, total acidity, ethanol content, color, antioxidant activity, total polyphenol content, and sensory testing were determined. The pH values were 3.9~4.2 in fresh aronia makgeolli (the fresh group), and 3.6~3.9 in crushed aronia makgeolli (the crushed group). The total acidity of all samples gradually increased during the fermentation period. The ethanol content was 10~15% after the second stage of fermentation, and was reduced followed by an increase in the addition rate of aronia, showing the lowest values in 50% crushed aronia makgeolli. As the aronia content increased, both the antioxidant activity and the total polyphenol content significantly increased. In the fresh group, low values were seen in early fermentation, which significantly increased according to the progress of fermentation, while the crushed group showed high values for 6 days. In the sensory evaluation, the color, flavor, bitterness, and overall acceptance of the makgeolli with 30% fresh aronia showed higher values than the control and other samples. In conclusion, the present study suggests that fresh aronia without undergoing the breaking process is a more suitable additive method than the crushed type for antioxidant activity and palatability of aronia makgeolli.

• Journal of Korea Water Resources Association
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• v.46 no.8
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• pp.807-819
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• 2013

This study proposes a new methodology for future water balance projection considering climate change by assigning a weight to each scenario instead of inputting future streamflows based on GCMs into a water balance model directly. K-nearest neighbor algorithm was employed to assign weights and streamflows in non-flood period (October to the following June) was selected as the criterion for assigning weights. GCM-driven precipitation was input to TANK model to simulate future streamflow scenarios and Quantile Mapping was applied to correct bias between GCM hindcast and historical data. Based on these bias-corrected streamflows, different weights were assigned to each streamflow scenarios to calculate water shortage for the projection periods; 2020s (2010~2039), 2050s (2040~2069), and 2080s (2070~2099). As a result by applying the proposed methodology to project water shortage over the Korean Peninsula, average water shortage for 2020s is projected to increase to 10~32% comparing to the basis (1967~2003). In addition, according to getting decreased in streamflows in non-flood period gradually by 2080s, average water shortage for 2080s is projected to increase up to 97% (516.5 million $m^3/yr$) as maximum comparing to the basis. While the existing research on climate change gives radical increase in future water shortage, the results projected by the weighting method shows conservative change. This study has significance in the applicability of water balance projection regarding climate change, keeping the existing framework of national water resources planning and this lessens the confusion for decision-makers in water sectors.

• Journal of the Korean earth science society
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• v.23 no.4
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• pp.357-368
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• 2002

In this study we have tried to explain the barrel-shaped morphology for young supernova remnants considering the dynamical effects of the ejecta. We consider the magnetic field amplification resulting from the Rayleigh-Taylor instability near the contact discontinuity. We can generate the synthetic radio image assuming the cosmic-ray pressure and calculate the azimuthal intensity ratio (A) to enable a quantitative comparison with observations. The postshock magnetic field are amplified by shearing, stretching, and compressing at the R-T finger boundary. The evolution of the instability strongly depends on the deceleration of the ejecta and the evolutionary stage of the remnant. the strength of the magnetic field increases in the initial phase and decreases after the reverse shock passes the constant density region of the ejecta. However, some memory of the earlier phases of amplification is retained in the interior even when the outer regions turn into a blast wave. The ratio of the averaged magnetic field strength at the equator to the one at the pole in the turbulent region can amount to 7.5 at the peak. The magnetic field amplification can make the large azimuthal intensity ratio (A=15). The magnitude of the amplification is sensitive to numerical resolution. This mens the magnetic field amplification can explain the barrel-shaped morphology of young supernova remnant without the dependence of the efficiency of the cosmic-ray acceleration on the magnetic field configuration. In order for this mechanism to be effective, the surrounding magnetic field must be well-ordered. The small number of barrel-shaped remnants may indicate that this condition rarely occurs.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.44 no.2
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• pp.117-124
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• 2018

In this study, cosmetic materials were developed using a new method of making juice through the fermentation of raw natural materials with microorganisms in order to supplement the advantages and disadvantages of an organic solvent extraction method and a microbial fermentation method. The natural products were selected from two colors (red, green) of paprika known to be rich in various colors and vitamins. The microorganisms used for fermentation were fermented by inoculating paprika with lactic acid bacteria (Lactobacillus plantarum) having sugar-hydrolyzed ability. First, we investigated the changes of physiologically active substances of two kinds of paprika juice and two kinds of fermented paprika juice. Total phenols content and total flavonoids content were higher in the fermented paprika juice than in the paprika juice, and especially in the fermented red paprika juice. Free radical scavenging effect and lipid peroxidation inhibitory effect were also showed an excellent antioxidative effect on paprika fermented juice, among which the effect of red paprika fermentation juice was the highest. The expression of MMP-1 in fermented red paprika juice with high antioxidant activity was inhibited by concentration-dependent expression of MMP-1 mRNA and MMP-1 protein. In the glycation experiments with aging, the anti-glycation effect of fermented paprika juice was highly inhibited by the production of advanced glycation end-products (AGEs), which was closely related to the antioxidant effect. In addition, the activity of senescence-associated ${\beta}$-galactosidase (SA-${\beta}$-gal), an indicator of cell senescence, was measured using human dermal fibroblast (HDF). The results showed that the cell senescence was inhibited when the cells were treated with fermented paprika juice. In conclusion, fermented paprika juice using lactic acid bacteria showed better antioxidative and anti-aging effects than paprika juice. Among them, fermented red paprika juice has the best antioxidant and anti-aging effect and can be applied as natural new material of antioxidant and anti-aging.

• Food Science and Preservation
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• v.23 no.7
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• pp.995-1003
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• 2016

Ulmus pumila L. bark underwent distilled water extraction under three temperature condition ($4^{\circ}C$, room temperature, or $80^{\circ}C$) and two extraction times (1, or 5 min) in order to develop a functional beverage products. Changes in yield, pH, color, total phenolic (TP) content, tannin content and antioxidant activity of the aqueous extracts were evaluated for each extraction temperature and duration. Extraction conditions did not affect yield or pH value of the extracts; however CIE $b^*$ values were high in extracts prepared under high extraction temperature ($80^{\circ}C$) and long extraction duration (5 min) conditions. Both extraction temperature and duration affected the TP and tannin contents of the extracts; however, all extraction conditions resulted in ${\geq}450\;mg\;GAE/g$ TP content and ${\geq}80\;mg\;CE/g$ tannin content. All extracts exhibited ABTS and DPPH radical scavenging ability similar to that of vitamin C. Nitric oxide inhibition activity was lower in the 5 min duration sample than in the 1 min sample. The $4^{\circ}C$ extraction temperature produced an extract with the highest reducing power and hydrogen peroxide values. Extraction temperature also affected sensory evaluation results with the $80^{\circ}C$ extraction temperature producing significantly higher flavor, bitterness, and color score, than those obtained under $4^{\circ}C$ and room temperature extraction conditions.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.4
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• pp.452-458
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• 2019

Coix lacryma-jobi var. ma-yuen (Rom. Caill.) Stapf (CL), which contains riboflavin and coixol, has traditionally been used to treat cancer and arthritis. However, no method for the simultaneous determination of riboflavin and coixol in CL sprouts has been established. In this study, we established and validated a high-performance liquid chromatography-diode array detection (HPLC-DAD) method for the identification and quantification of two reference markers, riboflavin and coixol, in CL sprout extracts. CL sprouts (whole sprouts and leaves) were subjected to extraction with 70% ethanol at room temperature and at 80 ℃ under reflux conditions. The two extractions were validated with respect to specificity, accuracy, precision, and linearity. The content of the two reference markers was highest in leaves extracted under reflux conditions (riboflavin, 8.23 ± 0.32 mg/g; coixol, 5.95 ± 0.04 mg/g). We also investigated the antioxidant activity of the extracts via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺) scavenging assays. The results indicated that extracts obtained from sprouts under reflux conditions had the strongest antioxidative effects (DPPH half maximal inhibitory concentration [IC₅₀], 68.9 ± 4.1 g/mL; and ABTS, IC₅₀, 34.9 ± 0.1 g/mL). These results can serve as baseline data for the simultaneous determination of the two reference marker compounds, riboflavin and coixol, and development of functional food materials using CL sprouts.

• Applied Biological Chemistry
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• v.49 no.3
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• pp.243-247
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• 2006

The biological activity of functional food source with thyme extracts were examined. Total phenol contents in the 60% ethanol extracts $(26.8{\pm}0.35\;mg/g)$ with thyme leaf was higher than water extracts $(25.7{\pm}0.20\;mg/g)$. This HPLC analysis is significant in that physiological activity is related with phenolic compound content such as rosemarinic acid, quercetin and chlorogenic acid. Electron donating ability was shown as 90.1% in the water extracts and 77.7% in the 60% ethanol extracts. Antioxidant protection factor of 60% ethanol extracts was higher than water extracts. Helicobacter pylori of the water extracts from thyme leaves did not have antimicrobial activity, but the 60% ethanol extracts revealed the high antimicrobial activity as 9 mm of clear zone in $50\;{\mu}g/ml$ of phenol content, 10 mm in $100\;{\mu}g/ml$, 13 mm in $150\;{\mu}g/ml$ and 16 mm in $200\;{\mu}g/ml$, respectively. Angiotensin converting enzyme inhibition activity showed no inhibition activity in 60% ethanol extracts but 39.9% inhibition activity in water extracts. Xanthine oxidase inhibition activity showed high inhibition activity at 73.5% in water extracts and 100% in 60% ethanol extracts. The result suggests the development of phenol compound in thyme as anti Helicobacter pylori, antioxidant and anti-gout agents.

• Restorative Dentistry and Endodontics
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• v.34 no.5
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• pp.406-414
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• 2009

The purpose of this study was to examine the effect of hydrogen peroxide at different application time and concentrations on the microtensile bond strength of resin restorations to the deep and the pulp chamber dentin. A conventional endodontic access cavity was prepared in each tooth, and then the teeth were randomly divided into 1 control group and 4 experimental groups as follows: Group 1, non treated; Group 2, with 20% Hydrogen peroxide ($H_2O_2$); Group 3, with 10% $H_2O_2$; Group 4, with 5% $H_2O_2$; Group 5, with 2.5% $H_2O_2$; the teeth of all groups except group 1 were treated for 20, 10, and 5min. The treated teeth were filled using a Superbond C&B (Sun medical Co., Shiga, Japan). Thereafter, the specimens were stored in distilled water at $37^{\circ}C$ for 24-hours and then sectioned into the deep and the chamber dentin. The microtensile bond strength values of each group were analyzed by 3-way ANOVA and Tukey post hoc test(p < 0.05). In this study, the microtensile bond strength of the deep dentin (D1) was significantly greater than that of the pulp chamber dentin (D2) in the all groups tested. The average of microtensile bond strength was decreased as the concentration and the application time of $H_2O_2$ were increased. Analysis showed significant correlation effect not only between the depth of the dentin and the concentration of $H_2O_2$ but also between the concentration of H202 and the application time(p < 0.05), while no significant difference existed among these three variables(p > 0.05). The higher $H_2O_2$ concentration, the more opened dentinal tubules under a scanning electron microscope(SEM) examination.

• The Korean Journal of Mycology
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• v.38 no.2
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• pp.172-178
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• 2010

The contents of proximate composition, free amino acids and phenolic acids in the Fomitella fraxinea cultivated-Rhus verniciflua stem bark(FRVSB), and its adipogenesis effect were investigated. The proximate composition(%) of FRVSB was as follows: moisture(7.64), ash(6.30), crude fat(3.86), crude protein(3.59) and sugar(not detected); while Rhus verniciflua stem bark(RVSB) contained 1.64, 8.09, 7.28, 6.48 and 5.39, respectively. The total free amino acids concentration was 97.41 mg% in FRVSB and 71.91 mg% in RVSB. Phosphoserine(55.06 mg%), ammonia(17.84mg%) and aspartic acid(6.05mg%) were predominant amino acids. The content of total phenolic acids was 422.89 ppm in ethanol extract and 283.86 ppm in water extract, with syringic and gallic acid as the main component. The FRVSB extracts showed a potent free radical scavenging activity for DPPH(2,2-diphenyl-1-picrylhydrazyl hydrate) with $IC_{50}$ of $28.54\;{\mu}g$(EtOH) and $54.70\;{\mu}g$(water), respectively, whereas $IC_{50}$ value of gallic acid was $1.84\;{\mu}g$. The protective effect of both ethanol and water extract the extracts against UV-induced oxidative stress in NIH3T3 was observed. The water extracts of FRVSB may promote adipogenesis in 3T3-L1 cells.