• Journal of the East Asian Society of Dietary Life
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• v.18 no.2
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• pp.190-197
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• 2008

The aim of this study was to determine the optimal cooking conditions in preparing jujube concentrates using various boiling times (5, 10, 15, 20 hours). The moisture contents of the concentrate samples ranged from 38.86 to 42.36%. Crude protein content was highest in the 15 hr-boiled concentrate, crude fat was highest in the 20 hr-boiled concentrate and both the 15 and 20 hr boiled concentrates had high crude fiber contents. There were no differences in color L- and a-values by boiling time; however, the b-value decreased with increasing boiling time. The pH levels of the concentrates ranged from 5.24 to 5.27, and the brix level increased with increasing boiling time. Glucose was the primary of free sugar in the concentrates and its highest level was 102.3 ${\mu}M$ in the 20 hr-boiled concentrate. The 15 hr-boiled concentrate had the highest electron donating ability to 46.68%. The total polyphenol contents of the concentrates ranged from 21.53 to 24.56%, in which the 15-boiled concentrate had the highest level (24.56%). In the sensory evaluation, the 15-hr-boiled concentrate again performed well, showing the highest overall acceptability scores. From these results, 15 hrs was the optimal boiling time for preparing jujube concentrate in terms of obtaining functional compounds and overall product acceptability.

• Journal of Astronomy and Space Sciences
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• v.21 no.4
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• pp.315-328
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• 2004

In this paper, we present a good example of extreme solar and geomagnetic activities from October to November, 2003. These activities are characterized by very large sunspot groups, X-class solar flares, strong particle events, and huge geomagnetic storms. We discuss ground-based and space-based data in terms of space weather scales. Especially, we present several solar and geomagnetic disturbance data produced in Korea : sunspots, geo-magnetograms, aurora, Ionogram, and Total Electron Content (TEC) map by GPS data. Finally, we introduce some examples of the satellite orbit and communication effects caused by these activities; e.g., the disturbances of the KOMPSAT-1 operational orbit and HF communication.

• Journal of the Korean Society of Food Culture
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• v.27 no.4
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• pp.367-373
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• 2012

In this study, physio-chemical, mechanical, and sensory characteristics of Tofu containing 0, 0.5, 1.0, and 2.0% Adenophora remotiflora powder were examined. In addition, we examined the potential of utilizing Adenophora remotiflora powder as a functional food material by estimating total phenol contents, electron-donating abilities, and hydroxyl radical scavenging activities of the hot water and ethanol extracts of Adenophora remotiflora powder in the range from 0~2.0%. The total phenol content of the ethanol extracts of Adenophora remotiflora powder was $487.93{\mu}g/mL$ while the that of the water extract of Adenophora remotiflora powder was $403.70{\mu}/mL$. The electron-donating abilities of the ethanol and water extracts of Adenophora remotiflora powder were 75.37 and 86.10%, respectively. The hydroxyl radical scavenging activities of the ethanol and water extracts of Adenophora remotiflora powder were 65.50 and 66.22%, respectively. We also evaluated the quality characteristics of Tofu containing Adenophora remotiflora powder. In the case of color values, as the level of Adenophora remotiflora powder increased, the values of L (lightness) and a (redness) decreased, whereas that of b (yellowness) increased. In the case of mechanical properties, as the level of Adenophora remotiflora powder increased, hardness, gumminess, and chewiness values increased (p<0.05), whereas springiness and cohesiveness values decreased (p<0.05). In the case of sensory evaluation, MPT1.0 scored significantly higher in color, flavor, tenderness, texture, and overall quality. To sum up, Tofu containing 1% Adenophora remotiflora powder showed the highest overall preference.

• Journal of Astronomy and Space Sciences
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• v.25 no.4
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• pp.335-346
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• 2008

Using the global total electron contents (TEC) measured by the TOPEX satellite from Aug. 1992 to Oct. 2005, we investigate the variations of the longitudinal wavenumber-4 (LW-4) structure in the equatorial anomaly (EA) crests with season, local time, and solar activity. Our study shows that the LW-4 structure in the EA crests ($5{\sim}20^{\circ}$ MLAT in both hemispheres) has clear four peaks at fixed longitude sectors during the daytime for both equinoxes and June solstice. In spite of being called a wavelike structure, however, the magnitudes and spatial intervals of the four peaks are far from being the same or regular. After sunset, the four-peak structure begins to move eastward with gradual weakening in its amplitude during equinoxes and this weakening proceeds much faster during June solstice. Interestingly, the longitudinal variations during December solstice do not show clear four-peak structure. All these features of the LW-4 structure are almost the same for both low and high solar activity conditions although the ion densities are greatly enhanced from low to high solar activities. With the irrelevancy of the magnetic activity in the LW-4, this implies that the large changes of the upper atmospheric ion densities, one of the important factors for ion-neutral interactions, have little effect on the formation of the LW-4 structure. On the other hand, we found that the monthly variation of the LW-4 is remarkably similar to that of the zonal component of wavenumber-3 diurnal tides at low latitudes, which implies that the lower atmospheric tidal forcing, transferred to the upper atmosphere, seems to have a dominant role in producing the LW-4 structure in the EA crests via the E-region dynamo.

• The Korean Journal of Food And Nutrition
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• v.24 no.3
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• pp.306-311
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• 2011

This study was performed to investigate the effect of Portulaca oleracea extract on the antioxidant and antimicrobial activities against Helicobacter pylori. The each solvent extracts prepared from Portulaca oleracea were investigated by measuring total phenolic compounds, electron donating ability, superoxide dismutase-like ability and thiobarbituric acid reactive substances The herb extractor extract yielded the highest content of total phenolic compounds(72.2 mg%). The electron donating abilities(EDA) of ethyl acetate and methanol extracts showed high antioxidant activity. The superoxide dismutase (SOD)-like abilities of ethyl acetate and petroleum ether extracts also showed some activity. The antioxidant activity of thiobarbituric acid reactive substances was not significant. The petroleum ether extract of Portulaca oleracea showed the highest antimicrobial activity at 10,000 ppm concentration.

• Journal of the Korean Society of Food Culture
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• v.19 no.5
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• pp.491-498
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• 2004

In order to study the quarantine and sanitization methods for dried red pepper, comparative effects of commercial fumigation (methyl bromide/MeBr, $phosphine gas/PH_{3}$ and gamma irradiation (5, 10 kGy) were investigated in terms of its physicochemical properties. There were no noticeable chances in pH and soluble solids among the untreated control, irradiated and fumigated samples soon after treatments, but some decrease was found in stored samples (especially soluble solid in fumigated samples) for 8 months under room temperature. Total sugar content was influenced by storage time rather than both treatments. Immediately after treatments, reducing sugar content was significantly reduced in the samples including pericarp when exposed to fumigants (p<0.05), while an apparent decrease was observed in the stored samples including seeds with negligible differences among treatment groups. The electron donating ability (EDA) of the extracts was high in the order of pericarp, whole pepper, powdered pepper and seeds, which was reduced during storage for 8 months particularly in the samples containing seeds. The EDA of irradiated samples during storage was equal to that of the control sample, whereas that of fumigated samples was relatively low (p<0.05).

• Journal of Ginseng Research
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• v.5 no.1
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• pp.65-72
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• 1981

In this experiment, observations were made on the effects of ginseng saponin, one of the major components of Korean ginseng (Panax ginseng, C. A. Meyer) root, on the membranes of microorganism (E. coli K-12), the concentration of intracelluar and extracellular cycle AMP therein, and uptake of U-14C-glucose. When the E. coli were grown on media containing 0.1% ginseng saponin, the growth was faster than for that of the control by about 30 minutes. The lysis of E. coli grown on the ginseng saponin medium increased to about double that of the control in the stationary phase. And the amount of protein and lipopolysaccharides in the outer cell meberances increased 25% and 80% respectively in comparison with the control. By electron microscope observation, it was shown that the periplasmic region of the E. coli grown on the ginseng saponin medium was widened it was observed that the cellular cyclic AMP content of the E. coli increased significantly to the hightest levels between the late exponential phase and early stationary phase. The total cyclic AMP content of E. coli grown on the ginseng saponin medium decreased about 50% when compared to that of the control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.655-662
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• 2000

Electron beam (EB) irradiation was applied to study microbial decontamination effects for kochujang powder by determining their microbiological and physicochemical qualities over gamma ray (GR) irradiation. The samples showed a high microbial population, such as 105~106 CFU/g of total aerobic bacteria, negative of yeasts & molds and coliforms. Total bacterial counts were decreased by 1~2 log cycles with EB irradiation at 5~7.5 kGy, and 10 kGy irradiation was enough to improve the microbiological quality by reducing populations to below 104CFU/g, which was similar to gamma energy. Such doses were effective for controlling the microbial growth in stored samples during storage for 4 months at room temperature. Decimal reduction doses (D10 value) on initial bacterial populations were 2.88~3.02 kGy in EB and 3.57~3.59 kGy in GR, which were influenced by initial populations and energy types applied. Based upon the above results, 7.5~10 kGy irradiation caused negligible changes in Hunter's color, capsaicin, fatty acid composition and organoleptic qualities. Considering the quality changes resulting from subsequent storage, such as a decrease in capsanthin content and an increase in TBA value in the samples, it is recommendable to irradiate kochujang powder at 7.5~10 kGy when used for food processing.

• Journal of Astronomy and Space Sciences
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• v.36 no.3
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• pp.159-168
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• 2019

In solstices during the solar minimum, the hemispheric difference of the equatorial ionization anomaly (EIA) intensity (hereafter hemispheric asymmetry) is understood as being opposite in the morning and afternoon. This phenomenon is explained by the temporal variation of the combined effects of the fountain process and interhemispheric wind. However, the mechanism applied to the observations during the solar minimum has not yet been validated with observations made during other periods of the solar cycle. We investigate the variability of the hemispheric asymmetry with local time (LT), altitude, season, and solar cycle using the electron density taken by the CHAllenging Minisatellite Payload satellite and the global total electron content (TEC) maps acquired during 2001-2008. The electron density profiles provided by the Constellation Observing System for Meteorology, Ionosphere, and Climate satellites during 2007-2008 are also used to investigate the variation of the hemispheric asymmetry with altitude during the solar minimum. During the solar minimum, the location of a stronger EIA moves from the winter hemisphere to the summer hemisphere around 1200-1400 LT. The reversal of the hemispheric asymmetry is more clearly visible in the F-peak density than in TEC or in topside plasma density. During the solar maximum, the EIA in the winter hemisphere is stronger than that in the summer hemisphere in both the morning and afternoon. When the location of a stronger EIA in the afternoon is viewed as a function of the year, the transition from the winter hemisphere to the summer hemisphere occurs near 2004 (yearly average F10.7 index = 106). We discuss the mechanisms that cause the variation of the hemispheric asymmetry with LT and solar cycle.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.777-782
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• 2003

Response surface methodology (RSM) was used to monitor the characteristics of ethanol extracts from Hericium erinaceus. A central composite design was applied to investigate the effects of independent variables, ethanol concentration $(X_1)$, and sample ratio $(X_2)$ on dependent variables, soluble solid $(Y_1)$, total phenols $(Y_2)$, crude protein $(Y_3)$, electron donating ability $(Y_4)$, and browning color $(Y_5)$ of the extracts. As the sample ratio increased, the soluble solid content increased. Ethanol concentration played a minor role. Total phenols and crude protein increased with sample ratio. Sample ratio had a greater effect than alcohol concentration in the extraction of soluble solid, total phenols, crude protein, and browning color, with an exception of electron donating ability. The optimum ranges at 2 hr extraction was $3.9{\sim}5.0\;g/l00\;mL$ in sample ratio and $36{\sim}52%$ in ethanol concentration. Predicted values at the optimized conditions were acceptable when compared to experimental values.