• The Korean Journal of Food And Nutrition
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• v.34 no.1
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• pp.15-25
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• 2021

This study aimed to investigate the antioxidant activities and quality characteristics of jelly added with Orostachys japonicus juice. The moisture content and the soluble solids content of the jelly samples decreased significantly with increasing content of O. japonicus. The pH was highest in the control samples, and the pH significantly decreased with the addition of increasing amounts of O. japonicus. In terms of the chromaticity measurements, the lightness value and redness value was highest in the control sample, and it decreased as the amount of added O. japonicus increased, whereas the yellowness value increased with increasing levels of O. japonicus added. The gumminess and chewiness of the jelly increased with the addition of increasing amounts of O. japonicus. On the other hand, the cohesiveness and adhesiveness of the jelly did not show statistically significant changes. The total polyphenol and DPPH radical scavenging activities of the jelly with 100% O. japonicus added were significantly higher than those of the jelly with 0% O. japonicus added. Regarding the sensory evaluation, the sample with 75% O. japonicus added was perceived to have the best color, flavor, O. japonicus flavor, chewiness, and overall preference.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.126-126
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• 2003

Performance of a laboratory scale closed seawater recirculating aquaculture system was evaluated. Twenty-kg Korean rockfish (130 fish) with an average body weight of 153.8 g was stocked. Over 107-day culture period, fish reached final density of 51.7 kg/m$^3$ (initial density, 33.3 kg/m$^3$) on the culture tank volume basis. On a daily basis, water addition was 3.4% of the total water volume in the system. Total ammonia nitrogen (TAN)concentrations were below 1 mg/L and nitrite nitrogen (NO$_2$-N) concentrations were within the range of 1-3 mg/L on most sampling days. TAN was removedin bead and sand filters and it was removed or produced in the sedimentation basin. Basically, NO$_2$-N was removed in the bead and sand filters while it was either removed or produced in the sedimentation basin. Nitrate nitrogen (NO$_3$-N) was produced in the bead filters and removed in the sand filter and sedimentation basin. Foam fractionator performed well in the recirculating system. The maximal daily removal values for total suspended solids (TSS) and protein were 10,9 g and 1.4 g, respectively. Whole water quality parameters were within the levels commonly recommendedfor fish culture on most of the sampling days. However, further studies are needed to evaluate the commercial feasibility of this system because of the small-scale system used in present experiment. At least, present study still provides some basic information for further studies of this kind of system.

• Ocean and Polar Research
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• v.25 no.4
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• pp.493-501
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• 2003

Performance of a laboratory scale closed seawater recirculating aquaculture system was evaluated. Twenty-kg of korean rockfish (130 fish) with an average body weight of 153.8g was stocked. Over a 107-day culture period, fish reached final density of $51.7kg/m^3$ (initial density, $33.3kg/m^3$) on the basis of the culture tank volume. On a daily basis, added water amounted to 3.4% of the total water volume in the system. Total ammonia nitrogen (TAN) concentrations were below 1mg/l and nitrite nitrogen $(NO_2-N)$ concentrations were within the range of 1-3mg/l on most sampling days. TAN was removed from bead and sand filters and it was removed or produced in the sedimentation basin. Basically, $NO_2-N$ was removed in the bead and sand filters, while it was either removed or produced in the sedimentation basin. Nitrate nitrogen $(NO_3-N)$ was produced in the bead filters and removed from the sand filter and sedimentation basin. The foam fractionator performed well in the recirculating system. The maximal daily removal values for total suspended solids (755) and protein were 10.9g and 1.4g, respectively. Whole water quality parameters were within the levels commonly recommended for fish culture on most of the sampling days. However, further studies are needed to evaluate the commercial feasibility of this system because of the smallscale system used in present experiment. At least, the present study still provides some basic information for further studies of this kind of system.

• Fisheries and Aquatic Sciences
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• v.6 no.4
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• pp.187-193
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• 2003

The performance of a foam fractionator to remove TAN, $NO_2,\;NO_3$, TSS, protein, and $PO_4-P$ at different superficial air velocities and foam overflow heights was evaluated in a lab-scale seawater recirculating system for culture of Korean rockfish (Sebastes schlegeli). The foam overflow rates increased with the increase of superficial air velocities, but decreased with the increase of foam overflow heights. Concentrations of all the water quality variables in the foam condensates increased with the increase of foam overflow height, but decreased with the increase of superficial air velocities. TSS, protein, and phosphate enrichment factors were within the range of 6.4-39.4, 1.6-7.3 and 1.2-3.9, respectively. Low values of TAN, $NO_2,\;and\;NO_3$ enrichment factors were obtained and they indicate that foam fractionation is rot an effective way to remove dissolved inorganic nitrogen. The calculated maximum daily removal values for TSS and protein were 10.9 and 1.4g, respectively.

• KSBB Journal
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• v.10 no.4
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• pp.421-427
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• 1995

A fungal strain, designated Aspevgillus sp. JS-42, was isolated and shown to produce an extracellular polysaccharide used as a bioflocsulant. The optimal medium composition for the production of flocculant with Aspergillus sp. JS-42 was glucose 3.0%, yeast extract 0.2%, $(NH_4)_2S0_4 0.1%, CaCI_2.2H_2 0.05%$ in distilled water. The optimum culture temperature and optimum culture pH for the production of the flocculant were $25^{\circ}C$ and pH 7.0, respectively. The highest production of flocculant was observed after 90 hours of cultivation at the optimal condition. The flocculant could efficiently flocculaled the tested solids suspended in aqueous solution and was stable at high temperature($100^{\circ}C$) and to pH range of from 2 to 10. The flocculant seems to be a kind of high viscous polysaccharide.

• Journal of Korea Water Resources Association
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• v.32 no.4
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• pp.501-510
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• 1999

Stream and groundwater qualities of small agricultural watershed in Kangwon Probince, Korea were monitored 1 to 2 years, and the relationships between stream and groundwater qualities and seasonal water quality changes analyzed. Flooded paddy fields influenced groundwater level and quality during rice culture. The differences between groundwater levels during rice culture and non-culture spans were between 0.8 and 2.91 m. Seasonal changes of total nitrogen and nitrate nitrogen concentrations of stream and groundwater were very similar and groundwater quality was thought to have a profound impact on stream quality of the research watersheds. Suspended solids and BOD maintained the first degree stream water quality throughout the monitoring period except for a few and short flooding spans. The concentrations of total phosphorus and total bacteria of both waters showed wide variations and any seasonal trends were not observed. Long-term monitoring studies on small rural watersheds were recommended to understand the pattern of both stream and groundwater quality changes with respect to land use, season and cultural practice, and to apply the results to develop effective water quality management policies for large river and domestic water supply systems.

• The Korean Journal of Mycology
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• v.36 no.1
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• pp.45-50
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• 2008

This study was carried out to investigate the promoting effect of wood flour on the mycelial growth of Lentinus lepideus and Lentinus edodes. To determine the optimal culture condition, we first examined the tissue origin of pine flour (Pinus densiflora) including needle, bark, root and xylem. Only the xylem-derived flour increased mycelial growth compared to no treatment control. The addition of the xylem flour (5 g/l) showed the highest increase and the glucose level in the basal medium was best at 10 g/l. The smaller particle size of the xylem flour showed the positive effect on mycelial growth; two-fold increase when supplemented with flour of which particle size is less than $106\;{\mu}m$ in diameter compared to $425\;{\mu}m$. The addition of the xylem flour continuously increased the mycelial production for 25 days while mycelia stopped growing within 15 days without the xylem flour. In addition, when woody flour obtained from the different tree species was applied to L. edodes mycelial culture, all treatments accelerated mycelial production compared to the control. Based on all results described above, we conclude that the supplementation of woody flour to culture medium may be an another promising way to increase mycelial production of economically important fungi.

• Food Science and Preservation
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• v.22 no.5
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• pp.768-777
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• 2015

Persimmon contains high levels of vitamins and phenolic compounds, as well as soluble solids, necessary for the fermentation of persimmon wine. Co-fermentation of persimmon wine was carried out using a mixed culture of Pichia anomala JK04, a Korean indigenous yeast that improves wine quality and flavor, and Saccharomyces cerevisiae Fermivin, an industrial wine yeast, in the following ratios: 9:1 (v/v), 5:5 (v/v), 1:9 (v/v) and 0:10 (v/v). During fermentation, the alcohol contents increased more slowly in samples of mixed culture than in samples of the single culture of S. cerevisiae Fermivin. The alcohol contents of all samples reached 12~13% (v/v) after 15 days. All samples of the mixed culture showed greater variety in flavor and taste than S. cerevisiae Fermivin only. In the sensory evaluation, mixed culture samples had higher scores in terms of flavor and overall preference than the single culture samples. Therefore, P. anomala JK04 is thought to improve the wine flavor of Korean domestic persimmon wine.

• Journal of Bio-Environment Control
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• v.4 no.1
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• pp.68-73
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• 1995

This study was carried out to investigate the effect of the concentration of nutrient solution on growth of tomato(Lrcopersicon esculentum Mill. cv. seokwang) in substrate culture. The substrates used in the experiment were perlite, vermiculite, and peatmoss. Tomato plants were treated with different concentrations of nutrient solution, viz. 0.5, 1.0, 2.0, 3.0, and 5.0mS/cm at seedling stage and transferred to different treatments, 1.0, 2.0, and 3.0mS/cm after transplanting in each substrate. Total fruit number, total yield, marketable fruit number, and marketable yield were much higher at 2.0-3.0mS/cm than at 1.0mS/cm in all three substrate culture. The percentage of malformed fruit was in order of peatmoss>perlite> vermiculite and Vitamin C content was vermiculite> perlite> peatmoss. In all three substrate culture, high marketable yield was shown when tomato plants grew with concentration of 2.0-5.0mS/cm at seedling stage and 2.0-3.0mS/cm after transplanting. The concentrations of nutrient solution after transplanting as well as at seedling stage had a great influence on total yield, marketable yield, and soluble solids. However total and marketable fruit number were considerably affected by the concentrations of nutrient solution after transplanting.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.5
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• pp.790-795
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• 1995

Flocculant-producing microorganisms were isolated from soil samples using kaoline as the flocculating test material. One strain that had high flocculating activity among them was selected and identified as Arcuadendron sp. TS-49. The favorable medium for production of the flocculant was 3% glucose, 0.2% yeast extract, 0.1% $NH_4Cl$, 0.01% $MgSO_4$, and 0.05% $MnSO_4$ in 150ml of T.W. with initial pH 7.0.The optimum culture temperature and pH were $30^{\circ}C$ and pH 7.0, respectively. The flocculant activity was observed most highly after 4 to 5 days of cultivation at the optimum condition and decreased significantly with the lapse of cultivation time. The flocculant was produced constituently and seemed to be degraded for ressimilation during cultivation. The productivity achieved by this system was about ten-fold higher than that of scrrening mediuim. This bioflocculant flocculated all tested solids, including various microorganisms and organic/inorganic compounds. Several qualitative analyses of the bioflocculant showed that it was a kind of glycoprotein containing sugars and protein.