• Korean Journal of Ecology and Environment
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• v.47 no.2
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• pp.71-81
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• 2014

A survey was carried out to understand the influence of hydrology on the composition, abundance and adaptive strategies of phytoplankton in artificial Lake Hwaseong, an estuarine reservoir with seawater exchange through a sluice. Samples were collected seven times from May to October 2012. Hydrological events (seawater exchange, rainfall) resulted in a wide variation in salinity along with nutrients and turbidity. Shifts in the dominant phytoplankton composition occurred on every survey. Chlorophyll-a ranged from 9.7 to $104.1{\mu}g\;L^{-1}$. Multivariate analysis allowed us to identify the four phases on phytoplankton community change. Phase I (May~June) was characterized by small-sized Gymnodinium sp. and Heterosigma akashiwo dominated in warm temperature and high salinity derived from seawater exchange, and followed by Cylindrotheca closterium blooms due to rainfall and winds during phase II (July and September). During phase III (August), the dominance of Oscillatoria spp. was correlated with high temperature and low salinity. Abundant cryptomonads were associated with lower temperature during phase IV (October). Adaptive strategies were identified in the phytoplankton as morphological and physiological characteristics. These strategies identified small-sized flagellates as CR-strategists, fast-growing opportunistic species, which might favor the weak stratification of lake due to the seawater exchange during phase I and IV. Dominant species during phase II and III were characterized with R-strategists, medium-sized stress-tolerant species, which might favor turbulence by river flow. The results indicate that stronger stratification following the termination of seawater exchange for the freshening might intensify the predominance of smaller flagellates. In conclusion, this study suggests that hydrology may drive phytoplankton community change and blooms through the controls of salinity, turbulence and nutrients.

• Korean journal of food and cookery science
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• v.22 no.3 s.93
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• pp.307-313
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• 2006

Tofu was prepared with various herbs (green tea, rosemary, lavender and thyme) and the tofu quality was investigated during storage. In the measurement of tofu color, the L and b values increased during storage period. Especially, the b value was very high at 8 days after storage. The pH value of tofu increased until 6 days of storage, but then decreased. The turbidity gradually increased until 6 days of storage and rapidly increased at 8 days of storage. The microorganism count of herb tofu was lower an that of control tofu during storage. Especially green tea tofu showed the lowest psychrotrophic microorganism count as $1.3{\times}10^8\;CFU/g$. In addition, lavender tofu showed the lowest aerobic mesophilic microorganism count $(2.0{\times}10^7\;CFU/g)$ at 8 days of storage. In texture analysis, hardness and chewiness of herb tofu increased with increasing storage period. Springiness increased to 2 or 4 days of storage but decreased after 6 or 8 days. Therefore, herb tofu is expected to have good quality physiologically as well as microbiologically.

• Korean Journal of Ecology and Environment
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• v.34 no.4 s.96
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• pp.327-336
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• 2001

Physical, chemical, and biological parameters were measured during the period from July 1993 to August 1994 near the Munui intake tower of Taechung Reservoir to evaluate effects of nutrients and suspended solids on algal chlorophyll-a and water clarity. Large amounts of precipitation during summer 1993 produced minimum conductivity ($88\;{\mu}S/cm$), minimum TN : TP (<40), and maximum total phosphorus (TP;$59\;{\mu}g/L$) and resulted in a chlorophyll-a peak ($79\;{\mu}g/L$) and minimum transparency (<1.5 m) among the seasons. At the same time, ratios of volatile suspended solids (VSS): non-volatile suspended solids (NVSS) were maximum (13.0),indicating that the reduced transparency was mainly attributed to biogenic turbidity in relation to phytoplankton growth. In contrast, severe drought in summer 1994 resulted in greater conductivity (>$120\;{\mu}S/cm$), water clarity (%gt;2 m), and lower TP and chlorophyll- a (<$10\;{\mu}g/L$) relative to those of summer 1993. Total phosphorus ($R^2=0.46$, n=59) accounted more variations of chlorophyll- a compared to total nitrogen ($R^2=0,29$, n=59). The mass ratios of TN : TP ranged from 39 to 222 and were strongly correlated with TP (r = -0.80) but not with concentrations of TN (r = 0.05). Ambient nutrient concentrations and TN : TP mass ratios indicated that seasonality of chlorophyll- a was likely determined by concentrations of phosphorus reflected by the distribution of rainfall. It was concluded that reductions of phosphorus during heavy rainfall may provide better water quality for the drinking water in the intake tower.

• Korean Journal of Poultry Science
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• v.34 no.2
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• pp.111-117
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• 2007

This experiment was conducted to research the effects of Yellow Clay(YC) on the sensory evaluation of cooked meat in broiler chicks. A total of 216 one day old broiler chicks were divided into 6 groups at random. The six groups are consisted of one control group, to which no YC was added, and 5 groups to which an amount of YC was differently added. Diets contained 0.5, 1.0, 2.0, 4.0 and 8.0% of YC and fed to the 5 group broilers for 6 weeks. The lightness of meat in the broilers treated with YC was significantly higher than that of the control group in after-cooking(P<0.05). Besides, the lightness of meat was higher after-cooking than before-cooking. The properties of hardness, gumminess and chewiness were significantly lowered in the groups treated with Yellow Clay, as the amount of Yellow Clay increased at before-cooking and after-cooking(P<0.05). The turbidity of stock was higher in the groups treated with Yellow Clay as the percentage level of Yellow Clay increased, compared with the control group(P<0.05). The acceptability of color, flavor, and texture of meat and stock was higher in the groups treated with Yellow Clay, when compared with that of the control group(P<0.05). In total, the group treated with the 4 percentage of Yellow Clay was the highest in the overall preference(P<0.05).

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.2
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• pp.3-6
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• 2012

Purpose : Samsung medical ceter shall find a cause of the interference factor and suggest a solution for it. Materials and Methods : A sample of $^{18}F$-FDG, radioactive pharmaceuticals produced by TRACERlab MX and FASTlab synthesizer. Gel-clot method uses Positive control tube and single test tube. Kinetic chromogenic method uses ENDOSAFE-PTS produced by Charles River. Results : According to Gel clot method of Endotoxin Tests at FASTlab, both turbidity and viscosity increased at 40-fold dilution and Gel clot was detected. In case of TRACERlab MX, Gel clot was detected in most of samples but intermittently not in a few of them. When using ENDOSAFE-PTS, sample CV (Coefficient of Variation) of FASTlab is 0% at all dilution rates whereas spike CV is 0% at 1-fold dilution, 0~35% at 10-fold, 3.6~12.9% at 20-fold, 5.2~7.1% at 30-fold, 1.1~17.4% at 40-fold, spike recovery; 0% at one-fold, 25 ~ 58% at 10-fold, 50 ~ 86% at 20-fold, 70~92% at 30-fold, and 75~120% at 40-fold. Sample CV of TRACERlab MX, is 0% at all dilution rates whereas spike CV is 1.4~4.8% at one-fold dilution, 0.6~19.9% at 10-fold, spike recovery; 35~72% at one-fold dilution and 77~107% at 10-fold. Conclusion : Gel clot does not seem to occur probably to H3PO4 which engages in bonding with Mg2+ion contributing gelation inside PCT. Dilution which is identical to reducing the amount of H3PO4, could remove interfering effects accordingly. Spike recovery was obtained within 70~150% - recommended values of supplier - at 40-fold dilution even in kinetic chromogenic method.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.2
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• pp.45-58
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• 2012

For the development of reference values and evaluation of water quality in various environmental conditions, we divided the coastal region around Korean peninsular into 5 distinctive ecological regions based on the influence of surface current, depth, tidal range, turbidity, and climate condition. We used national marine environment monitoring data collected by National Fisheries Research & Development Institute(NFRDI) from 2000-2009. For the reference values, we used maximum seasonal mean from 2000 to 2007 for DIN, DIP, and chlorophyll-a and minimum seasonal mean for secchi depth measured at stations without the influence of river runoff in each ecological regions. For the reference value of bottom dissolved oxygen saturation, we used minimum mean value of 90% calculated from minimal riverine influence stations of whole regions. We calculated enrichment score for each assessment criteria. The enrichment score of DIN, DIP, and Chlorophyll-a was 1 (=< reference value), 2 (< 110% of reference value), 3 (< 125% of reference value), 4 (< 150% of reference value), and 5 (> 150% of reference value). The enrichment score of DO saturation and Secchi depth was 1 (> reference value), 2 (> 90% of reference value), 3 (>75 % of reference value), 4 (> 50% of reference value), and 5 (< 50% of reference value). We calculated water quality index using weighted linear combination of five enrichment score for the comparison of whole regions. From the water quality index distribution calculated from all stations between 2000 and 2007 period, we classified into 5 grade based on the standard deviation calculated from total water quality index. We assigned grade very good(I), good(II), moderate(III), bad(IV), and very bad(V) when the water quality index was less than 23, minimum + 1 sd, +2 sd, +3 sd, and grater than minium+ 3 sd, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1171-1178
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• 2010

This study was carried out to compare the physicochemical characteristics of vinegars fermented from cereal crops with Incalgyun. The crude protein, mineral and $P_2O_5$ contents of vinegars fermented from cereal crops with Incalgyun were higher than the circulated brown rice vinegar (CBRV). Brix degree, turbidity and pH of vinegar fermented from cereal crops with Incalgyun were higher, and total acidity was lower than the CBRV. The glucose content of the CBRV was 4.89 mg/mL, and vinegars fermented from glutinous foxtail millet without and with Incalgyun were 5.62 and 5.58 mg/mL. The major organic acids were acetic acid and succinic acid. The total organic acid content of the CBRV was 41.92 mg/mL, and vinegars fermented from cereal crops without and with Incalgyun were 12.14~42.31 and 13.07~41.80 mg/mL. Total amino acid content of the CBRV was $63.75\;{\mu}g/mL$, and vinegars fermented from cereal crops without and with Incalgyun were 1,125.24~1,976.37 and $1,045.36{\sim}2,057.34\;{\mu}g/mL$. The total polyphenol content of CBRV was 2.31 mg/100 mL, and vinegars fermented from cereal crops without and with Incalgyun were 28.59~41.26 and 26.57~39.62 mg/100 mL. The ABTS and DPPH radical scavenging activities of the CBRV were 1.45 and 2.85 mg TEAC/100 mL. The highest ABTS and DPPH radical scavenging activities were 37.10 and 20.26 mg TEAC/100 mL at the vinegars fermented from nonglutinous foxtail millet and glutinous foxtail millet with Incalgyun, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.2
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• pp.301-307
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• 2010

This study evaluates quality of Nuruk, which is a source material of Takju, collected in Daegu and Gyeongbuk and investigates fermentation characteristics of Takju made of it. Totally 7 types of Nuruk were examined and their pH and titratable acidity were 5.4~5.9 and around 0.1%, respectively. Saccharifying activity was high in D, F, G, A and E Nuruk by recording over 300 mg%. Lactic acid bacteria count was the highest in G Nuruk with $3.78\times10^8$ and yeast and total microbe count recorded the highest levels, $3.78\times10^8$ and $3.47\times10^8$, respectively in B Nuruk. When quality characteristics of Takju made of each type of Nuruk were compared, alcohol content was the highest in G Nuruk by recording 19.0% and titratable acidity was 0.44~0.86% in all samples. Hunter's color, brown color and turbidity showed different levels according to types of Nuruk and all lactic acid bacteria, yeast and total microbe counts were the highest in A and E Nuruk. For alcohol components, E and G Nuruk showed high fusel oil content levels and methanol and fusel oil contents of all samples were suitable as standards, respectively. The total organic acid content was the highest in B Nuruk at about 4,000 mg% and it was 2,000 mg% and around 1,000 mg% in A, E, F and G Nuruk and C and D Nuruk, respectively. The content of total free amino acid was the highest in B Nuruk at 3,676 mg% and it was observed to be 1,890, 1,676 and 1,531 mg% in G, E and C Nuruk in that order, respectively. Sensory preference of subjects in their 20s was high overall in G and C Nuruk and that of those in their 40s was high in F and C Nuruk. From all of these results, the types of Nuruk largely affected quality and components of Takju and an appropriate method to consider useful purpose is needed.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.11
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• pp.1523-1528
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• 2008

This study was carried out to compare the physicochemical characteristics and sensory quality of Sikhye (a Korean traditional rice beverage) prepared with specialty rice varieties. The results showed that Ilpum had higher hulling recovery, milled/brown rice ratio, and milling recovery than Sulgaeng, Baegjinju, Baegjinju 1, and Dongjinchal. The alkali digestive value, protein content, and amylose contents of Sulgaeng were 6.3, 7.3% and 19.3%, respectively. The highest brix degree was $10.00^{\circ}Bx$ in Baegjinju Sikhye. The turbidity appeared at 0.4440, 0.4100, 0.3828, 0.3372, 0.1414 in Ilpum, Baegjinju, Baegjinju 1, Sulgaeng, and Dongjinchal Sikhye, respectively. There were no significant differences in pH and maltose contents among the groups. The highest L-value was 44.62 in Ilpum Sikhye. The a-value and b-value were $-1.66{\sim}-0.70$ and $-9.18{\sim}-5.19$, respectively. Finally, the sensory evaluation results indicated that there were no significant differences in appearance, aroma, and taste between the groups, and the Sulgaeng Sikhye showed higher overall quality than the Dongjinchal Sikhye as the control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.2
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• pp.199-204
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• 2006

This study was conducted to investigate the quality characteristics of noodles prepared with the addition of nanofiltered (NF) powder of sunmul. Noodles were prepared with different levels $(0\%,\;1.5\%,\;3\%\;and\;5\%,\;w/w)$ of NF powder and physico-chemical properties were examined. Results of rapid visco analyzer showed that peak, trough, final viscosity and set back decreased as the NF powder level increased. The weight and volume of cooked noodles increased with the addition of NF powder. Turbidity of soup also increased as the amount of NF powder increased, indicating higher cooking loss. The color of wet and cooked noodles became greenish yellow as the NF powder level increased. Hardness, springiness, gumminess and brittleness of cooked noodles decreased with the increasing amount of NF powder. Results of sensory evaluation showed that noodles prepared with up to $3\%$ addition of NF powder was considered to be as acceptable as noodles prepared without NF powder.