• Composites Research
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• v.33 no.6
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• pp.395-400
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• 2020

In this paper, we manufactured silsesquiaznae (SSQZ)-coated carbon nanotube (CNT) surface heating elements, which allowed stable heating at high temperatures. The prepared composite sheet was confirmed by FE-SEM that the SSQZ fully coated the surface of CNT sheet. Furthermore, it was also confirmed that the silicon carbonitride (SiCN) ceramic formed by heat treatment of 800℃ have no defects found and maintain intact structure. The CNT/SiCN composite sheet was able to achieve higher thermal stability than raw CNT sheets in both nitrogen and air atmosphere. Finally, the CNT/SiCN composite sheet was possible to heat up at a temperature of over 700℃ in the atmosphere, and the re-heating was successfully operated after cooling.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.6
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• pp.862-873
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• 2015

In this study, we investigated the physiochemical properties and biological activities of Gangwon-do endemic Makjang (MJ) products (12 types). The pH levels of all samples were in the range of 4.43 to 5.69, and MJ5 showed the highest pH (5.69). The salinities of all samples ranged from 11.1% to 16.9%. Hunter color values for L (lightness), a (redness), and b (yellowness) ranged from 26.2 to 36.9, 3.9 to 11.5, and 6.5 to 16.6, respectively. The amino nitrogen content of MJ2 was highest, whereas the total content of free amino acids of MJ11 (4,657.7 mg%) was highest. Total fatty acid contents of all samples ranged from 1,598.6 mg% to 2,874.4 mg%, with MJ10 showing the highest fatty acid content. The content of total polyphenolic compounds ranged from 401.48 to $746.67{\mu}g$ tannic acid equivalent/mL, with MJ11 showing the highest content. The 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiozoline-6-sulfonic acid) radical scavenging effects of MJ11, MJ8, and MJ4 were 51.30% and 82.5%, 41.29% and 67.0%, and 49.88% and 87.7%, respectively. MJ12 showed the strongest growth inhibitory effect on lung cancer A549 cells, whereas MJ5 showed the strongest growth inhibitory effect on AGS gastric cancer cell and MCF-7 breast cancer cell. MJ7 showed greater lipid accumulation inhibitory activity in HepG2 cells than the others. ACE inhibitory activity of MJ11 was the highest among the samples.

• Journal of Life Science
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• v.28 no.9
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• pp.1048-1055
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• 2018

In the current study, comparisons of Oenothera Biennis seed extracts with water, ethanol, methanol, and 70% ethanol in their total polyphenolics contents, anti-oxidant, anti-neurotoxicity, anti-cancer, and immune-modulatory activities were investigated. Compared with other extracts, those concentrations of total phenolics and flavonoids were the highest in MeOH extract (31.90 mg GAE/g and 20.66 mg QE/g). The radical scavenging and reducing power activities were dose-dependently increased by treatment of O. Biennis seed water, EtOH, MeOH, and 70% EtOH extracts. Furthermore, pretreatment of water, EtOH, and MeOH extracts significantly reduced glutamate-induced cytotoxicity in HT22 hipocampal neuron cells. In the case of cancer cells, MeOH extracts showed lower $IC_{50}$ values in HepG2 ($74.21{\mu}g/ml$), A549 ($188.24{\mu}g/ml$), MCF-7 ($186.42{\mu}g/ml$), and B16 ($101.80{\mu}g/ml$) than other extracts, where those water ($101.96{\mu}g/ml$) and EtOH ($788.39{\mu}g/ml$) extracts showed the lowest $IC_{50}$ activity in HT-29 and PC-3 cells, respectively. O. Biennis seed extracts did not show any cytotoxicity in RAW 264.7 macrophages at the concentration of $1-10{\mu}g/ml$, whereas 70% EtOH extract dose-dependently enhanced nitric oxide (NO) production in RAW 264.7 cells. Overall, we evaluated that various bioactive potentials of O. Biennis seed extracts which would relate with phenolic compounds abundance, thus these can be useful to future developments as functional food ingredients and natural medicines.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.1
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• pp.41-51
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• 1987

This study was carried out to prepare powdered smoked-dried mackerel which can be used as a soup base, and to examine storage stability and the taste compounds of Products. Raw mackerel are filleted, toiled for 10 minutes and pressed to remove lipids, and then soaked in extract solution of skipjack meat. This soaked mackerel are smoked 3 times to $10-12\%$ moisture content at $80^{\circ}C$ for 8 hours. And the smoked-dried mackerel were pulverized to 50 mesh. Finally, the powdered smoked-dried mackerel were packed in a laminated film $bag(PET/Al\;foil/CPP:\;5{\mu}m/15{\mu}m/70{\mu}m,\;15\times17cm)$ with air(product C), nitrogen(product N) and oxygen absorber(product O), and then stored at room temperature for 100 days. The moisture and crude lipid content of powdered smoked-dried mackerel was $11.3-12.3\%,\;12\%$, respectively, and water activity is 0.52-0.56. And these values showed little changes during storage. The pH, VBN and amino nitrogen content increased slowly during storage. Hydrophilic and lipophilic brown pigment formation showed a tendency of increase in product(C) and showed little change in product(N) and (O). The TBA value, peroxide value and carbonyl value of product(N) and (O) were lower than those of product (C). The major fatty acids of products were 16:0, 18:1, 22:6, 18:0 and 20:5, and polyenoic acids decreased, while saturated and monoenoic acids increased during processing and storage of products. The IMP content in products were 420.2-454.2 mg/100 g and decreased slightly with storage period. And major non-volatile organic acids in products were lactic acid, succinic acid and $\alpha-ketoglutaric$ acid. In free amino acids and related compounds, major ones are histidine, alanine, hydroxyproline, lysine, glutamic acid and anserine, which occupied $80.8\%$ of total free amino acids. The taste compounds of powdered smoked-dried mackerel were free amino acids and related compounds (1,279.4 mg/100 g), non-volatile organic acids(948.1 mg/100 g), nucleotides and their related compounds (672.8 mg/100 g), total creatinine(430.4 ntg/100 g), tetaine(86.6 mg/100 g) and small amount of TMAO. The extraction condition of powdered smoked-dried mackerel in preparing soup stock is appropriate at $100^{\circ}C$ for 1 minute. Judging from the results of taste and sensory evaluation, it is concluded that the powdered smoked-dried mackerel can be used as natural flavoring substance in preparing soups and broth.

• Journal of the East Asian Society of Dietary Life
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• v.23 no.6
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• pp.810-817
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• 2013

Cheonggukjang that was prepared with different concentrations of sea mustard [0% (control), 5% (SM5), 10% (SM10) and 15% (SM15)] were investigated. The pH of cheonggukjangs prepared with sea mustard was higher than that of control during fermentation for 72 hrs at $37^{\circ}C$. The total aerobes of the cheonggukjang variants reached 9.40 (control), 9.45 (SM5), 9.59 (SM10) and 9.59 (SM15) log CFU/g after fermentation for 72 hrs at $37^{\circ}C$. The amino nitrogen and viscocus substance contents of the cheonggukjang variants increased with fermentation time, SM5 showed the highest amino nitrogen content ($397.13{\mu}g/mL$) and viscocus substance content (6.53%) among various cheonggukjang after 72 hrs fermentation. The total polyphenol contents of various cheonggukjangs were increased with the sea mustard increased. The DPPH radical scavenging ability of the cheonggukjang variants were 68.09% (control), 77.91% (SM5), 80.72% (SM10) and 79.40% (SM15) and their ABTS radical scavenging ability were 86.66% (control), 89.01% (SM5), 91.32% (SM10) and 92.27% (SM15) after fermentation for 72 hrs. The sensory characteristics of the cheonggukjangs prepared with sea mustard showed higher than control in taste, flavor and overall acceptability but did not significantly differ.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.3
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• pp.363-368
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• 2013

The nutrients and antioxidative activities of fruits and leaves from Metasequoia glyptostroboides were investigated to provide basic data for the future development of functional foods. The nitrogen-free extract contents of fruit and leaves were 69.04% and 50.47%, respectively. Total phenolic content was higher in leaves (21.75 mg/GAE g) compared to the fruit (19.95 mg/GAE g). The mineral components of fruit and leaves mainly consisted of calcium (2,136.08 and 304.85 mg/100 g, respectively), potassium (1,355.53 and 1,144.04 mg/100 g, respectively), and phosphorous (426.30 and 350.50 mg/100 g, respectively). In terms of amino acid composition, aspartic acid, glutamic acid, proline, and leucine were relatively high, but methionine and cystine were low. The hot water extract from leaves was a more potent free radical-scavenger and had higher reducing activities than extracts from fruit. Thus, phenolics of M. glyptostroboides leaves can be utilized as an effective functional food substance for its natural antioxidant properties.

• Korean Journal of Food Science and Technology
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• v.39 no.5
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• pp.515-520
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• 2007

To establish the roasting conditions of dandelion leaves for the manufacture of processed foods such as beverages and tea, we investigated the physicochemical and sensory characteristics of dandelion leaves and their hot water extracts by roasting treatment. As the number of roasting times increased, the free sugar content of the roasted dandelion leaves decreased, and in particular, free amino acid and total polyphenol content decreased greatly after only 1 roasting treatment. The amino nitrogen and total polyphenol contents of the roasted dandelion leaf hot water extracts also decreased greatly, and their L-, a-, and b-values showed much lower values than those of the raw leaf extracts. However, a greater amount of reducing sugars was extracted in the roasted leaves than in the raw leaves, suggesting that the roasting process allows for easier extraction of the compounds in dandelion leaves. Five sensory characteristics, including astringent taste, bitter taste, peen flavor, burnt taste, and sweet odor, were deduced through quantitative descriptive analysis of the hot water extracts. Among them, astringent taste, bitter taste, and green flavor showed significant differences between roasting treatments. The sensory evaluation results show that as the number of roasting times increased, the palatability of the hot water extracts increased greatly, in terms of color and taste.

• Microbiology and Biotechnology Letters
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• v.31 no.3
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• pp.250-256
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• 2003

Lactic acid bacteria with amylolytic and acid producing activities can ferment starch directly to lactic acid thereby producing a monomer for the production of biodegradable poly lactic acid (PLA). In this study, the strain producing L-lactic acid from soluble starch was isolated from Nuruk. The isolated strain was identified as Enterococcus sp. through its morphological, cultural, biochemical characteristics as well as the 16S rDNA sequence analysis, and named Enterococcus sp. JA-27. Enterococcus sp. JA-27 produced exclusively L-lactic acid from soluble starch as a carbon source. The optimal conditions for the maximum production of L-lactic acid from Enterococcus sp. JA-27 were 30 C, pH 8, 1.5 % soluble starch as a substrate and 3.5 % tryptone as a nitrogen source, 0.1 % $K_2$$HPO_4$, 0.04 % $MgSO_4$. $7H_2$O, 0.014 % $MnSO_4$$.$4$H_2O$, 0.004% $FeSO_4$$.$$7H_2$O. Batch and fed batch culture were carried out and the former was more effective. L-Lactic acid production in the optimum medium was significantly increased in a 7 L jar fermenter, where the maximum L-lactic acid concentration was 3 g/L. For the purification of lactic acid in fermented broth, two stage ionexchange column chromatographies were employed and finally identified by HPLC.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.1
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• pp.1-6
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• 2006

Biological nutrient removal(BNR) process used in this study, which was packed with EPS(expanded polystylene) media, has more many advantages in aspect of reducing hydraulic retention time(HRT) of the process and having less effect of temperature in the winter season than commercial process in the present. Bench-scale study was performed using domestic wastewater. In the results, it was observed that the T-N removal efficiencies in HRT 6 hr and HRT 4 hr were 55% and 51%, respectively, showing the small reduction (about 4%) of T-N removal efficiency according to shortening of HRT. In comparison of T-N removal characteristic in summer and winter seasons, it showed that T-N removal efficiencies in summer and winter seasons were 65% and 54%, respectively, showing the 11% lower T-N removal efficiency in winter season than in summer season due to deterioration of nitrification in winter season. In the studies of influent loading rate and C/N ratio, the process showed stable effluent quality under the condition of broad influent loading rate and C/N ratio. Therefore, it is anticipated that the developed process in this study could be applicable to small wastewater treatment plant in nutrient removal.

• Membrane Journal
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• v.20 no.2
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• pp.142-150
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• 2010

A series of anion exchange composite membranes were prepared and characterized for electrodialysis processes used in the removal of nitrate nitrogen and ions in groundwater. The membranes were prepared as follows; first, fabric substrates were fully impregnated with monomer mixtures of vinylbenzylchloride (VBC), divinylbenzene (DVB), Styrene (ST) and $\alpha,\alpha$-Azobis(isobutyronitrile) (AIBN). Second, they were thermally polymerized to yield crosslinked poly (VBCST- DVB)/fabric composite membranes. Finally, the membranes were treated with trimethylamine (TMA) / acetone to give $-N^+(CH_3)_3^-$-containing poly(VBC-ST-DVB)/fabric membranes. The basic membrane properties such as ion exchange capacity (IEC), electric resistance and water content of the resulting membranes were measured as a function of VBC/DVB and TMA/Acetone content. As a result, the composite membranes showed lower electric resistance and higher IEC than commercial anion exchange membranes (AMX, Astom). Electrodialysis tests using the prepared membranes were carried out for the removal of various ions such as $NaNO_3$, $MgSO_4$ and NaF for 60 minutes. The results showed that the ions were removed below 1 mg/L within about 15 minutes which indicates that the anion exchange membranes prepared here could be applied to the electrodialysis process. as can be seen in the following that the ion conductivity values were almost no change after 15 minutes electrodialysis.