• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.7
• /
• pp.859-865
• /
• 2007

The chemical components and antioxidative activity of Korean gold kiwifruit were investigated. The values of pH, soluble solid and total acidity were 4.43${\pm}$0.16, 17.01${\pm}$0.04$^{\circ}Brix$, and 0.082${\pm}$0.02%, respectively. Hunter L, a, and b values were 49.80${\pm}$0.24, -6.79${\pm}$0.02, and 19.72${\pm}$0.18 value, respectively. Proximate compositions were as follows; moisture 78.62${\pm}$2.26%, crude protein 1.34${\pm}$0.25%, crude lipid 0.70${\pm}$0.06%, crude fiber 1.99${\pm}$0.13%, crude ash 0.99${\pm}$0.26%, and carbohydrate 16.36${\pm}$1.23%, respectively. Mineral elements were K 265.86${\pm}$5.00, P 71.82${\pm}$29.18, and Ca 23.84${\pm}$2.10 mg%, respectively. Free sugar compositions were sucrose (1.04${\pm}$0.18%), glucose (2.17${\pm}$0.21%) and fructose (1.86${\pm}$0.11%). Amino acid contents of Korean gold kiwifruit was very rich in glutamic acid 86.51 ${\pm}$5.58 mg/100 g and deficient in tyrosine 15.00${\pm}$4.91 mg/100 g. Organic acid compositions were quinic acid (6.65${\pm}$0.21 mg/g), malic acid (1.62${\pm}$0.13 mg/g) and citric acid (4.82${\pm}$0.21 mg/g). Contents of ascorbic acid and total phenols were 0.27${\pm}$0.06 mg/g and 0.047${\pm}$0.002 mg/g, respectively. The DPPH radical scavenging activity and reducing power of the water extract from Korean gold kiwifruit was 86.87% and 1.96 at a concentration of 25 mg/mL. The water extract showed considerable antioxidative activity against linoleic acid autoxidation in a dose-dependent manner.

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

• Journal of Food Hygiene and Safety
• /
• v.23 no.2
• /
• pp.98-107
• /
• 2008

The ozone has the oxidizing power which is powerful the fluorine and the antimicrobial spectrum of wide scope. Researches were carried out to use the merits that ozone has in various fields including the food industry, and many studies are also conducted nowadays for more efficient use of ozone. The ozone was permitted legally as a food additive and was practically used in the United States, Australia, Japanese etc. In November 2007, ozone water was permitted as a food additive in Korea and the interest in the use of ozone water has been on the rise in the Korea's food industry. As a olisinfectant method, ozone has many advantages. The maintenance and management expenses of ozone are lower than the installation cost at early stages and no by-products are generated after use it compared to others. Recently the demand of ozone as a olisinfectant method is increasing drastically. Although ozone water is popularly used to sterilize raw foods like fruits, vegetables and meats, the cases are still limited and were verified by the survey results. However, the use of ozone water is gradually being increased and is focused on food services. Ozone water refers to a state where ozone is dissolved into water to more conveniently use ozone. Accordingly, ozone water should be managed in regards with the amount and time of water-dissolved ozone, and the control of discharged ozone concentration is required for safe use of ozone water. The items to control mentioned above are directly related to the performance of the devices, and therefore, it is required to newly establish the performance criteria of ozone water manufacturing devices.

• Journal of Radiation Protection and Research
• /
• v.41 no.1
• /
• pp.31-39
• /
• 2016

Background: It is necessary to consider the overall countermeasure for analysis of nuclear activities according to the increase of the nuclear facilities like nuclear power and reprocessing plants in the neighboring countries including China, Taiwan, North Korea, Japan and South Korea. South Korea and comprehensive nuclear-test-ban treaty organization (CTBTO) are now operating the monitoring instruments to detect radionuclides released into the air. It is important to estimate the origin of radionuclides measured using the detection technology as well as the monitoring analysis in aspects of investigation and security of the nuclear activities in neighboring countries. Materials and methods: A three-dimensional forward/backward trajectory model has been developed to estimate the origin of radionuclides for a covert nuclear activity. The developed trajectory model was composed of forward and backward modules to track the particle positions using finite difference method. Results and discussion: A three-dimensional trajectory model was validated using the measured data at Chernobyl accident. The calculated results showed a good agreement by using the high concentration measurements and the locations where was near a release point. The three-dimensional trajectory model had some uncertainty according to the release time, release height and time interval of the trajectory at each release points. An atmospheric dispersion model called long-range accident dose assessment system (LADAS), based on the fields of regards (FOR) technique, was applied to reduce the uncertainties of the trajectory model and to improve the detective technology for estimating the radioisotopes emission area. Conclusion: The detective technology developed in this study can evaluate in release area and origin for covert nuclear activities based on measured radioisotopes at monitoring stations, and it might play critical tool to improve the ability of the nuclear safety field.

• Clean Technology
• /
• v.20 no.4
• /
• pp.375-382
• /
• 2014

This work investigated the plasma-catalytic decomposition of isopropyl alcohol (IPA) and the behavior of the byproduct compounds over monolith-supported metal oxide catalysts. Iron oxide ($Fe_2O_3$) or copper oxide (CuO) was loaded on a monolithic porous ${\alpha}-Al_2O_3$ support, which was placed inside the coaxial electrodes of plasma reactor. The IPA decomposition efficiency itself hardly depended on the presence and type of metal oxides because the rate of plasma-induced decomposition was so fast, but the behavior of byproduct formation was largely affected by them. The concentrations of the unwanted byproducts, including acetone, formaldehyde, acetaldehyde, methane, carbon monoxide, etc., were in order of $Fe_2O_3/{\alpha}-Al_2O_3$ < $CuO/{\alpha}-Al_2O_3$ < ${\alpha}-Al_2O_3$ from low to high. Under the condition (flow rate: $1L\;min^{-1}$; IPA concentration: 5,000 ppm; $O_2$ content: 10%; discharge power: 47 W), the selectivity towards $CO_2$ was about 40, 80 and 95% for ${\alpha}-Al_2O_3$, $CuO/{\alpha}-Al_2O_3$ and $Fe_2O_3/{\alpha}-Al_2O_3$, respectively, indicating that $Fe_2O_3/{\alpha}-Al_2O_3$ is the most effective for plasma-catalytic oxidation of IPA. Unlike plasma-alone processes in which tar-like products formed from volatile organic compounds are deposited, the present plasma-catalyst hybrid system did not exhibit such a phenomenon, thus retaining the original catalytic activity.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.43 no.2
• /
• pp.207-215
• /
• 2014

To investigate the biological benefits of Korean traditional vegetables, anti-oxidative and anti-inflammatory effects of ethanol extracts from blanched and dried sprouts of evening primrose (Oenothera laciniata, OL) and gooseberry (Actinidia arguta, AA) were measured. Total polyphenol and flavonoid contents of OL were higher than those of AA; OL contained 60.4 mg tannic acid/g dry weight and 31.9 mg rutin/g dry weight, while AA contained 33.0 mg tannic acid/g dry weight and 20.3 mg rutin/g dry weight. The $IC_{50}$ value for DPPH radical scavenging activity was $58.2{\mu}g/mL$ for OL ethanol extract and $122.1{\mu}g/mL$ for AA ethanol extract. The reducing power upon $500{\mu}g/mL$ of ethanol extract treatment was as strong as $52.1{\mu}g$ ascorbate eq./mL for OL and $45.3{\mu}g$ ascorbate eq./mL for AA. Regarding anti-inflammatory effects, inhibition rate against 5-lipoxygenase (LOX) and cyclooxygenase (COX)-2 activities were 29.5% and 79.5% for OL, as well as 11.5% and 39.1% for AA, respectively at a concentration of $250{\mu}g/mL$. Lipopolysaccaride ($1{\mu}g/mL$)-treated RAW 264.7 macrophage cells subjected to OL ethanol extract at various concentrations ($0{\sim}25{\mu}g/mL$) showed significantly reduced synthesis of nitrite oxide (NO), prostaglandin (PG) E2, and IL-6 in a dose-dependent manner without cytotoxicity, although TNF-${\alpha}$ synthesis was not affected. In conclusion, both OL and AA sprouts showed strong antioxidative activity, whereas OL showed very strong anti-inflammatory activity via effective reduction of NO, PGE2, and IL-6 synthesis in LPS-activated macrophage cells.

• Korean Chemical Engineering Research
• /
• v.54 no.6
• /
• pp.863-870
• /
• 2016

We investigated the physical/chemical phenomena that a slow loss of $CO_2$ inventory into sodium after the sodium-$CO_2$ boundary failure in printed circuit heat exchangers (PCHEs), which is considered for the supercritical $CO_2$ Brayton cycle power conversion system of a sodium-cooled fast reactor (SFR). The first phenomenon is plugging inside narrow sodium channels by micro cracks and the other one is damage propagation referred to as wastage combined with the corrosion/erosion effect. Experimental results of plugging shows that sodium flow immediately stopped as $CO_2$ was injected through the nozzle at $300{\sim}400^{\circ}C$ in 3 mmID sodium channels, whereas sodium flow stopped about 60 min after $CO_2$ injection in 5 mmID sodium channels. These results imply that if pressure boundary of sodium-$CO_2$ fails a narrow sodium channel would be plugged by reaction products in a short time whereas a relatively wider sodium channel would be plugged with higher concentration of reaction products. Wastage by the erosion effect of $CO_2$ (200~250 bar) hardly occurred regardless of the kinds of materials (stainless steel 316, Inconel 600, and 9Cr-1Mo steel), temperature ($400{\sim}500^{\circ}C$), or the diameter of the $CO_2$ nozzle (0.2~0.8 mm). Velocities at the $CO_2$ nozzle were specified as Mach 0.4~0.7. Our experimental results are expected to be used for determining the design parameters of PCHEs for their safeties.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.3
• /
• pp.366-372
• /
• 2006

This study is to investigate the physicochemical properties of differently pretreated chestnut starches during starch isolation and to examine their gelatinization properties by both heat and alkali treatments. One kind is starch A made by alkali method from peeled chestnut. The other is starch B made from chestnut with the outer layer. The results are as follows. Starch A has higher water binding capacity of 86.9% than starch B with 80.66%. Swelling powers of both starch A and B increased rapidly from $60^{\circ}C\;to\;80^{\circ}C$ in both, and since then it has changed a bit. Both began to show their solubility at $60^{\circ}C$ and increased continuously as the temperature went up. Starch A has higher swelling power and solubility than starch B. In iodine reaction, starch A has higher ${\lambda}max$ and absorbance at ${\lambda}max$ than starch B. X-ray diffraction patterns showed that starch A is type $C_b$ and that starch B is type B. Starch B has higher relative crystallinity of 37.0% than starch A with 36.2%. The results by differential scanning calorimetry revealed that starch A gelatinized from $66.95^{\circ}C$ to $77.5^{\circ}C$ and its enthalpy is 2.04 cal/g. And starch B gelatinized from $67.09^{\circ}C\;to\;77.5^{\circ}C$, and its enthalpy is 2.29 cal/g. Amylograms of chestnut starch at 6.5% concentration indicated that starch B needs higher onset temperature when beginning to gelatinize than starch A does. But starch A shows much higher peak viscosity, breakdown and setback than starch B does. Starch A shows higher viscosity, gel volume, and optical transmittance in gelatinization properties by alkali than starch B does.

• Journal of Korean Society of Environmental Engineers
• /
• v.22 no.2
• /
• pp.265-277
• /
• 2000

Laboratory experiments were conducted to investigate characteristics for removing ammonia-nitrogens by electrolysis methods. A stainless steel plate is used as the cathode and either $IrO_2{\backslash}Ti$ plate serves as the anode. Experiments were conducted to examine the effects of the operating conditions, such as the current density, retention time, electrode gap, $Cl^-/NH_4{^+}-N$ on the $NH_4{^+}-N$ removal efficiency. Possible optimum range for these operating variables are experimentally determined. The $NH_4{^+}-N$ removal efficiencies between plate type anode and net type anode were about same effect, but electrolytic power using net type anode is low than plate type anode. The $Cl^-/NH_4{^+}-N$ ratio was about $20.0kgCl^-/kgNH_4{^+}-N$ when $NH_4{^+}-N$ removal obtained 73 %, $Cl^-/NH_4{^+}-N$ ratio needs $27.6kgCl^-/kgNH_4{^+}-N$ so as to $NH_4{^+}-N$ completely remove. The removal efficiency of $NH_4{^+}-N$ increase with current density, retention time and $Cl^-/NH_4{^+}-N$ ratio, but decreased with increasing electrode gap. The relationship of operating conditions and $NH_4{^+}-N$ removal efficiencies are $$NH_4{^+}-N_{re}(%)=14.5364(Current\;density)^{0.7093}{\times}(HRT)^{1.0060}{\times}(Gap)^{-0.9926}{\times}(Cl^-/NH_4{^+}-N)^{1.0024}$$ With adding COD or/and alkalinity, relationships are $$NH_4{^+}-N_{re}(%)=9.8408(Current\;density)^{0.6232}{\times}(HRT)^{1.0534}$$ There existed a competition between the removals for $NH_4{^+}-N$ and $COD_{Cr}$ during electrolysis, the removal of $NH_4{^+}-N$ was shown to be dominant. $NH_4{^+}-N$ removal was high as addition of glucose and alkalinity.

• Economic and Environmental Geology
• /
• v.28 no.3
• /
• pp.259-269
• /
• 1995

Column leaching tests were conducted using fresh and weathered pulverised fuel ash of some 17 and 40 years old from two major British power plants, with deionised water and simulated synthetic industrial leachate. The former was to see the leaching behaviour of weathered ash and the latter was to see if the formation of secondary products from water and PFA interaction and ameliorating effect in removing metals from industrial leachates. Fresh PFA liberates elevated concentrations of surface-enriched inorganics, including Ca, Na, K, B, $Cr_{total}$, Li Mo, Se and $SO^{2-}_4$. This might indicate their association with the surface of PFA particles. In the column leaching tests using weathered ash and deionised water, elements are not readily leached but are released more slowly, showing relatively constant concentrations. For the case of weathered ash, some readily soluble surface-enriched elements appears to have been liberated in their early stage of leaching and the liberation of glass associated elements are thought to be more important function in controlling the element concentration. The result from column leaching tests exceed for a number of elements when compared with various Water Standards and suggests the leachate from PFA disposal mound needs dilution to achieve target concentrations. PF A shows element retention effect for many elements, including B, Fe, Zn, Hg, Ni, Li and Mo, in the order of fresh Drax ash > weathered Drax ash > Weathered Meaford ash in retaining capacity. Geochemical modelling using a computer program WATEQ4F reveals some solubility controlling secondary solid products. These include $CaSO_4{\cdot}2H_2O$ for Ca, $Al(OH)_3$ for Al and $Fe(OH)_3$ for Fe.