• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1213-1220
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• 2000

The mutagenicity of the thermally oxidized soybean oils was investigated. Each oil sample was taken after 0, 8, 16, 24, 32, 40, and 48 hours of heating at a temperature of $180{\pm}3^{\circ}C$, and was used to study the changes of peroxide value(POV), acid value(AV), iodine value(IV), conjugated dienoic acid content(CDA content, %), and fatty acid composition. Another set of samples was fractionated into non-oxidized and oxidized fractions by column chromatography using silica gel. The mutagenicity of the samples taken from the thermally oxidized oils as well as the non-oxidized and oxidized fractions was investigated with the Ames test. Bacterial tester strains used in the present study were the histidine auxotrophic strains of S. typhimurium TA100, TA1535 and TA 102 for the detection of base pair, and TA98 and TA1537 for frame shift mutations. Each set of samples was dissolved in tetrahydrofuran and tested at doses ranging from 0.05 to 5 mg/plate. The oxidized fractions increased significantly the number of $His^+$ revertant colonies of TA100, TA1537 and TA102, thereby showed mutagenic activity on these strains. However none of the oil samples taken within the 48 hours oxidation period showed any mutagenic activity with and without metabolic activation.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1271-1277
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• 2000

The extracts from tomatoes, apples, carrots, mallows, watercreses+pine needles, Angelica keiskei Koiz, jujubes and lemons were selected and mixed at the ratio of 3 : 3 : 3 : 1/2 : 1/2 : 1/2 : 1/2 : 1/5 on the basis of sensory evaluation. The mixed extracts were divided into three lots and treated as follows. The first lot was heated for 15 sec at $96^{\circ}C$ without centrifugation and filtration, the second filtered through a ultramembrane filter. For the third one, the ultrafiltrate combined with autoclaved retentates on the membrane filter and the previous centrifugal precipitation. The mixed juices were stored in the glass bottles with atmosphere or in film package with nitrogen gas. And then they were stored at $4^{\circ}$ and $20^{\circ}C$. During storage the treated juices showed $pH\;4.07{\sim}4.10$, titratable acidity $66.35{\sim}84.08$, soluble solid $7{\sim}9^{\circ}Brix$, reducing sugar $5.42{\sim}6.97%$, glucose $1.96{\sim}2.30%$ and fructose $3.46{\sim}4.14%$. The ultrafiltered juices showed yellow color, different from orange color of other treatment lots. Peroxidase activity and microbial population were inhibited by thermal treatment and ultrafiltration. The browning effects of the mixed juice of fruits and vegetables during storage were caused by ascorbic acid oxidation and non-enzymatic browning reaction, which could be reduced by change and packing with nitrogen gas instead of atmosphere inside bottles.

• Journal of Life Science
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• v.12 no.1
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• pp.87-95
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• 2002

It was observed that the hot water extract of the leaves of Capsicum annuum L., a Korean edible plant, had a potent anti-complementary activity. Crude polysaccharide fraction(CAL-0) was obtained by methanol reflux, ethanol precipitation, dialysis and lyophilization. CAL-0 contained 51.8% of total sugar, 8.2% of uronic acid and 16.8% of protein, and consisted of mainly arabinose, galactose and glucose as neutral sugars and galacturonic acid as uronic acid. The anti-complementary activity of CAL-0 decreased greatly by periodate oxidation, but was not changed by pronase treatment. Also, the anti-complementary activity of CAL-0 was reduced partially in the absence of the $Ca^{2+}$ ion. The crude polysaccharide CAL-0 was found to activate the C3 component both in the presence and in the absence of $Ca^{2+}$ through the crossed-immunoelectrophoresis suggesting that those involved in both classical and alternative complement pathway CAL-0 was further separated to an unabsorbed fraction(CAL-1) and six absorbed fractions(CAL-2longrightarrowCAL-7) on DEAE Sepharose CL-6B ion exchange column. Among them four major fractions in activity and yield were obtained, and consisted mainly of arabinose, galactose and glucose with various molar ratios. The major fraction, CAL-2, was purified to give a high molecular fraction(CAL-2-I) and a low molecular fraction(CAL-2-II) on Sepharose CL-6B column. The anti-complementary activity of CAL-2-I, a molecular weight of about 61,000, was higher than it of CAL-2-II.-II.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5376-5383
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• 2011

The objective of this study is the development of carbon-recycle technology, that converts carbon dioxide captured from flue gas to carbon monoxide or carbon for reuse in industrial fields. It is difficult to decompose $CO_2$ because $CO_2$ is very stable molecule. And then metal oxide was used as an activation agent or catalyst for the decomposition of $CO_2$ at low temperature. Metal oxides, which converts $CO_2$ to CO or C, were prepared using Ni-ferrite by solid state method and hydrothermal synthesis in this study. TPR/TPO and TGA were used as an analysis method to analyze the decomposition characteristics of $CO_2$. As the results, the reduction area of $H_2$ was high value at 15 wt% of NiO and the decomposition area of $CO_2$ was superior capacity at 5 wt% of NiO. However, TGA data showed contrary results that reduction area of $H_2$ was 28.47wt% and oxidation area by $CO_2$ was 26.95wt% at 2.5 wt% of NiO, one of the Ni-ferrite powders synthesized using solid state method. $CO_2$ decomposition efficiency was 94.66% and it is excellent results in comparison with previous studies.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.9
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• pp.4274-4282
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• 2011

In this study, Fenton reaction was studied for the possibility of applying as advanced treatment and its optimal condition for the removal of refractory organics from the dye wastewater. Fenton reaction was applied to remove refractory organics after the bio-treatment (secondary treatment) inside test laboratory and on-site pilot plant. Wastewater from the secondary treatment was used and its $COD_{Mn}$ was measured as 30~50mg/L. After the Fenton reaction, the optimal condition was found as pH 3~3.5, reaction time 2~2.5hr, chemical input ratio of ($FeCl_2$(33%)/$H_2O_2$(35%)) was 3 : 1. When chemical input ratio of ($FeCl_2$(33%)/$H_2O_2$(35%)) was at its optimal, amount of sludge volume ($SV_{2hr}$) was 21~28%. With pilot plant test, removal rate was heavily influenced by the hydraulic retention time(HRT), and optimum value of HRT was 2.0 hr. When pilot plant($2m^3/d$) was placed on-site and operated continuously, it showed steady and fairly good treatment of COD where COD removal rate was 60~70%, treated water showed below 20mg/L.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.459-463
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• 2017

Hot dip galvanizing in the steel plant is one of the most widely used methods for preventing the corrosion of steel materials including structures, steel sheets, and materials for industrial facilities. While hot dip galvanizing has the advantage of stability and economic feasibility, it has difficulty in repairing equipment and maintaining the facilities due to high-temperature oxidation caused by Zn Fume where molten zinc used in the open spaces. Currently, SM45C (carbon steel plate for mechanical structure, KS standard) is used for the equipment. If a part of the equipment is resistant to high temperature and Zn fume, it is expected to improve equipment life and performance. In this study, the manufactured Ni alloy was tested for its corrosion resistance against Zn fume when it was used in the hot dip galvanizing equipment in the steel plant. Two kinds of materials currently used in the equipment, new Ni alloy and Inconel(typical corrosion-resistant Ni alloy), were selected as the reference groups. Two kinds of molten metal were used to confirm the corrosion of each alloy according to the molten metal. Zn fume was generated by bubbling Ar gas from molten Zn in a furnace($500{\sim}700^{\circ}C$) and the samples were analyzed after 30 days. After 30 days, the specimens were taken out, the oxide layer on the surface was confirmed with an optical microscope and SEM, and the corrosion was confirmed using a potentiodynamic polarization test. Corrosion depends on the type of molten metal.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.7
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• pp.912-918
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• 2006

This study examined the improvement of bread quality with Curcula longa and Glycyorrhiza uralensis extract (CGE). When counted, the viable cell number in bread with 5% of CGE dramatically was decreased by about 1 log cycle as compared to that of bread without CGE. With regard to oxidation, the content of malonaldehyde diminished in breads with increasing amounts of CGE. Breads with 1 and 5% of CGE were shown to have the highest antioxidative effect. The moisture contents of bread with CGE and bread without CGE were not much different during the early storage period. After six days of storage, however, the moisture contents of bread without CGE and bread with 0.5% of CGE decreased about 16%. On the other hand, the moisture contents of bread with 1% and 5% of CGE did not change dramatically. Their moisture content was decreased by only 4% during the same storage period. Although color, lightness and redness gradually diminished with increasing amounts of CGE in bread, conversely yellowness increased. In the sensory evaluation, bread with 0.5% and 1% of CGE scored the highest: 3.66 and 3.67 out of 5, respectively. Bread with 5% of CGE scored the lowest of the various bread tested. From these results, the addition of 1% CGE in bread had a good effect on improvement of preservation and development of quality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.4
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• pp.316-322
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• 1983

In order to obtain elementary data of enzymatic browning of apples and apple products and to examine effectively inhibitory method of browning, we extracted polyphenol oxidase (EC 1.10.3.1) from apple (Ralls Janet) and investigated its general properties. The optimum conditions for the enzyme reaction were pH 6.0 and temperature of $30^{\circ}C$. The enzyme was very stable at pH 4.0, and at the range of pH 5.0-9.0 its activity was above 80% compared with pH 4.0. The enzyme was very stable by heating at $40^{\circ}C$ for 1 hour, and almost 50% of enzyme activity was lost by heating at $60^{\circ}C$ for 30 minutes. The polyphenol oxidase activity was enhanced by the addition of $Cu^{2+}$ and $Mn^{2+}$, respectively, meanwhile $Na^+$, $Hg^{2+}$ and $Co^{2+}$ inhibited the enzyme activity. The enzyme activity was greatly decreased in the presence of inhibitors such as cysteine, sodium metabisulfite and ascorbic acid. The polyphenol oxidase greatly catalyzed the oxidation of o-diphenols such as chlorogenic acid and catechol, which suggests that main substrate of polyphenol oxidase is o-diphenol compounds.

• Experimental and Molecular Medicine
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• v.50 no.11
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• pp.5.1-5.14
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• 2018

Oxidative stress-induced mitochondrial dysfunction is implicated in the pathogenesis of intervertebral disc degeneration (IVDD). Sirtuin 3 (SIRT3), a sirtuin family protein located in mitochondria, is essential for mitochondrial homeostasis; however, the role of SIRT3 in the process of IVDD has remained elusive. Here, we explored the expression of SIRT3 in IVDD in vivo and in vitro; we also explored the role of SIRT3 in senescence, apoptosis, and mitochondrial homeostasis under oxidative stress. We subsequently activated SIRT3 using honokiol to evaluate its therapeutic potential for IVDD. We assessed SIRT3 expression in degenerative nucleus pulposus (NP) tissues and oxidative stress-induced nucleus pulposus cells (NPCs). SIRT3 was knocked down by lentivirus and activated by honokiol to determine its role in oxidative stress-induced NPCs. The mechanism by which honokiol affected SIRT3 regulation was investigated in vitro, and the therapeutic potential of honokiol was assessed in vitro and in vivo. We found that the expression of SIRT3 decreased with IVDD, and SIRT3 knockdown reduced the tolerance of NPCs to oxidative stress. Honokiol ($10{\mu}M$) improved the viability of NPCs under oxidative stress and promoted their properties of anti-oxidation, mitochondrial dynamics and mitophagy in a SIRT3-dependent manner. Furthermore, honokiol activated SIRT3 through the AMPK-PGC-$1{\alpha}$ signaling pathway. Moreover, honokiol treatment ameliorated IVDD in rats. Our study indicated that SIRT3 is involved in IVDD and showed the potential of the SIRT3 agonist honokiol for the treatment of IVDD.

• Journal of agriculture & life science
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• v.45 no.4
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• pp.113-120
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• 2011

In vitro antioxidant activities and acetylcholinesterase (AChE) inhibitory effects of solvent fractions from aged raw garlic extracts were investigated. Total phenolics fractioned by hexane, chloroform, ethyl acetate and water from Aged raw garlic extracts were 3.70, 23.63, 31.27 and 2.35 mg/g, respectively. We found that ethyl acetate fractions had the highest in ABTS radical scavenging activities, ferric reducing antioxidant power and inhibitory effect on auto-oxidation of linoleic acid. Intracellular ROS accumulation resulting from $H_2O_2$ treatment of PC12 cells was significantly reduced when ethyl acetate fractions were present in the medium compared to PC12 cells treated with $H_2O_2$ only. In addition, we found that ethyl acetate fractions from aged raw garlic extracts resulted in a dose-dependent manner on AChE inhibition. Consequently, our results suggest that ethyl acetate fractions from aged raw garlic extracts may be useful as decreasing agents of oxidative stress and AChE inhibitors.