• The Korean Journal of Food And Nutrition
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• v.17 no.3
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• pp.294-301
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• 2004

Effects of superoxide dismutase(SOD), catalase(CAT), and such other proteins as bovine serum albumin(BSA), ovalbumin, lysozyme, and v-globulin on the autoxidation rates of L-ascorbic acid(AsA) in the absence of heavy metal ions and in the presence of Fe(III) or Cu(II) ions in water were examined. AsA was dissolved in a ultra-refined water at a concentration of 50 ${\mu}$M and 5 ${\mu}$M Fe(III) or 0.1 ${\mu}$M Cu(II) were added, and a oxygen gas was bubbled through the solution at a flow rate of 200 ml/min at 35$^{\circ}C$. The amount of remaining AsA in the reaction mixture was determined by using a UV spectrophotometer(at 265 nm). It was found that the Cu(II) at a concentration of 0.1 ${\mu}$M had a more accelerated for the autoxidation of AsA than Fe(III) at 5 ${\mu}$M. Moreover, it was confirmed that the ratio of remaining AsA was significantly larger in the presence of SOD, CAT, BSA, ovalbumin, lysozyme, and v-globulin than in the absence of proteins. The stabilization of AsA by various proteins were confirmed during the autoxidation of AsA in the presence of Fe(III) or Cu(II) in water. It was suggested that the non-enzymatic effects of SOD, CAT and some other proteins might be involves in the stabilization of AsA.

• Korean Journal of Food Science and Technology
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• v.33 no.3
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• pp.378-383
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• 2001

Formation of superoxide anion $O_2\bar{{\bullet}}$ in the autoxidation of L-ascorbic acid (AsA) in the presence of heavy metal ions were determined. The generation of $O_2\bar{{\bullet}}$ was studied by using superoxide dismutase (SOD) in aqueous and buffer solution, and using nitro bule tetrazolium (NBT) in methanol solution. The remaining amount of AsA was significantly higher in the presence of SOD than in its absence. It suggested that SOD stabilizes AsA in aqueous and buffer solution because of scavenging $O_2\bar{{\bullet}}$ formed during the autoxidation reaction of AsA in the presence of heavy metal ions. NBT has an absorption maximum at about 560 nm in methanol solution. The absorbance at 560 nm increased during the oxidation of AsA, suggested the formation of $O_2\bar{{\bullet}}$in methanol solution. Thus, the formation of $O_2\bar{{\bullet}}$ was confirmed during the autoxidation of AsA not only in aqueous solution but also in methanol solution in the presence heavy metal ions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.2
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• pp.261-269
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• 1997

The autoxidation of cholesterol and lipid was investigated in mackerel during its salting for 50 days. Furthermore, the effects of antioxidants such as ascorbic acid and BHA on their autoxidation were studied. The cholesterol of mackerel during salting was continuously decreased. Its content was quantified by 23.3mg/100g in salted control sample after 50 days and that is only about 33% of total cholesterol content in fresh mackerel. The addition of BHA in mackerel during salting inhibited cholesterol oxidation more effectively than ascorbic acid.7-Ketocholesterol, unique cholesterol oxidation products was detected in this experiment and malonaldehyde, one of lipid oxidation products, contineuosly increased in control sample all the salting days by the almost same pattern but in the additive samples of ascorbic acid or BHA by different patterns, respectively. BHA was more effective antioxidant against cholesterol and lipid autoxidation than ascorbic acid.

• Nutrition Research and Practice
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• v.8 no.2
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• pp.165-171
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• 2014

BACKGROUND: Groundwater is believed to possess many beneficial effects due to its natural source of various minerals. In this study, we examined the effects of natural Jeju groundwater S1 (Samdasoo$^{TM}$), S2 and S3 pumped up from different locations of Jeju Island, Korea, along with local tap water, on body weight gain, serum lipids and lipoproteins, and liver histopathology in high-fat diet-induced hyperlipidemic rats. MATERIALS/METHODS: Rats were randomly and equally divided into 6 groups. Different water samples were supplied to the hyperlipidemic rats as their daily drinking water and the widely-used anti-hyperlipidemic drug simvastatin was used as a positive control. Body weight, serum lipids and lipoproteins were measured weekly. Liver weight, liver index and liver histopathology were examined after the execution of the rats. RESULTS: After drinking Jeju groundwaters for two months, S2 but not S3 significantly reduced weight growth and serum triglycerides levels and increased high density lipoprotein-C (HDL-C) without affecting total cholesterol or LDL-C. S1 and particularly S2 significantly reduced the severity of liver hypertrophy and steatosis. All Groundwaters had much higher contents of vanadium (S3>S2>S1>>tap water) whereas S1 and S2 but not S3 markedly blocked autoxidation of ferrous ions. CONCLUSION: Jeju Groundwater S1 and particularly S2 exhibit protective effects against hyperlipidemia and fatty liver and hypothesize that the beneficial effect of Jeju Groundwaters may be contributed from blockade of autoxidation of ferrous ions rather than their high contents of vanadium.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.775-779
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• 1993

The effects of water activity and light on the oxidation of carotenoid were studied using both the model systems of carrot lipids and freeze dried carrot. Autoxidation of crude lipids from the freeze dried carrot and the stability of carotenoids in controlled systems varing water activities and/or lights were examined. The degree of autoxidation of crude lipid stored at $30^{\circ}C$ for 16 days was significant(p< 0.05) and 71.8% destruction of carotenoid in the crude lipids were observed. When the powdered solid models of freeze dried carrot were stored at $30^{\circ}C$ for 35 days under various water activities and the presence of light, the maximum stability of carotenoid was found at $a_{w}$ 0.42 and the damaging effect of lights on the stability of carotenoid was significant (p<0.05). The absoprtion spectra of carotenoids changed according to the degree of oxidation, but shifts of the maximum wavelength was not observed.

• Korean Journal of Food Science and Technology
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• v.25 no.4
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• pp.307-312
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• 1993

Antioxdant effect was studied in model system with linoleic acid methylester and tocochromanols $({\alpha}-,\;{\beta}-,\;{\gamma}-,\;{\delta}-tocopherol\;and \;{\alpha}-,\;{\gamma}-,\;{\delta}-tocotrienol)$ under definite autoxidation condition-temperature $(40,\;60,\;80^{\circ}C),\;O_2\;(0,\;10,\;20%\;O_2\;in\;N_2)$. 13-Hydroperoxy-9-cis-11-trans-, 13-hydroperoxy-9-trans-11-trans-, 9-hydroperoxy-10-trans-12-cis-, 9-hydroperoxy-10-trans-12-trans-octadecadienoic acid methylester as the major oxidation product were produced from linoleic acid methylester by autoxidation, analyzed with HPLC and antioxidant activities were compared by their quantitative changes. Experimental results showed that all added tocochromanols except ${\alpha}-tocotrienol$ had antioxidant effect at $60^{\circ}C$, and also ${\alpha}-tocopherol$, ${\alpha}-tocotrienol$ and ${\delta}-tocotrienol$ had prooxidant effect at $80^{\circ}C$. And cis/trans-hydroperoxide was predominantly produced at $40^{\circ}C$, but trans/trans-hydroperoxide at $80^{\circ}C$. Except no reproductive experimental data in produced hydroperoxides amount, the production ratio of cis/trans-:trans/trans-hydroperoxides in the autoxidation condition of range from $40^{\circ}C/10%,\;O_2\;to\;60^{\circ}C/20%\;O_2$ were as follows: ${\alpha}-T>{\alpha}-T_3>{\gamma}-T>{\beta}-T>{\gamma}-T_3>{\delta}-T>{\delta}-T_3$. This result showed that ${\alpha}-tocopherol$ among tocochromanols had the lowest antioxidant effect.

• Proceedings of the Korean Society of Toxicology Conference
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• 2001.05a
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• pp.124-124
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• 2001

Tetrahydropapaveroline(THP), a dopamine-derived 6,7-dihydroxy-l-(3',4'-dihydroxybenzyl)-1,2,3,4-tetrahydrosioquinoline, has been suspected as a possible dopaminergic neurotoxin to elicit Parkinsonism. Autoxidation or monoamine oxidase-mediated oxidation of THP and subsequent generation of reactive oxygen species (ROS) may contribute to the degeneration of dopaminergic neurons induced by this isoquinoline alkaloid.(omitted)

• Journal of the Korean Applied Science and Technology
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• v.4 no.1
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• pp.77-81
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• 1987

No difference was observed on autoxidative stability of triacylglycerols before and after randomyl interesterification. It indicate that randomization of the glyceride composition has no significant effect on the autoxidative stability. On the other hand, the autoxidation of randomyl interesterified vegetable oil was accelerated, caused mainly by decrease of tocopherols during the series of interesterification procedures.

• Bulletin of the Korean Chemical Society
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• v.8 no.4
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• pp.254-257
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• 1987

Palladium dichloro complexes catalysed the oxidation of cyclopentene by dioxygen in tetralin solvent at ambient temperature. Cyclopentanone formed mainly together with autoxidation products from both cyclopentene and tetralin. The oxidation seems to proceed by co-oxidation mechanism, where tetralin was first oxidized to its hydroperoxide which then oxidized cyclopentene to cyclopentanone. Mechanism of the other by-products formations has been discussed.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.5
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• pp.325-330
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• 1992

This paper deals with the antioxidative activities of some spices on the autoxidation of refined sardine oil. The various spices powders(120mesh) were added into the refined sardine oil at the level of $0.1\%$ (w/w), and then incubated at $37^{\circ}C$ Among spices tested, herb spices showed higher antioxidative activities than spicy and seed spices. Especially, the antioxidative activities of herb spices on peroxidation of refined sardine oil were most effective in rosemary and sage. Furthermore, the available antioxidative compounds of rosemary and sage were fractionated into petroleum ether-soluble and -insolubles. Petroleum ether-soluble fractions(PESF) obtained from rosemary and sage on the autoxidation of refined sardine oil had a great antioxidative activities. The yields of PESF obtained from rosemary and sage were $10.3\%\;and\;12.6\%$, respectively. The PESF of rosemary and sage showed higher antioxidative effects than butylated hydroxytoluene(BHT), and indicated predominant metal ion-scavenging effect in PESF-refined sardine oil systems.