• Journal of Ginseng Research
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• 제13권2호
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• pp.234-238
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• 1989

In the presence of a photosensitizer, rose bengal, phooxidatlon in serum total lipids has been studied and the effects of ginseng water extract and saponins on it have reviewed. In the presence of rose bengal, serum total lipids undergo photooxidation and produce lipid hydroperoxides. On the other hand, ginseng water extract and dial saponins largely inhibit photooxidation and decrease the amount of lipid hydroperoxides in serum total lipids.

• 한국환경과학회지
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• 제8권2호
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• pp.233-240
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• 1999

Industrial waste which highly loaded by halogenide phenols was photooxidized by laboratory-scale photooxidation of these organic impurities in the presence of aerotropic and titaniumdioxide as photocatalyst. The disapperance of organic compounds was determined as a function of the irradiation time. Some contaminants such as 2-chlorophenol, 2-bromphenol, 3-bromphenol, 4-bromphenol, 2,4-dibromophenol and 2,6-dibromophenol were photodegraded separately to obtain information on the reaction rates, reactivities, and reaction mechanisms of the photooxidation, and on the stoichiometric correlation between organic reactant and inorganic products concentration in the course of the photocatalytic photoreaction.

• Journal of Ginseng Research
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• 제14권1호
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• pp.30-35
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• 1990

The photooxidation of human erythrocyte ghosts has been studied and the effects of ginseng water extract on it have been investigated. In the presence of photosensitizer, rose bengal, human erythrocyte ghosts have caused photooxidation by lO2 and produced lip)id hydroperoxides. Ginseng water extract and d-${\alpha}$-tocofherol have inhibited photooxidation, ,whereas ascorbic acid has developed in low concentrations but inhibited in high concentrations. On the other hand, amounts of lipid hydroperoxide produced by photooxidation were decreased by addition of catalase after irradiation and according to sequential addition of ginseng water extract into it, the formation of lipid hydrolleroxide was decreased simultaneously.

• 한국식품조리과학회지
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• 제33권3호
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• pp.275-284
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• 2017

Purpose: This study was performed to evaluate the effects of sannamul or herb extract addition to a soybean oil-in-water emulsion during photooxidation in the presence of chlorophyll. Methods: The emulsion mainly consisted of purified soybean oil and citric acid buffer (pH 4.0) at a weight ratio of 4 to 6, with chlorophyll a addition at 6 mg/kg. Ethanol extract of daraesoon, samnamul, basil, or peppermint was selectively added to the emulsion at 400 mg/kg, and emulsions in glass serum bottles were oxidized at $5^{\circ}C$ under 2,600 lux light for 48 hours. Lipid oxidation of the emulsions was evaluated based on determination of headspace oxygen content, peroxide value, and p-anisidine value. Pigments and antioxidants were also monitored. Results: The emulsion with added samnamul extract with high contents of polyphenols and low chlorophyll content showed lower oxygen consumption, peroxide values, and p-anisidine values, whereas basil and peppermint extracts with high chlorophyll contents increased photooxidation. Chlorophylls were degraded during photooxidation of the emulsions, and the degradation rate was highest in the emulsion with added samnamul extract. Conclusion: The high antioxidant activity of samnamul extract in the photooxidation of soybean oil-in-water emulsion could be due to low chlorophyll content, high concentrations of polyphenol compounds in the extract, as well as rapid degradation of chlorophylls during oxidation.

• 한국응용과학기술학회지
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• 제4권2호
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• pp.25-30
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• 1987

In order to investigate the effect to antioxygenic substances in Pine Needles on the photooxidation of linoleic acid (linoleic acid 100mg/10ml ethanol) added antioxidants and antioxygenic substances in Pine Needles was irradiated by the tungsten lamp attached with red fitter. The Photo oxidation of linoleic acid (LA) was conformed with Lea method and rhodan method. The following results were obtained: 1. Photooxidation of LA was greatly increased the presence of photosensitizer. However the Photo oxidation of LA without photosensitizer was smoothly increased by the irradiation. 2. The Photo oxidation of LA without irradiation occured quite lately whether photosensitizer was present or absent. 3. Photooxidation of LA under the presence of photosensitizer was inhibited by the addition of $dl-{\alpha}-tocopherol$ and the acetone fraction of methanol extract of Pine Needles but inhibited by BHT. Photooxidation of LA increased gradually as the addition of BHT increased but decreased gradually as that of acetone fraction increased.

• Elastomers and Composites
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• 제50권1호
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• pp.1-6
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• 2015

Polybutadiene rubber (BR) has been well known that its physical and chemical properties are changed when it is exposed to ultraviolet light undergoing photooxidation. In this study, photooxdiation process of BR vulcanizate was investigated using a high pressure mercury lamp used as an outdoor lighting, which has high UV radiation efficiency and reasonable cost. Discoloration and crack formation of photooxdized BR vulcanite surface were examined using an image analyzer. Change of chemical functional groups of BR vulcanite surface by photooxidation was investigated using ATR-FTIR, and variation of the crosslink density with the UV irradiation time was investigated. By increasing the UV irradiation time, the crosslink density steeply increased after a period of time and did not increase any more. Formation of hydroxyl (~OH) and carbonyl (~C=O) groups on the BR vulcanizate surface increased and the1,4-cis unit was converted to the 1,4-trans unit as the photooxidation was proceeded.

• 한국대기환경학회지
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• 제21권1호
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• pp.15-26
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• 2005

An experimental investigation of the gas-phase photooxidation of toluene-NO$_{x}$-air mixtures at sub-ppm concentrations has been carried out in a 6.9 m3, indoor smog chamber irradiated by blacklights. Measured parameters in the toluene-NO$_{x}$ experiments included $O_3$, NO, NO$_2$, NO$_{x}$, CO, SO$_2$ toluene, and air temperature. The initial toluene concentration ranged from 225 ppb to 991 ppb and the initial concentration ratio of toluene/NO$_{x}$ in ppbC/ppb was in the range of 5～20. It was found that the variation of gaseous species with irradiation time caused by the photooxidation of toluene-NO$_{x}$-air mixtures depended on the initial toluene concentration for similar concentration ratio of toluene/NO$_{x}$. The dependency of initial toluene concentration on the photooxidation of toluene-NO$_{x}$-air mixtures for toluene/NO$_{x}$=5～6 seemed to be opposite to that for toluene/NO$_{x}$=10～11. The arriving time at maximum ozone concentration depended on both initial toluene concentration and initial concentration ratio of toluene/NO$_{x}$. However, the maximum concentration of ozone formed by photooxidation depended only on the initial toluene concentration.luene concentration.

• 한국대기환경학회지
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• 제21권1호
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• pp.27-38
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• 2005

An experimental investigation of the gas-phase photooxidation of toluene-NO$_{x}$-air mixtures at sub-ppm concentrations has been carried out in a 6.9 ㎥, indoor smog chamber irradiated by blacklights. Measured parameters in the toluene-NO$_{x}$ experiments included aerosol, $O_3$, NO, NO$_2$, NO$_{x}$ CO, SO$_2$ toluene, and air temperature. The initial toluene concentration ranged from 225 ppb to 991 ppb and the initial concentration ratio of toluene/NO$_{x}$ in ppbC/ppb was in the range of 5～20. It was found that the variation of aerosol number concentration with irradiation time caused by the photooxidation of toluene-NO$_{x}$-air mixtures depended on the initial toluene concentration for similar concentration ratio of toluene/NO$_{x}$. The dependency of initial toluene concentration on the photooxidation of toluene-NO$_{x}$-air mixtures for toluene/NO$_{x}$= 5～6 seemed to be opposite to that for toluene/NO$_{x}$=10～11. The maximum number concentration of aerosols formed by photooxidation and the aerosol yield depended on both initial toluene concentration and initial concentration ratio of toluene/NO$_{x}$. In this study, the aerosol yield, defined as aerosol formed per unit toluene consumed, was found to be 0.01～0.16.und to be 0.01～0.16.

• 한국식품영양과학회지
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• 제34권1호
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• pp.99-106
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• 2005

클로로필의 광산화에 미치는 $\beta$-카로텐과 비타민 C의 역할을 linoleic acid emulsion 모델 시스템과 피부조직 균질액을 이용하여 조사하고 이와 더불어 각각의 성분들의 조합시 일어나는 변화를 살펴보았다. Linoleic acid emulsion 모델 시스템에서 클로로필과 $\beta$-카로텐은 고농도에서 자외선 H에 의한 광산화를 촉진시키는 것으로 나타났으며 고농도의 비타민 C는 이를 억제시켰다. 갓김치에 함유되어 있는 클로로필, $\beta$-카로텐, 비타민 C 농도를 참고하여 이들을 조합하였을 때 자외선 B에 의한 광산화를 억제시켰으며 $\beta$-카로텐의 경우 단독으로 사용되었을 때에는 산화를 촉진하였으나 다른 항산화성분들과 함께 사용될 경우 항산화활성을 나타내었다. ICR mouse의 피부조직 균질액에 클로로필, $\beta$-카로텐, 비타민 C를 단독 또는 혼합하여 첨가하였을 때 클로로필 a, b 및 $\beta$-카로텐의 첨 가는 광산화를 가속화시켰다. 비타민 C의 경우 50 ppm을 첨가하였을 때에는 아무런 효과를 나타내지 않았으나 500 ppm을 첨가하였을 때에는 자외선 B에 의한 광산화를 효과적으로 억제시켰다. 500 ppm의 비타민 C에 클로로필과 $\beta$-카로텐을 혼합하였을 때에도 광산화가 억제되었으며 비타민 C의 농도가 중요하게 작용하였다.

• Food Science and Biotechnology
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• 제18권2호
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• pp.413-418
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• 2009

Effects of chlorophyll and visible light exposure on the volatile formations and headspace oxygen content were studied in lard model systems at $55^{\circ}C$. Samples with or without addition of chlorophyll under light underwent photosensization or photooxidation, respectively. Total volatiles (TI) in lard with 5 ppm chlorophyll photosensization were 19 times higher than those in visible light photooxidized samples for 48 hr while TI in lard with chlorophyll in the dark were not significantly different from those in photooxidized samples (p>0.05). Headspace oxygen content in photosensitized lard decreased from 21 to 15% for 48 hr but that in photooxidized lard or that in lard with chlorophyll in the dark did not change significantly (p>0.05), which indicates that lard system used in this study is a photosensitizer-free model system and the presence of chlorophyll accelerated the lipid oxidation only under visible light. Oxidation mechanisms of photooxidation with or without presence of photosensitizers under visible light were not the same based on the difference of oxidized volatile profiles and headspace oxygen depletion.