• Korean journal of food and cookery science
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• v.30 no.6
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• pp.785-791
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• 2014

The antioxidative activities of beverages with water or ethanol extracts from Maegmundong (Liriope platyphylla) were investigated with free amino acid and mineral analysis, as well as saponin, total phenolics and flavonoid determination. Antioxidative activity was evaluated by electron donating ability and ABTS radical scavenging activity. There was only a small difference between water extract beverages and ethanol-extract beverages with respect to their electron donating ability and ABTS radical scavenging activity, although the total saponin, total phenolics and flavonoid were found to be greater in the ethanol extract beverages than in the water extract beverages. Three major free amino acids of the Magemundong beverages with water- or ethanol extract were asparagine (58.30, 60.68 mg%), methionine (15.10, 13.95 mg%, respectively) and proline (12.31, 14.00 mg%, respectively). The most abundant mineral in the Maegmundong beverage with water and ethanol extract was potassium (238.68, 244.32 mg%, respectively).

• Journal of the Korean Applied Science and Technology
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• v.36 no.1
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• pp.13-22
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• 2019

The aim of the present investigation was to assess the oxidation inhibition by nitrogen oxide scavenging activity and physiological activities. Bioactive compound of proanthocyanidin $69.000{\pm}2.737mg$ catechin equivalents (CE)/g dry weight. Antioxidant effects (nitric oxide radical scavenging activity, nitrite scavenging activity, ${\beta}$-carotene bleaching assay and lipid peroxidation inhibition activity) of distilled water (DW), 70% ethanol and n-butanol extract of turmeric (Curcuma longa L.). Turmeric extracts yield were DW 17.11%, 70% ethanol 15.26% and n-butanol 4.12%, respectively. Oxidation inhibition activity of the samples exhibited a dose-dependent increase. However, in the current study, none of the samples evaluated showed activity as strong as the BHA and trolox. Total flavonoid content was the highest in the n-butanol extract, followed by 70% ethanol and DW extract. Further, nitrite scavenging activity was the highest for the n-butanol extract. As a result of this experiment, the turmeric can be utilized as a valuable and potential natural oxidation inhibition for the functional food industry.

• Korean Journal of Food Science and Technology
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• v.24 no.1
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• pp.7-10
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• 1992

The antioxidant effect of various concentration of Panax ginseng on pork and chicken breast was investigated in the condition of powder, water extract, ethanol extract and residue. Result showed that the antioxidant effect of each sample increased with increasing concentration of powder but the increment decreased with increasing concentration. Water extract and residue decreased lipid oxidation of pork and chicken breast. However, the effect did not increase proportionally with increasing concentration. Ethanol extract did not show a certain tendency in pork while it had an oxidation-promoting effect in chicken.

• Composites Research
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• v.34 no.5
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• pp.277-282
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• 2021

Graphene oxide can be reduced to graphene under supercritical fluid condition even without using a specific reducing agent or applying a high thermal process. In this study, a process for converting graphene oxide into graphene was studied under supercritical fluid conditions in methanol and ethanol solvents. When the structure of asprepared graphene was analyzed by using FE-SEM and XRD, the reduction of graphene oxide in supercritical fluid condition was more affected by the change of solvent than other variables such as concentration of graphene oxide and reaction time. The use of ethanol showed better results for the reduction than the use of methanol. The graphene prepared in this study was mixed with epoxy resin up to 20 wt.% to make composites, and the thermal conductivity of the composites were analyzed. Thermal conductivity of the composite increased proportionally with graphene loadings. The graphene prepared in supercritical ethanol condition was more effective on the thermal conductivity of the composite.

• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.622-632
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• 2018

The aim of the present study was to evaluate of turmeric (Curcuma longa L.) on the physiological activities and oxidation inhibitory action. The effects of various solvents (distilled water DW, 70% ethanol and n-butanol) on the total phenolics content (TPC) of turmeric and their corresponding biological activity were studied. Bioactive compound of total saponin $7.506{\pm}0.349mg\;SE/g$ dry weight. Turmeric extracts yield were DW (17.11%), 70% ethanol (15.26%) and n-butanol (4.12%), respectively. Oxidation inhibitory action of the samples exhibited a dose-dependent increase. However, in the current study, none of the samples evaluated showed activity as strong as the BHA, ascorbic acid and EDTA. Results showed that extraction solvent had significant effects on TPC and oxidation inhibitory action (DPPH radical scavenging activity, ABTS radical scavenging activity, reducing power and ferric reducing antioxidant power) of n-butanol. Turmeric exhibited the antioxidant properties, which suggests that the plant material could be used for further studies as a potential source for bioactive and natural antioxidant.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.8
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• pp.1102-1106
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• 2010

This study was carried out to investigate the effect of ethanol extract from citrus peels (CP-Et) against the alloxan-induced oxidative damage on HIT-T15, Hamster pancreatic $\beta$-cell. Total polyphenol and flavonoid contents in CP-Et were $57.00{\pm}2.91\;mg/g$ and $8.11{\pm}2.83\;mg/g$, respectively. Cell toxicity on HIT-T15 by CP-Et (0.125~0.75 mg/mL) was not observed. CP-Et (0.125 mg/mL) increased cell proliferation rate of HIT-T15, which was treated alloxan ($IC_{50}=11.58\;mM$) (cell viability=$80.52{\pm}3.29%$ of normal cell, p<0.05). In comparison with insulin secretion of oxidative damaged HIT-T15, 1.5 fold ($116.93{\pm}2.11\;{\mu}g/mg$ protein) was increased by treatment CP-Et treatment (0.125 mg/mL) in HIT-T15 (p<0.05). These results showed that CP-Et contribute to repairing cells and improvement of insulin expression on oxidative stress pancreatic $\beta$-cell, and also suggested application of CP-Et as a functional food material for type 2 diabetes.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.31.2-31.2
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• 2010

질화물계 발광다이오드는 소비전력이 낮고 발광효율이 높은 조명용 반도체소자로서 다양한 분야에 적용되고 있으나 질화갈륨 반도체 층 및 외부 공기와의 계면에서 발생하는 전반사로 인하여 광추출특성이 매우 낮은 문제점이 있다. 이를 해결하기 위하여 다양한 연구가 진행되고 있으며 투명전극 또는 p형 질화갈륨 층에 주기적인 나노 패턴을 형성하고 이에 따른 난반사 효과를 통해 전반사를 억제시키는 연구가 주로 진행되고 있다. 현재까지의 연구에서 발광다이오드의 광추출향상을 위한 나노 패턴은 플라즈마 식각공정을 통하여 형성되었지만 플라즈마 데미지에 의해 소자의 전기적 특성이 저하되는 문제점이 있었다. 본 연구에서는 플라즈마 식각 공정이 요구되지 않는 sol-gel 임프린팅 공정을 이용하여 발광다이오드의 ITO 투명전극 위에 산화아연 나노 패턴을 직접 형성하였다. Sol 솔루션은 에탄올에 zinc acetate dihydrate와 diethanolamine을 희석하여 제작하였고 이를 스핀코팅 방법을 통해 발광다이오드의 ITO 투명전극 층 위에 도포하였다. 이 후, 고 투습성의 PDMS (Polydimethylsiloxane) 몰드를 이용하여 $190^{\circ}C$에서 임프린팅을 진행하였고 이 과정에서 대부분의 솔벤트(에탄올)는 PDMS 몰드로 흡수되어 임프린팅 후에는 나노 패턴이 형성된 산화아연 gel 박막을 얻을 수 있었다. 최종적으로 $500^{\circ}C$에서 1시간 동안 열처리 하여 발광다이오드의 ITO 투명전극 위에 산화아연 나노 패턴을 형성하였다. 나노임프린팅 기반의 직접 패터닝 공정을 통하여 형성된 산화아연 패턴 층을 XRD 측정을 통해 결정성을 분석하였고 형성된 패턴의 형상을 SEM을 통해 확인하였다. 또한, 산화아연 패턴 유무에 따른 발광다이오드 소자의 광추출효율 비교를 위해 electroluminescence를 측정하였으며, 소자의 전기적 특성은 I-V 측정을 통해 분석하였다.

• Journal of the Korean Electrochemical Society
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• v.11 no.3
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• pp.141-146
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• 2008

Electrocatalytic activities and stabilities of Pt supported on Sb-doped $SnO_2$ (ATO) were examined for ethanol oxidation reactions. Pt colloidal particles were deposited on ATO nanoparticles (Pt/ATO) and the prepared electrocatalysts were characterized by X-ray diffraction, transmission electron microscopy (TEM), and cyclic voltammetry. Electrochemical activity of the Pt/ATO for ethanol electro-oxidation was compared to those of Pt supported on carbon (Pt/C) and commercial PtRu/C. The activitiy of the Pt/ATO was much higher than those of the Pt/C and commercial PtRu/C. The Pt/ATO exhibited much higher electrochemical stabilities than the Pt/C in 0.5M ${H_2}{SO_4}$ and in 0.5M ${H_2}{SO_4}$/1M ${C_2}{H_5}OH$. According to TEM, the growth rate of Pt particles was lower in the Pt/ATO than it was in the Pt/C. The ATO nanoparticle appears to be a promising support material that promotes electrochemical reactions and stabilizes catalyst particles in direct ethanol fuel cell.

• Journal of the Korean Society of Food Science and Nutrition
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• v.31 no.1
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• pp.81-86
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• 2002

The present study was conducted to investigate the effect of dietary supplementation of vitamin A or $\beta$-carotene on oxidative damage induced by acute ethanol administration. Sprague-Dawley rats were fed on the experimental diets supplemented with retinyl acetate (2.86 mg/kg diet) or $\beta$-carotene (15.2 mg/kg diet) for 5 weeks. After fed the diet, rats were administered 20% ethanol solution (3g/kg B.W.) acutely. Lipid peroxide values in hepatic tissue, hepatic antioxidative enzyme activities and contents of antioxidative nutrient such as vitamins A and E in serum and hepatic tissue were measured. Hepatic level of malondialdehyde decreased in $\beta$-carotene group compared to the control group. However, there was no significant difference between retinal acetate and $\beta$-carotene groups. Superoxide dismutase activity was higher in retinal acetate group than in the control group. Hepatic glutathione-S-transferase activity of retinal acetate and $\beta$-carotene groups significantly decreased as compared with that of control group. The hepatic content of retinol increased in retinal acetate and $\beta$-carotene groups, especially, in retinyl acetate group. But there was no significant difference in serum content of retinol among the groups. Hepatic content of $\alpha$-tocopherol was significantly increased in retinyl acetate and $\beta$-carotene groups. In conclusion, acute ethanol administration might induce lipid peroxidation, and the dietary supplementation of retinyl acetate or $\beta$-carotene improve partly the antioxidative system through activation of superoxide dismutase and retention of hepatic $\alpha$-tocopherol in ethanol-treated rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.11
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• pp.1767-1775
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• 2013

The purpose of this study is to investigate the total polyphenol and antioxidant activities of radish buds (Raphanus sativus L.) based on sprouting periods and extraction solvents in order to present basic data that are needed for using the radish buds as functional food material. The antioxidant activities were assessed by using various antioxidant models (DPPH, TBARS, Rancimat method, POV). The total polyphenol contents according to the extraction solvents were 84.11 and 296.51 mg/g, and the ethanol extract on day 4 of showed the highest value as 296.51 mg/g. As for DPPH radical-scavenging activity, on the day 4 of sprouting, water extracts indicated the highest scavenging activity by 86.67%, and the acetone extracts indicated a rather low scavenging activity as 77.23%. As for TBARS measurement of the radish bud extracts on day 4 of sprouting the extract of 70% ethanol was highest (71.48%). On day 8 of sprouting the TBARS value was increased and the methanol extract was highest (78.99%). As for the oxidative induction period on day 4 of sprouting in Rancimat measurement, the methanol extract was highest (6.07 hours) on day 4 and the antioxidant index was 1.16. On day 12 of sprouting, the general oxidative induction period tended to be reduced to 5.25 to 5.91 hours. In the peroxide value measurement on day 4 of sprouting and beginning of the storage, the extracts showed no difference between 3.02 meq/kg oil and 4.12 meq/kg oil, and on the day 60 of storage, the water extract (43.83 meq/kg oil) and the methanol extract (45.42 meq/kg oil) were lowest with higher antioxidant effect. In conclusion, the radish bud extract with higher total polyphenol contents and antioxidant activities may serve as functional material for food additives, such as natural antioxidants and food preserving agents.