• 한국환경과학회지
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• 제23권12호
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• pp.2129-2134
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• 2014

The antioxidant activities and total phenolics of four Rosaceae species Pourthiaea villosa (Thunb.) Decne, Sorbus commixta Hedlund, Sorbaria sorbifolia var. stellipila Maxim and Pyrus pyrifolia (Burm.f.) Nakai were determined. Phenolic content (polyphenol and flavonoid), radical scavenging activities [2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis (3-ethylnezthiazoline-6-sulfoic acid) (ABTS)] and ferrous ion chelating effect were evaluated. Total polyphenol and flavonoid contents were highest in Pourthiaea villosa (Thunb.) Decne and lowest in Pyrus pyrifolia (Burm.f.) Nakai. Phenolic contents of Pourthiaea villosa (Thunb.) Decne was $331.45{\pm}7.78$ and $90.4{\pm}3.5mg{\cdot}g^{-1}$. DPPH and ABTS radical scavenging activities were found to be lowest in Sorbus commixta Hedlund whereas Sorbaria sorbifolia var. stellipila Maxim and Pourthiaea villosa (Thunb.) Decne showed relatively good DPPH and ABTS radical scavenging activities. Ferrous ion chelating effect was highest in Pyrus pyrifolia (Burm.f.) Nakai ($1.05{\pm}0.04mg{\cdot}ml^{-1}$) and lowest in Sorbus commixta Hundlund ($4.22{\pm}0.71mg{\cdot}ml^{-1}$).

• 한국환경과학회지
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• 제28권4호
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• pp.393-401
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• 2019

The present study were conducted to determine physiological activities and antioxidant effects [2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity, reducing power, Ferric Reducing Antioxidant Power (FRAP) and Fe2+ (ferrous ion) chelating capacity] of 70% methanol, chloroform:methanol, 2:1 volume ratio (CM) and ethyl acetate extract of turmeric (Curcuma longa L.). Bioactive compound of tannin $0.125{\pm}0.007mg$ Catechin Equivalent (CE)/g dry weight. Turmeric extracts yield were 70% methanol 16.54%, CM 5.64% and ethyl acetate 4.14%, respectively. Antioxidant activity of the samples exhibited a dose-dependent increase. Results showed that extraction solvent had significant effects on total flavonoid content and antioxidant effects of ethyl acetate. But ferrous ion-chelating capacity of 70% methanol extract was higher than CM and ethyl acetate extract. From the results of this study, turmeric can be utilized as a valuable and potential nutraceutical for the functional food industry.

• 한국세라믹학회지
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• 제34권4호
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• pp.351-356
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• 1997

The origin of the variation of initial permeability in manganese-zinc ferrite polycrystals with a content of hematite was investigated. Initial permeability showed maximum with hematite content while there was no significant change in microstructure. Saturation magnetization increased with hematite content. So the variation of initial permeability was not explained on the basis of microstructural change or saturation magnetization. Temperature dependence of initial permeability revealed magnetocrystalline anisotropy was the origin of the variation of initial permeability. The change in magnetocrystalline anisotropy was ascribed to the variation in ferrous ion concentration. Therefore the variation of initial permeability in manganese-zinc ferrite polycrystals with a content of hematite was due to ferrous ion concentration via magnetocrystalline anisotropy.

• Journal of Microbiology and Biotechnology
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• 제21권2호
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• pp.192-196
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• 2011

Microbial induction of rusty-root was proved in this study. The enzymes hydrolyzing plant structural materials, including pectinase, pectolyase, ligninase, and cellulase, caused the rusty-root in ginseng. Pectinase and pectolyase produced the highest rusty-color formation. Ferrous ion ($Fe^{+++}$) caused the synergistic effect on rusty-root formation in ginseng when it was used with pectinase. The effect of ferric ion ($Fe^{++}$) on rusty-root formation was slow, compared with $Fe^{+++}$, probably due to gradual oxidation to $Fe^{+++}$. Other metal ions including the ferric ion ($Fe^{++}$) did not affect rusty-root formation. The endophytic bacteria Agrobacterium tumefaciens, Lysobacter gummosus, Pseudomonas veronii, Pseudomonas marginalis, Rhodococcus erythropolis, and Rhodococcus globerulus, and the rotten-root forming phytophathogenic fungus Cylindrocarpon destructans, caused rusty-root. The polyphenol formation (rusty color) was not significantly different between microorganisms. The rotten-root-forming C. destructans produced large quantities of external cellulase activity (${\approx}2.3$ U[${\mu}m$/min/mg protein]), which indicated the pathogenecity of the fungus, whereas the bacteria produced 0.1-0.7 U. The fungal external pectinase activities (0.05 U) and rusty-root formation activity were similar to those of the bacteria. In this report, we proved that microbial hydrolyzing enzymes caused rusty-root (Hue value $15^{\circ}$) of ginseng, and ferrous ion worsened the symptom.

• Corrosion Science and Technology
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• 제4권2호
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• pp.45-50
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• 2005

A 3% NaCl solution of 1 $dm^3$ circulated with 1.5 $dm^3/min$ by a pump for 24 h in the presence of magnetic field. An iron plate immersed in a $100cm^3$ of test solution for 24 h. The rest potential and pH on surface fixed after 3 h. Containing 0~120 ppm of Fe(II) ion, the dissolution in the magnetically treated solution rose comparing with that in the non-magnetically treated solution. The dissolution amount reached to maximum at 50 ppm, then fixed in the non-magnetically treated solution. When Fe(II) ion existed in the magnetically treated solution, dissolution accelerated a little. In the non-magnetic treated solution containing 10~125 ppm of Fe(III) ion existed, the dissolution accelerated. The dissolution amounts reached to maximum at 50 ppm, then decreased from maximum value. In the magnetically treated solution, the dissolution amounts reached to minimum until 50 ppm, then increased from minimum value. The dissolution amounts affected larger with increasing of magnetic flux density. Fe(II), Fe(III) ions and magnetic treatment affected to formation of $Fe(OH)_2$ and/or $Fe_3O_4$ films. The magnetically treated effects memorized about one month.

• Environmental Engineering Research
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• 제20권3호
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• pp.205-211
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• 2015

Reduced forms of iron, such as zero-valent ion (ZVI) and ferrous ion (Fe[II]), can activate dissolved oxygen in water into reactive oxidants capable of oxidative water treatment. The corrosion of ZVI (or the oxidation of (Fe[II]) forms a hydrogen peroxide ($H_2O_2$) intermediate and the subsequent Fenton reaction generates reactive oxidants such as hydroxyl radical ($^{\bullet}OH$) and ferryl ion (Fe[IV]). However, the production of reactive oxidants is limited by multiple factors that restrict the electron transfer from iron to oxygen or that lead the reaction of $H_2O_2$ to undesired pathways. Several efforts have been made to enhance the production of reactive oxidants by iron-induced oxygen activation, such as the use of iron-chelating agents, electron-shuttles, and surface modification on ZVI. This article reviews the chemistry of oxygen activation by ZVI and Fe(II) and its application in oxidative degradation of organic contaminants. Also discussed are the issues which require further investigation to better understand the chemistry and develop practical environmental technologies.

• 한국세라믹학회지
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• 제48권2호
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• pp.117-120
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• 2011

In this study, the redox state of iron in sodium silicate glasses was varied by changing the melting conditions, such as the melting temperature and particle size of iron oxide. The oxidation states of the iron ion were determined by wet chemical analysis and UV-Vis spectroscopy methods. Iron commonly exists as an equilibrium mixture of ferrous ions, $Fe^{2+}$, and ferric ions $Fe^{3+}$. In this study, sodium silicate glasses containing nanoparticles of iron oxide (0.5% mol) were prepared at various temperatures. Increase of temperature led to the transformation of ferric ions to ferrous ions, and the intensity of the ferrous peak in 1050 nm increased. Nanoparticle iron oxide caused fewer ferrous ions to be formed and the $\frac{Fe^{2+}}{Fe^{3+}}$ equilibrium ratio compared to that with micro-oxide iron powder was lower.

• 한국식품저장유통학회지
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• 제6권1호
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• pp.115-120
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• 1999

This study was carried out to investigate the effect of Pine needle extract on lipid oxidation and free radical reaction in iron sources reacted with active oxygen species. The results were summarized as follow; The pine needle extracts didn`t show a distinct effect on reduction of lipid oxidation if the iron ion didn`t exist in oil emulsion. The pine needle extracts played role as a strong chelating agents to bind iron ion if Ferrous iron(Fe\ulcorner) exist in oil emulsion. Ferric iron(Fe) was lower effect than Ferrous iron(Fe) on free radical reaction in oil emulsion. And also, the Fe\ulcorner reacted with pine needle extract did not show distinct effect on free radical reaction, compared to Fe\ulcorner reacted with pine needle extract. And also, Pine needle extracts reacted with H\ulcornerO\ulcorner were tended to show a low oxygen scavenging ability in case of H\ulcornerO\ulcorner only was existed, compared to those of H\ulcornerO\ulcorner + Fe\ulcorner complex. Pine needle extracts were the most powerful Fe\ulcorner binding agents, compared to other strong synthetic antioxidants such as EDTA and DTPA.

• 한국식품과학회지
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• 제9권2호
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• pp.157-164
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• 1977

본(本) 실험(實驗)은 대두유(大豆油)와 그 튀김면(麵)에, 한국(韓國) 상수도(上水道) 기준(基準) 또는 물리적(物理的)으로 정제(精製)한 지하수(地下水)에 함유가능(含有可能)한양(量)과 동일(同一)한 양(量)의 철(鐵) ion과 동(銅) ion을 각각(各各)에 첨가(添加)하여 그들에 의한 산패촉진정도(酸敗促進程度)를 측정(測定)하고, 아울러 일반적(一般的)으로 널리 쓰이고 있는 유지(油脂)의 황산화제(抗酸化劑)로서 BHA (butylated hydroxyanisole) 또는 citric acid가 이들 금속(金屬)에 의(依)한 산패촉진정도(酸敗促進程度)를 어느 정도 감소(減少)시키는 가를 비교(比較) 검토(檢討)하였다. 본(本) 실험(實驗)의 결과(結果), 대두유(大豆油)와 그 튀김면(麵)의 경우 모두, 철(鐵) ion 또는 동(銅) ion의 첨가(添加)는 이들 ion이 첨가(添加)되지 않은 경우와 비교(比較)할때 뚜렷한 산패촉진효과(酸敗促進?果)를 보였다. 특히, 동(銅) ion이 첨가(添加)된 경우에 있어서는 시간(時間)이 경과(經過)함에 따라 철(鐵)ion이 첨가(添加)된 경우보다 3배(倍) 내지 6배(倍)의 강(强)한 산패촉진효과(酸敗促進?果)를 보였다. 항산화제(抗酸化劑)인 BHA와 citric acid의 이들 금속(金屬)에 의(依)한 산패촉진(酸敗促進)에 대(對)한 저해작용도(沮害作用度)는 citric acid가 첨가(添加)된 경우가 BHA첨가(添加) 경우보다 컸으며, BHA가 첨가(添加)된 경우 그 효과(?果)는 극(極)히 미약(微弱)하였다. 또한 이들 항산화제(抗酸化劑)의 저해작용도(溫害作用度)는 동(銅) ion의 경우보다 철(鐵) ion의 경우에 더 효과적(效果的)인 것으로 보여진다.

• 한국응용과학기술학회지
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• 제32권2호
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• pp.312-319
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• 2015

In this study, n-butanol and ethyl acetate extracts were prepared from raw yam (Dioscorea batatas DECNE.). Their antioxidative potencies were investigated employing various in vitro methods, such as ferrous ion chelating, ${\beta}$-carotene bleaching assay, lipid peroxidation inhibition and nitric oxide (NO) radical scavenging and nitrite scavenging activity. The n-butanol fraction was assayed to possess stronger antioxidant activity by ${\beta}$-carotene bleaching assay, lipid peroxidation inhibition and NO radical scavenging activity. However, ethyl acetate extract was more effective in chelating ferrous ion and scavenging nitrite. Based on the results obtained, yam is a potential active ingredient that could be applied in antioxidation as well as bio-health functional food to take a good part in prevention of human diseases and aging.