• Korean Journal of Food Science and Technology
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• v.33 no.5
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• pp.626-632
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• 2001

The plant extracted from Nameko, Gallic, Green tea, Allspice, Polygonum multiflorum, Schizandra chinensis, Armeniacae and Pine needle were utilized to investigate the effects of extracts on free radical reaction, lipid oxidation and nitrite scavenging ability. The pH of ethanol extracts showed a higher than that of hot water extracts, among of which were showed the lowest pH 3.0 in Schizandra chinensis. The important factor of lipid oxidation were $Fe^{2+}$ ion and active oxygen, in which were bound by plant extracts in case of $Fe^{2+}$ ion existed. However, the hydroxyl radical scavenging ability of extracts were lowed, compared to extracts reacted with $Fe^{2+}$ ion. Among of them, the hydroxyl radical scavenging ability of Nameko and Pine needle extracts had a lower TBARS value than those of control. The iron content of extracts were less than 2.0 mg/100 g, but the total iron content of Schizandra chinensis extracts were 6.8 mg/100 g. The ethanol extracts of pine needle were higher than those of hot water extracts on the basis of $Fe^{2+}$ ion content. The ascorbic acid content of green tea showed 14.3 mg/100 g in hot water extracts and 16.7 mg/100 g in ethanol extracts. Electron donating ability of extracts showed more than 50%, except Nameko and allspices, which were higher in ethanol extracts than those of hot water extracts. The superoxide dismutase(SOD)-like activity of green tea showed 85.3% and 63.5% in hot water and ethanol extracts, respectively. The nitrite scavenging ability of green tea was the most effective in both extracts.

• Microbiology and Biotechnology Letters
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• v.30 no.3
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• pp.223-229
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• 2002

For the research of the natural marine antioxidant, several bacteria were isolated from the coast of jin-Hae in Korea. Among the marine bacteria studied, strain HJ-14, a gram-negative, motile, strait rod, aerobic, and $Na^{+}$ required bacterium showed high activity of 1,1-diphenyl-2-picrylhydrazyl radical scav- enging. The morphological, physiological, and biochemical characteristics of the strain HJ-14 were similar to those of the Alteromonas macleodii ATCC $27126^{T}$ . Thus, it was tentatively identified as Alteromonas sp. HJ-14. The compositions of major fatty acids in cell membrane of Alteromonas sp. HJ-14 were $C_{ 14:0}$ , $ C_{15:0}$ , $C_{16:0}$ and $C_{17:1}$ $_{w8c}$ , which also suggest that it is affiliated with Alteromonas sp. The optimum culture conditions for production of antioxidant materials with Alteromonas sp. HJ-14 were at $25$~$37^{\circ}C$ and pH 6~8. The optimum conditions for the production of antioxidant for carbon, inorganic nitrogen, and sodium chloride sources were 2.5%(w/v) dextrin, 0.5%(w/v) ammonium sulfate, and 2~6%(w/v) sodium chloride, respectively. The hydroxyl radical scavenging ability of Alteromonas sp. HJ-14 broth was 90.03%, which is higher than ascor-bic acid(83.28%) and lower than butylated hydroxyanisole(95.46%) and $\alpha$-tocopherol(97.17%).

• Applied Biological Chemistry
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• v.49 no.2
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• pp.145-148
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• 2006

Biological activities and application of Prunus sargentii Rehder were investigated. In the physiological activities, the electron donating ability (EDA) of ethanol extracts of Prunus sargentii Rehder was 85% in 100 ppm. SOD-like activity was inhibition about 50% in 1,000 ppm, it was gradual increased. As inhibitory effect of xanthine oxidase, it was more than 70% in 1,000 ppm and inhibitory effect of tyrosinase was a little low as 20% below 1,000 ppm.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.7
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• pp.942-948
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• 2011

The physiological activities of extracts from the leaf, stem, and fruit of Cudrania tricuspidata were investigated. The electron-donating ability (EDA) of the 70% (v/v) ethanolic extract of stem was 90.20%; this was the highest value of all the extracts tested and higher than the L-ascorbate solutions. The total polyphenol contents were the highest in the leaf extracts under all extraction conditions. Especially, 70% (v/v) methanolic extract of leaf contained the highest total polyphenol content of 224.48 mg%. SOD-like activity showed the highest activity in water extract of leaf at 64.53%. Tyrosinase-inhibitory activities were the most effective in all extracts of fruit. ACE inhibitory activities were the highest in water extract of fruit. Nitrite-scavenging abilities under acidic conditions (pH 1.2 and pH 3.0) were the most effective in all the extracts. The results of this study will be useful for understanding the physiological activities of Cudrania tricuspidata extracts.

• Food Science and Preservation
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• v.20 no.1
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• pp.134-139
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• 2013

This study was conducted to develop healthy foods or natural preservatives with garlic (Allium sativum L.), ginger (Zingiber officinale R.) and onion (Allium cepa L.). The polyphenol contents of garlic, ginger and onion juice were analyzed, and they were tested for antioxidative and antibacterial activities. Their antioxidative activities were investigated in terms of their electron donating activity (EDA), SOD-like activity and nitrite scavenging ablity (NSA). Their antibacterial activities were tested against four kinds of pathogenic bacteria (L. monocytogenes, S. aureus, E. coli O157:H7, and Sal. typhimurium). The yields of the garlic, ginger and onion juice were 28.2, 24.3 and 38.3 percent, and their total polyphenol contents were 1,254, 1,523 and 412 mg/100 mL, respectively. The EDAs of the garlic and ginger juice ranged from 95 to 98 percent and over 90 percent in the 40 percent diluted solution. Their SOD-like activities were 64 and 67 percent, repectively. Onion juice had lower activities in EDAs and SOD-like activity than those of garlic and ginger juice. The NSAs of the garlic, ginger and onion juice were 56.5, 52.4 and 50.2 percent, respectively. The garlic juices showed antibacterial activity against four kinds of pathogenic bacteria (L. monocytogenes, S. aureus, E. coli O157:H7 and Sal. typhimurium) and the highest such activity against Sal. typhimurium. From all the results of the experiments, it can be concluded that garlic, ginger, onion can be used as a natural preservatives and can help develope healthy foods because of their antibacterial and antioxidative activities and abundunt polyphenols.

• Food Science and Preservation
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• v.15 no.1
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• pp.111-117
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• 2008

As part of studies on functional food development from the acorn (Quercus acutissima CARRUTHERS), this study investigated the antioxidant properties of the acorn using response surface methodology. Optimal extraction conditions were established by monitoring total phenol levels, electron donating ability, antioxidant ability and nitrite-scavenging action using response surface analysis under a central composite design. The extraction temperature varied in the $30-70^{\circ}C$, the extraction time between 1-5 h, and the solvent ratio was in the interval 5-25mL/g of sample. Extracted total phenols were highest at $57.91^{\circ}C$, 4.08 h, and 22.39 mL/g. This extraction was influenced by solvent ratio, but not by extraction time or temperature. Electron donating ability was found to be highest at $60.37^{\circ}C$, 2.85h, and 6.47 mL/g. The highest antioxidant level was 2.09 AI at $37.11^{\circ}C$, 1.67 h, and 18.84 mL/g, and this value was greatly influenced by all of extraction temperature, extraction time, and solvent ratio. Nitrite-scavenging ability was found to be highest at $47.07^{\circ}C$, 1.24h, and 19.55mL/g. Changes in nitrite-scavenging ability were most influenced by solvent ratio, followed by extraction temperature, but no influence of extraction time within the range tested was found.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.1
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• pp.20-26
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• 2007

We analyzed the contents of polyphenol compounds, the antioxidant activity and the physiological activity to investigate the functional effects of extracts from Angelica dahurica by the reflux water extraction (RW), reflux ethanol extraction (RE) and pressure heating water extraction (PW). The content of phenolic compounds of PW was the highest at 156.30 mg/g, and those of RW and RE were 31.69 mg/g and 26.34 mg/g, respectively. The electron donating ability (EDA) were in the range of 30.56% $\sim$ 52.74% and superoxide dismutase (SOD) like activity were 10.96% $\sim$ 23.24% at 1,000 ${\mu}g/mL$. The nitrite scavenging ability of PW at pH 1.2 was 61.47%, higher than those of RW (16.81%) and RE (17.78%). The xanthine oxidase inhibitory were 90.91% and tyrosinase inhibitory rate of RE was the highest (51.71%) at the concentration of 5,000 ${\mu}g/mL$. All extracts were increased with increments of the extract concentrations.

• Korean Journal of Microbiology
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• v.39 no.3
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• pp.175-180
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• 2003

Microbial Fe(III) reduction is an important factor for biogeochemical cycle in anaerobic environments, especially sediment of freshwater such as lakes, ponds and rivers. In addition, the Fe(III) reduction serves as a model for potential mechanisms for the oxidation of organic compounds and the reduction of toxic heavy metals, such as chrome or uranium. Shewanella putrefaciens DK-1 was a gram-negative, facultative anaerobic Fe(III) reducer and used ferric ion as a terminal electron acceptor for the oxidation of organic compounds to $CO_{2}$ or other oxidized metabolites. The ability of reducing activity and utilization of various electron acceptors and donors for S. putrefaciens DK-1 were investigated. S. putrefaciens DK-1 was capable of using a wide variety of electron acceptor, including $NO_{3}^{-}$, Fe(III), AQDS, and Mn(IV). However, its ability to utilize electron donors was limited. Lactate and formate were used as electron donors but acetate and toluene were not used. Fe(III) reduction of S. putrefaciens DK-l was inhibited by the presence of either $NO_{3}^{-}$ or $NO_{2}^{-}$. Further S. putrefaciens DK-1 used humic acid as an electron acceptor and humic acid was re-oxidized by nitrate. Environmental samples showing the Fe(III)-reducing activity were used to investigate effects of the limiting factors such as carbon, nitrogen and phosphorus on the Fe(III) reducing bacteria. The highest Fe (III) reducing activity was measured, when lactate as a carbon source and S. putrefaciens DK-1 as an Fe(III) reducer added in untreated sediment samples of Cheon-ho and Dae-ho reservoirs.

• Food Science and Preservation
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• v.20 no.4
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• pp.592-596
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• 2013

To stabilize the basal extraction conditions of Leonuri herbal products, three kinds of Leonurus sibiricus water extracts were prepared with different extraction conditions (boiling extraction (I), high thermal process & boiling extraction (II), and wet grinding & boiling extraction (III)), and their physiological properties were investigated. The extraction yields of the L. sibiricus water extracts were from 13.02 to 15.90%, with no significant difference among them. The polyphenol contents were significantly high in extracts (II) and (III) than in extract (I). The $IC_{50}$ for the electron-donating ability was the smallest in extracts (II), (III) and (I) in ascending order. The ABTS radical scavenging ability was significantly higher in extracts (II) and (III) than in extract (I). Also, the ACE in hibition ability for 5 mg/mL of each extract was high in extracts (II) and (III), but there was no significant difference among the three extracts in terms of their nitrite scavenging abilities. Extraction processes (II) and (III) were shown to be useful for preparing Leonurus sibiricus water extracts with healthful properties.

• Korean Journal of Plant Resources
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• v.25 no.4
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• pp.379-386
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• 2012

This study was conducted to compare and analyze change of content of polyphenol and p-hydroxybenzyl alcohol (HBA), which is an index-component, and antioxidant activity between fermented Gastrodia elata Blume and non-fermented G. elata Blume. The polyphenol contents before and after the fermentation were 108.65 and 389.99 mg/mL respectively, and the content of index-component HBA increased from 2.46 mg/g before fermentation to 7.94 mg/g after fermentation. In comparison between the non-fermented G. elata Blume extract (NFGE) and fermented G. elata Blume extract (FGE) in DPPH, ABTS, and superoxide radical scavenging assay, we found that FGE showed more activity than NFGE as the extract was more concentrated. Especially, the superoxide radical scavenging activity was increased more than twenty times in FGE. In conclusion, we confirmed increase in the electron donating ability and radical scavenging when the dried G. elata Blume is fermented, and its further feasibility as an antioxidant.