• Preventive Nutrition and Food Science
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• v.14 no.3
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• pp.195-200
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• 2009

This study was carried out to investigate the biological activities of star anise extracts obtained from four different solvents (water, methanol, ethanol and chloroform) by measuring total polyphenol and flavonoid contents, DPPH radical scavenging, hydroxyl radical scavenging, nitrite scavenging activity and antimicrobial activity. The methanol extract showed the highest extraction yield, followed by ethanol, water and chloroform. The properties of the extracting solvents significantly affected the total polyphenol content. Methanol extracts contained more total polyphenols than any other extracts. The highest DPPH radical scavenging activity was found in methanol extract. The hydroxyl radical and nitrite scavenging activity were highest in methanol and ethanol extracts. In antimicrobial activity, water extract showed stronger activities than methanol and ethanol extract against Micrococcus luteus and Bacillus subtilis, and no inhibitory effects on Gram negative bacteria were found in all extracts at the concentration used.

• Food Science and Biotechnology
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• v.15 no.3
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• pp.351-356
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• 2006

In this study, we investigated the effect of adding a 1, 3, or 5% solution of germinated brown rice concentrate (GBRC) to fermented kimchi. During fermentation, the concentration of free amino acids and essential amino acids increased with increasing concentrations of GBRC. In particular, higher levels of free amino acids were associated with a sweet taste compared with controls. The ${\gamma}$-aminobutyric acid (GABA) content of kimchi containing the 5% GBRC solution was 3 times higher than that of controls. The total phenolic compound content (130 mg%) did not change significantly in the control group, but increased in 10 mg% increments as the GBRC concentration rose from 1 to 3 to 5%. 2,2-diphenyl-1-picryhydrazyl (DPPH) free radical scavenging activity and superoxide radical scavenging activity also increased with the GBRC concentration, with maximum activity during the ripe stage with GBRC measured at 79 to 82% compared with controls (30 to 71 %). The nitrite scavenging activity was 10% higher with GBRC compared with controls and was highest when the pH was 1.2. These results showed that the addition of GBRC is effective in improving the function of kimchi.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.3
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• pp.654-659
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• 2008

To confirm possibility of Nelumbo nucifera leaves as biofunctional material, we investigated the antioxidant activity and nitrite scavenging ability of ethanol extract from Nelumbo nucifera leaves. Nelumbo nucifera leaves were extracted with ethanol and concentrated under vacuum using rotary evaporator. Then, antioxidative activity and nitrite scavenging ability of the extract were examined in vitro. Electron -donating ability of the extract at RC50 was 90.19 ${\mu}g/mL$. After addition of 0.96 mg/mL, autooxidation of pyrogallol decreased to 66.19% by superoxide dismutase-like activity. In antioxidative activity of the extract against linoleic acid during incubation times of 24, 48, and 96 hours at $40^{\circ}C$, lipid peroxidation values significantly decreased to 72.53%, 82.00%, 84.69% with addition of 0.2 mg/mL, respectively. Total phenolic content was determined as gallic acid equivalents (GAE) and the value revealed to be $282.84\;{\pm}\;9.03$ GAE ${\mu}g/mg$ of the extract. Nitrite scavenging ability showed the most remarkable effect at pH 1.2, exhibited to 45.55% by addition of 0.2 mg/mL. These results suggest that ethanol extract from N. nucifera leaves can be used as bioactive and functional material.

• Korean journal of food and cookery science
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• v.16 no.4
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• pp.372-377
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• 2000

Six kinds of herbs(applemint, geranium, lemonbalm, rosemary, sage and thyme) were extracted with water and 95% methanol, and the electron donating ability, antibacterial activity and nitrite scavenging effect were examined. The electron donating ability of herbs ranged from 60.7 to 92.2% and the highest value was observed in geranium, followed by sage and lemonbalm. Antibacterial activity of methanol extracts was much stronger than that of water extracts and gram positive bacteria were more sensitive than gram negative bacteria. Rosemary and geranium exhibited excellent antimicrobial activities against a wide range of bacteria. Nitrite scavenging activity, which was measured at various pH conditions(1.2, 3.0, 3.6, 4.2), was the highest in all herbs at pH 1.2 and the lowest at pH 4.2, suggesting that it is pH dependent. Methanol fraction also provided higher nitrite scavenging effect than the water fraction.

• The Korean Journal of Food And Nutrition
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• v.34 no.2
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• pp.181-186
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• 2021

Antioxidant properties and antioxidant activities were analyzed for water extracts and 50% and 70% ethanol extracts of the leaf of Angelica gigas Nakai. The polyphenol and flavonoid contents in water, 50%, and 70% ethanol extract of the leaf of Angelica gigas Nakai, it was found that the polyphenol contents were 18.75 mg GAE/g, 28.95 mg GAE/g, and 34.73 mg GAE/g, respectively, and flavonoid contents were respectively. The DPPH IC50 scavenging activity was 45.84 mg/mL, 36.44 mg/mL, 19.11 mg/mL, respectively, and theABTS+ radical scavenging ability (1 mg/mL) was 28.73%, 22.79%, and 12.70%, respectively. Tyrosinase inhibitory activity, 70% ethanol extract, 50% ethanol extract, and water extract 33.14%, and 4.53%, respectively. Nitrite scavenging activity, 70% ethanol extract, 50% ethanol extract, and water extract were in the order of 1 mg/mL scavenging activity, 36.43%, 34.80%, and 18.85%, respectively.

• The Korean Journal of Food And Nutrition
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• v.28 no.2
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• pp.295-301
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• 2015

Biological compounds such as crude saponin and total polyphenol were determined in Allium hookeri roots and leaves. In addition, activities of DPPH radical scavenging activity, hydroxyl radical scavenging activity, ${\alpha}$-amylase inhibition activity and nitrite scavenging were detected in concentrates of 70% ethanol extracts of Allium hookeri roots and leaves. The crude saponin content of the roots and leaves were 4.28 mg/g, and 4.17 mg/g, respectively. Total polyphenol and total flavonoid content was higher in leaves than roots. Furthermore the DPPH radical scavenging activity and hydroxyl radical scavenging activities of leaves was higher than roots. For ${\alpha}$-glucosidase inhibitory activity, 70% ethanol extracts of Allium hookeri roots and leaves showed 60% activity inhibition at a 10 mg/mL concentration. Nitrite scavenging abilities under acidic conditions were most effective for Allium hookeri leaves extracts. These results suggested that Allium hookeri leaves might be used as the components of health functional food.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.3
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• pp.262-270
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• 2006

This study was performed to investigate the functional properties of roasted Pleurotus eryngii by the extraction conditions. Total phenolic compound content and electron donating ability (EDA) were high at 50% ethanol concentration. Superoxide dismutase (SOD)-like activity was high at 75% ethanol concentration. Nitrite scavenging ability increased as ethanol concentration in extracting solvent decreased. EDA decreased, SOD-like activity and nitrite scavenging ability increased as the extraction time increased. With the increase in extraction temperature, EDA and SOD-like activity decreased. But extraction temperature did not significantly affect the nitrite-scavenging ability With the increase in ratio of sample content to solvent, EDA, SOD-like activity and nitrite scavenging ability decreased. The results would be useful for understanding the extraction condition of roasted Pleurotus eryngii.

• Nutrition Research and Practice
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• v.1 no.3
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• pp.189-194
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• 2007

This study investigated in vitro antioxidant activity of Sonchus oleraceus L. by extraction solvent, which were examined by reducing power, hydroxyl radical-scavenging activity(HRSA) and 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assays. 70% MeOH extract had the greatest reducing power while EtOH extract had the greatest HRSA. The antioxidant activity of S. oleraceus extracts was concentration dependent and its $IC_{50}$ values ranged from 47.1 to $210.5\;{\mu}g/ml$ and $IC_{50}$ of 70% MeOH, boiling water and 70% EtOH extracts were 47.1, 52.7 and $56.5\;{\mu}g/ml$, respectively. 70% MeOH extract of S. oleraceus contained the greatest amount of both phenolic and flavonoid contents. The extracts tested had greater nitrite scavenging effects at lower pH conditions. The cytotoxic activity showed that EtOH extract had the best activity against the growth of stomach cancer cell. These results suggest that S. oleraceus extract could be used as a potential source of natural antioxidants.

• Food Science and Preservation
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• v.9 no.3
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• pp.351-355
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• 2002

The purpose of this study was to investigate the nitrite scavenging, eletron donating activity and antioxidant activity of wood vinegar on soybean oil. Wood vinegar was added to soybean oil in the quantities of 0.5, 1 and 5%. Nitrite scavenging effect of all concentrations diminished at higher pH, while in the case of pH 1.2, it showed a nitrite scavenging effect of more than 80% at concentration above of 100 ㎕/mL. The electron donating activity was about 80% at concentration above of 50 ㎕/mL. Soybean oil without the addition of wood vinegar was used as a control. The oxidation of these samples was determined by measuring the peroxide value(POV), thiobarbituric acid(TBA) value and acid value(AV). When wood vinegar was added 1 and 5%, the peroxide value wag lower than both the control and 0.1% BHT. TBA value were in the 5% wood vinegar tallowed by 1% wood vinegar, 0.1% BHT, 0.5% wood vinegar and the control, respectively. The results showed that the acid values were lowest in 5% wood vinegar, followed by the 0.1% BHT, 1% wood vinegar, 0.5% wood vinegar and finally the control.

• The Korean Journal of Food And Nutrition
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• v.33 no.1
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• pp.64-73
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• 2020

The purpose of this study was to investigate the antioxidant activity and β-glucan content of extracts extracted by varying the temperature at 30, 55 and 80℃ after hot air drying or freeze drying of Pleurotus ostreatus and Pleurotus eryngii. For the analysis antioxidant activity of each mushroom, β-glucan, total phenol, flavonoid contents, and DPPH·ABTS⁺·Nitrite assay were measured. Also, the β-glucan content, total flavonoid content and ABTS⁺ scavenging activity increased with freeze drying rather than hot air drying, and increased with increasing extraction temperature in both mushrooms. However, the total phenol and nitrite scavenging activity increased with hot air drying rather than freeze drying, and decreased with increasing temperature in both mushrooms. DPPH scavenging activity was not significant in both mushrooms, but decreased with increasing extraction temperature. Pearson's correlations between total flavonoid content and antioxidant activities were r=0.719~0.753 (p<0.01). As a result, the β-glucan content, total flavonoid content, and ABTS radical cation scavenging activity were highest during freeze drying and extraction at 80℃. And the highest total phenol content, DPPH radical scavenging activity and nitrite scavenging activity were obtained during hot air drying and extraction at 30℃.