• 한국식품조리과학회지
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• 제21권2호
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• pp.190-194
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• 2005

This study was conducted to investigate the changes in contents of total flavonoid and total polyphenol of three leafy vegetables, spinach(Spinacia oleracea L.), chard(Beta vulgaris L.), whorled mallow(Malva verticillata L.) by various blanching times. Total flavonoid and total polyphenol contents of spinach were 21.01 and 25.58 mg/g, those of chard were 26.02 and 35.14 mg/g, and those of whorled mallow were 16.80 and 19.94 mg/g, respectively. Total flavonoid and total polyphenol contents of chard were the highest among the leafy vegetables. Total flavonoid and total polyphenol contents of leafy vegetables were decreased according to blanching time. Especially, total flavonoid content of chard showed significant loss of $15-30\%$ by blanching time. Total polyphenol content of whorled mallow showed loss of $37-39\%$, but the decrease was not significant.

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.353-358
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• 2023

Barley (Hordeum vulgare) belongs to the Poaceae family. This study compared the polyphenol and flavonoid levels of unfermented and fermented barley sprouts using spectrophotometric assays. The findings indicated that fermentation greatly boosted the flavonoid content but caused only a slight increase in the polyphenol content. However, this does not imply that fermentation has no effects whatsoever on the polyphenol content of barley sprouts. This was due to the fact that some flavonoids cannot be detected by the wavelength used to calculate the overall polyphenol concentration. Both samples were subjected to high-performance liquid chromatography analysis and detected the flavonoids lutonarin, saponarin, isoorientin, isovitexin, and tricin-all of which have bioactive properties-most notably known for their antioxidant activity. These results augment the ongoing phytochemical profiling research and can possibly valorize the already thriving barley industry.

• Food Science and Biotechnology
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• 제17권6호
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• pp.1387-1390
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• 2008

This study evaluated the effects of heat treatment on antioxidant activity of Rehmannia radix Libosch (RRL). RRL was heated at various temperatures ($110-150^{\circ}C$) for various times (1-5 hr), and the total polyphenol, flavonoid content, and antioxidant activity were investigated. With increased heating temperature and exposure time, total content of polyphenol, flavonoid, as well as antioxidant activity increased. The highest total polyphenol and flavonoid contents were 21.65 and 3.56 mg/g, respectively, these values were occurred after heating for 3 hr at $150^{\circ}C$ (RRL was 5.09 and 0.83 mg/g, respectively). The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was highest value of 83.46% after heating for 3hr at $150^{\circ}C$. The 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) cation radical scavenging activity was highest value of 20.43mg ascorbic acid (AA) eq/g after heating for 2 hr at $150^{\circ}C$. There were highly significant differences in the total polyphenol, flavonoid content, and antioxidant activity among heating temperatures and times (p<0.001), with heating temperature having the greater effect.

• 농업과학연구
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• 제50권3호
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• pp.569-580
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• 2023

The aim of this study was to investigate the antioxidant effects of O. robusta stem extract (ORE) and to determine the total polyphenol and flavonoid contents. Free radical scavenging properties were evaluated using DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid)), and ·OH (hydroxyl radical) scavenging assays. Total polyphenol and flavonoid contents were measured using Folin-Ciocalteu reagent and aluminum chloride colorimetric methods, respectively. Active compounds of ORE were determined using high-performance liquid chromatography (HPLC). The results of the study showed that ORE exhibited DPPH, ABTS, and ·OH radical scavenging activities in a dose-dependent manner. Especially, 1,000 ㎍/mL of ORE showed the strongest radical scavenging properties against DPPH, ABTS, and ·OH. ORE contained total polyphenol content of 57.4 mg GAE/g and total flavonoid content of 5.4 mg QE/g, which may contribute to their antioxidant effects. As a result of HPLC, the contents of active compounds in ORE, dihydrokaempferol (0.65 ㎍/mL), and 3-O-methylquercetin (1.10 ㎍/mL) were confirmed. In conclusion, ORE may be useful as a functional material with antioxidant properties.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.307-312
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• 2003

헛개나무를 부위별 추출하여 total polyphenol과 flavonoid, Vitamin C equivalent antioxidant capacity를 연구한 결과 헛개나무의 수피와 열매에서 가장 많이 조사되었고 DPPH free radical scavenging activity에서도 수피와 열매에서 활성이 뛰어났다. 식물 추출물인 Polyphenol성 물질이 많이 존재 할 수록 항산화 활성은 뛰어났다.

• 한국자원식물학회지
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• 제26권3호
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• pp.347-354
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• 2013

Apple and pear are popular fruits consumed in Korea and are common fruit in daily diet. In order to compare the antioxidant activity of the apple and pear peels, total polyphenol contents, total flavonoid contents, $ABTS^+$ free radical scavenging activity, and DPPH free radical scavenging activity were measured from hot water, ethanol, and methanol extracts of the two fruit peels. The total polyphenol and flavonoid contents were highest in 95% methanol extracts of the apple peelsand 70% ethanol extract of the pear peels, respectively. Total polyphenol contents of the pear peels were higher than that of apple peels, and total flavonoid contents of the apple peels were higher than that of pear peels. The apple and pear peels had the highest $ABTS^{+{\cdot}}$ and DPPH free radical scavenging activity in 95% methanol extracts and 70% ethanol extracts, respectively. $ABTS^{+{\cdot}}$ and DPPH free radical scavenging activity of pear peels was higher than that of apple peels, and the DPPH free radical scavenging activity of apple and pear peels were detected in hot water, 95% methanol, and 70% ethanol extracts, respectively. Ascorbic acid, a synthetic antioxidant used as positive control, had significantly higher scavenging activity than the apple and pear peels. In conclusion, the apple and pear peelshave great potential as natural antioxidants. Therefore, above results should be considered to provide the possibility for the development of high functional antioxidants.

• Food Science and Biotechnology
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• 제16권5호
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• pp.828-831
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• 2007

We evaluated the effects of heat treatment on various properties of onion extracts (Allium cepa). Onion was heated at various temperatures ($110-150^{\circ}C$) for various times (1-5 hr), and the total polyphenol, flavonoid, and free sugar contents, and antioxidant activity were investigated. With increased heating temperatures and exposure times, the total contents of polyphenols and flavonoids, as well as antioxidant activity increased. The highest total polyphenol content (189.80 mg/100g) occurred after heating for 2 hr at $140^{\circ}C$. The highest total flavonoid content (252.51 mg/100g) occurred after heating for 3 hr at $150^{\circ}C$. The antioxidant activity assessed using the DPPH method was highest, at 2.1 mg/mL ($IC_{50}$ value), after heating for 2 hr at $150^{\circ}C$. Correlations between antioxidant activity and the total polyphenol, total flavonoid, and fructose contents were highly significant (all p<0.01). The optimal heating time and temperature were 2 hr and $130^{\circ}C$.

• 한국약용작물학회지
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• 제14권5호
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• pp.307-310
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• 2006

This study purposed to look for its uses by analyzing useful substances in kenaf (Hibiscus cannabin us L.) leaves based on the total polyphenol and flavonoid contents in the leaves, DPPH radical scavenging activity of leaf extract, SOD activity, etc. by different growth stage and variety. According to the results of experiment, the total polyphenol content was highest in Everglade-41 (27.9 mg/g dw.), the total flavonoid content was highest in Tainung-2 (42.3 mg/g dw.), and SOD activity was highest in Dowling (96.1 %). However, DPPH radical scavenging activity was similar among the three varieties.

• 한국식품과학회지
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• 제37권2호
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• pp.268-273
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• 2005

끓는 물에 의한 재래적인 방법과 전자렌지를 이용하여 데치는 방법이 시금치의 phytochemical 성분 및 위해성 요인의 변화에 미치는 영향을 살펴보았다. ${\beta}$-Carotene과 chlorophylls 함량은 데치기에 의해 대조군보다 유의적으로 증가하였으며, 특히 재래적인 방법이 전자렌지에 의한 방법보다 높은 함량을 보였는데 chlorophyll a 함량은 유의적으로 증가한 반면 ${\beta}$-carotene과 chlorophyll b 함량은 단지 함량만 증가하였을 뿐 유의적인 차이는 없었다. Ascorbic acid와 총 flavonoid 및 총 polyphenol 함량은 데치기에 의해 모두 감소하였으며, 전자렌지에 의한 방법이 재래적인 방법보다 높은 함량을 보였다. 이때 전자렌지에 의해 데쳤을 경우 ascorbic acid는 대조군과 유의적인 차이 없이 감소하였으나, 총 flavonoid와 총 polyphenol은 대조군보다 유의적으로 낮은 함량을 보여 다소 영향을 받는 것으로 나타났다. 총균과 대장균군 수는 데치기에 의해 모두 유의적으로 감소하였으며 특히 끓는 물에 의한 재래적인 방법이 전자렌지에 의한 데치기보다 약 20-25% 정도 유의적으로 낮았다. Nitrate는 데치기에 의해 감소하는 경향을 나타냈으며 특히 전자렌지에 의한 방법이 재래적인 방법보다 낮은 함량을 보였다.

• 한국응용과학기술학회지
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• 제35권4호
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• pp.1320-1326
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• 2018

건조방법을 달리한 초석잠(Stachys sieboldii Miq.)을 열수 및 70% 에탄올 용매로 추출하여 제조한 후 추출물 농도에 따른 총 flavonoid 및 총 polyphenol 함량, DPPH radical 소거활성, ABTS radical 소거활성, 산화적 스트레스로부터의 신경세포 보호효과에 미치는 효과를 조사하기 위하여 실시하였다. 초석잠 추출물들의 총 flavonoid와 총 polyphenol 함량은 동결건조 열수 추출물에서 각각 가장 높았다(p<0.05). DPPH 및 ABTS radical 소거활성은 농도의존적으로 증가하였으며, $1,000{\mu}g/mL$ 농도에서는 동결건조 열수추출물에서 유의적으로 가장 높게 나타났으나, 대조군인 비타민 C에 비해 유의적으로 낮았다(p<0.05). 신경세포 보호효과는 열품 및 동결건조 열수추출물에서 농도의존적으로 높게 나타났으며, 대조군인 비타민 C에 비해 낮았다(p<0.05). 본 연구를 통하여 열풍건조에 비해 동결건조 초석잠의 열수추출물이 총 flavonoid와 총 polyphenol 함량이 더 높게 함유되어 있어 항산화 활성 및 산화적 스트레스로부터의 신경세포 보호효과가 우수하게 나타내는 것이 관찰되었다.