• Korean Journal of Food Science and Technology
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• v.44 no.3
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• pp.337-342
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• 2012

The purpose of this study was to investigate total polyphenols, total flavonoid, and DPPH radical scavenging activity in 26 species of Korean natural plants and 14 species of medicinal plant extracts. The plant containing the highest total polyphenols and total flavonoids were Plantago asiatica, and Lespedeza cuneata G. Don, respectively. The content of polyphenols and flavonoids in natural plants was the highest in Lespedeza cuneata G. Don, which also demonstrated high DPPH radical scavenging activity. In medicinal plant extract, Saururus chinensis (Lour.) Baill and Artemisiae Asiaticae Herba had the highest level of total polyphenols (194.60 and 203.92 mg/g extract, respectively) and DPPH radical scavenging activity. Diospyros kaki Thunb and Dryopteris crassirhizoma did not contain high levels of total polyphenols (112.98, 121.46 mg/g extract, respectively) and flavonoids (46.10, 58.69 mg/g extract respectively), but DPPH radical scavenging activity was relatively high. Further study regarding plants that exhibit higher total polyphenols, total flavonoid, and DPPH radical scavenging activity is needed.

• Food Science and Preservation
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• v.18 no.1
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• pp.13-17
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• 2011

The proximate composition, and the levels of total phenols, phenolic acids, and DPPH radical scavenging activity in Cheongdobansi persimmon fruits assayed during development (from July to October), were investigated. All of moisture, crude protein and crude fiber contents decreased as picking time was delayed, however, crude fat content rose. Crude fiber content increased after September. Total phenol content tended to fall during development. The principal phenolic acids were chlorogenic acid, caffeic acid, p-coumaric acid and salicylic acid; the level of each phenolic acid tended to decrease during development. DPPH radical scavenging activity fell as picking time was delayed. Thus, harvest time influenced the levels of chemical components and the antioxidative properties of persimmon fruit. It follows that unripe fruit may be utilized as a raw material yielding many useful products.

• Korean Journal of Medicinal Crop Science
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• v.14 no.4
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• pp.234-238
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• 2006

Changes in the contents of total phenolic compounds in as Orostachys japonicus well as their antioxidant capacity according to the control of night-break, day-length control, variation in luminosity and amount of fertilizer used were examined. The results were compared with those obtained from wild Orostachys japonicus. The contents of the total phenolic compounds in Orostachys japonicus were roughly proportional to the increasing level of irradiation and nitrogen fertilization. The total content of phenolic compounds in the wild Orostachys japonicus of was higher than cultivated under various conditions. The antioxidant capacities of the Orostachys japonicus were increased roughly with increasing level of irradiation and nitrogen fertilization. Overall, the total content of phenolic compounds of Orostachys japonicus and their antioxidant capacity were not significantly affected by the amount of phosphorus and potassium fertilizer used.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.147-152
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• 1999

HPLC was used for determining polyphenols which are known as the functional compounds in the unripe apples Fuji and Aori. The changes in their contents caused by heat treatments were monitored. The carbohydrate contents in Fuji and Aori were 14.1% and 13.5% respectively. Both apple juices showed pH 3.2 and $8.0\;brix^{\circ}$, which were relatively low levels. The major polyphenols were composed of (+)-catechin, chlorogenic acid, (-)-epicatechin, and tannic acid. Total polyphenol contents in Fuji and Aori were 0.11, 0.12% by Folin-Denis method. HPLC analysis of polyphenols showed that four major components were contained by 0.06% in Fuji and 0.07% in Aori. Chlorogenic acid was three times higher in Fuji than in Aori. After water blanching, the area percent of polyphenols resulted in an increase by 3.54% in Fuji but a decrease by 2.93% in Aori. Pasteurization of juices led to decrease by 1.39% and 3.31% respectively. Blanching and pasteurization of unripe apple juices induced negligible changes in polyphenol contents during storage. During concentration, polyphenol contents increased in proportion to the concentration of unripe apple juices.

• Applied Chemistry for Engineering
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• v.9 no.2
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• pp.238-242
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• 1998

Wood powder filled phenolic resin composites of different composition were prepared and their mechanical properties were investigated for optimum conditions. The composites showed maximum mechanical strength when the phenolic resin content was 45 wt%. Polyurethane prepolymer(PU) was evaluated as a modifier of the phenolic resin composites. Blocking of the isocyanates in the PU with phenol was necessary for homogeneous mixing of raw materials for the components. Maximum mechanical strength of the PU modified composites was observed when the PU content was 5 wt%. It was found that the mechanical strength of the composites cured at $210^{\circ}C$ were higher than those of the composites cured at $150^{\circ}C$.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.83-83
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• 2018

최근 매실나무를 기주로 한 겨우살이의 인공재배에 성공함에 따라, 식 의약품과 화장품의 소재 및 산업화 가능성을 확인하기 위해 80% 에탄올 및 증류수 초음파추출물의 총 폴리페놀 플라보노이드 함량 및 DPPH free radical 소거능을 측정하였다. 경기도 남양주시에서 인공재배한 매실나무겨우살이(동결건조) 및 강원도 홍천에서 채취한 자연산 굴참나무겨우살이(열풍건조, $30^{\circ}C$, 7day)의 80% 에탄올, 증류수 초음파추출물에 대한 총 폴리페놀 및 플라보노이드함량 그리고 DPPH free radical 소거능을 측정한 결과, 시료의 농도에 비례하여 총 폴리페놀과 플라보노이드 함량 그리고 DPPH free radical 소거능이 증가하였다. 총 폴리페놀 함량은 매실나무겨우살이의 80% 에탄올 추출물이 5,000ppm에서 $192.63{\mu}g/ml$로 가장 많았으며, 굴참나무겨우살이의 물 추출물이 100ppm에서 $4.86{\mu}g/ml$로 가장 낮고 매실나무겨우살이가 모든 용매에서 더 많은 폴리페놀을 함유한 것으로 확인되었다. 총 플라보노이드 함량은 굴참나무겨우살이의 80% 에탄올 추출물이 5,000ppm에서 $83.59{\mu}g/ml$로 가장 높았으며, 매실나무겨우살이 물 추출물이 $4.6{\mu}g/ml$로 가장 낮았고 굴참나무겨우살이가 모든 용매에서 더 많은 플라보노이드를 함유한 것으로 확인되었다. DPPH free radical 소거능은 80% 에탄올 추출물 5,000ppm에서 매실나무겨우살이 81.75%로 시료 중 가장 높았고, 굴참나무겨우살이 물 추출물 100ppm이 3.55%로 가장 낮음을 확인할 수 있었다. 본 연구 결과에 따르면, 겨우살이를 초음파추출법으로 추출할 때, 80% 에탄올 초음파추출물이 더 많은 폴리페놀을 함유하여 80% 에탄올 추출물이 물 추출물보다 비교적 적합하였다. 80% 에탄올로 초음파추출 하였을 때 동결건조 한 매실나무겨우살이가 열풍건조한 자연산 굴참나무겨우살이보다 더 많은 폴리페놀을 함유하고 있고, 더 높은 DPPH free radical 소거능을 보여줌에 따라 식 의약품 그리고 화장품의 소재화 및 산업화의 가능성이 높음을 확인할 수 있었다.

• Korean journal of applied entomology
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• v.21 no.4 s.53
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• pp.222-226
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• 1982

Changes in levels of phenolic compounds such as total phenols, flavonols and anthocyanins in Macrophoma-infected apples were studied at various developmental stages of apple fruits. The amounts of total phenols in apple fruit flesh and peel drastically decreased as apples became mature. Apple rot resulted in concentration of total phenols somewhat lower than those of healthy apple flesh. The decline in amount of total phenols was distinct in infected fruit flesh of the cultivar Fuji, which was more susceptible to Macrophoma sp. than the cultivar Miller. Higher amounts of total phenols were found in infected than in heathy fruit peel. In the case of the cultivar Miller, increased accumulation of total phenols was pronounced in infected peel. Apple rot resulted in concentrations of flavonols much higher than those of healthy apples. In particular, the drastically increased accumulation of flavonols was detected in infected peel at the first collection on 10 July, when the cultivars tested were completely resistant to Macrophoma sp. Production of anthocyanins was increased considerably by apple rot: anthocyanins in infected fruits of the cultivar Miller increased markedly as compared with their concentration from healthy fruits. These results suggest that the altered phenolic metabolism in apple fruits may be associated with the development of apple rot.

• Korean Journal of Food Science and Technology
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• v.37 no.2
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• pp.178-182
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• 2005

Basic optimal extraction condition and stability data were determined for prediction of usefulness of olive leaf as functional food material. Solid contents of olive leaf extracts increased with increasing extraction temperature and ethanol content, and was the highest (38%) under $85^{\circ}C$, 80% ethanol, and 5 hr treatment conditions, Total phenol contents and electron-donating abilities of olive leaf extracts also increased with Increasing ethanol content, and were the highest under $25^{\circ}C$, 80% ethanol, and 1 hr treatment conditions, then slightly decreased during storage at $25,\;55,\;and\;85^{\circ}C$. Olive leaf extract showed high stability under acidic storage condition, while low under alkalic condition.

• Journal of Ginseng Research
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• v.24 no.4
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• pp.157-161
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• 2000

Cell growth and production of phenolic compounds by callus cultures of Panax ginseng C. A. Meyer were investigated under various phytohormones concentrations and inoculum size. The results indicated that the cell growt was improved by a MS medium supplemented with 2 mg/L of CPA. The maximum cell yield was obtained at inoculum size of 1 g/flasd. The production of phenolic compounds in the callus cultures was higher than those in the ginseng root. Especially, one cell line (20601) showed the highest content of phenolic compounds and antioxidant activity.

• Journal of the Korean Applied Science and Technology
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• v.34 no.1
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• pp.173-182
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• 2017

This study was conducted to investigate the change of Aaster scaber antioxidative activity, total phenolic compounds and flavonoids during the blanching processes. With two parameters such as blanching time and temperature, response surface methodology and central composite design was used to study the combined effect of blanching time (90 to 162 sec) and blanching temperature (75 to $99^{\circ}C$). We found that antioxidative activity, total phenolic compounds and flavonoids during the blanching processes were influenced by blanching temperature and time. Within process condition, total phenolic compounds and flavonoids were extracted 3.00 - 35.48 mg/g and 2.35 - 8.38 mg/g, respectively. DPPH radical scavenging activity was 42.10 - 67.14%. The change of total phenolic compounds, flavonoids, and DPPH radical scavenging activity was dependent of blanching temperature more than time. The total phenolic compounds was increased as temperature rise, but flavonoids not. However, DPPH radical scavenging activity was increased during the blanching process.