• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.775-781
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• 1995

This study was conducted to find out the variation in some medicinal components of Korean green tea by processing recipe and harvesting time in Bongsan-ri(steamroasted green tea) and Buchun-ri(roasted green tea) area. Total chlorophyll content of green tea grown at Bongsan-ri and Buchun-ri was 293mg% and 275mg% and ratio of chlorophyll a to chlorophyll b was 70:30 and 67:33 respectively. The later harvested one had the higher chlorophyll content but the chlorophyll content of the last harvested green tea at Buchun-ri decreased more sharply. Water-soluble pectin of green tea produced at Bongsan-ri and Buchun-ri was 2.05% and 1.84%, respectively. It also increased at the later harvested ones. Total amino acids content of Bongsan-ri and Buchun-ri tea was 2,156mg% and 1,723mg%, respectively. The later harvested tea showed the remarkably decreased. Caffein and catechins of Bongsan-ri and Buchun-ri tea were 2.03%, 11.52% and 2.62%, 14.05%, respectively, Total free catechins content of Bongsan-ri and Buchun-ri tea was 35.59% and 42.73%, and ester type was 58.09% and 44.47%, respectively. Extracted catechins and caffeins of green tea were increased when extracting water temperature was raised from $65^{\circ}C$ to 85$^{\circ}C$ and leaching time was lengthened from 3min. to 9min. About 89% catechins and 97% caffeins of green tea was extracted by nine minutes soaking in 85$^{\circ}C$ water.

• Journal of the Korean Society of Clothing and Textiles
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• v.23 no.1
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• pp.140-146
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• 1999

Colorants in green tea were extracted freeze-dried and analyzed to investigate the possibility of using as a natural dye. Fractionation of the colorants was carried out by column chromatograpy. Colorants in green tea were eluted into five fractions. All the fractions except fraction F2 showed absorption peakat 280nm. Fraction f2 showed absorption peak at 270nm and broad peak at 350nm, From the IR analysis it is speculated that fractions F2-F5 having similar stucture but different molecular weight are catechis. Silk fabrics dyes with fractions F1-F4 showed yellowish red color while sample dyed with fraction F5 showed red color. The colorants from green tea infusion was applied to silk wool nylon cotton and rayon fabrices. It showed relatively good affinity to protein and polyamide fibers bur low affinity to cellulose and regenerated cellulose fibers.

• YAKHAK HOEJI
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• v.55 no.4
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• pp.332-337
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• 2011

The purpose of this study was to investigate the effect of epigallocatechin gallate (EGCG) on the pharmacokinetics of nimodipine in rats. Pharmacokinetic parameters of nimodipine were determined in rats after oral and iv administration of nimodipine with or without EGCG and also the effect of EGCG on the cytochrome P450 (CYP) 3A4 and P-glycoprotein (P-gp) activity were evaluated. EGCG inhibited CYP3A4 and P-gp activity. EGCG significantly increased the area under the plasma concentration-time curve (AUC) and peak plasma concentration ($C_{max}$) of nimodipine. The absolute bioavailability (AB%) and relative bioavailability (RB%) of nimodipine by EGCG were increased by 16% and by 48%, respectively, compared to the control. In contrast, EGCG did not affect the intravenous pharmacokinetics of nimodipine. Based on these results, the increased bioavailability of nimodipine might be due to inhibition of CYP3A4 in the small intestine and/or in the liver and inhibition of P-gp in the small intestine by EGCG.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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• 2003.10a
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• pp.143.2-144
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• 2003

품종별 감잎의 주요성분과 항산화 활성을 비교하여 고기능성 감잎차의 우수성을 알리는 기초자료로 활용하고자 이 실험을 수행하였다. 상주둥시, 갑주백목, 월하시, 청도반시, 녹차(대조구)의 생엽을 7월 초순에 채엽 후 건조시켜 시료로 사용하였고, 비타민C, 카페인, 카테친, Gallic acid, 향기성분, 유리당, 유리아미노산, 칼슘, 항산화 활성을 조사하였다. 비타민C는 월하시 0.089%, 청도반시 0.079%, 갑주배목 0.032%, 상주둥시 0.015%, 녹차 0.01%로 비타민C 함량이 가장 많은 월하시가 녹차에 비해 8배정도 높았고, 카페인은 감잎 4품종 모두 발견되지 않았고, 녹차는 6.63%이었다. 카테친은 청도반시 0.35%, 갑주백목 0.34%, 월하시 0.24%, 상주둥시 0.18%, 녹차(대조구) 0.07%이였고, Gallic acid는 상주 둥시 0.32%, 갑주백옥 0.2%, 월하시 0.05%, 청도반시 0.03%, 녹차(대조구) 1.41%이었다. 칼슘은 청도반시 9516.1PPM, 영동월하시 6863.5PPM, 봉옥 6563.5PPM, 상주둥시 5420.1PPM, 녹차(대조구) 2349.7PPM이였고, 유리당은 감품종간에는 큰 차이는 없었으나 녹차에 비해 Xylose, fructose, Glucose, Sucrose의 함량이 높았고, Maltose의 함량에 일어서는 녹차가 높았다. 유리아미노산은 31항목을 조사하였고, 전체 함량은 상주둥시 60.40, 봉옥 53.21, 월하시 52.29, 청도반시 47.58, 녹차(대조구) 114.72nmo1/${\mu}\ell$이었다. 시료의 향기성분은 생엽을 건조시켜 전자코를 이용하여 분석하였고, 감잎 품종간에는 향기 패턴이 비슷한 경향이였으나, 녹차의 패턴과는 차이가 있었다. 감잎의 DPPH radical 소거활성은 상주둥시 RC$_{50}$($\mu\textrm{g}$)=64.5 청도반시 64.0, 월하시 42.0, 갑주백목 47.0, 녹차(대조구) 19.0으로 김잎품종중 월하시의 항산화 활성이 높았고, 녹차의 항산화 활성이 감잎에 비해 높았다.

• Korean Journal of Food Science and Technology
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• v.40 no.3
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• pp.265-270
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• 2008

This study examined the effects of treating green tea leaves with ozonated water by evaluating pesticide residue levels and catechin content. The pesticide residue levels of tea leaves treated with carbendazim, captain, diazinon, fenthim, dichlorvos, and chlorpyrifos ranged from 43.2 to 48.2 ppm. For leaves treated by soaking or watering with tap water, or with 0.25 ppm of ozone water for 30 min. Pesticide residue levels were reduced by 24.0-30.2%, 30.3-33.6%, 52.4-70.5%, and 65.5-80.2%, respectively. No major differences in catechin content were observed in the leaves according to the soaking and rinsing treatments using ozonated or tap water.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.2
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• pp.224-232
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• 2008

The health benefits associated with tea consumption have resulted in the wide inclusion of green tea extracts in botanical dietary supplements, which are widely consumed as adjuvants for complementary and alternative medicines. Tea contains polyphenols such as catechins or flavan-3-ols including (-)-epicatechin (EC), (-)-epigallocatechin (EGC), (-)-epicatechin gallate (ECG), and (-)-epigallocatechin gallate (EGCG), as well as the alkaloid, caffeine. The contents of catechins and caffeine in green tea are considered as a standard of quality evaluation of green tea. Therefor, the purpose of this study was to investigate the most suitable HPLC condition for simultaneous determination of catechins and caffeine in green tea extracts. The efficient HPLC analytical condition of catechins and caffeine contained green tea extracts was developed. The gradient elution employed a $250\;mm\;{\times}\;4.6\;mm$ i.d. YMC-pak ODS-AM 303 column. The gradient system was used two mobile phases. A gradient elution was performed with mobile phase A, consisting of 0.1% aqueous phosphoric acid, and mobile phase B, comprising 100% MeOH, and delivered at a flow rate of 1 mL/min as follows: $0{\sim}25\;min$, 80% A; $26{\sim}50\;min$, $80{\sim}70%$ A; 51 min, 80% A. $51{\sim}55\;min$, 80% A. The UV detection wavelength was set at 280 nm. The limit of detection (LOD) for catechins and caffeine standards were under 50 ng/mL.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.356-362
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• 2003

The present study was conducted to know the physicochemical properties of non fermented tea and fermented teas with the fermented time of 0 hr (non fermented tea), 10 hrs, 17 hrs (semi-fermented tea), 24 hrs (black tea), respectively The moisture content of non fermented tea, semi fermented, and black tea was 3.01% ~ 3.29%. The contents of reducing sugar, crude lipid, crude protein were increased and that of ascorbic acid was decresed with fermentation. The total contents of those increased as tea was more fermented. The contents of the citric acid and the malic acid were increased with fermentation, but the content of the succinic acid was decreased. However, the total content of organic acid was generally increased with fermentation. The total content of the amino acid was increased with fermentation. In non fermented tea, Thr+theanine, the Asp, and the Glu, were determined in order of content. In semi-fermented tea and black tea, Ter+theanine, Glu, and Asp were determined in order of content. The rate of essential amino acid in the total content of free amino acid was increased with fermentation. The content of theanine was 1.21% in non fermented tea and 1.50% in black tea. The contents of theanine were increased as tea was more fermented. The content of caffein was 3.57% in non fermented tea and 3.55 ~ 3.60% in semi-fermented tea and black tea. These results were inconsistent in the content of caffein. Five kinds of catechin, that is, cathechin, epigallocathechin, epicathechin, epigallocathechin gallate, and epicathechin gallate were extracted. The content of catechin was 14.18% in non fermented tea, but decreased sharply as tea was more fermented.