• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.2
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• pp.190-194
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• 2008

Physicochemical properties of the green tea component enriched mushroom (Flammulina velutipes) were investigated. The yield of mushroom was highest with green tea powder untreated sample and the yield was decreased by the addition of green tea powder. However, hardness was increased by the addition of green tea powder. Analysis of catechins and caffeine in mushrooms showed that catechins were not transferred into mushrooms, whereas caffeine content was increased. The content of total polyphenol in mushroom was not affected by the addition of green tea powder and crude catechins. Analyses of aroma patterns using the electronic nose based on GC with SAW sensor showed that new peaks occurred from 3 to 6 sec in green tea added mushroom. This study showed that functional components and quality of mushroom were possibly improved by incorporating green tea powder in growth medium.

• 한국약용작물학회:학술대회논문집
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• 2008.11a
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• pp.467-468
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• 2008

• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2003.11a
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• pp.61-64
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• 2003

• Bulletin of the Korean Chemical Society
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• v.30 no.6
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• pp.1373-1375
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• 2009

• Journal of Life Science
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• v.18 no.2
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• pp.273-278
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• 2008

Various biological resources from plants, animals, mushrooms, microorganisms, and foods were tested for the inhibitory activity against squalene synthase (SQS). Among 32 samples, more than one fourths (9 samples) exhibited significant SQS inhibitory activity. Interestingly, SQS inhibitory activity was detected in the samples such as green tea, fermented soybean paste, and plum juice. The SQS inhibitory activity of green tea was not only high but also stable. Its SQS inhibitors were supposed to be catechin derivatives, which have been known to be main bioactive components in green tea. The galloyl catechins showed higher SQS inhibitory activity compared to the nongalloyl catechins. Especially, (-)-epigallocatechin gallate appeared to be strongest inhibitor against squalene synthase ($IC_{50}=90{\mu}M$).

• Korean Journal of Food Science and Technology
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• v.31 no.4
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• pp.1024-1028
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• 1999

Green tea infusions were prepared by extracting them with aqueous solution of different pHs and their physicochemical properties were analyzed. Yellowness, chroma and total color difference values were increased as pH increased. The content of total amino acids in the green tea infusion was not influenced by pH values. Total catechin contents of the green tea infusion extracted at pH 4.0, 5.0, 6.0 and 7.0 were 32.28, 31.84, 31.14 and 14.70 mg/g, respectively. Among the four catechins investigated, epigallocatechingallate and epigallocatechin are more unstable as the pH was changed from 6.0 to 7.0. As pH increased, the extraction of caffeine was also increased. In conclusion, extraction at low pH is preferred for the preparation of green tea infusion.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.4
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• pp.1649-1654
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• 2016

Tea derived from the leaves and buds of Camellia sinensis (Theaceae) is consumed worldwide. Green tea contains various components with specific health-promoting effects, and is believed to exert protective effects against diseases including cancer, diabetes and hepatitis, as well as obesity. Of the various tea components, the polyphenol catechins have been the subject of extensive investigation and among the catechins, (-)-epigallocatechin gallate has the strongest bioactivity in most cases. Our research group has postulated that hepatocyte nuclear factor-$4{\alpha}$, sterol regulatory element-binding proteins, and tumor necrosis factor-${\alpha}$ are targets of green tea constituents including (-)-epigallocatechin gallate for their anti-diabetes, anti-obesity, and anti-hepatitis effects, respectively. Published papers were reviewed to determine whether the observed changes in these factors can be correlated with anti-cancer effects of green tea. Two major action mechanisms of (-)-epigallocatechin gallate have been proposed; one associated with its anti-oxidative properties and the other with its pro-oxidative activity. When reactive oxygen species are assumed to be involved, our findings that (-)-epigallocatechin gallate downregulated hepatocyte nuclear factor-$4{\alpha}$, sterol regulatory element-binding proteins, and tumor necrosis factor-${\alpha}$ may explain the anti-cancer effect of green tea as well. However, further studies are required to elucidate which determinant directs (-)-epigallocatechin gallate action as an anti-oxidant or a pro-oxidant for favorable activity.

• Culinary science and hospitality research
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• v.22 no.5
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• pp.267-276
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• 2016

This study used HPLC to analyze the contents of catechins, alkaloids, and theanine of commercial green tea. Green tea samples were stored for 6 months at five different temperatures, $30^{\circ}C$, $15^{\circ}C$, $4^{\circ}C$, $-15^{\circ}C$ and $-40^{\circ}C$. Catechins change in storage temperature was $30^{\circ}C$ > $15^{\circ}C$ > $4^{\circ}C$ > $-15^{\circ}C$ > $-40^{\circ}C$ stored for 6 months. Total alkaloids content higher levels were CAF(27.49 mg/g) with lower level of TB(2.16 mg/g) and TP(0.28 mg/g). The total alkaloids content decreased in the longer storage periods, a similar case with, although CAF were almost unchanged in all storage temperatures. The results indicate that temperature and storage time are important in the storage of green tea, with refrigerated and frozen conditions as preferable to increase or preserve the chemical compounds of the green tea.

• The Journal of the Korea Contents Association
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• v.12 no.11
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• pp.278-285
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• 2012

In an experiment in which fermentation was done by adding fungal species that have antibiosis but do not have cellulase, the extraction amount of EGC, EC, EGCG, and ECG increased in all samples that fermented by adding sun-dried salt compared to those that fermented only with green tea after fermenting green tea by mixing it with sun-dried salt. In the analysis conducted according to the days of fermentation, the high extraction amounts of EGC(epigallocatechin), ECG(epicatechin gallate), EC(epicatechin), and EGCG(epigallocatechin gallate) were detected on the second and third day. Furthermore, when fermentation was done by adding ferment bacillus, all types of catechin(EGC, EC, EGCG, ECG) extraction increased in Paenibacillus spp but in Bacillus amyloliquefaciens, EGC and EC decreased while EGCG and ECG increased; whereas in Bacillus pumilus and Bacillus subtilis all types of catechin(EGC, EC, EGCG, ECG) decreased. The results of the above experiment reveal that the largest amount of catechin was extracted from the result which conducted fermentation for three days together with sun-dried salt and Paenibacillus spp in the green tea.

• Korean Journal of Plant Resources
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• v.18 no.2
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• pp.351-358
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• 2005

The effects of thiamine-HCl or polyvinylpyrrolidone (PVP) on growth and catechin contents of calli from Camellia sinensis leaves were investigated to improve catechin productivity in callus cultures on the selective medium. The growth of calli was great on the proliferation medium (the MS medium with 0.2 mg/L 2,4-D and 1.0 mg/L TDZ) supplemented with $20{\sim}30\;mg/L$ thiamine-HCl. Although the caffeine content was low in calli compared to young leaves, the total content of catechins was high in calli. Particularly,(-)-epicatechin (EC) which not detected in young loaves was also detected in calli on the propagation medium containing thiamine-HCl or PVP. In addition, the (-)-epicatechingallate (ECG) content was significantly higher in calli than in young leaves. In conclusion, the proliferation medium supplemented with 30 mg/L thiamine-HCl as a vitamin source seemed to be optimal condition for the growth and catechin production in callus culture.