• Proceedings of the Korean Society of Life Science Conference
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• 2006.09a
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• pp.60.2-60.2
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• 2006

• Preventive Nutrition and Food Science
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• v.12 no.1
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• pp.7-10
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• 2007

Theaflavins (TF) and thearubigins (TR) were separated from Korean microbially fermented tea leaves. Contents of TF (74.4 $\mu$M/g) and TR (37.2%) were higher than reported for black tea fermented by oxidase. Antioxidant activities of TF, TR and EGCG were analyzed and protective effects of COS-7 cells against copper and cadmium-induced toxicity were investigated. TF and TR exhibited good inhibition rates of about 85$\sim$90% for antioxidant and scavenging activities of free radicals and protected COS-7 cells against apoptosis or damage caused by stress, such as cadmium and copper-oxidative injury, free radicals etc. These results indicate that TF, TR and EGCG have antioxidant and scavenging activities against free radicals and protect COS-7 cells from Cu, Cd induced injury.

• Journal of Biosystems Engineering
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• v.41 no.2
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• pp.85-92
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• 2016

Background: The same plant, Camellia sinensis, is used to produce all types of tea, and the differences among the various types arise from the different processing steps that are used. Based on the degree of fermentation, tea can be classified as black, green, white, or oolong tea. Of these, black tea is the most or fully fermented tea. The oxidized polyphenolic compounds such as theaflavins (TF) and thearubigins (TR) formed during fermentation are responsible for the color, taste, flavor, and aroma of black tea. Results: Research indicates that an optimum ratio of TF and TR (1:10) is required to ensure a quality cup of tea. The concentrations of TF and TR as well as desirable quality characteristics increase as fermentation time increases, reaching optimum levels and then degrading if the fermentation time is prolonged. It is also necessary to control the environment for oxidation. There are no established environment conditions that must be maintained during the fermentation of the ruptured tea leaves. However, in most cases, the process is performed at a temperature of $24-29^{\circ}C$ for 2-4 h or 55-110 min for orthodox tea or crush, tear, and curl (CTC) black tea, respectively, under a high relative humidity of 95-98% with an adequate amount of oxygen. Conclusion: The polyphenolic compounds in black tea such as TF and TR as well as un-oxidized catechins are responsible for the health benefits of tea consumption. Tea is rich in natural antioxidant activities and is reported to have great potential for the management of various types of cancers, oral health problems, heart disease and stroke, and diabetes and to have other health benefits such as the ability to detoxify, improve urine and blood flow, stimulate, and improve the immune system.

• Journal of Life Science
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• v.17 no.10
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• pp.1354-1360
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• 2007

Theaflavins (TF) and thearubigins (TR) are constituents of tea pigments which are polyphenols derived from Korean fermentation tea. After TF, TR and [(-) epigallocatechin-3-gallate](EGCG) have been applied to macrophage cell line (RAW264.7) nitric oxide (NO) synthesis and cytokines production were estimated. Cytokines production by enzyme linked immune-sorbent assay (ELISA) determined. NO production was increased by about 1.5-folds at the dose of $80\;{\mu}g/ml$ compared to control and lipopolysaccharide (LPS) stimulation when TF, TR and EGCG were applied to a RAW264.7 cell. Interleukin-6 (IL-6), Tumor necrosis factor ($TNF-{\alpha}$) and granulocyte-macrophage colony stimulating factor (GM-CSF) increased depended on concentrations of TF, TR and EGCG. The production of tumor necrosis $factor-{\alpha}$ increased highly in TR, TF and EGCG group with LPS. These results suggest that TF, TR and EGCG have immune-enhancement effect through the cytokine production. TF, TR and EGCG inhibited cancer cell viability, the anticancer effect of these polyphenols may explain the anti-tumor promotion action and antioxidant activity of these tea constituents.

• Journal of the Korean Society of Clothing and Textiles
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• v.22 no.4
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• pp.477-481
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• 1998

Colored components in black tea were extracted, freeze-dried, and analysed to investigate the possibility using as a natural dye. Fractionation of the colored components was carried out by gel permeation chromatography. The colored components in black tea were elected into seven fractions. Each fraction was analyzed by UV spectrophotometer. The early fluted fractions 1-4 did not show any absorption peaks in 320-700 nm and showed the increase in absorption as it approaches to short wavelength and are considered as highly polymerized colored substances. Fractions 5-6 showed tar at 350 m and are considered as thearubigins. Fraction 7 showed absorption peaks at 376 nm and 456 nm and is considered as theaflavin. IR spectra of each fraction show: Strong C=0 stretching band at 1650 cm-1 appears in fractions 1-4, but not in fractions 5-7. Strong C=0 stretching band at 1700 cm-L appears in fraction 3-7. C=0 stretching band at 1610 cm-1 appears as a shoulder in fraction 4 and progressively changes into strong peak in fraction 5-7. From these results, it is assumed that colored components in black tea consist of polyphenolic substances having different molecular weight which were formed during tea manufacturing process. The colorants from black tea infusion were applied to silk, wool, cotton and nylon fabrics. Black tea colorants showed high affinity to wool, silk and nylon, but very low affinity to cotton fabrics.

• Journal of Applied Biological Chemistry
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• v.55 no.1
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• pp.19-25
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• 2012

Green tea leaves were fermented for 15 and 30 days with Monascus pilosus which is known to produce functional statins (TMs), and the content of various biochemical constituents such as total polyphenol (TP), total flavonoid (TF), theaflavin, and thearubigin were analyzed and compared with that of non-fermented green tea (GT) and Pu-erh Chinese post-fermented tea (PU). In addition to the electron donating ability (EDA), ferric iron reducing power (FIRP), xanthine oxidase (XO) inhibitory activity, superoxide dismutase (SOD)-like activity, iron chelating activity (ICA) and hydrogen peroxide contents were also measured and compared with that of GT and PU. Content of TP and TF in the water and ethanol extracts in TMs were lower than those in GT and PU. Theaflavin and thearubigin contents of water and ethanol extracts in TMs were higher than those of GT. And, these components were increased depending on the period of fermentation. While, EDA and FIRP of TMs were lower than those of GT, XO inhibitory activity of TMs was higher than non-fermented tea. While, ICA of TMs was slightly higher than GT and PU, the content of hydrogen peroxide in TMs was markedly lower than GT. This results suggested that the green tea fermented by M. pilosus was valuable for oxidative stress-induced diseases by decreasing hydrogen peroxide, and forming theaflavins and thearubigins with functionality of genus Monascus.