• Journal of the Korean Society of Food Culture
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• v.25 no.3
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• pp.350-356
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• 2010

When extracts of KMG (Korean mountain ginseng) leaf tea and fermented KMG leaf tea were compared, the fermented KMG leaf tea extract showedhigher activity at each stage of density. Among the material groups, the KMG extract hadthe least profound SOD-like activity, and similar SOD-like activities were noted in the fermented KMG, KMG leaf tea, and fermented KMG leaf tea extracts. With regard to nitrite scavenging ability at a pH of 1.2, the KMG, fermented KMG, and KMG leaf tea groups exhibited similar results, and at pH 3.0, the KMG and KMG leaf tea extract groups exhibited more profound nitrite scavenging ability compared to the fermented groups. In the case of HeLa cell treatments, the KMG and fermented KMG leaf tea extracts exhibited cancer cell propagation restraint rates in excess of 30%, at a density of 1 mg/mL. And MCF-7 cells treated with fermented KMG and KMG leaf tea showedsimilar propagation restraint rates at more than 27% of cancer cells, at a density of 1 mg/mL. Among the materials, the KMG extract hadthe lowest cancer cell propagation restraint rate at 21%, and the fermented KMG leaf tea extract had the highest rate at more than 70%.

• Food Science of Animal Resources
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• v.32 no.4
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• pp.467-475
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• 2012

This study was carried out to investigate the effect of the addition level (0 ppm, 400 ppm, 800 ppm, and 1,200 ppm) of green tea extract on the lactic acid bacteria, oxidative stability, and aroma in kimchi-fermented sausage. The sample sausages were fermented at $24^{\circ}C/RH$ 89% until attained to a pH value of 4.9 (for 17 h), and then dried at $10^{\circ}C/RH$ 75-80% for 6 d. The lactic acid bacteria count and pH value were 7.5-7.7 Log CFU/g sausage and 4.30-4.33, respectively, at 6 d of ripening. The results of those did not show significant differences among all treatments. The formation of TBARS (2-thiobarbituric acid reactive substances) was significantly lowered by increasing the addition level of green tea extract. During ripening periods, the CIE $L^*$ and $a^*$ values decreased; however, the $b^*$ value increased due to the addition of green tea extract. Utilizing an electric nose, the aroma pattern was clearly discriminated between green tea extract treatments and the control. Therefore, in kimchi-fermented sausages, the high addition level of green tea extract improved the lipid oxidation stability. In addition, regardless of the addition level, green tea extract changed the aroma while reducing the color stability. Moreover, it did not have any effect on the growth of lactic acid bacteria.

• Journal of Environmental Health Sciences
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• v.21 no.1
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• pp.39-46
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• 1995

This study was carried out to investigate antibacterial activities of the green tea extract according to storage temperature as death velocity constant. The survey data were collected from seven green teas (2 Korean, 2 Japanese, 2 Chinease and 1 Vietnamese) and experimental strains were used E. coli No. 11234, Ent. aerogenes No. 11783, Ps. fiu. orescens No. 11210, S. marscens No. 11808, St. mutans No. 11823 and V. parahaernolyticus No. 11965. The experimental results obtained were as follows: 1. Antibacterial activities of the green tea extracts according to the strains were strikingly difference. That is, those of the samples appeared to be conspicuous on [St. mutans No. 11823 (Range of death velocity constant a day after, at 20$\circ$C 4.85~5.22) and V. parahaemolyticus No. 11965 (4.70~6.00) while E. coli No. 11234 (0.59~-0.30) and Ent. aerogenes No. 11783 (0.24~-0.11)] were not so. 2. To storage temperature at 5$\circ$C than that at 20$\circ$C, antibacterial activities of the green tea extract on Ps. fluorescens No. 11210, S. marscens No. 11808, E. coli No. 11234, and Ent. aerogenes No. 11783 were sensitived but St. mutans No. 11823 and V. parahaemolyticus No. 11965 were not related to those. 3. Antibacterial activities to the strains were increased within two days.

• The Korean Journal of Food And Nutrition
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• v.35 no.5
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• pp.313-323
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• 2022

To investigate antioxidant effects of tea tree root extracts using various extraction methods, cytotoxicity, DPPH and ABTS radical scavenging, SOD, nitrite scavenging activity and inhibitory activity of lipid peroxidation, reducing power, ferrous ion chelating activity were measured. Cytotoxicity for RAW 264.7 cells was not observed at concentrations treated with below 90 ㎍/mL in all extracts. The maximum DPPH radical, nitrite scavenging, SOD activity and inhibitory activity of lipid peroxidation were obtained at the ethylacetate and 70% ethanol extract. The maximum ABTS radical scavenging activity was obtained at the ethylacetate and hot water extract. However, in the case of reducing power and ferrous ion chelating activity, they were obtained at 70% ethanol and hexane extract, respectively. Nitrate scavenging activity showed the most excellent scavenging ability of 59.6% at 90 ㎍/mL of ethylacetate. The hexane extract had the highest ferrous ion chelating activity, showing 61.05% at 50 ㎍/mL, 66.07% at 70 ㎍/mL and 76.81% at 90 ㎍/mL, respectively. The results of this research show that the ethylacetate and 70% ethanol extracts of tea tree root can be used as a natural material for scavenging the radicals. However, future study is necessary to understand the mechanism of antioxidant activity by identification of substances.

• Journal of the Korean Society of Food Science and Nutrition
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• v.22 no.4
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• pp.374-380
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• 1993

Effect of green tea extract, on duodenal ulceration was studied in male Sprague Dawley rats treated with cysteamine, a drug, which causes duodenal ulcers in experimental animal. As a result, in the proximal duodenum, a significant decrease of ulceration was detected twenty four hours after cysteamine injection in rats raised in green tea extract for 63days. Special reference to duodenal alkaline phosphatase activity was measured in mucosal homogenates. In control rats raised in tap water Riven saline, significant decrease was observed in proximal duodenal alkaline phosphataes activity. The decrease effect seems site specific, since the enzyme in the distal duodenum remains. Moreover the effect cysteamine in control rats alkaline phosphatase is specific, because, in rats raised in green tea extracts did not show significant change in activity. It is suggested that green tea extract acts in ideal properties as an anti-duodenal ulcer agent.

• Biomedical Science Letters
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• v.16 no.4
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• pp.265-269
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• 2010

Puer tea is a traditional beverage originating from Yunnan area of China. We have analyzed 11 different commercial tea brands provided by Daboo Culture and Art Center. This study was carried out to evaluate the contents of polyphenols, antibacterial activity, antioxidantive ability and physiological activities of extracts from Puer tea. The electron donating ability was ranged from 57.26~99.16% and SOD-like activity was ranged from 1.4~10.4%. The inhibitory effect on the growth of cancer cell lines was examined by MIT assay. The Puer tea extract exhibited the greatest inhibitory effect at the concentration of 2% for all cancer cells tested.

• Korean Journal of Food Science and Technology
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• v.31 no.2
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• pp.361-367
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• 1999

It was reported that green tea extract has antioxidant and antimicrobial activities. To improve the quality of seasoned squid, green tea water extract was sprayed on seasoned squid (water content 25%) and water content was adjusted to 27% and 29%. During storage at $30^{\circ}C$, TBA value, total plate count, browning were analyzed. Browning were analysed by 3 different method (absorbance of water solubilized color, 5% KOH-methanol solubilized color and color difference meter). Water and 5% KOH-methanol solubilized color showed good correlation, but color index detected by color difference meter was not. Green tea water extract slowed TBA value increment and reduced total plate count, so it was supposed that green tea water extract acts positively in manufacturing seasoned squid.

• Applied Microscopy
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• v.41 no.3
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• pp.197-204
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• 2011

To investigate the alleviative effect of white tea water extract on the inflammation and skin barrier damage, skin aging animal model was produced by the irradiation of UVB to the backs of hairless mice for 12 weeks. And then experimental materials were applied topically for 4 weeks. At the 28th day of experiment, positive control (PC, 0.01% retinoic acid treatment) and experimental groups (E1, 1% white tea water extract treatment; E2, 2% white tea water extract treatment) had significantly (p<0.001) lower values of both skin erythema index and transepidermal water loss (TEWL) than the control (C, saline treatment) group. The appearance of mast cell and the degree of its degranulation in dermal and subcutaneous layers were remarkably reduced in E1 and E2 groups compared to the C group. It is found that white tea water extract is effective in skin barrier damage and inflammation in hairless mouse.

• Journal of the East Asian Society of Dietary Life
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• v.5 no.3
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• pp.309-315
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• 1995

In this study we isolate lactic acid bacteria from kimchi, which were identified as pediococcus pentosaceus and Lactobacillus bevis by using API 50 CHL Kit, some morphological and physiological tests, The water extract of green tea(50, 100, 500, 1000ppm) inhibieted the growth of pediococcus pentosaceus and Lactobacillus brevis in broth system. Furthermore, their time were prolonged to about 4hours at 500 to 1000ppm. The leakage amount of intracellular materials and Mg++ in tested bacteria cells increased with increasing concentration of green tea water extract.

• International Journal of Oral Biology
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• v.43 no.4
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• pp.193-200
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• 2018

The purpose of this study is to determine if natural extracts could be used as an additive in oral health food made with Weissella cibaria CMU (oraCMU). Natural extracts of green tea, mulberry leaf, licorice, and propolis, which are reported to have antimicrobial activities, were selected and used in this study. The minimum inhibitory concentrations (MIC) of extracts on periodontal pathogens such as Fusobacterium nucleatum and Porphyromonas gingivalis and their synergy effects with oraCMU by the fractional inhibitory concentrations methods were measured. From the results obtained, all the extracts showed no effect on the growth of oraCMU. Green tea extract showed the best antibacterial activity with MIC of 1.8 mg/ml against both F. nucleatum and P. gingivalis. In addition, green tea extract had a synergistic effect with oraCMU against F. nucleatum. Therefore, these results suggested that green tea extract is available as an additive in oral health food made with oraCMU.