• Natural Product Sciences
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• v.19 no.4
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• pp.281-285
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• 2013

This study was designed to investigate the nervous sedative effects of green tea. The sedative effect was evaluated by examination of Monoamine oxidases (MAOs) inhibitory activity in vitro in the brain and liver of rat fed on green tea cultivated and harvested from the different regions and periods. It showed that methanol extracts of green tea inhibited significantly the brain MAO-A activity. Especially late harvested green tea extracts showed potential inhibitory activity. The liver MAO-B activity was also inhibited by all of the green tea extracts with strong intensity. This study confirmed that major compounds of green tea such as catechin, epigallocatechin-3-gallate (EGCG) and L-theanine, which were well known for the main bioactive components in the tea plants, were not associated with the MAO inhibitory activities of green tea. These results suggested that a MAO inhibition activity comes from other minor tea components we have to search in the future.

• Korean journal of food and cookery science
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• v.23 no.2 s.98
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• pp.165-172
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• 2007

This study was conducted to investigate the antioxidant amounts and properties of barley leaf tea and green tea at under various leaching conditions. The leaching temperatures and times of the distilled water were 50, 70 and $90^{\circ}$C for 1, 3 and 5 min, respectively. The levels of crude fat and ash in the barley leaf tea were higher than those in green tea. Brown color intensity and flavonoid absorbance increased with leaching temperature. The highest vitamin C levels and water-soluble phenol resulted at $90^{\circ}$C for 3 min. The DPPH radical scavenging activities of the barley leaf tea and of green tea were 11.06 and 50.56%, respectively, compared to 2.9% for L-ascorbic acid (150 ppm). The nitrite scavenging activities of barley leaf tea and green tea were 95.11 and 74.88%, respectively. The SOD-like activities of barley leaf tea, green tea, and L-ascorbic acid (150 ppm) were 12.99, 8.33, and 12.75%, respectively. The antioxidant effect of green tea was higher than that of barley leaf tea and lastly, the SOD-like activity of barley leaf tea was as high as that of green tea.

• Korean journal of food and cookery science
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• v.17 no.3
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• pp.246-254
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• 2001

Effects of added green tea powder and Angelica keiskei powder on the quality characteristics of Yukwa were examined for the purpose of improving functioanality and variety of Yukwa, and usage of green tea Powder and Angelica keiskei. Dietary fiber contents of green tea powder were 5.2% soluble dietary fiber, 22% insoluble dietary fiber, while Angelica keiskei contained 28.9% soluble dietary fiber, 29.6% insoluble dietary fiber. Expansion rate of yukwa was 3,675% for control and the rates were slightly decreased as the addition level increased. Although Yukwas added 6% green tea and angelica keiskei powder were harder than the others when determined by rheometer, sensory evaluation results showed that hardness and mouthfeel were soft without any significant difference among the control and experimental samples. And internal structure of 4 and 6% green tea powder and those added angelica keiskei at three levels were evaluated by sensory panel as moderately compact. Overall acceptability of yukwa added 2% green tea Powder was the best of all while yukwas added angelica keiskei at three levels were evaluated as good. The results of peroxide value and TBA value showed that green tea powder had stronger antioxidative property than angelica keiskei. In conclusion addition of green tea powder by 2% level and angelica keiskei powder up to 4% would give us beneficial effects in the aspects of functionality and storage life of yukwa without any detrimental effects on the quality characteristics of it.

• Korean Journal of Veterinary Service
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• v.28 no.2
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• pp.91-98
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• 2005

Green tea was known which regulated adipocyte differentiation metabolism. The mechanism on the lipid decreased contents of TAG in the plasma. In addition, green tea increased the expression leptin mRNA, PPAR $\delta$ mRNA and TGF $\beta$. The tea tested was korean powdered green tea. In this experiment, Sprague-Dawley (SD) rats were fed $3\%$ green tea(powdered) for 3 weeks on the basal diet and obese diet and green tea grouts-fed pork meats. duck meats. The expression of leptin mRNA and PPAR $\delta$ mRNA were up-regulated in the green tea-fed groups compared with those of the not green tea-fed groups. There were no significantly difference on the expression of leptin mRNA and PPAR $\delta$ mRNA in green tea grouts-fed pork meats, duck meats as compared with the not fed green tea grouts meats. TGF $\beta$ mRNA. TNF $\alpha$ mRNA and adipsin mRNA were not expressed in the pork meats, duck meats. The expression of TGF $\beta$ mRNA, TNF $\alpha$ mRNA and adipsin mRNA were observed in the experimental rats but no significantly difference on the contents. Physiologic regulated genes were not expressed In the green tea grout-fed pork meats and duck meats.

• Journal of the Korean Society of Food Culture
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• v.20 no.6
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• pp.675-682
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• 2005

This study was aimed to determine microbiological quality by adding green tea extracts to chicken meat salad. For this study, Chicken meat salad were prepared with two production method. (method 1: addition of green tea extracts to boiling phase, method 2: addition of green tea extracts to salad dressing) Microbiological effects of green tea extracts were assessed during production process by measuring process time, temperature, pH and Aw and determining total plate counts and coliforms. Effects of green tea extracts on total plate counts and coliforms were observed during holding at 3, 10, $25{\pm}1^{\circ}C$ for 12 hours. Green tea extracts improved the microbiological quality and showed antibacterial properties when they are added to chicken meat salad.

• The Korean Journal of Food And Nutrition
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• v.11 no.6
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• pp.657-661
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• 1998

Green tea powder (3%, 6%, 9%) was added to green tea bread and physicochemical characteristics of green tea bread were investigated. As the result of measuring the pH of the dough, the pH of control was 5.6 and the pH of the investigated. As the result of measuring the pH of the dough, the pH of control was 5.6 and the pH of the samples were 5.34, 5.29 and 5.26 each. As it is seen above, there is no big difference in the pH of the three different dough. Therefore, it could be that the pH of the dough doesn't really affect on the volume of the bread. As the amount of the green powder was changed, the weight of bread, volume of bread, baking loss rate, the color of the surface, the tenderness of the crumb were affected. The 9% of the green powder gave the most distinguishable affect on these factors. As the amount of thee green tea green tea powder caused the change of color. The result of the sensory evaluation showed that the addition of the green tea powder affected significantly on the quality of the bread. Considering the result of the test, 3% of the green tea powder bread is the best for the production of the bread.

• The Korean Journal of Food And Nutrition
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• v.17 no.3
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• pp.266-271
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• 2004

In this study, rice was cooked with 0%, 0.5%, 1.0% and 2.0% green tea powder content to improve functionality of cooked rice. The effects of green tea powder content on the physical, texture and sensory characteristics of cooked rice were examined. Moisture contents of cooked rice with green tea powder were decreased with increasing amounts of added green tea powder. Initial pasting temperature of rice powder was showed an increase with increasing amounts of added green tea powder, besides peak viscosity was decreased. The solubility and swelling power were decreased with increasing amounts of added green tea powder. The color of cooked rice was darkened gradually with the increasing amounts of added green tea powder, and showed the dark green. Sensory adhesiveness was gradually decreased with the increasing amounts of added green tea powder, and cohesiveness, gummness, chewiness and hardness were increased. Sensory glassiness, overcook, stickiness and hardness had lower score than control group, but sensory color, flavor and overall acceptability had higher score with addition of 1.0% and 2.0% green tea powder. Concludingly, in items of overall sensory, cooked rice with 1.0% green tea powder showed the best result.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.1
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• pp.154-159
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• 1995

Inhibition of xanthine oxidase by tea extracts obtained from non-fermented tea(steamed green tea and roasted green tea), semi-fermented tea(oolong tea) and fermented tea(black tea) were investigated. The crude catechin fraciton had a hgher inhibitory effect against xanthine oxidase, and the effect was increased with the addition of tea extracts. Their inhibitory effect were hardly influenced until extracted three times with hot water. According to the investigation of catechins in the crude catechin fraction obtained from tea extracts, (-)-epicatechin-(EC), (-)-epicatechin gallate(ECg). (-)-epigallocatechin(EGC) and (-)-epigallocatechin gallate(EGCg) were 80.1$\mu\textrm{g}$/mg 113.5$\mu\textrm{g}$ /mg, 186.3$\mu\textrm{g}$/mg and 367.7$\mu\textrm{g}$/mg in steamed green tea, and 75.6$\mu\textrm{g}$/mg, 114.7$\mu\textrm{g}$/mg, 193.7 $\mu\textrm{g}$/mg and 381.9$\mu\textrm{g}$/mg in roasted green tea, and 69.4$\mu\textrm{g}$/mg, 110.0$\mu\textrm{g}$/mg, 127.1$\mu\textrm{g}$.mg and 464.9$\mu\textrm{g}$/mg in oolong tea, and 78.1$\mu\textrm{g}$/mg, 171.8$\mu\textrm{g}$/mg, 80.7$\mu\textrm{g}$/mg and 51.4$\mu\textrm{g}$/mg in black tea, respectively. Order of the content of these catechins was (-)-EGCg>(-)-EGC>(-)-ECg>(-)-EC in steamed green tea, roasted green tea and oolong tea, and was (-)-ECg>(-)-EGC>(-)-EC>(-)-EGCg in black tea. Also the concentration of catechins was hardly influeced until extracted three times. The inhibition ratio of xanthine oxidase by autherntic catechins was hardly influenced until extracted three times. The inhibition ratio of xanthine oxidase by authentic catechins was 94.9% and 87.6% by addition of 5.0$\mu\textrm{g}$/ml of (-)-EGCg and (-)-ECg, respectively. the inhibitors of xanthine oxidase were supposed to be due to (-)-ECg and (-)-EGCg in tea polyphenol compounds.

• Integrative Medicine Research
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• v.3 no.1
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• pp.4-10
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• 2014

Green tea and coffee consumption have been widely popular worldwide. These beverages contain caffeine to activate the central nervous system by adenosine receptor blockade, and due to the caffeine, addiction or tolerance may occur. In addition to this caffeine effect, green tea and coffee consumption have always been at the center of discussions about human health, disease, and longevity. In particular, green tea catechins are involved in many biological activities such as antioxidation and modulation of various cellular lipid and proteins. Thus, they are beneficial against degenerative diseases, including obesity, cancer, cardiovascular diseases, and various inflammatory diseases. Some reports also suggest that daily consumption of tea catechins may help in controlling type 2 diabetes. However, other studies have reported that chronic consumption of green tea may result in hepatic failure, neuronal damage, and exacerbation of diabetes, suggesting that interindividual variations in the green tea effect are large. This review will focus on the effect of green tea catechins extracted from the Camellia sinensis plant on type 2 diabetes and obesity, and the possible mechanistic explanation for the experimental results mainly from our laboratory. It is hoped that green tea can be consumed in a suitable manner as a supplement to prevent the development of type 2 diabetes and obesity.

• Journal of Nutrition and Health
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• v.32 no.4
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• pp.337-352
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• 1999

The effects of dried leaf powders and ethanol extract of persimmon, green tea and pine needle on lipid metabolism, lipid peroxidation and antioxidative activity were investigated in rats. Forty-nine male Spargue-Dawley rats weighing 107.8$\pm$1.8g were blocked into seven groups according to body weight. Rats were raised for four weeks with diets containing either 5%(w/w) dried leaf powders of one of three different Korea traditional teas, persimmon(Diospyros kaki Thunb), green tea(Camellia Sinensis O.Ktzc)or pine needle(pinus Koreansis Sieb. Et Zucc), or ethanol from equal amounts of each dried tea powder. Food intake, weight gain, food efficiency ratio, and weights of liver, kidney and epididymal fat were significantly higher in the green-tea-powder group, and significantly lower in the pine-needle-powder and pine-needle-extract groups. Persimmon-leaf powder was found to decrease plasma total lipid, triglyceride and cholesterol concentration by increasing fecal total lipid triglyceride and cholesterol excretions. Liver cholesterol concentration was significantly lower in the green-tea and pine-needle-extract groups. Red-blood-cell superoxide dismutase(SOD) and glutathione peroxidase(GSH-px) activities were significantly increased in rats fed green-tea extract. Liver SOD activity was increased in rats fed pine-needle powder or extract, and liver GSH-px activity was increased in rats fed greentea powder. Plasma and liver thiobarbituric acid reactive substance(TBARS) concentration were both decreased in rats fed dried leaf posers or extracts of persimmon or green tea. It is believed that high vitamin E levels in persimmon leaf, and high flavonoid, beta-carotene and vitamin C levels in green tea effectively inhibited lipid peroxidation. In conclusion, persimmon and green tea leaves were effective in lowering lipid levels and inhibiting lipid peroxidation in animal tissue, while pine needles were effective and lowering body weight gain. From these results, persimmon and green tea leaves can be recommended in the treatment and prevention of chronic discorders such as cardiovascular disease, cancer and aging. As ethanol extracts from these teas were also effecitive in lowering tissue lipid levels and inhibiting lipid peroxidation, we recommend the use of discarded tea grounds for this.