• Journal of the Korean Applied Science and Technology
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• v.23 no.2
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• pp.115-124
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• 2006

From the result of pharmacetical characteristics and analysis of Green-tea extract, it could obtain some conclusions as follows. The extract experiment of Green-tea appeared about 10%-extraction ratio as semi-solid state, and after dried in freezing from Green-tea extract of semi-solid state, it obtained about 65% Green-tea extract as solid state. In the results on antimicrobial experiment of Green-tea extract, number of S-typhimurium and fungus in microbe decreased more and more according to the time passage. This phenomenon could show that Green-tea extract keeps antimicrobial effect. In the results on antioxidation experiment of Green-tea extract, DPPH scavenging activity of free radical showed that Green-tea extract appears more remarkable reduction ability than reference samples. This phenomenon means that antioxidation of Green-tea extract appears higher than Vitamin-C and BHA sample. In the results on intrument analysis, the fatty and aromatic components of aniline, acetaldehyde, acetic acid, trichloroethylene, caffeine etcs from Green-tea extract was detected with GC/MS analysis and inorganic components of Ca, Mg, Cu, Mo, Sb, Ti etcs from Green-tea extract was detected with ICP/OES analysis.

• The Korean Journal of Food And Nutrition
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• v.13 no.1
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• pp.13-20
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• 2000

This study was designed the antioxidative effect of the ethanol extract obtained Rooibos tea (Aspalathus linearis) on various kinds of oil, and examined the synergistic effect of Rooibos tea extract by addition of citric acid to the antioxidation activity and also investigate to antioxidation effect of the extract in food production and storage peroids. The antioxidative activity of 0.2mg of Rooibos tea extract was showed similar to same doses of $\alpha$-tocopherol, BHA and BHT in linolieic acid-ethanol system. The antioxidative effect of the mixture with 0.1% Rooibos tea extract on lard was more effective than that of the mixture with same doses of $\alpha$-tocopherol, BHA and BHT. The antioxidative effect of Rooibos tea extract was showed slightly effects on lard or soybean oil. Antioxidative effects of Rooiboe tea extract in addition of citric acid as synergist showed more effective in linoleic acid-ethanol system, but did not showed in the other oils. In the application of Rooibos tea extract to food prodctuction and storage period, the antioxidative effect was more effective in biscult, preparation added lard mixed with 0.1% Rooibos tea extract.

• Journal of Community Nutrition
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• v.8 no.4
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• pp.207-213
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• 2006

The present study was conducted to investigate the effect of oolong tea extract on blood glucose level and antioxidant system in diabetic rats. The Sprague-Dawley rats were fed on AIN-76 based experimental diets containing 1 % oolong tea extract for 6 weeks. They were induced to be diabetic by receiving streptozotocin (45mg/kg BW) intramuscularly. Blood glucose, blood and hepatic concentration of vitamins A and E, and antioxidant enzyme activities were measured. Oolong tea extract feeding decreased the plasma glucose in diabetic rats. Dietary supplementation of oolong tea extract did not affect antioxidative enzyme activities such as superoxide dismutase, glutathione peroxidase and catalase in diabetic rats. The plasma level of retinol was increased in diabetic rats by feeding oolong tea extract. Plasma and hepatic levels of ${\alpha}$-tocopherol were higher in diabetic rats fed oolong tea extract. In conclusion, these results suggest that oolong tea extract consumption might reduce the plasma glucose in diabetic rats and protect the oxidative damage from diabetic stress to some extent.

• Journal of the East Asian Society of Dietary Life
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• v.10 no.1
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• pp.62-70
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• 2000

This study was conducted to investigated the kimchi quality of the addition of green tea extract and green tea leaf. Kimchi was examined for pH, titratable acidity, the changes in the number of microorganism, color,sensory evaluation . The pH and titratable acidity of kimchi at the addition of 5%, 1% of green tea extract and green tea leaf were higher and lower than those of control kimchi. the number of total microoranism at 21 days. were detected much more in the kimchi added green tea extract and green tea leaf than in control. The number of coliforms up to 7 days of fermentation were detected. And those at 14-21 days were not detected but those of 28 days were detected. The number of coliforms at 28 days were most lowest in the kimchi added green tea extract 3%. The number of lactic acid bacteria were detected more in the kimchi added green tea leaf. As a result of sensory evaluation during fermentation, the kimchi added green tea extract 5% was the highest score in carbonated taste. texture and overall quality. As the result of correlation between sensory characteristics and mechanical characteristics, it was found that sensory characteristics of sour taste is negatively related to the mechanical characteristics of L value, while it is positively related to the texture. The a values is negatively related to the sensory characteristics of overall quality. The b values is positively related to the sensory characteristics of sour taste.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.1
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• pp.100-106
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• 1999

Use of chemical preservative for controlling harmful microorganisms in food products has been debated due to public concerns about food quality because of perceived toxic and carcinogenic potential. Thus, use of non toxic natural antimicrobial agents has become essential. This study was investigated to determine the antimicrobial activity of water or ethanol extract of commercially available tea, and of solvent fractionated ethanol extracts obtained from steamed green tea. Both of water and ethanol extracts of green tea(steamed or roasted), oolong tea and black tea exhibited strong antimicrobial activity against gram positive and negative bacteria, but not effective against yeast and mold. Also, antimicrobial activity of ethanol extract of 4 different kinds of tea was stronger than that of water extract. Among 4 different tea, ethanol extract of steamed green tea was further fractionated. One thousand g/disk buthanol extract had the strongest antimicrobial activity against bacteria and mold. The concentration of the antimicrobial activity of buthanol extract in tested microorganisms ranged from 125~1000 g/disk except for Rhizopus javanicus. Antimicrobial activity of buthanol extract of steamed green tea was not destroyed by heating at 100oC for 60 min and at 121oC for 15 min, which is very stable over heat treatment. The inhibitory effect of the buthanol extract on the growth of Listeria monocytogenes and Staphylococcus aureus was investigated. Growth of both strains was started in the presence of 250 and 500 g/ml after 12 and 24 hour respectively, whereas complete inactivation of both strains was occurred in the presence of 1000 g/ml.

• Journal of Nutrition and Health
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• v.34 no.3
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• pp.285-298
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• 2001

The effects of dried leaf powders and water and ethanol extracts of persimmon and green tea on lipid metabolism, lipid peroxidation and antioxidative enzyme activity were investigated in 12-month-old rats. Forty-nine male Sprague-Dawley rats weighing 520$\pm$19g were blocked into seven groups according to body weight. Rats were raised for four weeks with control(no tea leaf powder or extracts) and experimental diets containing either 5%(w/w) dried leaf powders of persimmon(Diospyros kaki Thunb) or green tea(Camellia sinensis O. Ktze), or water or ethanol extract from equal amounts of each dried tea powder. Food intakes of all tea diet groups were higher than that of control. Weight gains and food efficiency ratios of all tea diet groups were not significantly different from those of control. All tea diets decreased plasma triglyceride level, especially, green tea powder and persimmon ethanol diets were more effective than other diet. All the tea diet groups showed decrease in liver triglyceride level, and persimmon powder and ethanol extract increased fecal triglyceride excretion. Plasma cholesterol levels of all the tea diet groups were not significantly different from the control, but control. Fecal cholesterliver cholesterol concegroups were significantlntrations of all tea y lower than that of ol excretions of persimmon powder, green tea ethanol extract, persommon ethanol extract and green tea ethanol extract groups were significantly higher than that of control. Plasma and liver thiobarbituric acid reactive substance(TBARS) concentrations of all the tea diet groups were lower than that of control. Especially, plasma TBARS concentrations of green tea powder and persimmon ethanol extract groups were sinificantly low. Red blood cell(RBC) superoxide dismutase(SOD) activities of persimmon ethanol extract and green tea water extract groups were increased, and RBC catalase activities of all experimental groups were not significantly different. RBC glutathione peroxidase(GSH-px) activities of persimmon ethanol extract, persimmon water extract and green tea powder groups were increased. Liver SOD activities of all the tea diet groups except green tea ethanol extract group were higher than that of control. Liver catalase activities of all experimental groups were not significantly different, and liver GSH-px activity of green tea powder group was significantly higher than that of control. In conclusion, dried leaf powders, and water and ethanol extracts of persimmon and green tea were effective in lowering lipid level, inhibiting lipid peroxidation and increasing antioxdative enzyme activities in 12-month-old rat. Green tea leaf powder with high contents of flavonoids and water soluble dietar fiber was most effective in lowering plasma triglyceride, cholesterol and TBARS level. (Korean J Nutrition 34(3) : 285~298, 2001)

• Food Science of Animal Resources
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• v.41 no.5
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• pp.840-854
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• 2021

The impact of green tea extract powder and rosemary extract powder, alone or in combination, on the quality characteristics of naturally cured pork sausages produced with white kimchi powder as a nitrate source was evaluated. Ground pork sausages were assigned to one of seven treatments: control (0.01% sodium nitrite and 0.05% sodium ascorbate), treatment 1 (0.3% white kimchi powder and 0.05% green tea extract powder), treatment 2 (0.3% white kimchi powder and 0.1% green tea extract powder), treatment 3 (0.3% white kimchi powder and 0.05% rosemary extract powder), treatment 4 (0.3% white kimchi powder and 0.1% rosemary extract powder), treatment 5 (0.3% white kimchi powder, 0.05% green tea extract powder, and 0.05% rosemary extract powder), and treatment 6 (0.3% celery juice powder, 0.05% green tea extract powder, and 0.05% rosemary extract powder). Naturally cured products had lower (p<0.05) cooking yield and residual nitrite content than control sausages. However, compared to the control, naturally cured products with white kimchi powder (treatments 1 to 5) showed similar the pH, oxidation-reduction potential, CIE L^* values, CIE a^* values, nitrosyl hemochrome content, total pigment content, and curing efficiency to the control. When the amount of green tea extract powder or rosemary extract powder was increased to 0.1% (treatments 2 and 4), lipid oxidation was reduced (p<0.05). These results indicate that green tea extract powder, rosemary extract powder, and white kimchi powder may provide an effective solution to replace synthetic nitrite and ascorbate used in traditionally cured products.

• Archives of Pharmacal Research
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• v.29 no.9
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• pp.786-794
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• 2006

We observed the suppressive effect of a powder formulation of African black tea extract prepared from the leaves of Camellia sinensis on type 2 non-insulin dependent diabetic mice, $KK-A^y/TaJcl$. Black tea extract significantly showed suppressive effect of the elevation of blood glucose on oral glucose tolerance test of 8 week-old $KK-A^y/TaJcl$ mice (p<0.05). Long-term treatment with black tea extract showed significant suppression of post-prandial blood glucose and obesity (p<0.05). The weight of the intestine of mice treated with black tea extract was significantly reduced (p<0.05). From these results, African black tea used in this study showed a suppressive effect on the elevation of blood glucose during food intake and the body weight.

• Journal of Nutrition and Health
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• v.31 no.6
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• pp.999-1005
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• 1998

This study was conducted to investigate the effect of late-harvested green tea extract on serum and tissue lipid contents and Ca absorption. Sprague-Dawley male rats weighing 200g were fed high fit diets containing no tea(control), 0.5%(0.5LG), 1.0% late-harvested green tea extract(1.0LG), and 1.0% early-harvested green tea extract(1.0EG) for 4 weeks. Though daily food intake of experimental groups showed no significant difference from that of control group, daily body weight gain and food efficiency ratio were lower in all groups fed green tea extract. The contents of serum triglyceride of 1.0LG and 1.0EG groups and the content of serum total cholesterol of 1.0LG group were significantly lower than those of control group. The values of serum HDL-cholesterol in groups fed green tea extract were higher than that in the control group. LDL-cholesterol and atherogenic indices of all groups fed green tea extract were significantly lower than those of the control group. The contents of total lipid and triglyceride in liver were significantly lower in only 1.0LG group. For epididymal fit pad, the contents of total lipid and triglyceride in 1.0LG and 1.0EG groups were lower than those in the control group. The contents of total lipid excreted in feces were higher in groups fed diets of 1.0% green tea extract. There was no significant difference among experimental groups in Ca absorption. These results suggest that the administration of late-harvested green tea extract decreases the contents of fat in the body without reducing Ca absorption. (Korean J Nutrition 31(6) : 999-1005, 1998)

• Food Science and Biotechnology
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• v.17 no.2
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• pp.421-424
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• 2008

Edible red algae paper coated with green tea ext Tact was prepared and determined the microbial growth and quality change of kimbab wrapped with the paper during storage. The paper coated with green tea extract had the antimicrobial activity against Listeria monocytogenes and Escherichia coli. After 12 hr of storage of kimbab, packaging with the paper coated with green tea extract decreased populations of total aerobic bacteria by 1 log cycle. Kimbab wrapped with the red algae paper coated with green tea extract had 5.5 mg malondialdehyde (MDA)/kg after 12 hr, in contrast to the control of 7.4 mg MDA/kg. Kimbab with red algae paper with green tea extract was better than the control in terms of sensory qualities. These results clearly indicate that kimbab can be packaged with red algae paper coated with green tea extract, resulting in extending its shelf life.