• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.3
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• pp.413-417
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• 2003

To evaluate the antimicrobial activity of green tea against putrefactive microorganism in steamed bread, antibacterial activity of green tea extract against well-known strains of spoilage bacteria (Bacillus subtilis ATCC 6633, Bacillus pulmilus KCTC 3348 and Bacillus cereus IFO 12113) and mold (Aspergillus niger KCCM l1239) in bread was determined using the paper disk method. The green tea extract (GTE) showed the inhibition effects on the growth of all the strains of bacteria and mold at 1, 2, 3% levels. The activity of GTE was stable in the wide range of pH (4~9) and temperature (50~20$0^{\circ}C$). When green tea powder (GTP: 1, 3, 5%) was added to steamed bread increase of total bacterial and mold counts declined during storage at 25"C as the levels of GTP increased. By addition of 5% GTP, mold appeared 1 day late extending shelf life of steamed bread compared to control bread without GTP. Therefore, the levels of GTP added to steamed bread could be more than 5% for extended shelf life and wholesomeness of steamed bread.read.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1185-1193
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• 2006

This study investigated the effects of green tea on the disorders of lipid metabolism, oxidative system and hepatic functions induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), using adult male rats (SD) for 3 weeks. These 36 animals were divided into four groups. TCDD ($50{\mu}g/kg$ BW) was intraperitoneally injected at the beginning of experiment. Green tea powder was added 1% or 3% levels in basal diets respectively. Relative weights of thymus were decreased about one-third of control group, but those of liver, brain and testis were significantly increased in rats treated TCDD. Neutrophill% and lymphocyte% by TCDD treatment was improved by green tea diets. In liver functional enzyme, elevation of glutamic oxaloacetic transaminase (GOT) and alkaline phosphatase (ALP) activities due to TCDD treatment was lowered by green tea diets. The concentrations of serum and liver lipids were significantly increased by TCDD treatment, however, those of serum and liver triglyceride tended to decrease by green tea diets. Fecal lipid excretion was increased in rats fed green tea diets. Especially, fecal total cholesterol level was significantly elevated by 3% green tea diets. The activities of superoxide dismutase (SOD) were increased in rats fed 3% green tea diets. Increment of benzphetamine N-demethylase (BPND) activity by TCDD treatment was declined by 1% green tea diets. These results indicate that green tea can exert improving effects on liver lipid accumulation and unfavorable hepatic functions, and elevate antioxidation.

• Korean journal of food and cookery science
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• v.18 no.1
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• pp.57-62
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• 2002

The purpose of this study was to investigate the antibacterial activity of green tea in mayonnaise against pathogenic bacteria (Escherichia coli O157:H7 and Salmonella typhimurium). Mayonnaise was prepared with salad oil, egg yolk, sugar, salt and vinegar, and green tea powder was added to the mayonnaise at 0.1, 0.3 and 0.5% for the experiment. Then, the mayonnaise samples with various levels of green tea were inoculated with about 10$\^$6/ cells/g of E. coli and S. typhimurium per 1 gram of mayonnaise and stored at 5$^{\circ}C$, 15$^{\circ}C$ and 25$^{\circ}C$ for 3∼9 days. Antibacterial activity of green tea was tested by the colony counting method for E. coli on violet red bile agar(VRBA) and S. typhimurium on xylose lysine desoxycholate agar(XLDA). The D-values of E. coli controls were 2.89, 2.73 and 2.13 days while those of S. typhimurium controls were 0.58, 0.53 and 0.52 days at 5$^{\circ}C$, 15$^{\circ}C$ and 25$^{\circ}C$, respectively Inhibitory effect of green tea in mayonnaise on the survival of E. coli and S. typhimurium was increased with increasing concentration of green tea and/or increasing storage temperature. The most effective antibacterial activity of green tea was shown against E. coli in mayonnaise during storage at 25$^{\circ}C$.

• Korean Journal of Agricultural Science
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• v.42 no.4
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• pp.407-414
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• 2015

To increase antioxidative activity of Chungkukjang, the protective effect of Seoritae Chungkukjang (SC) added with green tea powder against oxidative stress was evaluated under the cellular system using LLC-$PK_1$ cells. The treatment of 3-morpholinosydnonimine showed increase in lipid peroxidation, and decrease in endogenous anti-oxidant enzymes activity and cell viability. The methanol extract of SC inhibited lipid peroxidation by 70.9%, and significantly increased cell viability up to more than 33.2%. In addition, it enhanced superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities. Particularly, the addition of green tea in SC exerted protective effect against oxidative stress by ONOO- through elevation in activities of SOD and GSH-Px, and inhibition of lipid peroxidation. More addition of green tea showed stronger protective activity. These results suggest that the addition of green tea to SC leads to the increase in the antioxidative effect of Chungkukjang through elevation in antioxidative enzyme activities and protection from lipid peroxidation.

• The Korean Journal of Food And Nutrition
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• v.19 no.2
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• pp.227-233
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• 2006

The effects of adding green tea powder(GTP) on the quality and storage characteristics of sikhe, Korean traditional sweet rice drink, were studied, The values of sweetness and pH of the sikhe with GTP were $18.40{\sim}18.50%\;and\;5.81{\sim}5.85$, respectively. The L and a values were decreased, but the b value was highly increased when the amounts of GTP were increased. Sensory evaluation showed that color and flavor of sikhe made of GTP were the highest among the treatments. However, sweetness of sikhe with GTP was lowered as the addition of GTP was increased. Sensory attributes such as taste, tenderness, aftertaste and overall acceptability were significantly higher in sikhe perpared with 2% GTP than those of control group(p<0.05). During the storage, pH of the sikhe with GTP was not significantly changed at the nineteenth day of storage, but pH of control group was markedly decreased. The L, a and b values showed no significant changes during storage.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.7
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• pp.980-985
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• 2000

Influences of Japanese green tea powder (GTP) supplementation to commercial diet on laying performance and egg quality were studied by using 60 laying hens. The experimental diet with or without 0.6% GTP was given ad libitum to the birds during the period from 6 to 71 weeks of age. The birds started egg production from 21 wk of age regardless GTP feeding. Body weight, feed intake, egg weight tended to decrease with GTP supplementation, while egg production rate tended to increase. Haugh unit score was significantly increased with GTP, which accompanied with the increased albumen height. These were observed almost throughout the laying period over 50 wk. Gel proportion in thick albumen was decreased as storage time is prolonged, then higher values of the gel proportion were recorded in the eggs from GTP group. Thick albumen of the eggs from GTP-fed layers had more carbohydrate than that from control layers. All these indicate physical stability of thick albumen in the eggs from GTP group. Thiobarbituric acid content of egg yolk tended to remain lower in the eggs from GTP group during 5-10 days of storage at room temperature. Levels of egg yolk cholesterol and yolk lipid were significantly reduced by GTP feeding. There were no significant differences in eggshell weight, shell thickness and shell strength between the two groups. Thyroid gland and liver from hens slaughtered at 71 wk of age did not differ in weight irrespective of GTP feeding. The present results suggest that GTP could modify components of edible part of egg, leading to the characteristics favourable to consumers such as high durability of thick albumen and less cholesterol in yolk, without altering general performance of the layers throughout this year round experiment.

• Journal of the East Asian Society of Dietary Life
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• v.12 no.2
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• pp.135-140
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• 2002

Mungbean starch gels(MSG) was prepared by adding green tea powder(GP) in the ratio of 0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5% and 3.0% and tested for sensory characteristics, chromaticity and rheological properties. In sensory evaluation test, 1.5% GP added MSG gave the highest score in color, 1% GP added MSG in flavor and overall quality and 0.5% and 1.0% GP added MSG was evaluated higher than control in general. In chromaticity tests lightness(L) value of MSG decreased as the ratio of GP increased. In rheometer test, 2% and 2.5% GP added MSG showed the high values in hardness, cohesiveness, gumminess and brittlness.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.3
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• pp.552-556
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• 2001

The purpose of this study was to investigate the antioxidant effect of aqueous green tea(AGT) on soybean oil. AGT was freeze-dried and 20% of the freeze-dried aqueous green tea powder (AGTP) was added to soybean oil in the quantities of 0.5%, 1% and 5%. Soybean oil without the addition of AGTP was used as a control. Soybean oil with 0.02% butylated hydroxytoluen(BHT) was used as another experimental sample. Each sample was stored at 6$0^{\circ}C$ for 15 days. The oxidation of these samples was determined by measuring the acid value (AV), peroxide value (POV), and thiobarbituric acid (TBA) value. The result showed that the acid values were lowest in 0.02% BHT, followed by the 0.5% AGTP, 1% AGTP, 5% AGTP and finally the control. When AGTP was added, the peroxide value was lower than both the control and 0.02% BHT. The lowest TBA values were in the 0.5% AGTP followed by 0.02% BHT, 1% AGTP, 5% AGTP and the control, respectively. The 5% AGTP (285 min), 1% AGTP (249 min) and 0.5% AGTP (238) demonstrated longer induction periods, compared to the control (204 min) and the BHT (229 min) by Rancimat method.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.6
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• pp.1580-1584
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• 2005

Antioxidative activities of catechin from green tea extracts were examined by the methods of 1,1-Diphenyl-2-picrylhydrazyl (DPPH) electron donating ability, hydroxy scavenging activity and the inhibitory effect on xanthine oxidase activity. The resulted demonstrated the fact that Catechin one (containing Green tea extracts plus catechin 51%) of green tea extracts product showed at 65.5% in electron donating activity on the DPPH. The electron donating ability on the DPPH of Catechin one was increased to 10% than purified catechin. Catechin one showed the activity at 64.5% in scavenging activity using hydroxy radical method. To the Catechin one provided to increase the hydroxy scavenging activity up to 3 fold. Inhibitory effects of the catechin one measured with xanthine oxidase method was 6.5%. Although the antioxidative activity of catechin (98% purified) was lower than that of Catechin one (containing Green tea extracts plus catechin 51%) in same catechin concentrations ($5{\mu}g$, respectively). Therefore, we may suggest that Catechin one can be used as a functional food additive possessing the potent antioxidative activity.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.5
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• pp.495-500
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• 2004

This study was carried out to develop a new product using Cheonggukjang (fermented soybean product) and sub-ingredients(lactic acid bacillus powder, chlorella, lactose, green tea). Fresh Cheonggukjang was dried by a infrared drying(50℃, 36hr) and powdered by a roll mill. The powder was mixed with sub-ingredients and then moulded as tablet type by a press moulder. The pH of tablet was low with the addition of lactobacillus and total sugar content was high with the addition of lactose. Disintegration, absorption capacity and textural properties of tablet were not affected by the addition of any sub-ingredient. Color of non-added tablet was yellow to red, but changed to green when chlorella was added. Sensory properties(color, taste, flavor, chewiness, hardness, acceptability) were not affected by the addition of sub-ingredients. The results indicate that functional healthy tablet could be made from Cheonggukjang powder and various sub-ingredients.