• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.1
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• pp.132-139
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• 2004

This study was peformed in order to compare general components, color, free amino acid, fatty acid and organic acid contents between commercial doenjang (C-1, C-2, C-3) and green tea doenjang (GT). The moisture content in green tea doenjang was higher than that in commercial doenjang, but the contents of crude protein, carbohydrate and energy in commercial doenjang were higher than those in green tea doenjang. The crude lipid and fiber contents of commercial doenjang were similar to green tea doenjang. Catechin content of green tea doenjang was 2.3%. The total content of free amino acids in commercial doenjang ranged from 2,739∼6,380 mg% in which it showed wide variation among samples and the total content of free amino acids in green tea doenjang was 3000 mg%. Glutamic acid was almost high in commercial doenjang except one product but green tea doenjang was low. Linoleic acid (51%) was the highest content among the fatty acids. The major organic acid in both commercial and green tea doenjang was oxalic acid and its content in commercial times higher than in green tea doenjang. The antioxidant activity of green tea doenjang was higher than that of commercial doenjang.

• Culinary science and hospitality research
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• v.5 no.2
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• pp.133-146
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• 1999

Green tea is popular as health food these days and has effects of anti-cancer and an-agering. A various Foreign countries produce green health cookie adding the first, the second and third classes green tea on a commercial. The cookie is produced by wheat flour adding 4% green tea. The changes of taste depending on the quality of green tea are examined through the five sense and the mechanical inspection. The results are as follow: First, as the quality of green tea is higher score is achieved. Second, as the quantity of green tea is increased, the goods are harder in the five sence inspection. Third, as the quality of green tea is higher, brightness is lower in the measurement of color. Therefore, this study indicates that it is desirable to use the good qualify of green tea in case of producing cookie on a commercial scale.

• Journal of the Korean Society of Food Culture
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• v.22 no.5
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• pp.615-620
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• 2007

Physicochemical and sensory characteristics of the green tea dasik varying the added value of oligosaccharide were investigated and the products were surveyed by elementary school students regarding the acceptability. Protein and ash contents were significantly higher and fat contents were significanlty lower in the samples with oligosaccharides compared to those in commercial ones(p<0.05). Commercial samples had significantly higher values in all of the textural characteristics using textural analyzer compared to those of the developed dasik sample groups. In analytical sensory evaluation, varying the amount of oligosaccharide, commercial samples had significantly higher values of sweetness, hardness, and cohesiveness and lower values of savory aroma and falvor compared to those of developed dasik(p<0.05). Savory aroma and flavor were highly negatively correlated with textural hardness, springiness, chewiness, gumminess, and cohesiveness(p<0.01), while sensory sweetness and hardness were significantly positively correlated with textural springiness(p<0.05), chewiness, gumminess, and cohesiveness(p<0.01). When surveying elementary school students regarding the acceptability of green tea dasik and commercial samples, green tea dasik 2 was the most preferred with significance in color. Regarding aroma, green tea dasik 1 received the highest acceptability (p<0.05). In the flavor, both dasik 1 and 2 received higher score than those of the commercial dasik. In overall acceptability, both green tea dasik 1 and 2 were preferred to the commercially sold ones with significance(p<0.05).

• Journal of the Korean Society of Food Culture
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• v.22 no.5
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• pp.609-614
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• 2007

Quality characteristics of dasik were studied with varied the levels of rice grain particle size and green tea powder and compared them with commercially sold dasik. Among the samples with the same number of grinding times, the sample groups with the higher amount of green tea showed significantly the less mosture content(p<0.05). Hardness was higher in the samples containing higher amount of green tea among the ones with the same grain size (p<0.05). The M13G0.5 was evaluated to have the highest savory aroma with significance (p<0.05), and C1 to have the highest sweetness by sensory analysis. The developed dasik samples with lower rice grain particle size had significantly lower adhesiveness, chewiness, gumminess, and cohesiveness compared to those of commercial sample groups. In sensory tests, the compared groups showed significantly the higher savory aroma and flavor and very lower hardness when compared to those of commercial sample groups. With the results above, dasik with with varied the levels of rice grain particle size and green tea powder were developed with improved qualities compared to those of commercially sold dasik.

• Korean Journal of Food Science and Technology
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• v.54 no.2
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• pp.228-234
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• 2022

Various types of tea have been cultivated to obtain different flavors and enhance their functional properties. The objective of this study was to investigate the physicochemical properties of γ-aminobutyric acid (GABA) teas produced from commercial Korean green, white, and black teas. The concentration of total minerals was reduced in GABA green tea and GABA white tea but was improved in GABA black tea. The essential, non-essential, and total free amino acid contents were remarkably increased in the GABA teas. The amino acid GABA content was increased by 561.00 and 294.20 times in GABA white tea and GABA black tea, respectively. The antioxidant potential was not reduced, although the total polyphenol and total flavonoid contents decreased in GABA green tea and GABA black tea. The results indicated that the overall nutritional value of commercial green, white, and black teas could be improved by processing them into GABA teas.

• Korean Journal of Food Science and Technology
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• v.24 no.2
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• pp.177-179
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• 1992

The theanine contents of commercial green teas manufactured by the different harves times(1st tea, 2nd tea and 3rd tea) and processes(steamed and parched teas) were determined by amino acid analyzer. There were remarkable differences in the theanine contents among teas of the different harvest times. The theanine content in 1st steamed green tea was 2235 mg% and one in 1st parched green tea was 2106 mg%. The theanine contents in 2nd, 3rd tea were gradually decreased. There were slight differences in the theanine contents among teas of the different process.

• Journal of Life Science
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• v.5 no.2
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• pp.20-20
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• 1995

The aroma components of commercial green teas picked inAugust were collected and identified. The extract of aroma compounds in green tea were accoimplished by a modified rotary evaporation. The concentrated wxtracts were analyzed and identified by GC and GC-MS. In GC analysis, T$_{R}$ value of GC represented bt KI value which standardized. The most abundant components of green teas picked in August were 1-Penten-3-ol, trans, trans-2, 4-heptadienal, linalool, $\beta$-ionone and nerolidol.

• Journal of Life Science
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• v.5 no.2
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• pp.76-80
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• 1995

The aroma components of commercial green teas picked inAugust were collected and identified. The extract of aroma compounds in green tea were accoimplished by a modified rotary evaporation. The concentrated wxtracts were analyzed and identified by GC and GC-MS. In GC analysis, T$_{R}$ value of GC represented bt KI value which standardized. The most abundant components of green teas picked in August were 1-Penten-3-ol, trans, trans-2, 4-heptadienal, linalool, $\beta$-ionone and nerolidol.

• Korean Journal of Medicinal Crop Science
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• v.14 no.6
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• pp.322-328
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• 2006

Green tea is of particular source as it has been found to have strong antioxidant activities. The extracts of green tea during the commercial harvest seasons from April, 2003 to August, 2003 were compared. The purpose of this study was to determine the correlation between the polyphenol content of green teas and its antioxidant activities. The con-tent of total polyphenols was analyzed and several antioxidant testings were performed. The levels of total polyphenols were higher in the green teas (e.g. Woojeon, Sejak) harvested during very early spring and lower in the green teas harvested late(eg. Ipha, Yepcha). In particular, the free radical scavenging, the inhibition of LDL oxidation, the cytoprotective effect and the inhibition of DNA damage were correlated with the total polyphenol contents of green tea extracts harvested early spring such as Woojeon, Sejak and Jungjak. The results obtained here show that all extracts of green teas including purified green tea catechin, GTC, have strong antioxidant activities on oxidative stress in vifrθ. The variation in polyphenol content and antioxidant activities among various types of green tea by the harvesting time may provide critical information for investigators and consumers using tea in purposes of nutrition and chemoprevention.

• Preventive Nutrition and Food Science
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• v.4 no.2
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• pp.92-96
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• 1999

The effects of aqueous extracts from Korean commercial teas on excessive free radicals were examined utilizing spin trapping, 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical and lipid peroxidation. A potent scavenging effect of green tea and oriental senna tea was dound using sipin trapping. The most effective teasagainst the DPPH radical was green tea, followed inorder by pine leak tea, Chinese gutta percha tea and orietnal senna tea. Similar to the effects of DPPH radical , green tea, pine leaf tea, Chinese gutta percha tea and oriential senna tea had an inhibitory effect on lipid peroxidation. These findings predict that Korean tea is a promising material for scavenging free radicals, and for curing diseases related to free-radical reactions.