• The Korean Journal of Food And Nutrition
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• v.18 no.1
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• pp.94-101
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• 2005

The present study was conducted to know the physicochemical properties of Korean tea according to degree of fermention. The moisture content of green tea, blue tea, yellow tea and black tea was 2.02∼2.04%. The content of total nitrogen was 3.78 % in green tea and 3.49∼4.03% in fermented tea. The content of the mineral was highest in Ca, Mg. The content of vitamin C was 670.62 mg in green tea and 169.7∼85.03 mg in fermented tea. The content of vitamin C were increased as tea was more fermented. The composition of vitamin E and β-carotene was green tea> blue tea> yellow tea> black tea. The content of the rutin was 0.12 % in green tea and 1.37% in black tea. The content of rutin was increased with fermentation. The content of total amino acid of green tea was 2270.9 mg. The content of main amino acid of Glu, Asp, and Leu was 342.01 mg, 165.32 mg, and 161.69 mg and the hightst content of Glu. The content of total amino acid of black tea was 2,219.08 mg. Total amino acid content of fermented tea increased in the order of black tea> blue tea> yellow tea, and among the tea, the content of black tea was the highest in the fermented tea. The content of caffeine was 1.17% in green tea and 1.05∼1.32% fermented tea. These results were nothing in the content of caffeine during the fermentation. The content of theanine was 0.95% in green tea and 0.73∼1.42% in fermented tea. The content of total catechin was highest in green tea, and decreased sharply as tea was more fermented. Flavonoid content of 1.05% in green tea. DPPH radical scavenge activities of the teas 4.73∼19.5% mg.

• The Korean Journal of Food And Nutrition
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• v.37 no.2
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• pp.100-109
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• 2024

This study examined the quality characteristics and antioxidant properties of sword bean tea available in domestic markets. Each product of sword bean tea had distinct appearance characteristics. The color, pH, brownness, and turbidity of the tea varied significantly across different products, with tea bags showing higher levels of brownness and turbidity. The total polyphenol content of hot water extraction ranged from 165.13 to 517.69 mg gallic acid equivalents (GAE)/100 g sample for pod tea, 999.36 to 2,054.74 mg GAE/100 g sample for tea bag tea, and 74.62 to 275.00 mg GAE/100 g sample for grain tea, respectively. Similarly, the total flavonoid content, measured in terms of catechin equivalents (CE), ranged from 39.51 to 65.00 mg CE/100 g sample for pod tea, 86.57 to 253.63 mg CE/100 g sample for tea bag tea, and 32.94 to 38.63 mg CE/100 g sample for grain tea, for hot water extraction. The DPPH and ABTS radical scavenging activities of pod tea were 95.68 to 276.19 mg TE/100 g sample and 270.87 to 804.21 mg trolox equivalents/100 g sample, respectively, for hot water extraction. These results suggest the need to establish quality standards to ensure consistent quality of sword bean tea.

• 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.31 no.3
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• pp.280-287
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• 2015

Sujeonggwa is a popular Korean traditional beverage. However, consumers only prepare it at home on special occasions due to the time and effort required. Developing a convenient form of Sujeonggwa may promote its consumption. The objectives of this study were to 1) develop Sujeonggwa in a tea bag using different sweeteners and 2) describe the characteristics of Sujeonggwa's flavor in tea bag samples and 3) determine how well consumers accept the tea bag samples. A total of four types of Sujeonggwa in a tea bag were developed: two samples with varying amount of sugar, another sample using sugar and stevia and the last sample using sugar and short chain fructo-oligosaccharide as a sweetener. A commercial ginger tea and cinnamon tea were used as control products. Descriptive analysis was conducted on the same six samples and a descriptive panel identified its attributes. A total of 61 consumers evaluated acceptability using a nine-point hedonic scale and how they felt about intensities of the samples using a just-about-right scale. The results indicated that consumers liked Sujeonggwa samples in a tea bag more than commercial ginger tea and cinnamon tea.

• Korean journal of food and cookery science
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• v.15 no.5
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• pp.475-482
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• 1999

This study was carried out to prepare green tea by traditional roasting process, Kujeungkupo, and to determine its sensory characteristics. The carotenoid content in green tea was increased by roasting and reached 1,317 mg/100 g by Kujeungkupo. Of all carotenoids, the contents of lutein and $\beta$-carotene were 1,170 mg/100 g and 111.1 mg/100 g, respectively. The total cathechin content in green tea was 14.57 g/100 g after 9th roasting. The more the number of roasting the little contents of cathechin in green teas. Of all cathechin, epigallocathechingallate was the highest(6.80g/100 g) followed by epicathechingallte and epicathechin. total cholrophyll content was 141 mg/100 g of green tea. The free sugar content in Kujeungkupo green tea wet 2.18 g/100 g, of which sucrose comprised 46% (1.01 g/100 g). The color value ($\Delta$E) of Kujeungkupo green tea was 16.25. In sensory evaluation, sweet taste was the highest in green tea roasted 3 times and the flavor was best in that roasted 5 times. The sweet and astringent tastes of green tea had negative relationships with a and b values. The content of cathechin in green tea had a negative relationship with sweet taste and a positive relationship with astringent taste.

• Journal of the Korean Home Economics Association
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• v.34 no.2
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• pp.329-339
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• 1996

The purpose of this study was to investigate effect of the amounts of unpolished glutinous rice flour with green tea powder difference of adding amount on the sensory and objective characteristics of Heunmi-nokcha-injulmi which is KOREAN TRADITIONAL RICE CAKE supplemented with green tea. The results were as follow : According to sensory evaluation of Heunmi-injulmi, the score of the color, flavor, chewiness, and overall of adding green tea were higher than those of no-adding green tea, especially the best acceptance was shown in adding 2% green tea. The more the amount of green tea powder was increased, the more the hardness and gumminess of Heumni-injulme was increased in the textural profiles, whereas the cohesiveness and elasicity of those was decreased. The moisture content of Heunmi-injulme adding green tea powder was ranged to 42-45%, and it was increased as the amount of green tea powder be increased. The more the amount of adding green tea powder was increased, the more yellow and green color was changed darker and stronger. Refer to this study with the advisable recipe for as follow : Heunmi-nokcha-injulmi adding 294g(98%) unpolished glutinous rice flour and 6g(2%) green tea powder.

• Journal of the Korean Home Economics Association
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• v.34 no.3
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• pp.233-243
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• 1996

The purpose of this study was to investigate effect of the amounts of unpolished glutinous rice flour with green tea powder difference of adding method on the sensorty and objective characteristics of Heunmi-nokcha-injulmi which is KOREAN TRADITIONAL CAKE supplemented with green tea. The results were as follow: According to sensory evaluation of Heunmi-injulmi adding twice infused green tea powder, the acceptance was the bast in the hardness, moistness, chewiness, and overall quality when adding 6% green tea. The more the amount of two infused green tea power was increased, the more the hardness of Heunmi-injulmi was increased in the gextural profiles, whereas the cohesiveness, elasticity, and chewiness of those was decreased. The moisture content of Heunmi-injulmi adding infused green tea powder was ranged to 41-44%, and it was decreased as the amount of two infusedgreen tea powder be increased. The more the amount of adding green tea powder was increased, the more yellow and green color was changed darker and stronger. The Overall quality in the sensory measurement of Heunmi-injulmi adding two infused green tea powder had positive correlation with Adhesiveness in the measurement of food testing machine. Refer to this study with the advisable recipe for Heunmi-nokcha-injulmi as follow : Heunmi-nokcha-injulmi adding 282g(94%) unpolished glutinous rice flour and 18g (6%) two infused green tea powder.

• Korean Journal of Plant Resources
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• v.28 no.6
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• pp.734-742
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• 2015

The purpose of this research was to find the most appropriate process for making yacon leaf tea. We applied both green tea and black tea brewing and fermenting methods for producing yacon leaf tea. This research included consumer test and descriptive analysis of professional trained panel on yacon tea tastes and flavors. Both consumer test and descriptive evaluation preferred yacon tea produced by black tea brewing and fermenting methods because it tasted less bitter and had a sweet, delicate taste. According to orthogonal transformation resulting from varimax rotation, first principal component was positively affected by black tea brewing and fermenting methods, while it was negatively affected by green tea brewing and fermenting methods. As a result, the study concluded black tea brewing and fermenting methods were appropriate for producing yacon leaf tea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.869-874
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• 2005

The purpose of this study was to determine the qualities of loaf breads added with green tea powder, minimum fermented tea powder (fermented for 10 hrs), medium fermented tea powder (fermented for 17 hrs), and black tea powder (fermented for 24 hrs). The moisture content of loaf bread added with green tea and three types of fermented tea was $36.02\~36.44\%$ and was similar to the control group of $36.98\%$. The content of crude protein and ash of loaf bread added with green tea powder and fermented tea was higher than that of control group. The water holding capacity of loaf bread added with green tea powder was the highest and was followed by the fermented tea added group and the control group. The volume and specific volume of loaf bread were high in tile order of the control group, the fermented tea added group, the green tea added group. The lightness of loaf bread got lower, while the redness and the yellowness of the bread 9ot higher as loaf bread was added with more fermented tea. The hardness of loaf bread get higher, but the cohesiveness got lower as loaf bread was added with the more fermented tea. The gumminess and chewiness of loaf bread added with black tea powder were the highest. The result of sensory evaluation of the loaf bread showed that the preference of the color was tBle highest in the control group, while the preference of the flavor and the taste was the highest in the green tea group and the minimum fermented tea group. The preference of overall acceptability of loaf bread was the highest in the minimum fermented tea group.

• Journal of the Korean Society of Food Culture
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• v.5 no.1
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• pp.101-106
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• 1990

The findings of the historical study of the proprieties of Korean traditional tea ritual, based on documents, are as follows. 1. The proprieties of tea ritual for the Imperial Sanctuary and the Buddhist proprieties of tea ritual for Buddha was celebrated during the Silla dynasty. 2. The proprieties of tea ritual during the Koryo dynasty developed in various types, such as the propreieties of tea ritual for the Imperial government, Buddha, Confucians.