• Fibers and Polymers
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• 제7권3호
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• pp.255-261
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• 2006

There is increasing interest in the many beneficial aspects of green tea to human such as anti-carcinogenic, anti-aggregant, anti-allergic, anti-bacterial, anti-mutagenic, and anti-oxidant activities. Besides these beneficial aspects, it has been reported that green tea ingredients, especially polyphenolic families (i.e., catechin), have some UV protection property both in vivo and in topical applications. In this study, green tea extract was used as a dyeing stock for cotton and the UV protection property of the dyed cotton fabric was examined. To increase the affinity of cotton fiber to the polyphenolic components in the green tea extract, a natural biopolymer, chitosan, was used as mordanting agent. The effects of chitosan concentration in mordanting on the dyeing characteristics and the UV protection property were examined. Chitosan mordanted green tea dyed cotton showed better dyeing characteristic and higher UV protection property compared with the unmordanted green tea dyed cotton. As the chitosan concentration in mordanting increased, the dyeing efficiency and the UV protection property also increased. Therefore, adapting chitosan mordanting in green tea dyeing can increase the UV protection property of cotton fabrics to some extent.

• 한국조리학회지
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• 제5권2호
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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.

• 한국식품조리과학회지
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• 제20권1호
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• pp.112-118
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• 2004

The purpose of this study was to find the optimal mixing conditions of three different amounts of gelatin, green tea powder and sucrose for preparation green tea powder jelly. A central composite design involving gelatin(12 ∼ 16g), green tea powder(3∼5g) and sucrose(40∼60g) was used to investigate the sensory characteristics of green tea powder jelly. Sensory characteristics, such as hardness, elasticity, sweetness, transparency, color, flavor and overall quality of green tea powder jelly, were measured using a response surface methodology computer program. The overall optimal conditions that satisfied all the sensory properties of green tea powder jelly were 13.4g gelatin, 4.2g green tea powder and 50.8g sucrose.

• 가정과삶의질연구
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• 제26권6호
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• pp.71-82
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• 2008

The purpose of this study was to identify factors affecting the purchases of well-being tea drinks based on the analysis of demographic characteristics, well-being oriented consumer behaviors, and consumer consciousness toward well-being tea drinks. The subjects of this study were undergraduates and graduate students in Seoul. The findings were summarized as follows: 1. Well-being oriented consumer behavior patterns were categorized in three factors; non-dietary life, selective dietary life, and regular/temperate behavior and consumer consciousness toward well-being tea drinks were categorized in two factors; habit/ familiarity and health/ economical efficiency. 2. Multiple regression analysis was used for finding out factors affecting the purchases of well-being tea drinks; independent variables were demographic characteristics(sex, monthly average family income and the amount of personal expenditure), well-being oriented consumer behavior factors and consumer consciousness factors toward well-being tea drinks. Weekly purchase frequency of well-being tea drinks was defined as a dependent variable. As a result, the purchases of well-being tea drinks were influenced in order of regular/temperate behavior, the consciousness of health/ economical efficiency, the amount of personal expenditure and the consciousness of habit/ familiarity. Especially, regular/temperate behavior negatively affected the purchases of well-being tea drinks.

• Journal of Nutrition and Health
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• 제29권8호
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• pp.861-866
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• 1996

Tannins in plant foods and beverages may produce antinutritional or toxic effects although some proteins with high affinity for tannins seem to function as defense mechanism to tannin toxicity. Our objectives were to investigate of tea tannins, iron and protein and to evaluate the role of proteins in tannin effects on iron solubility. Iron solubility in vitro was measured using tea with and without proteins. Mixtures of tea, protein in varying concentrations(either gelatin or bovine serum albumin), and iron(eithe 10 or 50ug/mL) were prepared. Controls contained water in place of tea. Iron bioavailability was assessed by measuring iron solubility in the simulated gastric condition with pepsin digestion. Bound iron was removed by centrifugation and soluble in tea alone. When iron concentratin was 10ug/mL, addition of small amounts of protein to tea dramatically reduced iron solubility, but solubility of iron increased in the tea mixturea as the concentration of protein was increased. The percnetage of iron that precipitated was much greater at 10ug Fe/mL than the values at 50ug Fe/mL suggesting that the iron binding sites on the tea-protein complex was saturated. These results suggest that interactions of iron with tea tannins are influenced by the concentratins of protein and iron.

• 한국조리학회지
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• 제14권4호
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• pp.1-13
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• 2008

The antioxidant activity and quality characteristics of bread made from waxy black rice flour(WBRF) and green tea powder were investigated. The bread was manufactured with 1% of green tea powder and 10, 20, 30 or 40% of WBRF(w/w). The group of 40% of WBRF and green tea powder significantly showed the highest bread weight and volume. Lightness(L value) and yellowness(b value) decreased, but redness(a value) increased with increasing WBRF contents in mixture. Hardness, gumminess and chewiness were the lowest in the control group, but springiness was the lowest in the group of 40% of WBRF and 1% of green tea powder. The sensory scores of appearance, external and crumb color, grainy in the group of 40% of WBRF and 1% of green tea powder were the significantly lowest. Overall acceptabilities of the groups of 10% and 30% of WBRF with 1% of green tea powder were not significantly different from the control group. The group of 40% of WBRF and 1% of green tea powder showed the highest DPPH radical scavenging effect and TEAC content. Thus, if the mixture of green tea powder and WBRF would be used, it might be proper to use 1% of green tea powder and 10% of WBRF mixture considering the quality and antioxidant activity of bread.

• Natural Product Sciences
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• 제19권4호
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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.

• Journal of Life Science
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• 제12권2호
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• pp.75-79
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• 2002

Tea catechins, the most important compounds in tea polyphenols, can efficiently scavenge superoxide anion free-radical ($O_2$.), hydroxyl radical. (.OH) The mechanism of scavenging active oxygen free radicals was investigated by ESR spin trapping technique and Chemiluminescence. Results showed that various tea catechins constitute an antioxidant cycle in accordance with the decreasing order of the first reductive potential, and produce the effect of cooperative strength each other. Esterificated catechins could scavenge active oxygen free radicals more effectively than the non-esterificated ones. When.OH and $O_2$.- were scavenged by (-)-epigallocatechin gallate [(-)- EGCG], the stoichiometric factors were 6, and the rate constants of scavenging reaction reached $7.71{\times}10^6$ and $3.52{\times}10^{11}$ L $mmol^{-1}s^{-1}$, respectively. In the mean time, tea catechins could scavenge superoxide anion fiee radical ($O_2$-.) and hydroxyl radical (.OH) in a dose dependent manner. But at higher concentration or pH value, tea catechins can induce the prooxidant.

• 한국식품영양학회지
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• 제13권1호
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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.

• 한국식품조리과학회지
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• 제31권3호
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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.