• Journal of the East Asian Society of Dietary Life
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• v.14 no.2
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• pp.156-160
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• 2004

This study was carried out to examine the changes of chlorophyll a and b contents by the extraction temperatures and the number of soaking using five kinds of Korean green teas(3 kinds of green tea and 2 kinds of tea bag) which were obtained from a local market in Daegu city, Korea. The chlorophylls were extracted with 80% acetone, and determined by a visible spectrophotometer. The concentration of chlorophyll in Sulrok(tea bag) were the highest among all kinds of teas when they were extracted at 60, and decreased with the number of soaking increased. On the other hand, the chlorophyll content of green teas was the highest at 80, and decreased with the increase of the number of soaking as the tea bag did. It was found that the Korean tea bag contained more chlorophyll than green teas did, and green teas contained significantly more chlorophyll b than chlorophyll a.

• Journal of Veterinary Clinics
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• v.26 no.1
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• pp.41-47
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• 2009

Ingredient analysis and the medical action of various teas are accomplished on multi angle. However, the research regarding the prevention and a treatment of oral cavity disease, which use the green tea, is still insufficient relatively. In this experiment, the virtue of green tea bag on periodontal disease was studied. This experiment was used in 11 beagles. As a test group, 6 beagles were rinsed their tooth with green tea bag. The remaining 5 beagles were rinsed with filter paper which was soaked with normal saline. The test found no statistical significance in gingival index, plaque index, calculus index and dental pocket depth. But the number of bacteria colonies decreased significantly in test groups. The periodontal disease is related to the number of bacterial colonies. Therefore, this results show that the green tea bag is effective for periodontal disease.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.4 no.3
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• pp.279-283
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• 2003

This study was carried out to establish the manufacturing formulation of tea-bag type garlic tea. In order to eliminate of garlic-specific odor and taste, the masking effect of various additives against garlic flavor was determined with sensory evaluation. Leaves of green tea, arrowroot and Solomon's seal were screened as highly effective auxiliary ingredients in garlic tea. When two materials among the selected three auxiliary materials were mixed the same percentage, overall flavor of garlic tea synergistically was enhanced. The optimum concentration of garlic powder and stevioside as a sweetener were 20∼30％ and 1％, respectively. Therefore, three types formulation of garlic tea was establish. When the color, turbidity and total solid concentration of three formulated garlic teas were compared with those of commercially available formulated green tea containing unpolished rice, the latter was more yellowish color and the former was more superior to turbidity and total solid concentration.

• Journal of the East Asian Society of Dietary Life
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• v.16 no.1
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• pp.107-112
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• 2006

This study analyzed the changes of chlorophyll and ascorbic acid contents according to the extraction temperatures and the number of soakings using five kinds of Korean and Japanese green tea(3 kinds of green tea and 2 kinds of tea bag) which were obtained from local markets in Korea and Japan. The findings are as follows: 1. The chlorophyll contents of Japanese green tea were $2\sim3$ times higher than those of Korean green tea. 2. The chlorophyll contents of Korean green tea in high and middle grades were increased with increasing temperature $(80>70>60^{\circ}C)$ but the contents in low grade were increased with decreasing temperature. The contents of chlorophyll in Japanese green tea were almost similar in low, middle and high grades. 3. Ascorbic acid content was higher in low grade Korean green tea but it was higher in high and middle grades of Japanese green tea. Chlorophyll contents of Japanese green tea were higher than those of Korean green tea but ascorbic acid contents of Korean green tea were higher than those of Japanese green tea.

• Journal of the Korean Society of Food Culture
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• v.15 no.5
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• pp.398-412
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• 2000

The purposes of this study are : (a) to investigate the attitude to various coffee and tea of women, (b) to analyze the characteristics of each classified group according to eating frequency, and (c) to abstract the factors which can influence the consumption of coffee and tea. Questionnaires were hand delivered to 1,200 women residing in Seoul. A total of 1012 was usable: resulting in 84% response rate. Statistical data analysis was completed using SAS Package program for the one way-analysis of variance(ANOVA), Duncan's multiple comparison test, factor analysis and analysis of covariance (ANOCOVA). (a) Instant coffee was most consumed(22.1 times a month), green tea in tea bag(8.7), Donggulre tea(8.3), Coffee (72) in order of frequency. Among Korean traditional tea Donggulre tea(8.3) and Yuja tea (2.0) were most prefered but still a minute quantity of Korean traditional tea was enjoyed. (b) Coffee and Black tea was regarded unhealthful but habitual, delicious and familiar beverage. Green tea was regarded good for health but not so habitual, practical and familiar. The consumer awareness can be grouped into 3 clases : Healthy factor, Habitual Practical factor, Familiar factor. (c) The sociodemographic characteristics of women influenced the beverage consumption. Women in their 30s and 40s consumed much of instant coffee and coffee. 10s and 20s consumed much of canned coffee. Working women drank much of instant coffee and green tea in tea bag. Women in highest income group$({\geq}\;4,000,000\;won/month)$ consumed much of coffee. (d) The factors which influenced the eating frquency of those beverages were various. The eating frequency of instant coffee was influenced by the age, familiar factor and habitual practical factor. And coffee were influenced by income level, habitual practical factor. The frequency of green tea in tea bag was influenced by habitual practical factor and familiar factor, green tea was influenced by healthy factor and habitual practical factor, Donggulre tea was influenced by habitual practical factor.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.7
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• pp.1079-1084
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• 2004

The present study was conducted to compare antioxidant activity of green teas, fermented teas and other related common teas by examining radical scavenging activity using DPPH (2,2 diphenyl l-picryl hydrazyl). Scavenging activity ($SC_{50}$/) of epigallocatechin gallate (EGCG) for 0.1 mM DPPH radical was 5.5 $\mu$M or 4.2 mg/L by weight, then catechin, 14 $\mu$M or 2.5 mg/L and vitamin C, 22 $\mu$M or 3.9 mg/L, respectively. Kyokuro tea (okro) powder of 24.2 mg/L or green tea powder of 25.2 mg/L was used to reach $SC_{50}$/ for 0.1 mM DPPH. One serving of 2 g green tea provides antioxidant activity equivalent to 109∼147 mg EGCG, 145∼185 mg catechin or 131∼168 mg vitamin C. Teas from the first harvest had the highest radical scavenging activity when compared with later harvest green teas grown in the same region, but there is virtually no difference by the harvest time. A Chinese green tea, Dragon well had the highest antioxidant activity among other green teas tested providing antioxidant capacity equivalent to 168 mg EGCG or 188 mg vitamin C per 2 g serving, but partially fermented Chinese teas had much lower antioxidant activity than any green tea tested. Black tea which is fully fermented showed as strong antioxidant activity as green teas (76.3 mg vs 86.7∼67.6 mg per tea bag). One tea bag of green teas from market provided antioxidant capacity equivalent to 52∼86 mg EGCG, 70∼105 mg catechin or 63-96 mg vitamin C. Teas made of persimmon leaf, pine needle, mulberry leaf had comparatively low anti-oxidant activity equivalent to 2.5∼4.8 mg EGCG or 15∼21 mg vitamin C per teabag. The third brewed green tea still had enough antioxidant activity, while tea from tea bag brewed for 3 min or 5 min did not have any difference in their antioxidant activity. More systemic studies are needed to clarify the relationship between tea catechins and antioxidant capacity focusing on how growing, harvest time, fermentation and other processes can influence on this.

• Journal of the Korean Society of Food Culture
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• v.22 no.4
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• pp.449-453
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• 2007

Using green tea(GT), oolong tea(OT), black tea(BT) and green tea bag(GTB) out of tea products in market, this study quantified polyphenol and catechins as anti-oxidant substances and analyzed their respective anti-oxidant capacities. As a result, more epigallocathechin(EGC) was found in GT and GTB as well as caffein(CAF) in GT and BT. GT contained more epigallocathechin gallate(EGCG) than other tea types. Both FRAP and ORAC, as two methods of analyzing anti-oxidant capacities, showed that GTB had highest anti-oxidant capacities, while OT had lowest of all. By brand, it was found that all the 3 brands of GT had similarly high anti-oxidant capacities, but there were differences in the anti-oxidant activities of GTB and BT depending on brand. Out of catechin components, it was found that epicatechin(EC), epicathechin gallate(ECG) and EGCG were major components affecting anti-oxidant capacities.

• Korean Journal of Food Science and Technology
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• v.51 no.4
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• pp.356-360
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• 2019

To evaluate antioxidant capacities and total phenolic, flavonoid, and catechin contents of pure green tea packaged in tea bags, green tea bags of 10 commercial brands were purchased and analyzed. Considering commonly used infusion methods, green tea bags were extracted using 150 mL of spring water at $70^{\circ}C$ for 2 min. Ten brands of green tea showed a wide range of total phenolic content (46.3-93.9 mg gallic acid equivalents/g), total flavonoid content (10.3-21.7 mg catechin equivalents/g), and antioxidant capacities (88.8-175.6 mg and 87.9-183.5 mg vitamin C equivalents/g for DPPH and ABTS assays, respectively). Total catechin content of green tea ranged from 33.8-74.7 mg/g, which corresponded to 43.0-108.3 mg/150 mL of cup. Collectively, these results suggest that daily consumption of 3.8-12.5 cups of green tea packaged in tea bags meets the recommended daily intake of catechins in green tea extract as a health functional foods in Korea.

• Journal of the Korean Society of Food Culture
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• v.21 no.1
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• pp.8-16
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• 2006

This study was performed by questionnaire to investigate the preference and intake frequency of Korean traditional commercial beverages. The subjects were consisted of 320 participants in Daegu and Kyungpook area. 'Chain market' scored 49.4% as purchasing place of traditional beverages. 'Tea bag' scored 31.6% as the favorite package of traditional beverages. On the reasons of drinking traditional beverage 'good for health' scored the highest with 31.3% respondents, followed by 'good smell' with 14.4%. Coffee and traditional tea were the choice of beverage after having a rich meal and on occasion of entertaining guests. The favorite foods in ordinary days were 'tea', 'alcohol', 'ice cream', 'nuts' and 'cookie'. More than thirty percent of the respondents, both male and female, raised the need of improvement in taste of traditional beverage. In the intake frequency, Korea traditional beverages obtained 1.80 points as a whole. 'Green tea' scored highest(3.40points) while 'mulberry-leaf tea' received the lowest score of 1.31 points. The preferred Korean traditional drinks were 'greed tea', 'shick hae', 'citron tea', 'misitgaru', 'maesil tea', 'rice tea' in the order. On the other hand, the preference for 'mulberry-leaf tea', 'boxthom tea', 'ginger tea', 'chrysanthemum tea' and 'omija tea' was very low. The people who are on twenties preferred 'shick hae', 'honey tea', 'citron tea', 'black tea' and 'misitgaru' more than the other generation.

• Asian-Australasian Journal of Animal Sciences
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• v.24 no.5
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• pp.616-622
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• 2011

This study evaluated the fermentation characteristics and protein degradation dynamics of wet green tea grounds (WGTG) silage. The WGTG was ensiled with distilled water (control), or lactic acid bacteria (LAB), enzyme (E), formic acid (FA) and formaldehyde (FD) prior to ensiling. Three bag silos for each treatment were randomly opened at 0, 3, 7, 14, 28 and 60 days after anaerobic storage. For all the treatments, except for FA, there was a rapid decline in pH during the first 7 days of ensiling. LAB treatment had higher lactic acid content, lower ammonia-N ($NH_3$-N) and free-amino nitrogen (FAA-N) contents than other treatments (p<0.05). E treatment had higher lactic acid, water-soluble carbohydrates (WSC) and non-protein nitrogen (NPN) content than the control (p<0.05). FA treatment had higher $NH_3$-N and FAA-N content than the control (p<0.05). FD treatment had lower NPN and FAA-N content than the control, but it did not significantly inhibit the protein degradation when compared to LAB treatment (p>0.05). Results indicate that LAB treatment had the best effect on the fermentation characteristics and protein degradation of WGTG silage.