• Title/Summary/Keyword: Black tea

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The effect of different drinks on the color stability of different restorative materials after one month

  • Tekce, Neslihan;Tuncer, Safa;Demirci, Mustafa;Serim, Merve Efe;Baydemir, Canan
    • Restorative Dentistry and Endodontics
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    • v.40 no.4
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    • pp.255-261
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    • 2015
  • Objectives: The aim of this study was to evaluate the effect of three different drinks on the color parameters of four different restorative materials. Materials and Methods: Three different composites (Filtek Ultimate Universal Restorative, Filtek Ultimate Flowable, and Filtek Silorane, 3M ESPE) and a polyacid-modified composite resin material (Dyract XP, Dentsply DeTrey GmbH) were evaluated. Eighty-four disc-shaped specimens of 8 mm in diameter and 2 mm in thickness were prepared (n = 21 each). Color coordinates ($L^*a^*b^*$, ${\Delta}L^*$, ${\Delta}a^*$, ${\Delta}b^*$, and ${\Delta}E^*$) were measured using a $V{\dot{I}}TA$ Easyshade Compact ($V{\dot{I}}TA$ Zahnfabrik) after 24 hr of storage (baseline) and after 30 day of storage in three different beverages of black tea, Coca cola, or water (control) (n = 7). In each beverage, the specimens were stored three times a day, one hr each, for 30 day. The color changes (${\Delta}E$) were calculated and were analyzed by Kruskal-Wallis and Dunn multiple comparison test. Results: The color difference (${\Delta}E^*$) of the resin materials ranged between 1.31 and 15.28 after 30 day of immersion in the staining solutions. Dyract XP in Coca cola ($15.28{\pm}2.61$) and black tea ($12.22{\pm}2.73$) showed the highest mean ${\Delta}E^*$ value after 30 day, followed by Filtek Ultimate Universal Restorative ($5.99{\pm}1.25$) and Filtek Ultimate Flowable ($4.71{\pm}1.40$) in black tea (p < 0.05). Conclusions: The compomers displayed unacceptable color changes at the end of 30 day in all beverages. Among resin composites, the silorane based composite exhibited relatively good color stability than the others. Filtek Ultimate Universal Restorative and Filtek Flowable showed similar color changes in all beverages.

In vitro antioxidant activity of black tea (Camellia sinensis L.) residue extract (홍차박 추출물의 in vitro 항산화 활성)

  • Kim, Dong Chung
    • Journal of Applied Biological Chemistry
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    • v.62 no.3
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    • pp.281-286
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    • 2019
  • A black tea (Camellia sinensis L.) residue extract (BTRE) was prepared by 30% ethanol extraction to evaluate its in vitro antioxidant activity. The yield and polyphenol content of BTRE were $22.4{\pm}1.18%$ and $23.2{\pm}1.02{\mu}g$ gallic acid equivalents/mg-extract, respectively. Antioxidant activity of BTRE proportionally increased as BTRE concentration increased. $IC_{50}$ values of BTRE for cation radical, free radical and nitrite scavenging were 141.8, 108.1, and $397.2{\mu}g/mL$, respectively. Also $IC_{50}$ value of BTRE for ferric reducing anti-oxidant power was $97.8{\mu}g/mL$. BTRE effectively inhibited linoleic acid peroxidation. These results imply that BTRE possessed potent antioxidant activity, thus being utilized as a physiologically active material.

Antioxidant and Anticancer Activities of Yak-Sun Tea Prepared by Oriental Medicinal Herbs (한방생약재를 이용한 약선차의 항산화 및 항암효과)

  • Choi, Il-Sook;Cha, Eun-Jung;Lee, Youn-Ri;Kim, Jae-Keun
    • The Korean Journal of Food And Nutrition
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    • v.25 no.3
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    • pp.447-453
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    • 2012
  • Various types of tea are consumed as a popular beverage worldwide particularly in Asian countries such as Korea, China, and Japan. The purpose of this study was to investigate the mineral contents, antioxidant properties and anticancer activity of Yak-Sun tea that is prepared by six oriental medicinal herbs. The results of the mineral contents were as follows; Ca, Mg, and Na contents were higher than those of green tea, whereas Fe, P, and K contents were lower than those of green tea. The total phenolics and flavonoid content of the Yak-Sun tea were higher than those of green and black teas. The $IC_{50}$ values of DPPH radical, hydroxyl radical, hydrogen peroxide radical scavenging of Yak-Sun tea were 0.78, 1.58, and 2.04 $mg/m{\ell}$, respectively, whereas the radical scavenging values of ${\alpha}$-tocopherol was 0.06, 0.05, and 0.09 $mg/m{\ell}$, respectively. When cancer cells were treated with Yak-Sun tea, the anticancer activity increased in a dose dependent manner. HCT116 colon cancer cell lines were dramatically increased, as compared to other cancer cell lines, such as MCF-7, H460, and MKN45 cell lines. The results of this study demonstrated that Yak-Sun tea could function as a tea to enhance health conditions for antioxidant and anticancer activity.

Monitoring of Leaching Conditions for Functional Components of Black Tea Using Response Surface Methodology (반응표면분석에 의한 홍차로부터 기능성 성분의 침출조건 모니터링)

  • Shin, Gyoung-Ah;Lee, Go-Eun;Oh, Young-Hwan;Noh, Jung-Eun;Yoon, Sung-Ran;Lee, Jeong-Eun;Kim, Gui-Ran;Jeon, Eun-Ju;Chung, Hun-Sik;Kim, Jeong-Sook;Kwon, Joong-Ho
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.37 no.1
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    • pp.66-71
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    • 2008
  • This study was conducted to predict optimum leaching conditions for functional components of black tea. Two variables were used to determine the optimum leaching temperature and leaching time with a five-level central composite design and response surface methodology. Soluble solid, reducing sugar, total phenolics, and total flavonoid contents increased as leaching temperature and time increased. The ranges of maximum leaching conditions for these components were $78.28{\sim}87.08^{\circ}C$ and $3.97{\sim}4.27min$. Vitamin C level was maximal at $61.29^{\circ}C$ and 2.68 min. Electron donating ability showed the highest values at $68.30^{\circ}C$ and 0.54 min. Based upon the superimposed results, it was predicted that the optimal ranges of leaching conditions for some functional components from black tea were $63{\sim}79^{\circ}C$ for $1.5{\sim}2.1$ min.

Low-temperature Rendering Technology Applied to Extract Black Beans, Peony and Green Tea for Scalp Repair (저온용출법을 이용한 검은콩, 작약, 녹차 추출물의 두피 개선 효과)

  • Min, Dae-Jin;Park, Nok-Hyun;Hwang, Jung-Sun;Moon, Sung-Ho;Lee, Ki-Hyun;Lee, John-Hwan;Ahn, Soo-Mi;Kim, Han-Kon
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.35 no.1
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    • pp.41-46
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    • 2009
  • Problems with scalp lead to hair loss, dandruff, itchiness, and other illness. No clear causes of these problems have been found and it is difficult to treat them. Therefore, the best way to prevent and treat any problems with scalp is to maintain physiological homeostasis of scalp to keep it healthy. Recently, many scalp and hair product brands have attempted to use medicinal herbs which have been extracted in hot water and mixed with other ingredients due to mass-production and standardization issues. However, many nutrients and active substances are destroyed by hot-water extraction. Therefore, this study has applied low-temperature rendering to minimize destruction of substances to extract black beans, peony, and green tea that are known to improve conditions of scalp. Then, their contribution to the improvement of scalp health was assessed. In result, it was found that low-temperature rendering retains over two times greater anti-oxidizing strengths than hot-water extraction and that the extracts from low-temperature rendering effectively strengthen follicles and hair, moisturize scalp, and prevent itchiness. Therefore, low-temperature rendered black beans, peony, and green tea extracts can be used to make effective scalp treatments.

A Study on the Factors Affecting the Consumption of Coffee and Tea among Female in Seoul (여성의 커피와 다류의 섭취에 영향을 주는 요인에 관한 연구)

  • Sohn, Kyung-Hee;Lee, Min-June;Min, Sung-Hee;Lee, Hyun-Jou
    • 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.

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Antibacterial Activities of Phenolic Components from Camellia sinensis L. on Pathogenic Microorganisms

  • Shin, Jung-Sook;Chung, Ha-Sook
    • Preventive Nutrition and Food Science
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    • v.12 no.3
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    • pp.135-140
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    • 2007
  • Antibacterial activities of the major phenolic components from Camellia sinensis L. were investigated against several pathogenic microorganisms including Gram-positive strains like Staphylococcus aureus ATCC 29213 and Streptococcus pyogens 308A; and Gram-negative strains like Escherichia coli ATCC 25922, Escherichia coli 078, Pseudomonas aeruginosa 9027, and Enterobacter cloacae 1321E. The MIC values demonstrate that both (-)-epicatechin and (-)-epigallocatechin were more considerably toxic against Staphylococcus aureus ATCC 29213 than the other two catechins like (-)-epicatechingallate and (-)-epigallocatechin-3-gallate. (-)-Epicatechingallate and (-)-epigallocatechin-3-gallate were most inhibitory against Escherichia coli ATCC 25922. As a result, (-)-epicatechin showed predominant antibacterial activities among tea varieties. The contents of major polyphenolic components such as four catechins, theaflavin, and quercetin were different according to fermentation processes. The total contents of four catechins were ranged from 13.81 to 1.33%, with (-)-epigallocatechin-3-gallate being dominant among tea varieties; theaflavin was found the characteristic pigment in fully-fermented black tea.

Physiological and Pharmacological Activites of Nutraceutical Tea by Leaves and Flowers of Domestic Camellia(Camellia japonica)

  • Lee, Sook-Young;Cha, Young-Ju;Lee, Jang-Won;Hwang, Eun-Ju;Kwon, Su-Jung;Cho, Su-In
    • Proceedings of the Plant Resources Society of Korea Conference
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    • 2003.10b
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    • pp.48-49
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    • 2003
  • This project was conducted to development several camellia tea mixed herb teas having any physiological effects. Leaves of tea tree contain many compounds, such as polysaccharides, volatile oils, vitamins, minerals, purines, alkaloids(eg. caffeine) and polyphenols(catechins and flavonoids). Although all three tea types(green, oolonr and black) have antibacterial and free radical capturing(antioxidizing) activities, the efficacy decreases substantially the darker the variety of tea is. This is due to lower contents of anti-oxidizing polyphenols remaining in the leaves. Unlike tea tree(Camellia sinensis), the biochemical features and effects of camellia(Camellia japonica) are not well known. Fresh mature leaf of sasanqua camellia(C. sasanqua), roasted young leaf tea(C. japonica) and fresh mature leaf and bark of camellia had high antibacterial activity against P. vulgaris and B. subtilis. In antifungal activity bioassay, young leaf roasted teas of camellia and sasanqua camellia had high activity against C. albicans and T. beigelil. Plant extracts from Camelia japonica had higher inhibitory activity against fungi than against bacteria. In cytotoxic effect against human acute myelogenous leukaemia cell extracts including fresh leaf(200$\mu\textrm{g}$/m1), bark(230$\mu\textrm{g}$/ml) and flower tea (320$\mu\textrm{g}$/m1)inhibited growth of AML cells.(중략)

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Research on Drinking Traditional Beverages among College Students in Seoul (전통 음료에 대한 서울 지역 대학생의 인지도 및 섭취 실태 조사)

  • Kim, Yun-Sung;Hwang, Su-Jung
    • Culinary science and hospitality research
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    • v.12 no.4 s.31
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    • pp.213-224
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    • 2006
  • This study was to investigate the factors affecting drinking Korean traditional beverages and the drinking habits of college students in Seoul. The research was carried out by asking them to drink 10 kinds of traditional drinks. They were composed of 45.5% of boys and 54.5% of girls who were $18\sim21$ years old, studying food related science (63.9%), and mostly (86.6%) living in a nuclear family in collective residents (60.4%) like an apartment. The number of students whose family's monthly incomes were over 3 million won was the largest as 37.1%. Their mothers were housewives (58.4%) mostly aged $46\sim50$ as 47.0%. In the research on the preference of students for the traditional drinks, most of them, 78.7%, showed their liking for the drinks because of their good taste (61.%). The number of students who answered they got the drinks by homemaking was the largest as 39.6%. Most of them, 66.3%, preferred fruit drinks, 19.8% soda drinks, 11.4% traditional drinks and 2.5% functional drinks. 31.2% of the drinks mostly taken at home was green tea, followed by sweet rice drink, Shik-hae. Among the drinks coming into the market, sweet rice drink was preferred in general as 25.7%, and the next was green tea 16.8%, ume drink (Maesil tea) 14.9%, rice tea 13.9%, fruit punch (Sujeonggwa) 11.4%, black tea 7.9%, honey tea 4.5%, ginseng tea 2.5% and jujube tea 2.5%. In the research on 'whether the students had experience preparing the traditional drinks or not', many of them, 62.4%, answered "No". And in the questionnaire asking on 'whether they liked to receive a training on making traditional drinks or not', 87.6% of them showed their wish to get the training. In the question on the reason why the students did not like to take the training on traditional drinks, the number of students who answered that it was complicated and hard to prepare was the largest as 53.0%.

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