Stability of Green Tea Catechins

Zhu, Qin; Zhang, Anqi; Tsang, D.; Huang, Yü; Chen, Zhenyu

doi:10.1021/jf9706080

Cited by 391 publications

(296 citation statements)

References 12 publications

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“…Estudos prévios sobre o preparo do chá verde têm demonstrado que o modo de preparo, tempo de infusão, forma de acondicionamento da erva, temperatura e a proporção peso seco da erva/quantidade de água utilizada têm grande influência na quantidade de compostos fenólicos e nas atividades antioxidantes extraídas (ASTILL et al, 2001;CHEN et al, 2001;ZHU et al, 1997). No presente estudo, foi avaliado também o efeito do volume de extração, mantendo-se sempre a mesma proporção de erva:água.…”

Section: Extração De Sólidos Totais Atividade Antioxidante E Compostunclassified

Chá verde brasileiro (Camellia sinensis var assamica): efeitos do tempo de infusão, acondicionamento da erva e forma de preparo sobre a eficiência de extração dos bioativos e sobre a estabilidade da bebida

Nishiyama¹,

Costa²,

Costa³

et al. 2010

Ciênc. Tecnol. Aliment.

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Section: Extração De Sólidos Totais Atividade Antioxidante E Compostunclassified

Chá verde brasileiro (Camellia sinensis var assamica): efeitos do tempo de infusão, acondicionamento da erva e forma de preparo sobre a eficiência de extração dos bioativos e sobre a estabilidade da bebida

Nishiyama¹,

Costa²,

Costa³

et al. 2010

Ciênc. Tecnol. Aliment.

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“…The studies of epithelial transport/bioavailability are performed in conditions mimicking physiological condi-tions, involving pH 6.0-7.4. However, phenolic compounds were reported to be labile at neutral and mildly alkaline pH [Zhu et al, 1997]. They can easily oxidise at pH higher than 6.5.…”

Section: Introductionmentioning

confidence: 99%

Stability of Phenolic Compounds Isolated from Cocoa, Green Tea and Strawberries in Hank’s Balanced Salt Solution under Cell Culture Conditions.

Kosińska¹,

Xie²,

Diering³

et al. 2012

Pol. J. Food Nutr. Sci.

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The study analysed the stability of polyphenols present in extracts isolated from cocoa, green tea and strawberries in Hank's Balanced Salt Solution buffers. The extracts were incubated under conditions commonly used for intestinal absorption experiments with human epithelial cells. The polyphenols were analysed with HPLC-DAD-FLD-MS method. The concentrations of most of the polyphenols monitored changed during 2 h of incubation. The fl avan-3-ols of cocoa exhibited similar stability and all were more stable at pH 6.5 than 7.4. The concentration of procyanidin B2 at pH 7.4 decreased to the highest extent. Green tea predominant catechins: epigallocatechin gallate and epigallocatechin, were very vulnerable in HBSS both at pH 6.5 and 7.4; their specific molecular structure may be responsible for this phenomenon. The anthocyanins of a strawberry extract were more stable at pH 6.5. The considerable increase in ellagic acid concentration at pH 7.4 might be explained by possible degradation of other compounds of the extract. It is highly recommended to perform stability tests before transport experiments in a cell culture model in order to avoid misinterpretation of results.

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“…38,39 To obtain good separation, acetonitrile-water and methanolwater, both containing acid, were investigated as mobile phases. With methanol-water the peaks of compounds 6 and 7 always coeluted.…”

Section: Resultsmentioning

confidence: 99%

Condensed Tannins from the bark of Guazuma ulmifolia Lam. (Sterculiaceae)

Lopes

Rocha

Almeida

et al. 2009

J. Braz. Chem. Soc.

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Das cascas de Guazuma ulmifolia Lam. (Sterculiaceae) foram isolados e identificados nove compostos: ent-catequina, epicatequina, ent-galocatequina, epigalocatequina, epiafzelequina-(4β→8)-epicatequina, epicatequina-(4β→8)-catequina (procianidina B1), epicatequina-(4β→8)-epicatequina (procianidina B2), epicatequina-(4β→8)-epigalocatequina, e a nova substância 4'-O-metil-epiafzelequina. Suas estruturas foram elucidadas com base nos dados espectrais e da literatura. A "impressão digital" de um extrato semipurificado por cromatografia líquida de alta eficiência foi realizada em coluna C18, com uma mistura de acetonitrila (0,05% de ácido trifluoroacético):água (0,05% de ácido trifluoroacético) (v/v) com vazão de 0,8 mL min -1 . O volume injetado da amostra foi de 100 µL e o comprimento de onda 210 nm.From the bark of Guazuma ulmifolia Lam. (Sterculiaceae), nine compounds were isolated and identified: ent-catechin, epicatechin, ent-gallocatechin, epigallocatechin, epiafzelechin-(4β→8)-epicatechin, epicatechin-(4β→8)-catechin (procyanidin B1), epicatechin-(4β→8)-epicatechin (procyanidin B2), epicatechin-(4β→8)-epigallocatechin, and the new compound 4'-O-methylepiafzelechin. Their structures were elucidated on the basis of spectral and literature data. HPLC fingerprint analysis of the semipurified extract was performed on a C18 column, with a mixture of acetonitrile (0.05% trifluoroacetic acid):water (0.05% trifluoroacetic acid) (v/v) with a flow rate of 0.8 mL min -1 . The sample injection volume was 100 µL and the wavelength was 210 nm. Keywords: Guazuma ulmifolia, condensed tannins, HPLC, fingerprint IntroductionDespite extensive destruction, it is believed that the rainforests still preserve 30 million individual species, roughly half of all life forms on earth and 2/3 of all plants, without mentioning the importance of these forests to the earth's weather and atmosphere. In South America, the Amazon tropical forest covers approximately 665 million hectares, of which 60% lies within Brazil, covering 59% of the country's territory, in nine states: Acre, Amapá, Amazonas, Maranhão, Mato Grosso, Pará, Rondônia, Roraima and Tocantins. 1 The importance of conserving the Amazon tropical forest is not limited only to the animal and plant species themselves, but also to the rich knowledge of the local people about the use of medicinal plants. Their knowledge stems as much from the necessity for alternative treatments because of low purchasing power and the difficulty of access to medical assistance, as from the profound cultural influence of the indigenous peoples of the region.It is known that rapid social, cultural and economic changes strongly affect local knowledge of how to use natural resources. The problems stemming from this cultural loss are irreversible, and this loss reduces the possibilities of sustainably developing a region based on local experience. 2 The discussion of alternatives for development and their relationship with the productive use of biodiversity is recent in Brazil. A proposal for sustainable d...

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Stability of Green Tea Catechins

Cited by 391 publications

References 12 publications

Chá verde brasileiro (Camellia sinensis var assamica): efeitos do tempo de infusão, acondicionamento da erva e forma de preparo sobre a eficiência de extração dos bioativos e sobre a estabilidade da bebida

Chá verde brasileiro (Camellia sinensis var assamica): efeitos do tempo de infusão, acondicionamento da erva e forma de preparo sobre a eficiência de extração dos bioativos e sobre a estabilidade da bebida

Stability of Phenolic Compounds Isolated from Cocoa, Green Tea and Strawberries in Hank’s Balanced Salt Solution under Cell Culture Conditions.

Condensed Tannins from the bark of Guazuma ulmifolia Lam. (Sterculiaceae)

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