Thesis (M.Sc)--University of Limpopo, 2010. / Black tea (Camellia sinensis) and black tea combined with bush tea (Athrixia phylicoides) were analyzed for their polyphenol content, antioxidant activity and tannin content. Solvent extraction methods were used for extracting polyphenols, antioxidant activity and tannin content. Total phenols were determined using the Folin-Ciocalteu method, antioxidant activity using Trolox Equivalent Antioxidant Capacity (TEAC) assay and tannin content using vanillin-HCl method. Polyphenol content, antioxidant activity and tannin content were calculated using regression equation Y=MX+C, where C=intercept, Y= Absorbance of the sample and M= Gradient. Results of black tea in this study showed that total polyphenols, antioxidant activity and tannin content decreased with decrease in temperature and time and this was attributed to the release of polysaccharides at 90°C. At 90°C for 3 minutes 7.68mg/100g of total polyphenol, 3.85μmol/g of antioxidants and 2.81mg/100g of tannin were obtained and this amount decreased to 5.50mg/100mg for total polyphenols, 1.31μmol/g for antioxidant activity and 0.72mg/100mg for tannin content at 30°C for 10 minutes. Combining the two tea types (50:50) resulted in a significant (p<0.005) decrease in total polyphenols, antioxidant and tannin content. Results of this study showed that at high temperature of 90°C for 3 minutes 2.64mg/100g for total polyphenol, 2.48μmol/g for antioxidants and 1.8mg/100g for tannin were obtained and these amounts decreased to 1.39mg/100mg for total polyphenols, 0.35μmol/g for antioxidant activity and 0.64mg/100mg for tannin content at 30°C for 10 minutes. Thus high brewing temperature causes increase in total polyphenols, antioxidant activity and tannin content of the combined teas. This study showed that black tea and combined black tea and bush tea solutions had large TEAC radical scavenging activity which can be related to total polyphenols and catechins. The antioxidant activity of the tea solution increased with increase in extraction temperature and duration of soaking. It is recommended that 3-min soaking temperature of 90 °C of black tea and combined bush tea and black tea can be used due to the highest total polyphenols and antioxidant activity obtained.

Made available in DSpace on 2014-06-11T19:32:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-06-12Bitstream added on 2014-06-13T20:24:25Z : No. of bitstreams: 1 majewski_m_dr_sjc.pdf: 368417 bytes, checksum: abb039d29f6c3474a49eaf77b2977d69 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo deste trabalho foi avaliar in vitro a atividade antifúngica e a citotoxicidade do ácido peracético e extrato vegetal de Camellia sinensis a (chá verde) e também avaliar o efeito antifúngico da anfotericina B e fluconazol em 22 cepas de Candida spp. isoladas da cavidade bucal de pacientes HIV positivos. Para determinação da concentração fungicida mínima e concentração inibitória mínima (CFM e CIM) em células planctônicas, foram realizadas diluições seriadas do extrato e do ácido peracético em placas de 96 poços em caldo RPMI tamponado, em suspensões padronizadas de cada cepa de Candida (106 células/mL). Após determinação da concentração do extrato e do ácido peracético no CIM e CFM, foi preparado o biofilme de cada cepa em placas de 24 poços utilizando-se corpos-de-prova de resina acrílica (n=10), as quais foi adicionado 0,1 mL da suspensão de Candida e 2mL caldo BHI sacarosado. As placas foram incubadas e mantidas a 37° por 5 dias. Após a incubação, os corpos-de-prova foram lavados em solução fisiológica e colocados em imersão por 5 minutos no ácido peracético ou no extrato vegetal. Os corpos-de-prova foram sonicados e realizadas diluições seriadas, 0,1 ml de cada diluição foi semeada em placas de ágar Sabouraud em duplicata e incubadas em estufa bacteriológica (37ºC/48 h). Posteriormente foi realizada a contagem das unidades formadoras de colônia (UFC/mL). Os dados foram avaliados estatisticamente utilizando-se teste de Mann Whitney (p<0,05) para o biofilme, observação visual para CIM e CFM, Tukey e Anova para citotoxicidade. Foi avaliada a citotoxicidade do ácido peracético e extrato de chá verde em macrófagos de camundongos (RAW 264.7), para verificar a viabilidade celular... / The objective of this study was to evaluate the in vitro antifungal activity and cytotoxicity of peracetic acid and plant extract from the Camellia sinensis (green tea) and also to evaluate the antifungal effect of amphotericin B and fluconazole in 22 strains of Candida spp. isolated from the oral cavity of HIV positive patients. To determine the minimum fungicidal concentration and minimum inhibitory concentration (CFM and CIM) in planktonic cells, were performed serial dilutions of the extract and peracetic acid in 96-well plates in RPMI broth buffered in standardized suspensions of each strain of Candida (106 cells / mL). After determining the concentration of the extract and peracetic acid in CIM and CFM, the biofilm was prepared for each strain in 24-well plates using body-of-proof acrylic resin (n = 10), which was added 0, 1 mL of the suspension of Candida sucrose and 2 ml BHI broth. The plates were incubated at 37 ° and maintained for 5 days. After incubation, the bodies of the test piece was washed in saline and placed for 5 minutes immersion in peracetic acid or the plant extract. The bodies of the test piece were sonicated and serial dilutions performed, 0.1 ml of each dilution was seeded on Sabouraud agar plates in duplicate and incubated in a bacteriological incubator (37 º C/48 h). Was subsequently performed the counting of colony forming units (CFU / mL). The data were statistically analyzed using Mann Whitney test (p <0.05) for the biofilm, visual observation for CIM and CFM, ANOVA and Tukey for cytotoxicity. We evaluated the cytotoxicity of peracetic acid and green tea extract in mouse macrophages (RAW 264.7) to verify the cell viability of these substances. The results showed that there was feasibility of peracetic acid and green tea extract in the cells analyzed. The antifungal agents have... (Complete abstract click electronic access below)

PINTO, N. B. Avaliação da atividade neuroprotetora do extrato padronizado de Camellia sinensis e de seus princípios bioativos: envolvimento de ações anti-inflamatórias e antioxidantes. 2015. 296 f. Tese (Doutorado em Farmacologia) - Faculdade de Medicina, Universidade Federal do Ceará, Fortaleza, 2015. / Submitted by Erika Fernandes (erikaleitefernandes@gmail.com) on 2015-11-05T14:03:38Z No. of bitstreams: 1 2015_tese_nbpinto.pdf: 9261753 bytes, checksum: 4bd9df04382dd73463d692c4c5fbd540 (MD5) / Approved for entry into archive by Erika Fernandes(erikaleitefernandes@gmail.com) on 2015-11-05T14:03:49Z (GMT) No. of bitstreams: 1 2015_tese_nbpinto.pdf: 9261753 bytes, checksum: 4bd9df04382dd73463d692c4c5fbd540 (MD5) / Made available in DSpace on 2015-11-05T14:03:49Z (GMT). No. of bitstreams: 1 2015_tese_nbpinto.pdf: 9261753 bytes, checksum: 4bd9df04382dd73463d692c4c5fbd540 (MD5) Previous issue date: 2015-02-27 / Parkinson's disease (PD) is a neurodegenerative disorder characterized by destruction of nigrostriatal dopaminergic neurons. Current treatment is only symptomatic and, to date, there are no drugs capable of inhibiting neuronal degeneration. So great is the demand for neuroprotective agents to prevent or slow the progression of this disease. The Camellia sinensis is a species of the family Theaceae, popularly known as green tea (CV). Several studies have shown the beneficial effects of this plant and its bioactive principles against neurodegenerative diseases. The objective of this study was to evaluate the neuroprotective effect of standardized extract of green tea and its catechins, epicatechin (EC) and epigallocatechin 3-gallate (EGCG), the PD model induced by 6-OHDA in rats, as well as studying the CV effect in models of inflammation and nociception. The animals (male Wistar rats, 180-250 g) were treated orally with HP (25 or 50 mg / kg), catechins (EC and EGCG at a dose of 10 mg / kg), the combination of CV (25mg / kg) + L-DOPA (25 mg / kg) with L-DOPA alone (at doses of 25 or 50 mg / kg) for 14 consecutive days; the treatments were started 1 hour before the unilateral striatal lesion by 6-OHDA (24 mg / 2μL). In behavioral tests, the results showed a significant increase in the number of rotations induced by apomorphine, decreased locomotor activity in the open field test, increased immobility time in the test in forced swimming, increased platform against time in the test water maze and increased the number of falls in the route of the test rod in the injured animals with 6-OHDA, compared to false-operated animals. These changes were partly or fully reversed after treatment with CV, CV + L-DOPA, EC, EGCG and L-DOPA alone. The 6-OHDA triggered neuronal death, as shown by reduced levels of dopamine and metabolites (DOPAC and HVA) in the striatum lesioned right compared to non-lesioned striatum left (contralateral). This depletion was significantly attenuated in injured and treated with CV, L-DOPA, EC, EGCG and association CV 25 25 + L-DOPA; these same drugs decreased levels of TBARS (indicator of lipid peroxidation) and nitrite / nitrate (oxidative stress indicator) in the striatum of rats with striatal injury by 6-OHDA. In vitro experiments have shown that CV (0.1-100 ug / uL) showed a strong antioxidant effect, by reducing the production of oxidizing substances in human neutrophils stimulated by PMA. In Nissl staining, it was observed that the injured animals and treated with CV, and CV EGCG + L-DOPA there was preservation of hippocampal neurons. Treatment with CV and CV + L-DOPA increased immunoreactivity for TH and decreased immunostaining for COX-2 in the striatum as well as the CV and EGCG attenuated the markup for iNOS in the hippocampus of treated animals compared to the control group. It was observed that the CV potentiate the effect of L-DOPA, showing a possible synergistic effect between these drugs. In another stage of the study, we evaluated the anti-inflammatory / nociceptive CV. Thus, the paw edema model induced by carrageenin and dextran, there was a decrease in volume of paw edema of rats after treatment with VC, compared to the control group (treated only with distilled water). The CV produced antinociceptive effect in the formalin test and the writhing induced by acetic acid, but also in the hot plate test and Hargreaves, possibly through the activation of opioid receptors and reducing the inflammatory process. In these tests nociception and inflammation, the CV potentiate the effects of morphine, indomethacin and dexamethasone. Therefore, our results demonstrated the neuroprotective effects of the CV and its bioactive principles, EC and EGCG, probably due to its anti-inflammatory and antioxidant properties, making future therapeutic options for the prevention or treatment of neurodegenerative diseases such as disease Parkinson. / A doença de Parkinson (DP) é uma desordem neurodegenerativa caracterizada pela destruição dos neurônios nigroestriatais dopaminérgicos. O tratamento atual é apenas sintomático e, até o presente momento, não existem drogas capazes de inibir a degeneração neuronal. Assim é grande a procura por agentes neuroprotetores que possam impedir ou retardar a progressão desta doença. A Camellia sinensis é uma espécie da família Theaceae, popularmente conhecida como chá-verde (CV). Vários estudos têm demonstrado os efeitos benéficos desta planta e de seus princípios bioativos contra doenças neurodegenerativas. O objetivo deste trabalho foi avaliar o efeito neuroprotetor do extrato padronizado do chá-verde e de suas catequinas, epicatequina (EC) e epigalocatequina 3-galato (EGCG), no modelo de DP induzida por 6-OHDA em ratos, bem como estudar o efeito do CV em modelos de inflamação e nocicepção. Os animais (ratos Wistar machos, 180-250 g) foram tratados por via oral com CV (25 ou 50 mg/kg), catequinas (EC ou EGCG, na dose de 10 mg/kg), a associação de CV (25 mg/kg) + L-DOPA (25 mg/kg) e com L-DOPA sozinha (nas doses de 25 ou 50 mg/kg) durante 14 dias consecutivos; os tratamentos foram iniciados 1h antes da lesão estriatal unilateral por 6-OHDA (24 µg/2µL). Nos testes comportamentais, os resultados mostraram que houve um aumento significativo do número de rotações induzidas por apomorfina, diminuição da atividade locomotora no teste do campo aberto, aumento do tempo de imobilidade no teste no nado forçado, aumento do tempo de encontro da plataforma no teste do labirinto aquático e aumento do número de quedas no teste do rota rod nos animais lesionados com 6-OHDA, em comparação com os animais falso-operados. Essas modificações foram, em parte ou totalmente, revertidas após os tratamentos com CV, CV + L-DOPA, EC, EGCG e L-DOPA sozinha. A 6-OHDA provocou morte neuronal, evidenciada pela redução dos níveis de dopamina e metabolitos (DOPAC e HVA) no estriado direito lesionado quando comparado com o estriado esquerdo não-lesionado (contralateral). Essa depleção foi significativamente atenuada nos animais lesionados e tratados com CV, L-DOPA, EC, EGCG e associação CV 25 + L-DOPA 25; estas mesmas drogas diminuíram os níveis de TBARS (indicador de peroxidação lipídica) e nitrito/nitrato (indicador de estresse oxidativo) no estriado de ratos submetidos a lesão estriatal por 6-OHDA. Experimentos in vitro demonstraram que o CV (0,1-100 µg/µl) apresentou um forte efeito antioxidante, ao reduzir a produção de substâncias oxidantes em neutrófilos humanos estimulados por PMA. Na coloração de Nissl, observou-se que nos animais lesionados e tratados com CV, EGCG e CV + L-DOPA houve uma preservação dos neurônios hipocampais. Os tratamentos com CV e CV+L-DOPA aumentaram a imunorreatividade para TH e diminuíram a imunomarcação para COX-2 no estriado, bem como o CV e EGCG atenuaram a marcação para iNOS no hipocampo dos animais tratados, em relação ao grupo controle. Observou-se que o CV potencializou os efeitos da L-DOPA, evidenciando um possível efeito sinérgico entre essas drogas. Em outra etapa do estudo, avaliou-se a atividade anti-inflamatória/antinociceptiva do CV. Assim, no modelo de edema de pata, induzido por carragenina ou dextrano, verificou-se uma diminuição do volume do edema da pata dos ratos, após tratamento com CV, em relação aos do grupo controle (tratado apenas com água destilada). O CV produziu efeito antinociceptivo, nos testes da formalina e das contorções abdominais, induzidas por ácido acético, como também nos testes da placa quente e de Hargreaves, possivelmente através da ativação de receptores opioides e da redução do processo inflamatório. Nestes testes de nocicepção e inflamação, o CV potencializou os efeitos da morfina, indometacina e dexametasona. Portanto, nossos resultados evidenciaram os efeitos neuroprotetores do CV e de seus princípios bioativos, EC e EGCG, possivelmente decorrentes de suas propriedades anti-inflamatórias e antioxidantes, tornando-as opções terapêuticas futuras para a prevenção ou tratamento de doenças neurodegenerativas, como a doença de Parkinson.

Orientador: Paulo Henrique dos Santos / Coorientadora: Ticiane Cestari Fagundes Tozzi / Banca: André Luiz Fraga Briso / Banca: Eduardo Bresciani / Resumo: Objetivo: Avaliar a influência de inibidores de proteases no potencial de degradação do colágeno das dentina sadia, esclerótica e afetada por cárie. Materiais e métodos: Trinta e nove molares humanos foram utilizados, treze para cada condição dentinária. Três fatias foram obtidas de cada dente, cada uma imersa em diferentes soluções: 1) saliva artificial; 2) clorexidina 2%; 3) EGCG 0,5%. Após incubação nas soluções por 1h, amostras foram sujeitas à degradação enzimática pela colagenase derivada da Clostridium histolyticum. Propriedades mecânicas de nanodureza (HIT) e módulo de elasticidade (Er) dos três diferentes tipos de dentina foram mensuradas antes e após a degradação, bem como a resistência à tração do colágeno. Resultados do teste de resistência à tração e nanoindentação foram submetidos à ANOVA dois e três fatores para medidas repetidas, e pós-teste de Tukey (α=0,05). Resultados: Maiores valores de resistência à tração foram encontrados para dentina sadia, nos grupos controle (40,30 ± 21,38 MPa) e EGCG 0,5% (30,05 ± 19,67 MPa). Antes da degradação, maiores valores de HIT (0,237 ± 0,062 GPa) e Er (5,58 ± 1,75 GPa) foram encontrados para o grupo EGCG 0,5%, na dentina afetada por cárie. Após a degradação, grupo clorexidina 2% apresentou maiores valores de HIT e Er para dentinas sadia (0,134 ± 0,020 GPa e 3,57 ± 0,40 GPa) e esclerótica (0,201 ± 0,048 GPa e 4,30 ± 0,56 GPa). Conclusões: O uso da clorexidina 2%, principalmente em dentina esclerótica, mostrou-se mais efet... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Objetive: To evaluate the influence of proteases inhibitors on the collagen degradation from sound, sclerotic and caries-affected dentin. Materials and Methods: Thirty-nine human molars were used, thirteen for each dentin condition. Three slices were obtained from each tooth, each one immersed in different solutions: 1) artificial saliva; 2) 2% chlorhexidine; 3) 0.5% EGCG. After incubation in the solutions for 1h, samples were subjected to enzymatic degradation by collagenase derived from Clostridium histolyticum. Mechanical properties of nanohardness (HIT) and elastic modulus (Er) of the three types of dentin were measured before and after degradation, as well as the microtensile strength. Results of the microtensile strength and nanoindentation tests were submitted to ANOVA two and three factors for repeated measurements, and Tukey post-test (α = 0.05). Results: Higher values ​​of tensile strength were found for sound dentin in control (40.30 ± 21.38 MPa) and 0.5% EGCG (30.05 ± 19.67 MPa) groups. Before degradation, higher values ​​of HIT (0.237 ± 0.062 GPa) and Er (5.58 ± 1.75 GPa) were found for the 0.5% EGCG group in caries-affected dentin. After degradation, 2% chlorhexidine group had higher values ​​of HIT and Er for sound (0.134 ± 0.020 GPa and 3.57 ± 0.40 GPa) and sclerotic (0.201 ± 0.048 GPa and 4.30 ± 0.56 GPa) dentin. Conclusions: The use of 2% chlorhexidine, mainly in sclerotic dentin, was shown to be more effective in promoting increase in the microtensile st... (Complete abstract click electronic access below) / Mestre

Submitted by Bruna de Oliveira null (bruna_dol@hotmail.com) on 2017-08-28T18:37:05Z No. of bitstreams: 1 Dissertação FINAL.pdf: 2838275 bytes, checksum: 88512cc2a992ddfbe636d76b31127af8 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-08-29T18:02:32Z (GMT) No. of bitstreams: 1 reis_bo_me_araca.pdf: 2838275 bytes, checksum: 88512cc2a992ddfbe636d76b31127af8 (MD5) / Made available in DSpace on 2017-08-29T18:02:32Z (GMT). No. of bitstreams: 1 reis_bo_me_araca.pdf: 2838275 bytes, checksum: 88512cc2a992ddfbe636d76b31127af8 (MD5) Previous issue date: 2017-08-15 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Objetivo: Avaliar a influência de inibidores de proteases no potencial de degradação do colágeno das dentina sadia, esclerótica e afetada por cárie. Materiais e métodos: Trinta e nove molares humanos foram utilizados, treze para cada condição dentinária. Três fatias foram obtidas de cada dente, cada uma imersa em diferentes soluções: 1) saliva artificial; 2) clorexidina 2%; 3) EGCG 0,5%. Após incubação nas soluções por 1h, amostras foram sujeitas à degradação enzimática pela colagenase derivada da Clostridium histolyticum. Propriedades mecânicas de nanodureza (HIT) e módulo de elasticidade (Er) dos três diferentes tipos de dentina foram mensuradas antes e após a degradação, bem como a resistência à tração do colágeno. Resultados do teste de resistência à tração e nanoindentação foram submetidos à ANOVA dois e três fatores para medidas repetidas, e pós-teste de Tukey (α=0,05). Resultados: Maiores valores de resistência à tração foram encontrados para dentina sadia, nos grupos controle (40,30 ± 21,38 MPa) e EGCG 0,5% (30,05 ± 19,67 MPa). Antes da degradação, maiores valores de HIT (0,237 ± 0,062 GPa) e Er (5,58 ± 1,75 GPa) foram encontrados para o grupo EGCG 0,5%, na dentina afetada por cárie. Após a degradação, grupo clorexidina 2% apresentou maiores valores de HIT e Er para dentinas sadia (0,134 ± 0,020 GPa e 3,57 ± 0,40 GPa) e esclerótica (0,201 ± 0,048 GPa e 4,30 ± 0,56 GPa). Conclusões: O uso da clorexidina 2%, principalmente em dentina esclerótica, mostrou-se mais efetivo em promover aumento na resistência à tração e nas propriedades mecânicas, antes e após a degradação. A EGCG 0,5% apresentou melhor efeito sobre as propriedades mecânicas na dentina afetada por cárie, especialmente antes da degradação enzimática. Relevância Clínica: O efetivo conhecimento do mecanismo de ação de inibidores de proteases em diferentes tipos de dentina poderia contribuir para melhoria da resistência do substrato e para maior longevidade dos processos de união sobre este tecido. / Objetive: To evaluate the influence of proteases inhibitors on the collagen degradation from sound, sclerotic and caries-affected dentin. Materials and Methods: Thirty-nine human molars were used, thirteen for each dentin condition. Three slices were obtained from each tooth, each one immersed in different solutions: 1) artificial saliva; 2) 2% chlorhexidine; 3) 0.5% EGCG. After incubation in the solutions for 1h, samples were subjected to enzymatic degradation by collagenase derived from Clostridium histolyticum. Mechanical properties of nanohardness (HIT) and elastic modulus (Er) of the three types of dentin were measured before and after degradation, as well as the microtensile strength. Results of the microtensile strength and nanoindentation tests were submitted to ANOVA two and three factors for repeated measurements, and Tukey post-test (α = 0.05). Results: Higher values ​​of tensile strength were found for sound dentin in control (40.30 ± 21.38 MPa) and 0.5% EGCG (30.05 ± 19.67 MPa) groups. Before degradation, higher values ​​of HIT (0.237 ± 0.062 GPa) and Er (5.58 ± 1.75 GPa) were found for the 0.5% EGCG group in caries-affected dentin. After degradation, 2% chlorhexidine group had higher values ​​of HIT and Er for sound (0.134 ± 0.020 GPa and 3.57 ± 0.40 GPa) and sclerotic (0.201 ± 0.048 GPa and 4.30 ± 0.56 GPa) dentin. Conclusions: The use of 2% chlorhexidine, mainly in sclerotic dentin, was shown to be more effective in promoting increase in the microtensile strength and mechanical properties, before and after the degradation. The 0.5% EGCG showed a better effect on mechanical properties in caries-affected dentin, before the enzymatic degradation. Clinical Relevance: The effective knowledge of the mechanism of action of protease inhibitors in different types of dentin could contribute to the improvement of the resistance of the substrate and to the longer longevity of the bonding processes on this tissue. / FAPESP: 2015/10566-7

Memoria para optar al Título Profesional de Ingeniero Agrónomo / El presente estudio tuvo como objetivo evaluar la composición fenólica y la capacidad antioxidante de 20 productos de té verde y negro, adquiridos en un supermercado en la ciudad de Santiago de Chile, seleccionando productos dentro de un amplio rango de precios. Como procedimiento se utilizó la extracción líquida emulando el consumo doméstico del producto. La determinación de fenoles totales por el método de Folin-Ciocalteau permitió observar una gran variabilidad del orden del 880 a 1822 mg de equivalentes de ácido gálico/L. En su conjunto, la variedad Darjeeling obtuvo mayores resultados, y las mezclas los menores. El contenido de taninos totales fue en promedio significativamente mayor en el té negro (1013 mg/L) que en el verde (570 mg/L). Las variedades Darjeeling y Ceylán presentaron conjuntamente la mayor cantidad de estos compuestos. Utilizando la técnica de HPLC-DAD se identificaron y cuantificaron los 8 compuestos de mayor presencia en las muestras, correspondientes a ácido gálico, epigalocatequina, cafeína, epigalocatequina galato, epicatequina galato, quercetina, kaempferol y teaflavina. El té negro mostró de manera significativa la mayor cantidad de los compuestos mencionados, a excepción de las catequinas, las cuales en promedio se encontraron en mayor cantidad en el té verde. Entre las muestras de té negro analizadas, Darjeeling mostró los mayores contenidos de catequinas. Por otro lado Ceylán exhibió mayor cantidad de teaflavinas, seguido por las mezclas y Darjeeling, mientras que en las muestras de té verde no se detectaron. El color determinado a una longitud de onda de 420 nm reveló una alta correlación negativa de -0,82 con el total de catequinas. Las menor intensidad colorante y mayor contenido de fenoles fueron observados conjuntamente en las muestras de té verde y negro de la variedad Darjeeling. La capacidad antioxidante medida a través de ORAC-FL y expresada como μM Equivalentes de Trolox/g fue considerablemente mayor (1426 - 2557,9 μMET/g) en el té verde que en el té negro (1020,2 - 1321,7 μMET/g), concordando con la mayor parte de la literatura citada. Los resultados obtenidos proveen información sobre la composición fenólica y capacidad antioxidante de un número considerable de productos consumidos en Chile, y otorgan al consumidor la posibilidad de elegir objetivamente aquellos productos que reporten mayores efectos beneficiosos para su salud. / The aim of this research was to evaluate the phenolic composition and antioxidant capacity of 20 differents tea products (4 green and 16 black teas) purchased in a local supermarket of Santiago, Chile. Products were selected within a wide price range with the purpose of encompass most of the population consumption. In order to simulate household brewing conditions for a cup of tea, teas were prepared using an aqueous extraction procedure. Determination of the total phenols by Folin-Ciocalteau method showed high variability among samples (880 to 1822 mg gallic acid equivalents/L). In average, the results were higher in Darjeeling variety, while blended teas showed the lowest values. The total tannin content in black teas was in average (1013 mg/L) significantly higher than in green tea (570 mg/L). Both, Darjeeling and Ceylon exhibit the highest value of these compound types. By using the technique of HPLC-DAD were identified and quantified the 8 major compounds present in the samples, corresponding to: gallic acid, epigallocatechin, caffeine, epigallocatechin gallate, epicatechin gallate, quercetin, kaempferol and theaflavin. Black tea samples presented the highest amount of the aforementioned compounds, with the exception of catechins, which on average were higher in green tea. Among the tested black teas samples Darjeeling variety showed the highest content of catechins. Ceylon exhibited the highest concentration of theaflavins, followed by blended teas and Darjeeling samples, while in Green tea theaflavins were not detected. The color assay determined using a wavelength of 420 nm showed a high negative correlation of -0.82 with total catechins. Samples with less color intensity and higher content of phenols were both the green tea and Darjeeling variety. The antioxidant capacity measured by ORACFL exhibited substantially higher ranges (1426 to 2557.9 μMET/g) in green tea samples than in black tea samples (1020.2 to 1321.7 μMET/g), agreeing with other authors. The results provide information on the phenolic composition and antioxidant capacity of a considerable number of tea products consumed in Chile, and allow the consumer to objectively select those that generate greater benefits for their health.

A concerning situation has developed over the past few years where several tea estates had to close down due to high labour costs and low profitability. Solutions are desperately required to save these estates from further regression and to prevent others from joining their ranks. One solution is to redirect the tea factories from the current production of black tea to producing a value added commodity such as a high quality green tea extract with an increased market value. The aim of this study was to find an economically viable PPO inactivation method that can be implemented in existing tea factories for the production of high quality instant green tea. Further enhancement of quality may then be achieved by high throughput cultivar screening where those with a higher natural catechin to caffeine content will be favourable. Six different PPO inactivation methods (steaming, blanching, fluid bed drying, panfrying, grilling over direct heat and grilling over indirect heat) were explored. Four independent experiments were performed in duplicate with these six methods using fresh tea leaves donated by a tea estate in Tzaneen, South Africa. All samples were dried in a fluid bed drier and milled after PPO inactivation. Biochemical analysis of specific quality parameters followed where extractions from these green tea leaf samples were tested for theaflavin content, caffeine content, flavan-3-ol content, total free amino acid content, colour and taste. The six PPO inactivation methods were compared by data evaluation of the individual quality parameters where certain quality parameters carried a higher weight than others. For the purpose of this project, the catechin to caffeine ratio was the most important quality determinant to yield a high value IGT. Also, to prove effectiveness of the PPO inactivation method, low TF content was compulsory. All PPO inactivation methods explored proved successful in rapidly inactivating PPO enzyme. As hypothesised, a significant difference in biochemical composition is brought about between green teas produced by employing different PPO inactivation methods. Blanching was found to be the most efficient PPO inactivation method as well as the method resulting in the highest catechin to caffeine ratio (16.67:1 for 4 min blanch vs. 5.72:1 for 17 min FBD as determined by HPLC analysis). A freeze dried extract from a 1.5 minute blanched sample (IGT) was compared with foreign IGTs originating from Sri-Lanka, Kenya, China and India by HPLC analysis. A more than two fold greater catechin to caffeine ratio was obtained for the sample originating from the blanching method (9.08:1 vs. 2.81-5.02:1). A high quality, naturally low caffeine, instant green tea can therefore be produced by utilizing the blanching method of PPO inactivation. To allow for inter and intra cultivar screening, tentative identification of novel catechins (digallated catechins) and their HPLC retention times was done using HPLC-ESI-MS/MS. Potential HPLC retention times for EC-digallate were detected at tR 62.0 ± 0.2, 70.7 ± 0.1 and 76.7 ± 0.2 minutes while tR 64.6 ± 0.1 and 65.8 ± 0.1 minutes were detected for EGC-digallate. With this information at hand, cultivars of a higher quality, hence increased economical potential, can be identified upon confirmation by NMR. HPLC-ESI-MS/MS screening coupled with NMR confirmation is to be continued to detect several other novel flavan-3-ols that could not be detected in the 4 IGTs of different origin used in this study. This study gives an overview of the biochemical differences between green tea leaves prepared using six different PPO inactivation methods. The aim of this study was met by identification of the significant increase in quality brought about by PPO inactivation using the blanching method, which is also economical for use in Africa. Blanching of tea leaves caused a significant decrease in caffeine. Therefore, the 1st hypothesis, stating that the six polyphenol oxidase inactivation methods investigated will produce instant green teas with different catechin to caffeine ratios, is accepted. Also, a means to perform large scale screening of individual tea trees in Africa for their novel flavan-3-ol content was provided by tentative identification of these novel catechins by LC-MS. Thus, the 2nd hypothesis, stating that application of LC-MS will aid in the identification of HPLC retention times of compounds (novel catechins) from a crude extract, is also accepted. / Dissertation (MSc)--University of Pretoria, 2009. / Biochemistry / unrestricted

京都大学 / 0048 / 新制・論文博士 / 博士(農学) / 乙第13215号 / 論農博第2864号 / 学位論文||H30||N5153(農学部図書室) / (主査)教授 川島 茂人, 教授 星野 敏, 教授 藤原 正幸 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DGAM

Submitted by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2018-09-27T17:53:00Z No. of bitstreams: 1 ALVARO SOSA MACHADO.pdf: 1403839 bytes, checksum: ecb430aded30475dee48fa2ac550cd0d (MD5) / Approved for entry into archive by Marcos Anselmo (marcos.anselmo@unipampa.edu.br) on 2018-09-27T17:53:12Z (GMT) No. of bitstreams: 1 ALVARO SOSA MACHADO.pdf: 1403839 bytes, checksum: ecb430aded30475dee48fa2ac550cd0d (MD5) / Made available in DSpace on 2018-09-27T17:53:12Z (GMT). No. of bitstreams: 1 ALVARO SOSA MACHADO.pdf: 1403839 bytes, checksum: ecb430aded30475dee48fa2ac550cd0d (MD5) Previous issue date: 2018-02-23 / A prática regular de exercício intenso é benéfica à saúde, mas quando realizada em dias consecutivos pode intensificar os efeitos deletérios da fadiga muscular, podendo gerar perda de atividade neuromuscular, aumento do dano às fibras musculares e incremento do risco de lesão. Estratégias para inibir ou retardar estes efeitos da fadiga, principalmente o estresse oxidativo, são desejáveis. Nesse contexto, o extrato de chá verde (ECV), derivado da Camellia sinensis, pode ser útil, visto que tem conhecidas propriedades anti-inflamatórias e antioxidantes. Neste estudo, nosso objetivo foi verificar se a suplementação com extrato de chá verde beneficia marcadores de dano muscular, estresse oxidativo e desempenho em condição de fadiga. Dezesseis atletas amadores treinados, todos homens, foram testados durante exercício de 9 ciclismo em duas condições de exercício: sem suplementação sem fadiga; e com suplementação (placebo, n=8; extrato de chá verde 500 mg/dia durante 15 dias, n=8) com fadiga (extensão de joelhos até a exaustão induzida em dois dias consecutivos). Coletas sanguíneas para determinação de marcadores de dano muscular e estresse oxidativo, e medidas de eletromiografia, para determinação da ativação elétrica neuromuscular dos vastos laterais, além de parâmetros de treinamento e frequência cardíaca, foram quantificados e comparados entre os grupos nas diferentes condições. Os valores normalizados de eletromiografia root mean square e mediana da frequência da eletromiografia não diferiram entre a pedalada sem e com fadiga no grupo chá verde, enquanto que o grupo placebo apresentou prejuízo na contratilidade muscular decorrente da fadiga. O maior custo de frequência cardíaca confirma que esse redução na EMG foi combinada por um aumento do esforço na tarefa. O ECV também foi capaz de inibir dano muscular e evitar o estresse oxidativo, ao contrário do grupo placebo na comparação entre as pedaladas sem e com fadiga. Dessa forma, as propriedades antioxidantes do chá verde parecem evitar o dano muscular induzido pelo estresse oxidativo e preservar a contratilidade muscular de atletas submetidos à fadiga em dias consecutivos. Sendo assim, a suplementação com chá verde pode ser considerada como uma estratégia válida para o treinamento físico em tarefas extenuantes. / The regular practice of intense physical exercise benefits health, but when the sessions are accomplished in consecutive day it migh intensify some deleterious effects of muscle fatigue, which can impair efficiency, promote muscle damage and increase injury risk. The interest in strategies to avoid or delay such effects, especially the oxidative stress, are desirable. In this regard, the green tea extract, from Camellia sinesis, can be useful due to its recognized antioxidant and antiinflamatory properties. Here our purpose was to determine whether the supplementation with green tea extract can benefit markers of muscle damage, oxidative stress and performance in exercise under fatigue. Sixteen male athletes trained were evaluted in cycling exercise under two conditions: without supplementation and without fatigue, and supplemented (placebo n=8; extrato de chá verde, n=8, 500 mg/dia durante 15 dias) and with fatigue (knee extension until exhaustion in two consecutive days). Blood 11 samples served to determine markers of muscle damage and oxidative stress. Electromyography was employed to monitore the muscle activation from vastus lateralis, as well as training parameters like heart rate, were quantified and compared between the groups and exercise conditions. Muscle activation did not differ between the cycling with and without fatigue in the green tea group, whereas in the placebo group there a loss of contractility due to fatigue. A higher cost observed by the higher heart rate support that reduction in the activation in the placebo group relies on the effort associated to the performance of the cycling exercise. Green tea supplementation was able to avoid increase in the muscle damage and oxidative stress in response to the exercise compared to the placebo group. Therefore, the properties of green tea seem to delay or avoid the muscle damage resultant of oxidative stress and preserves the contractility in athletes submitted to exercise under a fatigue state. As a conclusion, the supplementation with green tea can be considered a valid strategy in the physical training during extenuant tasks.

O chá é uma das bebidas mais consumidas no mundo. Os chás provenientes da planta Camellia sinensis possuem altos teores de antioxidantes, o que significa que podem ter diversos efeitos benéficos na preservação da saúde. Durante séculos, a humanidade procura formas de conservar melhor e por mais tempo os alimentos que consomem. O processo de irradiação de alimentos é uma técnica amplamente utilizada em todo o mundo e é indicada por diversos órgãos de saúde e sanitários de diversos países. A radiação interage com o material causando dois tipos de efeitos, o efeito direto e o efeito indireto. No efeito direto a radiação interage com a molécula de DNA, causando a quebra dessa molécula, inativando a célula. No efeito indireto, que representa 70% da interação, a radiação quebra a molécula de água presente no meio, em um processo chamado de radiólise, criando uma série de radicais livres que vão interagir com os componentes celulares, levando a morte da célula. Portanto, o objetivo deste trabalho foi estudar os efeitos da radiação gama em dois tipos de chás da planta Camellia sinensis irradiados com diferentes valores de atividade de água. As amostras de chá verde e chá preto tiveram suas Aw ajustadas a três valores (Aw alta, Aw média e Aw baixa). As amostras foram irradiadas em fonte de 60Co nas doses de 0; 1,0; 1,5; 2,0; 2,5; 5,0; 7,5 e 10,0 kGy. As análises utilizadas foram: microbiologia por semeadura de superfície, quantificação de fenólicos totais, análise da atividade antioxidante por ORAC e identificação e quantificação dos principais antioxidantes presente nessas bebidas. Foi possível constatar que quanto maior a quantidade de água livre presente no meio, menor foi a dose para realizar o controle microbiológico. O chá verde mostrou ser um pouco mais suscetível a irradiação com alta Aw do que o chá preto, pois houve variação da quantidade de fenólicos e flavonóides, diminuindo a quantidade desses compostos em algumas doses, mas também houve aumento da quantidade em outras doses. Entretanto em ambos os chás, essas mudanças podem ser consideradas insignificantes, uma vez que não houve diferença da atividade antioxidante em doses de até 10 kGy. A dose de 5,0 kGy foi a dose mínima que garantiu o controle microbiológico e não causou alterações nos parâmetros analisados. / Tea is the most consumed beverage in the world. Teas from Camellia sinensis plant have high levels of antioxidants, which mean that they may have several beneficial effects on health preservation. For centuries, mankind looks for ways to conserve better and for a longer time the food that they eat. The food irradiation process is a largely technique used worldwide, and is recommended by many health agencies and authorities of several countries. The radiation interacts with the material causing two kinds of effects, the direct and the indirect effect. In the direct effect the radiation interacts with the DNA molecule, breaking it, and then inactivates the cell. In the indirect effect, which represents 70% of the interaction, the radiation breaks the water molecule in a process denominated radiolysis, creating a number of free radicals that will interact with the cellular components, leading to the cell death. Therefore, the aim of this work is to study the effects of gamma radiation on two kinds of tea from Camellia sinensis plant irradiated with different water activities. The green tea and black tea samples had their Aw adjusted to three values (high Aw, medium Aw, and low Aw). The samples were irradiated in 60Co source at doses of 0, 1.0, 1.5, 2.0, 2.5, 5.0, 7.5, and 10.0 kGy. The analyses used were: microbiology by plate count, total phenolic compounds quantification, antioxidant activity by ORAC assay, and identification and quantification of main antioxidants in these beverages. It was noted that the greater the quantity of free water present in the medium, the lower was the dose to achieve microbiological control. The green tea showed to be a little more susceptible to irradiation by high Aw once there was more variation in the amount of flavonoids and phenolics than the black tea, decreasing the amount of these compounds in some doses, but increasing the amount in other ones. However in both teas, these changes can be considered insignificant, since there was no difference in antioxidant activity at doses up to 10 kGy. The dose of 5.0 kGy was the minimum dose that secured the microbiological control and had no changes on the parameters analyzed.