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Potencial neuroprotetor da Camellia sinensis e do exercício físico em um modelo de doença de Alzheimer / Neuroprotective potential of Camellia sinensis and physical exercise in a model of Alzheimer's diseaseSchimidt, Helen Lidiane 16 July 2018 (has links)
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Previous issue date: 2018-07-16 / A Doença de Alzheimer (DA) causa déficits cognitivos e de memória, entre outros. O mecanismo de desenvolvimento da DA incluí processos inflamatórios e estresse oxidativo em virtude do acúmulo da proteína β-amilóide no cérebro. Por seu potencial antioxidante, chás provenientes da Camellia sinensis e o exercício físico são estratégias neuroprotetoras eficazes em diversos modelos de déficits cognitivos. No entanto, não está claro se tanto as variedades dos chás da Camellia sinensis quanto os diferentes tipos de exercício possuem o mesmo potencial neuroprotetor na DA. Adicionalmente, poucos estudos investigam estratégias de neuroproteção em modelos de DA associado a fatores de risco da doença, como uma dieta hipercalórica. Considerando esse contexto, determinamos o potencial neuroprotetor de diferentes chás provenientes da Camellia sinensis e de diferentes configurações de exercício físico em um modelo de DA associada ou não a dieta hipercalórica. Após a realização de uma série de experimentos bioquímicos e comportamentais, concluímos que (a) o chá verde tem maior potencial neuroprotetor no modelo de DA, (b) uma dieta hipercalórica associada ao modelo de DA não potencializa déficits cognitivos e dano oxidativo no hipocampo, e (c) o exercício de força possui potencial neuroprotetor no modelo de DA estudado e é a única estratégia que também atua no sistema colinérgico. / Alzheimer's disease (AD) causes cognitive and memory deficits, and other. The mechanism of AD onset includes inflammatory processes and oxidative stress due to the accumulation of β-amyloid protein in the brain. Teas from Camellia sinensis and physical exercise are effective neuroprotective strategies in several models of cognitive deficits. However, it is unclear whether Camellia sinensis tea varieties have the same neuroprotective potential in AD, as well as whether different exercise configurations have the same neuroprotective potential in AD. Additionally, few studies investigated prevention strategies in AD models associated with additional risk factors, such as a hypercaloric diet. Here we determine the neuroprotective potential of different teas from Camellia sinensis and different exercise configurations in a model of AD associated or not to a hypercaloric diet. After completing a serie of biochemical and behavioral experiments, we conclude (a) that green tea has the greater neuroprotective potential in the AD model, (b) a hypercaloric diet associated with the AD model did not potentiate cognitive deficits and oxidative damage in the hippocampus, and (c) strength exercise has neuroprotective potential in the AD model studied, being the only exercise also influencing the cholinergic system.
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Formulação à base de Epigalocatequina-3-galato, derivada do chá verde, desenvolvida para uso endodôntico: estudo físico-químico e biológico / Formulation based on Epigallocatechin-3-gallate, derived from green tea, developed for endodontic use: physicochemical and biological studyDanielly Cunha Araújo Ferreira 28 August 2015 (has links)
O chá verde, obtido da Camellia sinensis, é uma das bebidas mais populares em todo o mundo e, recentemente, tem sido foco de pesquisas científicas por apresentar efeitos benéficos na saúde geral. Estudos laboratoriais e epidemiológicos sugerem que, dentre os polifenóis que compõem o chá verde, a Epigalocatequina-3-galato (EGCG) é o mais bioativo e responsável por sua ação antioxidante, anti-inflamatória, antimicrobiana, inativadora de LPS bacteriano, anticarcinogênica, antitumoral, anti-angiogênica, anti-hipertensiva e reparadora tecidual, podendo atuar na prevenção e tratamento do câncer, doenças cardiovasculares, neurodegenerativas, hepáticas e renais. Em diversas doenças ósseas, a EGCG também desempenha um importante papel protetor, atuando na indução da mineralização e inibição da osteoclastogênese. No entanto, seus possíveis efeitos na inflamação e na reabsorção óssea associadas à lesão periapical ainda não foram avaliados. Portanto, o objetivo do presente estudo foi desenvolver uma formulação para uso endodôntico à base de EGCG com propriedades físico-químicas e biológicas que permitam seu uso como curativo de demora entre sessões. As formulações testadas incluíram: EGCG diluída em água e diferentes concentrações de EGCG (1,25; 5; 10 e 20 mg/mL) veiculadas em polietilenoglicol 400 (PEG). O óxido de zinco foi utilizado como agente radiopacificador. Em função da possível degradação dos produtos fenólicos em função do ambiente e do tempo, uma solução obtida por meio do contato prolongado da EGCG com o dente também foi avaliada (produto da degradação). Inicialmente, foi realizada a caracterização físico-química da formulação de EGCG por meio de espectrofotometria em Ultravioleta/Visível (UV/Vis), em contato com soluções contendo zinco, óxido de zinco e acetato de zinco. Os estudos biológicos foram realizados para avaliar sua compatibilidade tecidual no tecido subcutâneo de camundongos, por meio da avaliação do extravasamento plasmático após 24 horas e da análise de aspectos macroscópicos e microscópicos aos 7, 21 e 63 dias após a inserção de tubos de polietileno contendo as formulações. Neste estudo, uma pasta a base de hidróxido de cálcio (Calen®) foi utilizada como controle. Na análise macroscópica, realizada por meio de fotografias, foram atribuídos escores aos parâmetros de ulceração epitelial, vascularização, necrose e edema. Na análise microscópica, realizada em microscopia de luz convencional e de fluorescência, foram avaliados os parâmetros de infiltrado inflamatório, vascularização, focos de abscessos, cápsula fibrosa, edema e necrose. Os escores dos resultados biológicos foram submetidos à análise estatística utilizando o teste do Qui-quadrado ou Exato de Fisher e para análise dos resultados quantitativos do extravasamento plasmático foi utilizada análise de variância (ANOVA), seguida pelo pós-teste de Tukey. O nível de significância adotado foi de 5%. Os estudos físico-químicos mostraram que a EGCG manteve seu comprimento de onda original em 274 nm quando associada ao óxido de zinco, tendendo à formação de uma banda de absorção em 325 nm. A associação da EGCG com acetato de zinco ocasionou diminuição da banda de absorção em 274 nm e formação de uma nova banda em 323 nm. Os estudos biológicos mostraram, nos parâmetros macroscópicos que, em todos os períodos avaliados, todas as formulações apresentaram compatibilidade tecidual, com ausência de ulceração epitelial, presença de leve necrose tecidual superficial, edema e vascularização, não havendo diferença significante entre os grupos avaliados (p>0,05). Na análise microscópica, em todos os períodos foi verificada ausência de focos de abscesso, edema e necrose e presença de suave ou moderado infiltrado inflamatório, cápsula fibrosa e neovascularização, semelhante entre todos os grupos (p>0,05). A avaliação dos espécimes corados com HE em microscopia de fluorescência favoreceu a visualização dos vasos sanguíneos e de fibras colágenas, constituindo metodologia adicional para esta finalidade. Na avaliação do extravasamento plasmático, o produto da degradação da ECGG apresentou extravasamento de corante azul de Evans por grama de tecido inferior (0,0514 ±0,0220 mg/mL) às demais formulações testadas (p<0,05). Conclui-se que a formulação tópica à base de EGCG, desenvolvida para uso endodôntico, apresenta propriedades físico-químicas estáveis e compatibilidade tecidual. / The green tea, obtained from the Camellia sinensis, is one of the most popular drinks in the world and has recently been in the focus of scientific research due its beneficial effects on general health. Laboratory and epidemiological studies suggest that, among the polyphenols found on green tea, the epigallocatechin-3-gallate (EGCG) is the most bioactive and responsible for its antioxidant, anti-inflammatory, anti-microbial, bacterial LPS inactivation, anticarcinogenic, anti-tumoral, anti-angiogenic, anti-hypertensive and tissue repair and can act in the prevention and treatment of cancer, cardiovascular disease, neurodegenerative, liver and kidney diseases. In several bone diseases, EGCG also plays a major protective role, acting in inhibition of osteoclastogenesis and induction of mineralization. However, their possible effects on inflammation and bone resorption associated to apical periodontitis have not been evaluated. Therefore, the aim of this study was to develop a EGCG based formulation for endodontic use with physicochemical and biological properties that allow its use as intracanal dressing between sessions. The formulations tested included: EGCG diluted in water and different concentrations of EGCG (1.25, 5, 10 and 20 mg/ml) diluted in polyethylene glycol 400 (PEG). Zinc oxide was used as radiopacifier agent. Due to the possible degradation of phenolic compounds as a function of the environment and time, a solution obtained through prolonged contact with the tooth EGCG was also evaluated (degradation product). Initially, physicochemical characterization of EGCG formulation was performed by ultraviolet spectrophotometry/Visible (UV/Vis) in contact with solutions containing zinc, zinc oxide and zinc acetate. Biological studies were conducted to evaluate its tissue compatibility with subcutaneous tissue of mice by means of the evaluation of plasma leakage after 24 hours and the examination of macroscopic and microscopic features at 7, 21 and 63 days after insertion of polyethylene tubes containing the formulations. In this study, a calcium hydroxide pastebase (Calen®) was used as control. The macroscopic analysis performed by means of photographs, assigned scores to epithelial ulceration, vascularization, necrosis and edema parameters. Microscopic examination performed in conventional and fluorescence microscopy assessed the inflammatory infiltrate, vascularization, abscesses spots, fibrous capsule, edema and necrosis parameters. The scores of biological results were statistically analyzed by the chisquare test or Fisher\'s exact and for the quantitative analysis of the results of plasma extravasation the analysis of variance (ANOVA) followed by Tukey\'s post-test were used. The significance level was 5%. The physico-chemical studies showed that EGCG maintained its original wavelength at 274 nm when added to zinc oxide, tending to the formation of an absorption band at 325 nm. The combination of EGCG with zinc acetate led to decreased absorption band at 274 nm and formation of a new band at 323 nm. Biological studies showed, in the macroscopic parameters in all periods, that all formulations showed tissue compatibility, with no epithelial ulceration, presence of mild superficial tissue necrosis, edema and vascularization, with no significant difference between the groups (p > 0.05). On microscopic examination, in all periods was verified absence of abscess foci, edema and necrosis and the presence of mild or moderate inflammatory infiltrate, fibrous capsule and neovascularization, similar among all groups (p> 0.05). The evaluation of the specimens stained with HE under fluorescence microscopy enhancve the visualization of the blood vessels and collagen fibers, constituting an additional methodology for this purpose. In the evaluation of plasma extravasation, the product of degradation of ECGG presented values of Evans blue dye extravasation by gram of tissue (0.0514 ± 0.0220 mg / mL) lower to the other tested formulations (p <0.05). It is concluded that the topical formulation based on EGCG developed for endodontic use, presented stable physical and chemical properties and tissue compatibility.
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Auxinas e tipos de estacas no enraizamento de Camellia sinensis / Auxins and types of cuttings on rootings of Camellia sinensisLuigi Tancredi Campo Dall'Orto 26 August 2011 (has links)
Com o objetivo de avaliar a influência de cultivares, tipos de estacas de Camellia sinensis e doses de ácido indolbutírico no enraizamento de estacas, dois experimentos foram conduzidos em casa de vegetação, no delineamento experimental em blocos ao acaso com 16 tratamentos, no esquema fatorial 2 x 2 x 4, ou seja, tipos de estaca (herbácea e lenhosa), cultivares (Camellia sinensis IAC 259 e Yabukita) e quatro doses de ácido indolbutírico (AIB) (0, 30, 60 e 90 mg L-1), com quatro repetições. Cada repetição foi composta por 20 estacas da porção mediana dos ramos das plantas matrizes, coletadas em duas épocas do ano (verão e inverno). As estacas foram cortadas em bisel e mantidas com uma gema e uma folha inteira, com 5 a 7 cm de comprimento. A região basal das estacas recebeu ou não tratamento com ácido indolbutírico (AIB), através da imersão de 2,5 cm da base em solução aquosa do produto por 24 horas. Posteriormente, elas foram colocadas em bandejas de isopor de 72 células contendo vermiculita de grânulos médios. As estacas herbáceas apresentaram maior porcentagem de enraizamento com a aplicação de AIB comparada às estacas lenhosas, sendo que as estacas coletadas no período do verão apresentaram maior porcentagem de enraizamento em menor espaço de tempo, quando comparadas com as estacas coletadas no período do inverno. Estacas da cultivar Yabukita apresentaram maior potencial de enraizamento em relação às estacas da cultivar IAC 259. As concentrações recomendadas de AIB para o enraizamento de estacas de Camellia sinensis variaram de 56 a 83 mg L-1 em função da cultivar. / Aiming to evaluate the influence of Camellia sinensis cultivars, types of cuttings and doses of IBA on rooting, two experiments have been conducted in a green house in the experimental design in blocks randomized with 16 treatments, arranged in a 2 x 2 x 4, that is, cutting types (herbaceous and woody), cultivars (Camellia sinensis \'IAC 259\' and \'Yabukita\') and four doses of butyric acid (IBA) (0, 30, 60 and 90 mg L -1) with four replications. Each replication consisted of 20 cuttings from the middle portion of the branches from the mother plants, collected in two seasons (summer and winter). The cuttings were cut in bevel and maintained with a bud and a leaf, with 5-7 cm long. The basal cuttings have received or not treatment with indol butyric acid (IBA) by immersion of 2.5 cm from the base in an aqueous solution of the product for 24 hours. Later, they have been placed in trays with 72 cells containing medium granules of vermiculite. Herbaceous cuttings have presented higher percentages of rooting with IBA application compared to hardwood cuttings, and cuttings collected in summer have showed the highest percentage of rooting in the shortest time compared with the cuttings collected in winter. Yabukita cultivars cuttings had higher rooting potential in relation to the IAC 259 cuttings. IBA level to the rooting of Camellia sinensis varied from 56 to 83 mg L-1 according to cultivars
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Produção de biofilme (membrana de biocelulose) por Gluconacetobacter xylinus em meio de resíduos de frutas e folhas de chá verde / Biofilm production (biocellulose membrane), production by Gluconacetobacter xylinus in fruits residues and green tea mediumDenise Cristina Moretti Vieira 04 April 2013 (has links)
A biomembrana, que é uma membrana de celulose bacteriana (C6H10O5)n formada na superfície do meio de cultivo durante a fermentação acética, foi obtida através do cultivo associado de Gluconacetobacter xylinus (formalmente Acetobacter xylinum) e Saccharomyces cerevisiae em meio de folhas de chá verde, resíduos de frutas (abacaxi, mamão, laranja), resíduos de vegetais (beterraba), vinho e colágeno em condições estáticas a 28 ± 2°C de 7 a 30 dias de cultivo. Foi incorporado à biomembrana, extrato hidroalcoólico de Calendula officinalis, devido as suas propriedades anti-inflamatórias, antioxidantes e cicatrizantes. A espessura, o diâmetro e o peso da biomembrana foram mensurados e foram calculados a produtividade, bem como o fator de conversão de açúcar em celulose. A caracterização da biomembrana foi realizada por Differential Scanning Calorimetric, espectroscopia infravermelho, Brunauer-Emmett-Teller, resistência à tração e alongamento, microscopia eletrônica (Escola Politécnica - USP) e difração de raio-X. Através destas análises verificou-se que a biomembrana obtida nos diferentes meios de cultivo é composta por celulose, o tamanho médio dos poros variou de 517,9 a 1582,0 nm, a resistência à tração variou de 0,76 a 4,32 kN/m e o índice de cristalinidade entre 75% e 91%, a espessura da biomembranas variou de 0,16 a 6,38 mm. Foram realizados 576 experimentos, a maior produtividade (8,23 g de celulose/dia) foi atingida no meio de mamão com suco de laranja (suco de mamão: 50% v/v e suco de laranja: 19% v/v) em 7 dias de cultivo. O maior fator de conversão (2,36 g celulose/g de açúcar) foi obtido no meio de chá verde em 25 dias de cultivo. A adição de 1,5% p/v de colágeno ao meio de chá verde dobrou a massa da biomembrana. A incorporação do extrato de calêndula aumentou a flexibilidade, a cristalinidade e as propriedades mecânicas da biomembrana de chá verde. / The biomembrane, cellulose membrane (C6H10O5)n formed in medium surface, was obtained from an associate culture Gluconacetobacter xylinus (formally Acetobacter xylinum) and Saccharomyces cerevisiae in green tea leaves, fruit residues (pineapple, papaya, orange), vegetables residues (beet), wine and collagen media in static condition , at 28 ± 2 ºC in 7 - 30 days cultivation. The Calendula officinalis hydroalcoholic extract was incorporated in the Biomembrane, due to its anti-inflammatory, anti-oxidants and cicatrizing proprieties. The biomembrane thickness, diameter and weight were measured. The productivity and conversion factor from cellulose to sugar were calculated. The biomembrane caracterization was performed by Differential Scanning Calorimetric, infrared spectroscopy, Brunauer-Emmett-Teller, resistance to tension, elongation, eletrocnic microscopy and raio-X difraction. In these analyses were verified that biomembrane obtained in different media were composed by cellulose, average porous size varied from 517.9 to 1582.0 nm, the resistance to tension varied from 0.76 to 4.32 kN/m and cristalinity index varied from 75% to 91%. The biomembrane thickness varied from 0,16 to 6,38 mm. It was performed 596 tests, the highest bacterial cellulose yield (8.23 ± 0.58 g cellulose/day) was obtained in papaya with orange (papaya juice: 50% v/v and orange juice: 19% v/v) in 7 cultivation days. The highest conversion factor (2,36 g cellulose/g sugar) was obtained in green tea medium in 25 days. The addition of 1.5% w/v collagen to the green tea media increased 2 times the biomembrane weight. The biomembrane absorption capacity for water and Marigold hydroalcoholic extract (1:1), were from 1.73 to 22 and, from 1.75 to 24 times dry weight, respectively. The Marigold extract improved the green tea biomembrane flexibility, cristalinity, and physical proprieties.
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Auxinas e tipos de estacas no enraizamento de Camellia sinensis / Auxins and types of cuttings on rootings of Camellia sinensisDall'Orto, Luigi Tancredi Campo 26 August 2011 (has links)
Com o objetivo de avaliar a influência de cultivares, tipos de estacas de Camellia sinensis e doses de ácido indolbutírico no enraizamento de estacas, dois experimentos foram conduzidos em casa de vegetação, no delineamento experimental em blocos ao acaso com 16 tratamentos, no esquema fatorial 2 x 2 x 4, ou seja, tipos de estaca (herbácea e lenhosa), cultivares (Camellia sinensis IAC 259 e Yabukita) e quatro doses de ácido indolbutírico (AIB) (0, 30, 60 e 90 mg L-1), com quatro repetições. Cada repetição foi composta por 20 estacas da porção mediana dos ramos das plantas matrizes, coletadas em duas épocas do ano (verão e inverno). As estacas foram cortadas em bisel e mantidas com uma gema e uma folha inteira, com 5 a 7 cm de comprimento. A região basal das estacas recebeu ou não tratamento com ácido indolbutírico (AIB), através da imersão de 2,5 cm da base em solução aquosa do produto por 24 horas. Posteriormente, elas foram colocadas em bandejas de isopor de 72 células contendo vermiculita de grânulos médios. As estacas herbáceas apresentaram maior porcentagem de enraizamento com a aplicação de AIB comparada às estacas lenhosas, sendo que as estacas coletadas no período do verão apresentaram maior porcentagem de enraizamento em menor espaço de tempo, quando comparadas com as estacas coletadas no período do inverno. Estacas da cultivar Yabukita apresentaram maior potencial de enraizamento em relação às estacas da cultivar IAC 259. As concentrações recomendadas de AIB para o enraizamento de estacas de Camellia sinensis variaram de 56 a 83 mg L-1 em função da cultivar. / Aiming to evaluate the influence of Camellia sinensis cultivars, types of cuttings and doses of IBA on rooting, two experiments have been conducted in a green house in the experimental design in blocks randomized with 16 treatments, arranged in a 2 x 2 x 4, that is, cutting types (herbaceous and woody), cultivars (Camellia sinensis \'IAC 259\' and \'Yabukita\') and four doses of butyric acid (IBA) (0, 30, 60 and 90 mg L -1) with four replications. Each replication consisted of 20 cuttings from the middle portion of the branches from the mother plants, collected in two seasons (summer and winter). The cuttings were cut in bevel and maintained with a bud and a leaf, with 5-7 cm long. The basal cuttings have received or not treatment with indol butyric acid (IBA) by immersion of 2.5 cm from the base in an aqueous solution of the product for 24 hours. Later, they have been placed in trays with 72 cells containing medium granules of vermiculite. Herbaceous cuttings have presented higher percentages of rooting with IBA application compared to hardwood cuttings, and cuttings collected in summer have showed the highest percentage of rooting in the shortest time compared with the cuttings collected in winter. Yabukita cultivars cuttings had higher rooting potential in relation to the IAC 259 cuttings. IBA level to the rooting of Camellia sinensis varied from 56 to 83 mg L-1 according to cultivars
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CROSS-IDEOLOGICAL SOLAR POWER COALITIONS IN THE AMERICAN SOUTH: AN ADVOCACY COALITION APPROACHToibin, Brian T. 01 January 2018 (has links)
Abstract
CROSS-IDEOLOGICAL SOLAR POWER COALITIONS IN THE AMERICAN SOUTH: AN ADVOCACY COALITION APPROACH
By Brian T. Toibin, Ph.D.
A dissertation submitted in partial fulfillment of the requirements for the degree of
Doctor of Philosophy in Public Policy and Administration at Virginia Commonwealth University.
Virginia Commonwealth University, 2018.
Major Director: Dr. Damian Pitt
Associate Professor of Urban and Regional Studies and Planning
L. Douglas Wilder School of Government and Public Affairs
The purpose of this study was to explore two particular cross-ideological coalitions that have formed in order to promote pro-solar power policies in Georgia and Florida through the lens of the Advocacy Coalition Framework. The membership of the coalitions include individuals and organizations from opposite sides of the current prevailing ideological spectrum which united to support pro-solar policies for reasons that are consistent with their ideological worldview. The coalition in Georgia is known as the Green Tea Coalition and the coalition in Florida is known as Floridians for Solar Choice.
This qualitative study was guided by the following questions: 1) Why did supporters of solar power organize themselves into the particular coalition structures represented by Georgia’s Green Tea Coalition and the Floridians for Solar Choice Coalition?; 2) How have Georgia’s Green Tea Coalition and the Floridians for Solar Choice Coalition successfully managed their policy coalitions?; 3) How effective are these coalitions perceived to be by public policy players outside the coalitions?; 4) Do the Green Tea Coalition and the Floridians for Solar Choice Coalition represent an Advocacy Coalition approach?
Engaging these questions through the effective theoretical lens of the Advocacy Coalition Framework revealed a compelling example of cross-ideological cooperation within an increasingly divided political culture. Significant lessons concerning the formation and successful operation of coalitions were learned. The importance of strategic alliances, public belief systems, policy messaging, electorate education, policy learning, and careful political positioning are a few of the factors that enabled these coalitions to find success. The political success of these coalitions significantly advanced the role that solar power will be allowed to play in the future energy portfolio of these two influential states in the American South and across the country.
While the positive results for the future of solar power engineered by the coalitions are impressive, perhaps the most important lessons revealed by the study concern the potential for progress and cooperation on other complex issues. A portfolio of difficult issues awaits action by persons of good faith willing to find a cooperative path on which to move forward. Coalitions will be required to address many of these difficult problems. The lessons and example provided by these two cross-ideological coalitions may help others produce a their own blueprint to encourage cross-ideological cooperation. This cooperation will be required if progress is to be made for the well being of current and future generations.
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Evaluación del efecto de la incorporación de Camellia sinensis L. (té verde) sobre el contenido de flavonoides, capacidad antioxidante y aceptación sensorial de un yogurt probiótico / Evaluation of the effect of the incorporation of Camellia sinensis L. (green tea) on the flavonoid content, antioxidant capacity and sensory acceptance of a probiotic yogurtCanale Vásquez, Alessandra, Michilot Soto, Tamara 24 July 2019 (has links)
Objetivo: Evaluar el efecto de la incorporación de Camellia sinensis L. (2%, 4% y 6% de extracto de té verde) sobre el contenido de compuesto fenólicos, capacidad antioxidante y aceptación sensorial de un yogurt probiótico. Material y métodos: Estudio experimental de laboratorio dónde se elaboró un yogurt probiótico con té verde añadido en distintas concentraciones de 2%, 4% y 6%. Además, se evaluó la aceptabilidad sensorial y se analizó las características físicoquímicas de cada muestra. Asimismo, para determinar el contenido de polifenoles se utilizó el método de Folin-Ciocalteau y, el método de DPPH (2,2-difenil-1-1-picrilhidrazilo) para determinar la capacidad antioxidante. Resultados: Se encontró que en el yogurt probiótico con 6% de té verde añadido había 1.64 mg/mL de contenido de polifenoles, casi el triple del contenido de polifenoles que en el yogurt probiótico con 2% de té verde añadido. Además, se encontró que el yogurt con mayor porcentaje de té verde añadido (6%) obtuvo 61% de decoloración del reactivo de DPPH, lo que nos indica mayor capacidad antioxidante a comparación de las muestras con menor porcentaje de té verde añadido. Conclusión: A mayor contenido de compuestos fenólicos, mayor es la capacidad antioxidante de un yogurt probiótico con té verde añadido, además de ser el que mayor aceptabilidad sensorial alcanzó, siendo su olor y sabor los atributos más apreciados por los panelistas no entrenados quienes le otorgaron un puntaje de 4 en una escala hedónica de 5 puntos, lo que equivale a un “le gusta moderadamente”. / Objective: To evaluate the effect of Camellia sinensis L. (2%, 4% and 6% of green tea extract) incorporation on the content of phenolic compounds, antioxidant capacity and sensory acceptance of a probiotic yogurt. Material and methods: In this experimental laboratory study, probiotic yogurt with added green tea was elaborated using three concentrations of green tea extract (2%, 4% and 6%), and the sensory acceptability and the physical-chemical characteristics were determined for each concentration. Likewise, to determine the content of polyphenols, the Folin-Ciocalteau method was used, and the DPPH method (2,2-diphenyl-1-1-picrylhydrazyl) was used to determine the antioxidant capacity. Results: It was found that in the probiotic yogurt with 6% green tea extract added there was 1.64 mg / mL of polyphenol content, almost triple the polyphenol content than in the probiotic yogurt with 2% green tea added. In addition, it was found that the yogurt with the highest percentage of green tea added (6%) obtained 61% discoloration of the DPPH reagent, which indicates greater antioxidant capacity compared to samples with a lower percentage of green tea added. Conclusion: The higher the content of phenolic compounds, the greater the antioxidant capacity of a probiotic yogurt with green tea added, besides being the one with the highest sensory acceptability, its smell and taste were the attributes most appreciated by the untrained panelists who gave it a score of 4 on a hedonic scale of 5 points, which is equivalent to a "moderately like". / Tesis
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EFFECT OF STARCH-POLYPHENOL INTERACTIONS ON STARCH HYDROLYSISGuzar, Igor 08 January 2013 (has links)
Phenolic compounds have attracted much attention due to numerous health benefits, including high antioxidant properties, reduced risk of cancer, and inhibition of digestive enzymes. Recent research has suggested that different phenolic compounds may interact with starch. The first objective was to investigate the effect of green or black tea extracts on hydrolysis of wheat, rice, corn, and potato starches. Cooking starches in the presence of either tea reduced their hydrolysis. Potato starch cooked with black tea was the most effective treatment. Observations suggested that hydrolysis may be affected by interactions and by impact on specific enzymes based on starch structure. The second objective was to determine if similar effect could be observed in product system. Addition of green tea extract to sponge cake significantly reduced in vitro starch digestibility, thus could reduce the expected glycemic index. In addition, significant increases in dietary fibre, resistant starch, and antioxidant properties were observed.
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L'utilisation des plantes médicinales en grossesse : prévalence, déterminants et risque de prématuritéMoussally, Krystel January 2009 (has links)
Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal
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Avaliação do potencial antioxidante de extratos vegetais, isolados ou associados sinergicamente a antioxidantes sintéticos, aplicados ao óleo de linhaçaEpaminondas, Poliana Sousa 30 September 2013 (has links)
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Previous issue date: 2013-09-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Faced with the need to find new natural sources, able to replace partially or totally artificial antioxidants, reducing the phenomenon of oxidation and ensuring increased shelf life of edible oils, we sought to investigate the behavior of natural extracts of garlic, green tea and ginger on linseed oil, for their ability to protect against lipid oxidation. For this, the ethanol and methanol/ acetonic extracts of garlic (EEGL and MAEGL), green tea (EEGT and MAEGT) and ginger (EEGG and MAEGG), respectively, were initially compared for total phenolic content (TPC), by Folin-Ciocalteau method, as the antioxidant capacity, by Radical-Scavenging Activity of the DPPH (RSA-DPPH), by Ferric Reducing Antioxidant Power (FRAP) and by β-carotene/ linoleic acid system method, and the thermal stability, by Thermogravimetry/ Differential Thermal Analysis (TG/ DTA). The thermal and oxidative stability of the linseed oil added with ethanolic extracts, singly or with synthetic compounds tert-butylhydroquinone (TBHQ) and butylated hydroxytoluene (BHT), were evaluated, respectively, by Thermogravimetry/ Differential Thermal Analysis (TG/ DTA) and accelerated oxidation tests, such as accelerated storage test in oven, Pressurized Differential Scanning Calorimetry (P-DSC), PetroOxy and Rancimat. The extracts showed the following descending order of TPC: EEGT (483.45 ± 15.23 mg GAE.g-1) ~ MAEGT (469.28 ± 17.84 mg GAE.g -1) > EEGG (235.49 ± 1.34 mg GAE.g-1) > MAEGG (60.36 ± 1.90 mg GAE.g-1) > EEGL (10.55 ± 0.76 mg GAE.g-1) > MAEGL (3.01 ± 0.15 mg GAE.g mg-1 dry matter ). For the tests to determine the antioxidant capacity, green tea extracts showed higher RSA-DPPH and FRAP, compared to other samples. The extracts showed the following decreasing order of thermal stability : EEGT (111 ºC) ~ MAEGT (110 ºC) > EEGL (104 ºC) > EEGG (96 ºC) > MAEGL (68 ºC) > MAEGG (63 ºC). Despite the low response TPC and small compared to RSA-DPPH and FRAP, the ethanol extract of garlic showed considerable ability to inhibit lipid peroxidation, by β-caroteno/ácido linoleic system, and high thermal stability, attributed to organosulfur compounds. Considering the oxidative stability tests of samples of additived oil, it was found that the ethanolic extract of garlic, alone or synergistically associated with the BHT or TBHQ, protected the linseed oil in a manner similar to or even higher than synthetic antioxidants alone, by P-DSC and PetroOxy assays, keeping it in good condition overall until the 8th day accelerated storage in an oven at 60 ºC. Extracts of green tea and ginger offered protection to linseed oil until the 4th day of storage accelerated when combined synergistically to TBHQ, also demonstrating good oxidative stability by P-DSC, PetroOxy and Rancimat techniques. The results suggest the feasibility of using green tea and ginger extracts as partial substitutes (LOGT / TBHQ (50/50) and LOGG / TBHQ (50/50)) and garlic extract as total substitute (LOGL 100) of synthetic antioxidants, being alternative natural sources of antioxidants for application to the edible oil industry. / Diante da necessidade de descobrir novas fontes naturais, capazes de substituir os antioxidantes artificiais parcial ou totalmente, atenuando o fenômeno da oxidação e garantindo o aumento da vida de prateleira de óleos comestíveis, buscou-se investigar o comportamento de extratos naturais de alho, chá verde e gengibre sobre o óleo de linhaça, quanto à capacidade de proteção contra a oxidação lipídica. Para isso, os extratos etanólicos e metanol/ acetônicos de alho (EEGL e MAEGL), chá verde (EEGT e MAEGT) e gengibre (EEGG e MAEGG), respectivamente, foram inicialmente comparados quanto ao conteúdo de fenólicos totais (TPC), pelo método de Folin-Ciocalteau, quanto à capacidade antioxidante, pelos métodos de sequestro do radical DPPH (RSA-DPPH), do poder de redução do ferro (FRAP) e do sistema β-caroteno/ácido linoleico, e quanto à estabilidade térmica, por meio de Termogravimetria/ Análise Térmica Diferencial (TG/ DTA). As estabilidades térmica e oxidativa do óleo de linhaça adicionado dos extratos etanólicos isolados ou associados aos compostos sintéticos terc-butil-hidroquinona (TBHQ) e butil-hidroxitolueno (BHT) foram avaliadas, respectivamente, por meio das técnicas TG/ DTA e de ensaios de oxidação acelerada, como Calorimetria Exploratória Diferencial Pressurizada (P-DSC), PetroOxy, Rancimat e teste de estocagem acelerada em estufa. Os extratos avaliados apresentaram a seguinte ordem decrescente de TPC: EEGT (483.45 ± 15.23 mg GAE.g-1) ~ MAEGT (469.28 ± 17.84 mg GAE.g-1) > EEGG (235.49 ± 1.34 mg GAE.g-1) > MAEGG (60.36 ± 1.90 mg GAE.g-1) > EEGL (10.55 ± 0.76 mg GAE.g-1) > MAEGL (3.01 ± 0.15 mg GAE.g-1 extrato seco). Para os ensaios de determinação da capacidade antioxidante, os extratos de chá verde apresentaram maior RSA-DPPH e FRAP, em relação às demais amostras. Os extratos apresentaram a seguinte ordem decrescente de estabilidade térmica: EEGT (111 ºC) ~ MAEGT (110 ºC) > EEGL (104 ºC) > EEGG (96 ºC) > MAEGL (68 ºC) > MAEGG (63 ºC). Apesar do baixo TPC e da pequena resposta frente a RSA-DPPH e FRAP, o extrato etanólico de alho apresentou considerável capacidade de inibição da peroxidação lipídica, pelo sistema β-caroteno/ácido linoleico, e alta estabilidade térmica, atribuídos aos compostos organossulfurados. Considerando os ensaios de estabilidade oxidativa das amostras de óleo aditivado, verificou-se que o extrato etanólico de alho, isolado ou sinergicamente associado ao TBHQ ou ao BHT, protegeu o óleo de linhaça de forma similar ou até superior aos antioxidantes sintéticos isolados, diante dos ensaios de P-DSC e PetroOxy, mantendo-o em bom estado de conservação geral até o 8º dia de armazenamento acelerado em estufa a 60 ºC. Os extratos de chá verde e gengibre ofereceram proteção ao óleo de linhaça até o 4º dia de estocagem acelerada, quando associados sinergicamente ao TBHQ, demonstrando ainda boa estabilidade oxidativa diante das técnicas P-DSC, PetroOxy e Rancimat. Os resultados sugerem a viabilidade de utilização dos extratos de chá verde e gengibre como substitutos parciais (LOGT/ TBHQ (50/50) e LOGG/ TBHQ (50/50)) e o extrato de alho como substituto total (LOGL 100) de antioxidantes sintéticos, sendo fontes alternativas naturais de antioxidantes para a aplicação na indústria de óleos comestíveis.
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