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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
351

Compostos bioativos de polpa e subprodutos de frutas tropicais: quantificação, atividade antimicrobiana e encapsulamento / Bioactive compounds in pulps and byproducts of tropical fruits: quantification, antimicrobial activity and nanoencapsulation

Silva, Larissa Morais Ribeiro da January 2014 (has links)
SILVA, Larissa Morais Ribeiro da. Compostos bioativos de polpa e subprodutos de frutas tropicais: quantificação, atividade antimicrobiana e encapsulamento. 2014. 108 f. Tese (Doutorado em tecnologia de alimentos)- Universidade Federal do Ceará, Fortaleza-CE, 2014. / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-07-07T19:26:11Z No. of bitstreams: 1 2014_tese_lmrsilva.pdf: 2283546 bytes, checksum: 64374433ae09a06ec47f9593fad6d41e (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-07-21T20:26:58Z (GMT) No. of bitstreams: 1 2014_tese_lmrsilva.pdf: 2283546 bytes, checksum: 64374433ae09a06ec47f9593fad6d41e (MD5) / Made available in DSpace on 2016-07-21T20:26:58Z (GMT). No. of bitstreams: 1 2014_tese_lmrsilva.pdf: 2283546 bytes, checksum: 64374433ae09a06ec47f9593fad6d41e (MD5) Previous issue date: 2014 / Currently, there is a demand for natural antimicrobials for use in the food industry. Some tropical fruits have a promising potential , not investigated at the moment. This study aimed to identify and quantify resveratrol, quercetin and coumarin in pulps and byproducts of tropical fruits, develop nanoparticles with extracts that showed higher levels of these compounds and evaluate the antimicrobial activity against Listeria sp. and E. coli K12. The Surinam cherry and mango byproducts, as well as caja, acerola and Surinam cherry pulps showed higher levels of quercetin, representing sources of this substance. Guava and Surinam cherry byproducts showed resveratrol in their content, may be considered as sources of this compound. Similarly, for coumarin, passion fruit, guava and Surinam cherry byproducts, as well as mango pulp, can be considered natural sources. Among the analyzed material, the acerola pulp and passion fruit and guava byproducts were selected for further characterization and nanoencapsulation. Nanoparticles synthesized using co-glycolide (PLGA) 65:35 poly lactide showed higher particle sizes (from 153.37 to 376.70 nm), as compared with the synthesized PLGA 50:50 (136.53 to 369.25 nm). All samples showed low polydispersity index, corresponding to a heterogeneous distribution in the emulsion analyzed for particle size obtained. The nanoparticles synthesized with PLGA 65:35 showed higher encapsulation efficiency, with the exception of the sample containing acerola (best EE % for PLGA 50:50) and for the release analysis, all samples showed similar behavior, providing maximum release compound within 30 minutes, with constant release thereafter during 72 hours analysis. In general, nanoparticles synthesized with PLGA 65:35 had lower minimum inhibitory concentration for E. coli K12 and L. monocytogenes compared with the 50:50 PLGA nanoparticles synthesized. The synthesis of PLGA nanoparticles using extracts of fruits (especially using PLGA 65:35) may have important applications in the food industry to inhibit microorganisms (E. coli K12 and L. monocytogenes). Besides antimicrobial activity, these compounds show various fruits with antioxidant properties, which are responsible for reducing the risk of various diseases. / Atualmente há uma demanda por antimicrobianos naturais para uso na indústria de alimentos e, neste sentido, as frutas tropicais apresentam, um potencial promissor, porém ainda pouco investigado. Este trabalho teve como objetivo identificar e quantificar resveratrol, quercetina e cumarina em polpas e subprodutos de frutas tropicais, elaborar nanopartículas com os extratos que apresentaram maiores teores destes compostos e avaliar a atividade antimicrobiana contra os microrganismos Listeria sp. e E. coli K12. Os subprodutos de pitanga roxa e manga, assim como as polpas de cajá, acerola e pitanga roxa apresentaram maiores teores de quercetina, representando fontes desta substância. Subprodutos de goiaba e pitanga apresentaram resveratrol em suas constituições, podendo ser considerados fontes deste composto. Para a cumarina, os subprodutos de maracujá, goiaba e pitanga, assim como a polpa de manga, podem ser considerados fontes naturais. Entre os materiais analisados, a polpa de acerola e os subprodutos do maracujá e da goiaba foram selecionados para posterior caracterização e nanoencapsulação. As nanoparticulas sintetizadas utilizando ácido poli lactídeo co-glicolídeo (PLGA) 65:35 apresentaram maiores tamanhos de partícula (153,37 a 376,70 nm), quando comparadas às sintetizadas com PLGA 50:50 (136,53 a 369,25 nm). Todas as amostras apresentaram baixo índice de polidispersidade, correspondendo a heterogênea distribuição na emulsão analisada quanto ao tamanho das partículas obtidas. As nanopartículas sintetizadas com PLGA 65:35 apresentaram maior eficiência do encapsulamento (%EE), com exceção da amostra contendo acerola, a qual apresentou melhor EE% para PLGA 50:50. Em relação à análise de liberação, todas as amostras avaliadas apresentaram comportamento semelhante, obtendo liberação máxima do composto nos primeiros 30 minutos, apresentando liberação constante após esse período, durante 72 horas de análise. De uma maneira geral, as nanopartículas sintetizadas com PLGA 65:35 apresentaram menor concentração inibitória minima para E. coli K12 e L. monocytogenes quando comparadas às nanopartículas sintetizadas com PLGA 50:50. A síntese de nanopartículas de PLGA utilizando extratos fenólicos de frutas, especialmente utilizando PLGA 65:35, pode apresentar importantes aplicações, como na indústria de alimentos, a conservação desses produtos, considerando seu efeito na inibição de microrganismos (E. coli K12 e L. monocytogenes). Além do efeito antimicrobiano, essas frutas apresentam diversos compostos com propriedades antioxidantes, que são responsáveis pela redução do risco de diversas doenças.
352

Avaliação do potencial antioxidante de macroalgas marinhas do litoral cearense. / Antioxidant potential of marine macroalgae from the ceará coast.

Cavalcante, Kelma Maria dos Santos Pires January 2012 (has links)
CAVALCANTE, Kelma Maria dos Santos Pires. Avaliação do potencial antioxidante de macroalgas marinhas do litoral cearense. 2012. 122 f. : Tese (doutorado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia de Pesca, Fortaleza-CE, 2012 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-27T13:00:44Z No. of bitstreams: 1 2012_tese_kmspcavalcante.pdf: 783385 bytes, checksum: 8eabc3394f4206e331baee2a713c7002 (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-27T13:00:57Z (GMT) No. of bitstreams: 1 2012_tese_kmspcavalcante.pdf: 783385 bytes, checksum: 8eabc3394f4206e331baee2a713c7002 (MD5) / Made available in DSpace on 2016-07-27T13:00:57Z (GMT). No. of bitstreams: 1 2012_tese_kmspcavalcante.pdf: 783385 bytes, checksum: 8eabc3394f4206e331baee2a713c7002 (MD5) Previous issue date: 2012 / Seaweeds are sources of a wide variety of beneficial compounds for human. Many of these compounds have antioxidant activity, such as phenolic compounds, carotenoids, and vitamin E. The aim of this research was to evaluate the in vitro antioxidant activity of 50% methanolic extracts from seaweed collected in the coastline of Ceará State, Brazil. The methods used were: DPPH radical scavenging, ferrous ion chelation (FIC), ferric reducing antioxidant power (FRAP), and β-carotene bleaching. In addition to in vitro antioxidant activity, the total phenolic content (TPC) was measured by the Folin-Ciocalteu method, followed by a phytochemical prospecting to point out which are the main classes of compounds present in the algal extracts. The quantification of carotenoids (α- and β-carotene, and lutein) and vitamin E (α- and -tocopherol) was carried out by HPLC. In general, the extracts of brown algae showed the highest ability to scavenger the DPPH radical, the largest FRAP and the highest TPC, followed by extracts of green and red algae. The greatest FIC was observed in red alga extracts, followed by brown and green alga extracts. The high antioxidant activity in β-carotene/linoleic acid model system of green and red alga extracts ranged from 65% to 95%, however it represented less than 40% in brown alga extracts, exception to Padina gymnospora extract which presented activity up to 92%. The majority of the algal extracts analyzed in this study presented activity similar to or even greater than those observed in positive controls (quercetin, BHA, BHT, ascorbic acid, α-tocopherol, β-carotene and EDTA). Fenols were detected in brown algae only; anthocyanins, anthocyanidins, chacons, aurons and leucoanthocyanins were observed in some species of Rhodophyta Phylum. All the other classes of phenolic compounds were found in at least one species within each Phylum, exception to flavononols which have not been detected in green alga extracts. TPC was the main responsible for the ability to scavenger the DPPH radical, FIC and FRAP in green and red algae. On the other hand, in brown algae TCP was influenced only by FRAP. All extracts of green, red and brown algae exhibited the presence of β-carotene and lutein. The latter was the major carotenoid within Chlorophyta and Rhodophyta. Naturally absent in brown algae, α-carotene was not detected in five species of Chlorophyta and Rhodophyta algae. α-Tocopherol was determined in all species, except Ulva fasciata and U. lactuca extracts. The isomer δ-tocopherol was quantified in eleven out of twenty-three alga species. Antioxidant activity and levels of compounds in the algal extracts were different, but all of them showed antioxidant potential. / As macroalgas marinhas são fontes de compostos com atividade antioxidante como compostos fenólicos, pigmentos carotenóides e vitamina E. O objetivo deste trabalho foi avaliar a atividade antioxidante in vitro de extratos metanólicos (50%) de macroalgas cearenses, através da capacidade de sequestrar o DPPH, habilidade de quelação do íon ferroso (FIC), poder de redução do ferro (FRAP) e degradação do β-caroteno. Além disso, também foi determinado o conteúdo de compostos fenólicos pelo método de Folin-Ciocalteu, seguido de uma prospecção fitoquímica para indicar possivelmente as principais classes de compostos. Os teores de α- e β-caroteno, luteína e α- e -tocoferol foram quantificados por cromatografia líquida de alta eficiência. De um modo geral, capacidade de sequestrar o DPPH, FRAP e conteúdo de compostos fenólicos foram maiores nos extratos das algas pardas, seguidos dos das algas verdes e vermelhas. FIC mais elevada foi observada nos extratos das algas vermelhas, seguidas das pardas e verdes. No sistema modelo β-caroteno/ácido linoléico as maiores atividades foram determinadas nas clorófitas e rodófitas, tendo variado de 64,8% a 95,3%, nas ocrófitas, inferiores a 40,5%, com exceção de Padina gymnospora com cerca de 92%. Os extratos algáceos analisados apresentaram atividades antioxidantes semelhantes ou superiores aos controles positivos (quercetina, BHA, BHT, ácido ascórbico, α-tocoferol, β-caroteno e EDTA). Fenóis foram detectados apenas em algas pardas; antocianinas, antocianidinas, chaconas, auronas e leucoantocianidinas foram observadas apenas em algumas espécies do Filo Rhodophyta; as demais classes de compostos fenólicos investigadas foram observadas em pelo menos uma espécie dentro de cada Filo, com exceção de flavanonóis que não foram encontrados nos extratos de algas verdes. O conteúdo de compostos fenólicos foi o principal responsável pelas atividades de sequestro do DPPH, FRAP e FIC nas algas verdes e vermelhas. Nas pardas esses compostos só influenciaram no FRAP. β-Caroteno e luteína foram quantificados em todos os extratos de algas verdes, vermelhas e pardas, sendo a luteína o carotenóide majoritário nas clorófitas e rodófitas. Com exceção das algas pardas que naturalmente não possuem α-caroteno, apenas os extratos de cinco espécies de clorófitas e rodófitas não apresentaram esse composto. Todos os extratos analisados apresentaram α-tocoferol, menos Ulva fasciata e U. lactuca. Extratos de onze espécies apresentaram δ-tocoferol. As atividades antioxidantes e os teores de compostos detectados nos extratos algáceos foram distintos, mas todos eles apresentaram potencial antioxidante.
353

Extraction, identification and antioxidant activity of the phenolic secondary metabolites isolated from the leaves, stems and fruits of two shrubs of the Ericaceae family / Extraction, identification et activité antioxydante des métabolites secondaires phénoliques isolés des feuilles, branches et fruits de deux arbrisseaux de la famille des Ericacées

Bujor, Oana-Crina 19 April 2016 (has links)
La myrtille et l’airelle rouge, deux arbrisseaux de la famille des Ericacées, sont consommées comme des aliments, boissons et suppléments alimentaires pour leur valeur nutritionnelle et leur richesse en polyphénols antioxydants. Dans les plantes, la qualité et la quantité de composés phénoliques sont influencées par les parties morphologiques de la plante à utiliser. En particulier, les composés phénoliques des végétaux exercent leur activité antioxydante dans la protection des lipides alimentaires et le compartiment gastrique a été proposé comme le site majeur pour le stress oxydatif lié au régime alimentaire. L’objectif général de cette thèse était d’étudier les variations saisonnières des composés phénoliques d’extraits de feuilles, branches et fruits de la myrtille et de l’airelle rouge ainsi que l’activité antioxydante de ces extraits. Pour cette étude, des extraits aqueux et hydroéthanoliques (fruits uniquement) des échantillons collectés en mai, juillet et septembre pendant les années 2013-2014 ont été obtenus par extraction assistée par microondes.Les analyses qualitatives et quantitatives par UPLC / MS des extraits de la myrtille ont montré la présence de dérivés de l’acide caféique et de l’acide p-coumarique et des glycosides de flavonols dans les feuilles tandis que des oligomères de flavanols étaient aussi présents dans les branches, et ce dans des quantités élevées. La thioacidolyse a révélé de faibles degrés de polymérisation (2-4) et l’(-)-épicatéchine comme unité principale des flavan-3-ols. Il existe une très bonne corrélation entre la Somme des Composés phénoliques par UPLC et la Teneur en Polyphenols Totaux ou l’activité antioxydante dans le test DPPH, excepté pour les feuilles du mois de mai. Ces dernières sont relativement riches en dérives de l’acide p-coumarique. Les effets de la saison apparaissent plus marqués pour les feuilles qui présentent une plus grande activité antioxydante et teneur en polyphénols en juillet et septembre. Ces paramètres sont optimaux en juillet pour les branches de myrtille. La période de de cueillette peut être définie en fonction des structures phénoliques désirées.Dans l’airelle rouge, la présence prédominante de monomères et oligomères de flavanols et de glycosides de quercétine a été identifiée dans toutes les parties morphologiques. Les proanthocyanidines contiennent la (+)-catéchine et la (-)-épicatéchine comme unités d'extension et terminale. De plus, la teneur en polyphénols totaux (méthode de Folin, UPLC) a montré une augmentation légère mais significative de mai à septembre pour les feuilles et les branches. Cette augmentation a été confirmée pour l'activité antioxydante dans le test DPPH pour les feuilles et les branches en 2014.L’activité antioxydante des extraits de myrtille et d’airelle rouge lors de l’inhibition de l’oxydation lipidique (accumulation de diènes conjugués) a été évaluée dans des conditions in vitro simulant la digestion. Tout d'abord, l'inhibition de l’oxydation lipidique a été conduite sur des émulsions huile de tournesol-dans-eau stabilisées par la sérum albumine bovine (BSA) ou des phospholipides d’œuf (PL), qui simulent l’état physique des lipides alimentaires lors de la digestion gastrique. L’oxydation a été initiée par la metmyoglobine, une forme de fer apportée par la viande rouge. Dans les deux modèles d’émulsions, les extraits aqueux des branches et des feuilles et l’extrait hydroethanolique de fruit de myrtille sont des inhibiteurs plus efficaces de l'oxydation lipidique durant la première phase de digestion (pH 5) que durant la seconde phase (pH 3). D’autre part, un extrait de feuilles de myrtille a été testé dans un modèle complet de digestion in vitro statique (étapes orale, gastrique et intestinale). L'oxydation lipidique, rapide lors de la l’étape gastrique (systèmes BSA et PL) et puis plus lente lors de l'étape intestinale (système PL), a été totalement inhibée par l'extrait de feuilles de myrtille. / Bilberry and lingonberry, two shrubs of the Ericaceae family, are consumed as food, beverage and dietary supplements due to their nutritional value and richness in antioxidant polyphenols. In plants, the quality and quantity of phenolic compounds are influenced by the parts of the plant to be used. In particular, plant phenolic compounds provide antioxidant activity in the protection of dietary lipids from oxidation and the gastric compartment has been proposed as a major site for diet-related oxidative stress. The aim of this thesis is to simultaneously assess the seasonal variations of phenolic compounds in leaves, stems, and fruits of bilberry and lingonberry extracts, as well as their antioxidant activity. For this study, aqueous and hydroethanolic (only fruits) extracts of bilberry and lingonberry samples collected in May, July and September during the years 2013-2014 were obtained under microwave-assisted extraction.In bilberry extracts, qualitative and quantitative analyses by UPLC/MS showed the presence of caffeoyl derivatives, p-coumaroyl derivatives, and flavonol glycosides in leaves whereas in stems, flavanol oligomers were additionally identified in significant amounts. Thioacidolysis revealed low degrees of polymerization (2-4) and (-)-epicatechin as the main flavan-3-ol unit. The sum of the phenolic compounds by UPLC was highly correlated with the Total Polyphenol Content and the antioxidant activity in the DPPH test for all the extracts except those of May leaves. The latter were relatively richer in p-coumaric acid derivatives. Seasonal effects were more marked for leaves which exhibited higher antioxidant activities and phenolic contents in July and September when these parameters were maximum in July for bilberry stems. The harvest period can be refined based on the desired phenolic structures. For lingonberry, the predominant presence of monomers and oligomers of flavanols and quercetin glycosides was found in all the morphological parts. Proanthocyanidins contain (+)-catechin and (-)-epicatechin as both extension and terminal units. The sum of the phenolic compounds by UPLC was less correlated with the Total Polyphenol Content and the antioxidant activity in the DPPH test than in bilberry. Furthermore, the total phenolic content (Folin method, UPLC) showed a slight but significant increase from May to September for both leaves and stems. This increase was confirmed for the antioxidant activity by the DPPH test for both leaves and stems in 2014.The antioxidant activity of bilberry and lingonberry extracts against lipid oxidation (formation of lipid-derived conjugated dienes) was evaluated under in vitro simulated digestion conditions. Firstly, the inhibition of lipid oxidation was performed using sunflower oil-in-water emulsions stabilized by bovine serum albumin (BSA) or egg yolk phospholipids (PL), both emulsifiers mimicking dietary components. Oxidation was initiated by metmyoglobin, a form of dietary iron from red meat. In both emulsion models, aqueous extracts from stems and leaves and the hydroethanolic fruit extract of bilberry proved to be more efficient inhibitors of lipid oxidation in the early phase of digestion (pH 5) than during the second phase (pH 3). Secondly, a bilberry leaf extract was tested in the inhibition of lipid oxidation in a complete static in vitro digestion model (oral, gastric and intestinal phases). The fast lipid oxidation in the gastric step (BSA and PL systems) and the slower lipid oxidation in the intestinal step (PL system) were totally inhibited by the bilberry leaf extract.
354

Extraction des molécules à haute valeur ajoutée par eau sous critique et fractionnement par procédés membranaires : Valorisation des co-produits de la vigne et du vin par des procédés éco-innovants / Extraction of high-value added compounds by subcritical water and fractionation by membrane processes : Valorization of vine and wine by-products by eco-innovative processes

Yammine, Sami 03 May 2016 (has links)
Ce travail a porté sur l'extraction de substances naturelles de sous-produits de la vigne en mettant en œuvre des procédés "verts" tels que l'extraction par eau sous-critique et la purification par filtration membranaire. Ces procédés représentent une alternative à l'extraction par solvant, traditionnellement utilisée dans la production de substances bio-sourcées. La majeure partie de cette étude a été menée sur des marcs de raisin de cépages variés, l'extraction a été optimisée et comparée sur la base du rendement, de la composition chimique et de l'activité antioxydante des extraits obtenus. De tous les cépages testés, les extraits de Dunkelfelder ont présenté l'activité antioxydante la plus élevée et la concentration en familles de molécules polyphénoliques la plus importante. En outre, ce marc de raisin de Dunkelfelder a été utilisé comme modèle afin d'optimiser les différents paramètres du procédé tels que la température, la pression et le temps de séjour hydraulique. Après la phase d'extraction par eau sous-critique, les extraits obtenus se sont révélés riches en de nombreuses familles de molécules. Ainsi, une étape de purification des composés cibles avant usage industriel s'est révélée indispensable. Le couplage de l'extraction par eau sous-critique avec des procédés membranaires représente une solution innovante pour la purification de ces extraits. Des essais de filtration tangentielle de l'extrait ont été menés avec onze membranes d'ultrafiltration (100 kDa à 2 kDa) et neuf membranes de nanofiltration (1000 Da à 150 Da). Le suivi du procédé s’est appuyé sur une détermination des paramètres opératoires optimisés et sur la détermination des coefficients de rétention des différentes familles des macro et micromolécules. Les résultats obtenus ont démontré que l'utilisation des technologies membranaires pourrait dans le futur, constituer une innovation technologique pour la purification des composés bio-actifs / This work has dealt with extraction of natural substances from winery by-products using "green" processes such as extraction by subcritical water and purification by membrane processes. These processes are an alternative to solvent extraction traditionally used in the natural products industry. Main part of the work was done on different grape pomace, extraction was optimized and compared in terms of yield, chemical composition, and antioxidant activity of extracts. Dunkelfelder extracts exhibited the strongest antioxidant activity and comparison of chemical compositions of the different extracts indicated. Furthermore this Dunkelfelder grape pomace was used as model in order to optimize the different process parameters such as temperature, pressure and hydraulic retention time. After the subcritical water extraction, extracts produced were found to be rich in several families of molecules. An essential purification step of target compounds prior to industrial use was indispensable. Coupling the subcritical water with membrane processes offers an innovative solution for the purification of these extracts. Thereby, the extract was assayed in a cross-flow apparatus against eleven membranes of ultrafiltration (100 to 2 kDa) and nine membranes of nanofiltration (1000 to 150 Da). The monitoring of the process was carried out by determining performance parameters and retention coefficients of different families of macro and micromolecules. The results obtained have demonstrated that the use of membrane technologies could bring innovative changes in the recovery of bioactive compounds for future industries.
355

Desenvolvimento tecnológico e otimização de formas farmacêuticas sólidas contendo alto teor de produto seco por aspersão de Phyllanthus niruri L. (Euphorbiaceae) / Technological development and optimization of solid dosage forms containing high amount of spray dried extract of Phyllanthus niruri L. (Euphorbiaceae)

Souza, Tatiane Pereira de January 2004 (has links)
Phyllanthus niruri é largamente utilizada na medicina tradicional, principalmente, para o tratamento de cálculos renais. Estudos farmacológicos comprovam sua eficácia e segurançaa terapêutica, sugerindo os polifenóis, presentes na sua constituição química, como possíveis responsáveis por esta atividade biológica. Estes dados concedem a esta espécie qualidades favoráveis para o planejamento de um medicamento fitoterápico. Nesse sentido, foi inicialmente ideada uma forma farmacêutica sólida. Para tanto foi desenvolvido e validado um método analítico por cromatografia líquida de alta eficiência (CLAE) visando ao controle de qualidade da matéria-prima vegetal, produtos derivados e finais.O sistema cromatográfico foi capaz de separar satisfatoriamente três substâncias, uma das quais foi identificada como ácido gálico. Para as demais, os dados espectroscópicos no UV sugerem ser uma flavona e um derivado do ácido gálico. O produto seco por aspersão (PSA) foi obtido em torre de secagem semi-industrial, dotada de aspersor rotatório. Entretanto, o produto apresentou elevada sensibilidade à umidade atmosférica, dificultando a elaboração de comprimidos contendo alto teor desse material. Ambas as técnicas de granulação estudadas, por via seca e por via úmida, originaram granulados com satisfatórias propriedades reológicas e bom rendimento operacional. A granulação por via úmida, devido à alta solubilidade do PSA, só foi possível com emprego de solventes orgânicos. Neste caso, a resina acrílica, Eudragit E, foi utilizada com a finalidade de agente aglutinante e proteção do PSA contra a umidade atmosférica. A avaliação do comportamento dos granulados frente às diferentes umidades ambientais demonstrou que os obtidos por via úmida, contendo Eudragit E na proporção igual ou superior a 5 %, foram menos sensíveis à umidade, principalmente quando comparados com o PSA e granulados obtidos por via seca. No entanto, sua compressão causou retardo na cedência do PSA. O comportamento compressional do PSA e dos granulados, avaliados através do modelo de Heckel, mostrou que ambos apresentaram comportamento essencialmente plástico, com exceção do granulado obtido por via seca que mostrou simultaneamente comportamento plástico e fragmentativo. O estudo de compressão com o PSA, como pó e granulado, foi realizado visando à obtenção de comprimidos com alto teor de PSA e características tecnológicas de alta resistência mecânica, rápido tempo de desintegração e baixa sensibilidade à umidade. A granulação por via seca pareceu reunir maiores vantagens em relação ao processamento tecnológico. Os comprimidos obtidos por essa via, continuararn apresentando elevada sensibilidade à umidade. Assim, a viabilidade de revestimento pelicular dos comprimidos, utilizando Eudragit E como filmógeno, foi analisada. O estudo evidenciou resultados promissores, uma vez que a película de revestimento permitiu uma sorção de umidade mais lenta, conduzindo a um melhor comportamento do produto quando armazenado em ambiente de elevada umidade relativa, sem alteragäo significativa da cedência dos marcadores químicos. / The Phyllanthus niruri is largely used in the folk medicine, mainly to treat kidney stones. Pharmacological studies confirm its therapeutic efficacy and safety, suggesting the phenolic compounds, present in its chemical constitution as probable responsible for this biological activity. These facts ascribe to this plant favorable proprieties to design a phytotherapic drug. Initially was planned a solid dosage form. To quality control purpose of the plant raw material, derivatives and final products was developed and validated an analytical method by High Performance Liquid Chromatography (HLPC). The chromatographic system was capable to separate three substances. One of them was identified as gallic acid, and the others, the UV spectroscopic data suggested a flavone and a gallic acid derivate. The spray dried extract (SDE) was elaborated using a semi-industrial spray dryer equipment with rotatory atomizer. The SDE showed high sensibility to atmospheric humidity, which makes difficult the elaboration of tablets containing high amount of this material. Both granulation techniques studied, by dry or wet ways, generated granulates with adequate rheological properties and valid operational result. The wet granulation, due to the high SDE solubility, only was possible using organic solvents. In this case, the acrylic resin Eudragit E was used as binder agent and protection against the atmospheric moisture. The evaluation of granulate behavior in the ambient with different relative humidity showed that those obtained by wet granulation, containing Eudragit E at equal or superior proportion to 5 % were less sensible to humidity, mainly when compared to SDE and dry granulates. However the compression of wet granulates caused delay in the SDE release. The compressional behavior of SDE and the wet granulates, evaluated by Heckel's plot, indicated a plastic behavior, while dry granulates showed, simultaneously, fragmentative and plastic one. The SDE compression study, as powder and granulate, was done aiming to obtain tablets with high amount of SDE and technological characteristics of high tensile strength, short disintegration time and low sensibility to humidity. The dry granulation seemed to fulfill more advantage to the technological process. However, all tablets demonstrated high sensibility to humidity. Therefore, film coated tablets, using Eudragit E as polymeric film former, evidenced promising results allowing a slower wet sorption and leading to a better product behavior when stored at relative high wet place.
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Fotossíntese, crescimento e composição química em plantas de Theobroma cacao L. submetidas a diferentes concentrações de silicato de potássio e sua interação com insetos-praga / Photosynthesis, growth and chemical composition in plants of Theobroma cacao L. subjected to different concentrations of potassium silicate and its interaction with insect-pests

Pinto, Diego Guimarães 18 February 2011 (has links)
Made available in DSpace on 2016-12-23T13:48:27Z (GMT). No. of bitstreams: 1 Dissertacao de Diego Guimaraes Pinto.pdf: 624592 bytes, checksum: 20066ab5dc6e544c63b249480bbde358 (MD5) Previous issue date: 2011-02-18 / The control of insect pests through the use of pesticides, is still the most method used in the cultivation of cocoa. However, due to environmental issues, there need to seek new alternatives of control less harmful the environment and to humans. In this context, silicon is a nutrient that is being used in various cultures, due to its beneficial effects on plant physiology and protection to the attack of insect pests and disease. The aim of this study was to evaluate the photosynthesis, growth and chemical composition in three cacao genotypes under different concentrations of potassium silicate and its interaction with insect pests. Two experiments were conducted, the first being installed under an agroforestry system comprising Bactris gasipaes and Theobroma cacao, in a randomized block design, with four replications, in a factorial 3 x 3, consisting of three genotypes (TSH 1188, CCN 51 and Catongo), three doses of potassium silicate (0, 3 and 6 mL L-1) applied to leaves. Were conducted evaluations of vegetative growth, of kinetics of fluorescence emission from chlorophyll a, of chlorophyll content, of incidence and degree of damage caused by insect pests, beyond from the silicon content in the leaves. The growth of cacao genotypes was reduced with the application of doses of potassium silicate, possibly due to the partition of assimilates that were being used in the biosynthesis of compounds involved in plant resistance to insects. The genotype TSH 1188 showed the highest increase in growth and dry matter compared to CCN 51 and Catongo, being the only genotype that showed the highest content of chlorophyll and improvement in parameters of chlorophyll fluorescence when applied to 3 mL L-1 potassium silicate, mainly in the energy flow of photosystem II and the index of performance of the plant for absorption (PIABS) and total (PITOTAL). The application of potassium silicate at dose 6 mL L-1 significantly reduced the incidence and level of damage by insect pests in cocoa genotypes. However, did not have significant effect of the application of potassium silicate on the silicon content in the leaves of the genotypes of cacao studied in relation to the control. The second experiment was conducted in a greenhouse with the same treatments and statistical design of experiment previous. In it were evaluated gas exchange, foliar concentrations of soluble phenolic compounds total, the chlorophyll fluorescence a, besides a preference test with a chance of free choice with aphids. The highest rates of photosynthesis and stomatal conductance were found in TSH 1188 and CCN 51. These same genotypes showed higher index of performance (PIABS and PITOTAL), a result of increased density of centers reaction active of photosystem II (RC/ABS), quantum yield of PSII (φP0 / (1-φP0)) and efficiency of reactions redox beyond the quinone a-(ᴪ0/1-ᴪ0). The application of potassium silicate increased net photosynthesis, but did not affect the performance indices (PIABS and PITOTAL). The phenolic content increased in genotypes CCN 51 and Catongo, the preference of the aphid was reduced with application of 6 mL L-1 of potassium silicate only in TSH 10 1188. Due on the results from the two experiments, application of silicon is promising to increase the resistance of cacao insect pests, since it promotes the increase of photosynthetic activity and production of plant metabolites involved in defense mechanisms of the cacao tree / O controle de insetos-praga mediante o uso de agroquímicos, ainda é o método mais utilizado no cultivo do cacau. No entanto, devido à questões ambientais, há necessidade de buscar novas alternativas de controle menos danosas ao ambiente e ao homem. Nesse contexto, o silício é um nutriente que está sendo utilizado em diversas culturas, devido a seus efeitos benéficos na fisiologia da planta e na proteção ao ataque de insetos-praga e de agentes causadores de doenças. O objetivo deste trabalho foi avaliar a fotossíntese, o crescimento e a composição química em três genótipos de cacau submetidos a diferentes concentrações de silicato de potássio e sua interação com insetos-praga. Foram realizados dois experimentos, sendo o primeiro instalado sob um sistema agroflorestal constituído por Bactris gasipaes e Theobroma cacao, no delineamento de blocos ao acaso, com quatro repetições, em arranjo fatorial 3 x 3, constituído de três genótipos (TSH 1188, CCN 51 e Catongo), três doses de silicato de potássio (0, 3 e 6 mL L-1) aplicadas via foliar. Foram realizadas avaliações do crescimento vegetativo; da cinética de emissão da fluorescência da clorofila a, dos teores de clorofila, da incidência e nível de dano provocado por insetos-praga, além dos teores foliares de silício. O crescimento vegetativo dos genótipos de cacau foi reduzido com a aplicação das doses de silicato de potássio, possivelmente em função da partição de assimilados que estariam sendo utilizados na biossíntese de compostos envolvidos na resistência da planta a insetos. O genótipo TSH 1188 apresentou maior incremento do crescimento vegetativo e massa seca quando comparado ao CCN 51 e Catongo, sendo o único genótipo que apresentou maior índice de clorofila e melhoria nos parâmetros de fluorescência da clorofila a quando aplicado 3 mL L-1 de silicato de potássio, principalmente no fluxo de energia do fotossistema II e nos índices de desempenho da planta para absorção (PIABS) e total (PITOTAL). A aplicação de silicato de potássio na dose 6 mL L-1 reduziu significativamente a incidência e o nível de dano provocado por insetos-praga nos genótipos de cacau. No entanto, não houve efeito significativo da aplicação de silicato de potássio sobre o teor de silício nas folhas dos genótipos de cacau estudados em relação ao controle. O segundo experimento foi instalado em casa de vegetação com os mesmos tratamentos e delineamento estatístico do experimento anterior. Nele foram avaliadas as trocas gasosas foliares, os teores foliares de fenóis solúveis totais; a fluorescência da clorofila a, além do teste de preferência com chance de livre escolha com pulgões. As maiores taxas fotossintéticas e condutância estomática foram encontradas no TSH 1188 e CCN 51. Estes mesmos genótipos apresentaram maiores índices de desempenho (PIABS e PITOTAL), resultado do aumento da densidade de centros de reação ativos do fotossistema II (RC/ABS), do rendimento quântico de FSII (φP0/(1-φP0)) e da eficiência das reações de oxi-redução além da quinona a- (ᴪ0/1-ᴪ0). A aplicação de silicato de potássio aumentou a fotossíntese líquida, mas não afetou os 8 índices de desempenho (PIABS e PITOTAL). Os teores de fenóis aumentaram nos genótipos CCN 51 e Catongo, já a preferência do pulgão foi reduzida com a aplicação de 6 mL L-1 de silicato de potássio apenas no TSH 1188. Em função dos resultados obtidos nos dois experimentos, a aplicação de silício é promissora no aumento da resistência do cacaueiro a insetos-praga, uma vez que promove o aumento da atividade fotossintética da planta e da produção de metabólitos envolvidos nos mecanismos de defesa do cacaueiro
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Maladie des taches noires de l'ananas : étude des relations hôte-pathogène et compréhension des mécanismes physiologiques de résistance / Pineapple fruitlet core rot disease : host-pathogen interactions and physiological mechanisms of resistance involved

Barral, Bastien 14 December 2017 (has links)
La maladie de la tache noire affecte les fruits d’ananas mature, les rendant impropre à la consommation. Actuellement, aucune méthode de contrôle n'est disponible pour cette maladie. Une meilleure connaissance du pathosystème est nécessaire pour trouver des moyens de lutte efficaces.Des entretiens et échantillonnages menés auprès de producteurs durant l’hiver austral révèlent une prévalence de la maladie de 74%. Les champignons pathogènes appartiennent à plusieurs espèces : Fusarium ananatum (72% des isolats), Talaromyces stollii (21%), F. oxysporum (6%) et F. proliferatum (1%). Leur potentiel toxinogène a été déterminer, Les champignons du genre Fusarium ont produit des mycotoxines identifiées comme les fumonisines FB1, FB2 et la beauvericine. Sur un milieu de culture ananas, une concentration en beauvericine de 34959 µg kg-1 a été mesurée pour l’espèce F. proliferatum.Une méthode d’inoculation de Fusarium ananatum directement dans le parenchyme a permis de décrire la réponse du biochimique du fruit. La voie des phénylpropanoïdes est sollicitée, particulièrement avec l’élicitation du caffeoylisocitrate et du coumaroylisocitrate dans la zone infectée. Une comparaison des profils métaboliques montre que la réponse du fruit à une inoculation est plus importante chez le cultivar résistant ‘MD-2’ que chez le cultivar sensible ‘Queen’. La majorité des métabolites élicités par l’attaque sont déjà présents dans les fruits sains mature de la variété résistante. Le potentiel antifongique des composés phénoliques à était évalué. Les acides coumarique, caféoylquinique et férulique inhibent la croissance du mycélium à des concentrations similaires à celle trouvées dans les fruits infectés.Une approche par imagerie a permis de décrire l’anatomie des fruits des deux cultivars et notamment la fusion imparfaite des sépales et bractée chez ‘Queen’. Les nectaires et les parois carpellaires jouent un rôle clef dans le processus d'infection et de colonisation de Fusarium ananatum. / Fruiltet core rot (FCR) disease affects the fruits of mature pineapples. Current disease controls are not available. A deeper knowledge of the pathosystem is needed to find an effective means of control FCR.A diagnostic survey conducted with producers during the southern winter revealed a prevalence of the disease of 74%. Pathogenic fungi belong to several species: Fusarium ananatum (72% isolates), Talaromyces stollii (21%), F. oxysporum (6%) and F. proliferatum (1%). Their toxinogenic potential was determined. Fusarium fungi produced mycotoxins identified as fumonisins FB1, FB2 and beauvericin. On a pineapple culture medium, a concentration of beauvericine of 34959 μg kg-1 was measured for the species F. proliferatum.A method of inoculating Fusarium ananatum directly into the parenchyma allowed to describe the biochemical response of the fruit. The phenylpropanoids pathway is involved, particularly with the elicitation of caffeoylisocitrate and coumaroylisocitrate in the infected zone. A comparison of the metabolic profiles shows that the response to inoculation of resistant cultivar 'MD-2' is higher than in the sensitive cultivar 'Queen'. Most of the metabolites elicited by the attack are already present in healthy mature fruits of the resistant variety. The antifungal potential of the phenolic compounds was evaluated. Coumaric, caffeoylquinic and ferulic acids inhibit mycelial growth at concentrations similar to those found in infected fruits.An imaging approach allowed to describe the anatomy of the fruits of the two cultivars, to identify the key roles played by nectaries and carpel margins in the infection and colonization process of Fusarium ananatum.
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Vinificação em tinto de uvas americanas: efeito das técnicas de pré-secagem das uvas e de chapéu submerso nos perfis químico e sensorial / Red winemaking: effect of grape pre-drying and submerged cap on the chemical and sensory profiles

Castilhos, Maurício Bonatto Machado de [UNESP] 15 March 2016 (has links)
Submitted by Maurício Bonatto Machado de Castilhos (mbonattosp@yahoo.com.br) on 2016-03-21T14:52:28Z No. of bitstreams: 1 Tese Bonatto_corrigida_final.pdf: 3969473 bytes, checksum: b52bf638d9c0de021358f0dd1af6792a (MD5) / Approved for entry into archive by Sandra Manzano de Almeida (smanzano@marilia.unesp.br) on 2016-03-22T16:52:25Z (GMT) No. of bitstreams: 1 castilhos_mbm_dr_sjrp.pdf: 3969473 bytes, checksum: b52bf638d9c0de021358f0dd1af6792a (MD5) / Made available in DSpace on 2016-03-22T16:52:25Z (GMT). No. of bitstreams: 1 castilhos_mbm_dr_sjrp.pdf: 3969473 bytes, checksum: b52bf638d9c0de021358f0dd1af6792a (MD5) Previous issue date: 2016-03-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A produção brasileira de vinhos encontra-se em constante especialização e tem como objetivo incrementar a qualidade dessas bebidas a fim de atender e superar as expectativas dos consumidores. Diante desse contexto, algumas entidades governamentais pesquisam o melhoramento genético de uvas almejando produzir matérias-primas com características singulares a fim de elaborar vinhos com qualidade ímpar e de caráter regional. Adicionalmente, cientistas da área pesquisam variações no processo de vinificação e, através dessas técnicas, promovem variações no perfil químico dos vinhos, respondendo positivamente no perfil sensorial descritivo e de aceitação. Esse estudo pesquisou os efeitos da pré-secagem das uvas e o emprego do chapéu submerso e explorou o comportamento químico e sensorial de vinhos elaborados com uvas americanas e híbridas. Os resultados mostraram que os vinhos elaborados pelo processo de pré-secagem das uvas apresentaram forte degradação de compostos fenólicos como antocianinas e flavonóis, sendo os flavan-3-óis (galoilados ou não) e proantocianidinas os que apresentaram maior resistência ao calor produzido pela secagem. De uma forma geral, tais vinhos foram descritos como amargos, adstringentes, encorpados, pungentes e persistentes por apresentarem elevada concentração desses compostos fenólicos. Os vinhos elaborados pelo processo de chapéu submerso não apresentaram diferenças significativas nos conteúdos de antocianinas, piranoantocianinas e flavonóis quando comparados aos vinhos elaborados pelo processo tradicional de vinificação, sendo descritos com elevada intensidade de cor e matiz violeta, além de apresentarem, em alguns casos, aroma foxado e frutado evidente. Apresentaram elevada aceitação em alguns casos, sendo considerados como alternativa ao tratamento tradicional. / Brazilian wine production is in constant specialization and aims to enhance the quality of red wines in order to meet and exceed consumer expectations. Thus, some governmental entities develop genetic improvement programs aiming at producing grapes with singular features that will be employed in the production of regional wines, i.e., wines whose features indicate their origin of production. Moreover, scientists from enological area study the variations in winemaking aiming at promoting such improvement on the chemical properties of wines, enhancing their acceptance sensory profile. Therefore, this study aimed at analyzing the effects of grape pre-drying and submerged cap in order to explore the chemical and sensory behavior of red wines produced from Vitis labrusca grapes and their hybrids. The results showed that the wines produced from pre-drying process presented relevant degradation of the phenolic compounds, mainly anthocyanins and flavonols; and flavan-3-ols (galloylated or not) and proanthocyanidins were the compounds that seemed to be less affected by the heat produced by the pre-drying procedure. In general, these wines were described as bitter, astringent, full-bodied, pungent and persistent to palate due to their high concentration of these aforementioned compounds. Wines produced form submerged cap winemaking presented no significant differences from the wines elaborated by traditional process concerning anthocyanin, pyranoanthocyanin and flavonol contents, and were described as colorful with intense violet hue and strong foxy and fruity aroma. These wines presented higher acceptance in some cases and were considered as an alternative to the traditional winemaking treatment.
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USO DE ANTIOXIDANTES NATURAIS NA PRESERVAÇÃO DO ESTADO OXIDATIVO DE SALSICHAS / USE OF NATURAL ANTIOXIDANTS IN PRESERVING THE OXIDATIVE STATUS OF SAUSAGES

Casarotto, Julie 28 March 2013 (has links)
Lipid oxidation is one of the main causes of loss in food quality. In order to prevent oxidative deterioration and organoleptic changes in foods, industries use antioxidants agents. In past few years, the use of natural antioxidants derived from plant extracts, fruits and cereals has attracted the interest of researchers and consumers because they are, generally, healthier and safer than artificial ones. Phenolic compounds are hydroxylated aromatics substances of great structural diversity, which have antioxidant activity and, therefore, they have been widely studied as natural antioxidants in foods. Barley (Hordeum vulgare) and grapes have large amounts of phenolic compounds and their antioxidant activity is broadly known. The objective of this study was to extract phenolic compounds of agroindustrial residues as barley and Merlot and Moscato grapes (Vitis vinifera), from beer and wine production, to apply these extracts in sausages and to evaluate their antioxidant potential. As comparation parameter it was used the synthetic antioxidant sodium erythorbate, generally used in meat products. It were evaluated proximate composition, pH, color, texture, fatty acid profile, oxidative stability (peroxide value, thiobarbituric acid reactive substances TBARS and volatile compounds derived from lipid oxidation) and sensory quality of treatments along 60 days of storage at 4 °C. Color stability was improved by addition of extract of vinification residues from Merlot grape, furthermore, the addition of natural extracts had little effect on texture parameters of sausages. It was observed that the natural extracts, as well as sodium erythorbate, were effective in delaying lipid oxidation, measured by TBARS, until day 30, and the treatment with Merlot residue extract was the most efficient. The fatty acid profile was significantly affected by the storage time of the samples and slightly affected by the addition of antioxidants. It was observed a reduction in the percentage of unsaturated fatty acids and an increase in saturated ones throughout the experiment, which showed the progression of lipid oxidation during the period. The production of different volatile compounds during storage featured each period, being the start period featured by a greater presence of aldehydes, the day 30 featured by presence of volatile 2-butoxyethanol and the day 60 featured by 3-hydroxy-2-butanone. In sensory analysis, only the treatment with extract of brewery residues was rejected by judges in all periods for taste and odor. These results demonstrate that the extracts of vinification residues, especially from Merlot grape, are efficient antioxidants and its can be effectively used in sausages without causing losses to the sensory quality of the product. / A oxidação lipídica é uma das principais causas da perda de qualidade dos alimentos. Com o intuito de evitar a deterioração oxidativa e alterações organolépticas nos alimentos, as indústrias lançam mão do uso de agentes antioxidantes. Nos últimos anos, a utilização de antioxidantes naturais obtidos a partir de extratos de plantas, frutos e cereais, tem atraído o interesse de pesquisadores e consumidores por, normalmente, serem mais saudáveis e seguros que os antioxidantes artificiais. Os compostos fenólicos são substâncias aromáticas hidroxiladas de grande diversidade estrutural, que apresentam ação antioxidante e, por isto, vêm sendo muito estudados como antioxidantes naturais em alimentos. A cevada (Hordeum vulgare) e as uvas apresentam grande quantidade de compostos fenólicos e possuem reconhecida atividade antioxidante. O objetivo deste trabalho foi extrair os compostos fenólicos de resíduos agroindustriais de cevada e uvas Merlot e Moscato (Vitis vinifera), resultantes da produção de cerveja e vinhos, aplicar estes extratos em salsichas e avaliar o seu potencial antioxidante. Como parâmetro para comparação foi utilizado o antioxidante sintético eritorbato de sódio, comumente empregado em produtos cárneos. Foram avaliadas a composição centesimal, pH, a cor, textura, o perfil de ácidos graxos, a estabilidade oxidativa (índice de peróxidos, substâncias reativas ao ácido tiobarbitúrico TBARS e compostos voláteis oriundos da oxidação lipídica) e a qualidade sensorial dos tratamentos ao longo de 60 dias de armazenamento a 4 ºC. A estabilidade da cor foi melhorada pela adição de extrato de resíduos de vinificação de uva Merlot, além disso, a adição dos extratos naturais teve pouca influência nos parâmetros de textura das salsichas. Observou-se que os extratos naturais, assim como o eritorbato de sódio, foram eficientes em retardar a oxidação lipídica, avaliada através de TBARS, até o dia 30, sendo o tratamento adicionado de extrato de uva Merlot o mais eficiente. O perfil de ácidos graxos foi significativamente afetado pelo tempo de armazenamento das amostras e pouco afetado pela adição de antioxidantes. Foi observada diminuição nos percentuais de ácidos graxos insaturados e aumento nos saturados ao longo do experimento, o que demonstrou a progressão da oxidação lipídica durante o período. A produção de compostos voláteis ao longo do armazenamento caracterizou cada período, sendo o início do experimento caracterizado por maior presença de aldeídos (hexanal), o dia 30 pela presença do volátil 2-butoxietanol e o dia 60 pela cetona 3-hidroxi-2-butanona. Na análise sensorial somente o tratamento adicionado de extrato de resíduos de cervejaria apresentou baixa aceitabilidade pelos julgadores em todos os períodos quanto ao sabor e odor. Estes resultados demonstram que os extratos de resíduo de vinificação, em especial de uva tinta (Merlot), são antioxidantes eficientes e podem ser utilizados em salsichas, sem causar perdas à qualidade sensorial do produto.
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ESTUDO DA ATIVIDADE ANTIOXIDANTE IN VITRO E CARACTERIZAÇÃO CROMATOGRÁFICA EM EXTRATOS DE PLANTAS MEDICINAIS DA AMAZÔNIA / EVALUATION OF THE IN VITRO ANTIOXIDANT ACTIVITY AND CHROMATOGRAPHIC CHARACTERIZATION IN MEDICINAL PLANTS EXTRACTS FROM AMAZONIA

Silveira, Géssica Domingos da 12 March 2014 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Most of the free radicals generated in the body is derived from oxygen and are associated with the development of many diseases. Medicinal plants are a natural resource in the treatment prevention of diseases and have been used for the first healthcare. These properties of the plants are related to the presence of phenolic compounds which possess several pharmacological and antioxidant properties. The high performance liquid chromatography has been used to identify and quantify these compounds in plants. Therefore, this study developed and validated an HPLC - PAD method using gold as working electrode to characterize 12 phenolic compounds in herbal extracts from Amazon. The extracts from Connarus perrotettii var angustifolius, Mansoa alliacea, Cecropia palmata, Cecropia obtusa, Bauhinia variegata and Bauhinia alboflava showed the presence of at least one of the antioxidants compounds under study. Furthermore, the species showed in vitro antioxidant activity against reactive oxygen species. The acetate fraction of the species M. alliacea showed the highest in vitro antioxidant activity (70.85 ± 4.06%) against the superoxide radical. Front of the peroxyl radical, the species C. palmata was responsible for the hidhest antioxidant activity (95.33 ± 0.95%) and against hydroxyl radical species C. obtusa showed the highest scavenging activity (98.19 ± 5.93). The study of the in vitro antioxidant activity of these species coupled with chemical characterization of their extracts comprises an important key to potential in vivo studies. Moreover, the compounds identified and quantified in these species extracts have pharmacological properties and may be linked to popular use of these medicinal plants / A maioria dos radicais livres gerados no organismo é derivada do oxigênio e estão associados ao desenvolvimento de diversas doenças. As plantas medicinais são um recurso terapêutico natural na prevenção de patologias e têm sido utilizadas a milênios pela humanidade nos primeiros cuidados com a saúde. Muitas dessas propriedades das plantas estão relacionadas com a presença de compostos fenólicos os quais possuem diversas propriedades farmacológicas e antioxidantes. A cromatografia líquida de alta eficiência tem sido utilizada na identificação e quantificação desses compostos em plantas. Dessa forma, o presente trabalho desenvolveu e validou um método de HPLC PAD utilizando eletrodo de ouro como eletrodo de trabalho para a caracterização de 12 compostos fenólicos em extratos de plantas medicinais da Amazônia. Os extratos das espécies Connarus perrotettii var angustifolius, Mansoa alliacea, Cecropia palmata, Cecropia obtusa, Bauhinia variegata e Bauhinia alboflava demonstraram a presença de pelo menos um dos compostos antioxidantes em estudo. Além disso, as espécies apresentaram atividade antioxidante in vitro frente à espécies reativas de oxigênio. A fração acetato da espécie M. alliacea demonstrou a maior atividade antioxidante in vitro (70,85 ± 4,06 %) frente ao radical superóxido. Frente ao radical peroxil, a espécie C. palmata foi responsável pela maior atividade antioxidante (95,33 ± 0,95 %) e frente ao radical hidroxil a espécie C. obtusa demonstrou a maior atividade sequestradora (98,19 ± 5,93). O estudo da atividade antioxidante in vitro dessas espécies aliada a caracterização química dos seus extratos compreende uma importante chave para possíveis estudos in vivo. Ademais, os compostos identificados e quantificados nos extratos dessas espécies apresentam propriedades farmacológicas comprovadas e podem estar associados ao uso popular dessas plantas medicinais.

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