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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.
211

Recherche de marqueurs biochimiques et génétiques de l'adaptation des caféiers cultivés aux variations climatiques / Biochemical and genetic markers of the adaptation of cultivated coffee to climatic variations

Vestalys, Ialy Rojo 30 November 2018 (has links)
La baisse de la production et la prolifération des maladies engendrées par le changement climatique dans la caféiculture, particulièrement pour Coffea arabica, conduit à chercher de nouvelles pratiques culturales et étudier la réponse adaptative des caféiers aux modifications environnementales. En se basant sur l’importance des composés phénoliques dans la réponse des plantes aux stress et sur la richesse des caféiers en ces composés antioxydants, la réponse adaptative des caféiers cultivés en plein champ a été étudiée en s’intéressant à l’évolution du contenu des feuilles en ces composés dans différentes conditions de culture simulées par un gradient altitudinal, des cultures sous ombrage ou l’obtention de plants greffés. Les analyses biochimiques montrent que certains composés phénoliques s’accumulent dans les feuilles en réponse à la modification d’un paramètre météorologique spécifique. Ainsi, acides chlorogéniques et flavanols sont plus accumulés en cas de sécheresse alors que les flavonols glycosylés s’accumulent sous forte radiation solaire. La comparaison avec C. canephora permet de valider ces marqueurs. Les analyses transcriptomiques indiquent une différence d’expression des gènes de biosynthèse de ces composés suivant le stade de croissance de la feuille. Elles montrent également que la réponse à la lumière passe par la surexpression de nombreux gènes codant des HSP ainsi que ceux impliqués dans la photosynthèse et la glycosylation des flavonoïdes. Enfin, ces résultats montrent l’intérêt, suivant l’altitude, de l’ombrage et du greffage pour la culture de C. arabica. / The decline in production and the proliferation of diseases caused by climate change in coffee growing, especially for Coffea arabica, leads to search new cultural practices and to study the adaptive response of coffee trees to environmental changes. Based on the importance of phenolic compounds in the response of plants to stress and the richness of coffee in these antioxidant compounds, the adaptive response of coffee grown in the field was studied by looking at the evolution of the leaf content in these compounds under different culture conditions simulated by an altitudinal gradient, shaded cultures or obtaining grafted plants. Biochemical analyzes show that certain phenolic compounds accumulate in the leaves in response to the modification of a specific meteorological parameter. Thus, chlorogenic acids and flavanols are more accumulated in case of drought while glycosylated flavonols accumulate under strong solar radiation. The comparison with C. canephora validates these markers. Transcriptomic analyzes indicate a difference in expression of the biosynthesis genes of these compounds according to the stage of growth of the leaf. They also show that the response to light is the overexpression of many genes encoding HSPs as well as those involved in photosynthesis and flavonoid glycosylation. Finally, these results show the interest, according to altitude, of shading and grafting for the cultivation of C. arabica.
212

Estudo do efeito de tratamento enzim?tico sobre as caracter?sticas de qualidade de ard?sia e sua influ?ncia no aroma de chocolate

Nascimento, Hilana Salete Silva Oliveira 26 June 2015 (has links)
Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2015-09-09T23:59:26Z No. of bitstreams: 1 TESE - VERS?O FINAL - HILANA SALETE SILVA OLIVEIRA.pdf: 2650992 bytes, checksum: c49b570e274076a6845058a800581217 (MD5) / Made available in DSpace on 2015-09-09T23:59:26Z (GMT). No. of bitstreams: 1 TESE - VERS?O FINAL - HILANA SALETE SILVA OLIVEIRA.pdf: 2650992 bytes, checksum: c49b570e274076a6845058a800581217 (MD5) Previous issue date: 2015-06-26 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / A recurring problem in the chocolate industry is the low quality of cocoa beans, which influences the chocolate aroma. One possibility to contribute to solve this problem is the application of commercial exogenous enzymes on slate. This work proposed detection and sequencing, by mass spectrometry, of the peptides present in slates subjected to treatment with microbial enzyme proposed by Oliveira et al. (2011). Associated to the analysis of peptides was studied the concentration of phenolic compounds and antioxidant activity since the reduction of phenolics in cocoa processing steps is known to cause reduction of astringency and bitterness contributing to the formation of important compounds for the chocolate aroma. The results indicate that although the qualitative standard of the hydrophobic amino acids present in the peptides responsible for the mixture of chocolate aroma is more important than the quantitative standard, the presence of the amino acids leucine, alanine, phenylalanine, and tyrosine in appropriate amounts is essential for obtaining desired aroma. The proposed treatment caused a reduction in the phenolics concentration, which is desirable for a chocolate aroma, and in antioxidant activity. In general, the profile peptide, the phenolic content and antioxidant activity of treated slate resembled more good quality almonds suggesting the effectiveness of the proposed treatment. Research the market and trends indicated favorable conditions for diffusion of the proposed treatment in the process industries. / Um problema recorrente na ind?stria de chocolate ? a baixa qualidade das am?ndoas de cacau, o que influencia o aroma do chocolate. Uma forma de contribuir para solucionar este problema ? a aplica??o de enzimas ex?genas comerciais sobre a ard?sia. Esse trabalho prop?s a detec??o e sequencimento, por espectrometria de massas, dos pept?deos presentes em ard?sia submetidas ao tratamento com enzima microbiana proposto por Oliveira et al. (2011). Associado ?s an?lises de pept?deos, foi feito um estudo da concentra??o de fen?licos e atividade antioxidante, uma vez que a redu??o de fen?licos nas etapas de processamento do cacau ? conhecida por causar redu??o da adstring?ncia e amargor, contribuindo para a forma??o de compostos importantes para o aroma de chocolate. Os resultados indicam que embora o padr?o qualitativo dos amino?cidos hidrof?bicos presentes na mistura de pept?deos respons?veis pelo aroma de chocolate seja mais importante que o padr?o quantitativo, a presen?a dos amino?cidos leucina, alanina, fenilalanina e tirosina em propor??es adequadas ? essencial para a obten??o do aroma desejado. O tratamento proposto causou redu??o na concentra??o de fen?licos, o que ? desej?vel para o aroma de chocolate, e na atividade antioxidante. De modo geral, o perfil de pept?deos, o teor de fen?licos e a atividade antioxidante de ard?sia tratada foi muito mais semelhante ao das am?ndoas de boa qualidade sugerindo a efici?ncia do tratamento proposto. Pesquisas de mercado e tend?ncias indicaram condi??es interessantes ? difus?o do tratamento proposto nas ind?strias de processamento.
213

Ověření vlivu rozpustných fenolických látek na aktivitu extracelulárních enzymů v rašeliništích

KOVÁŘOVÁ, Lucie January 2018 (has links)
The aim of the study was to verify the influence of the soluble phenolic compounds on the activity of extracellular enzymes. We tested the effect of aerobic and anaerobic conditions and addition of soluble phenolic compounds on potential activity of extracellular enzymes in two laboratory experiments. The results showed, that potential activities of oxidative extracellular enzymes such as phenol oxidase and peroxidase did not decline in anaerobic incubations, and have no oxygen requirement. Potential activities of hydrolytic enzymes was not inhibited by phenolic compounds and are oxygen related or have no oxygen relationship. No negative relationship between hydrolytic enzymes and phenolic compounds was observed. In summary, our results do not support the ''enzymatic latch'' hypothesis.
214

Potencial antioxidante de extratos de especiarias em sistemas modelo e na estabilidade oxidativa do óleo de soja / Antioxidant activity of spices extracts in model systems and in the oxidative stability of soybean oil

Sichieri, Ana Paula Marques Pino 18 October 2013 (has links)
A degradação oxidativa dos lipídeos é um fator preponderante que limita a vida útil dos alimentos, reduzindo suas qualidades nutricionais e organolépticas. A utilização de antioxidantes durante o processo de fabricação pode diminuir consideravelmente a extensão da oxidação lipídica, desencadeada pela reação de radicais livres. A crescente preocupação pelo consumo de alimentos mais saudáveis e livres de aditivos sintéticos tem recebido maior atenção pelas indústrias, que atualmente tem procurado por alternativas mais naturais, como o uso de antioxidantes provenientes de especiarias, como uma forma promissora de substituição dos compostos sintéticos. O objetivo deste trabalho foi estudar as condições de obtenção de extratos hidroalcoólicos de cravo (Syzygium aromaticum), canela (Cinnamomum verum) e pimenta dedo-de-moça (Capsicum annuum) e sua aplicação em óleos de soja refinado, armazenado em embalagens de vidro, em comparação com amostras adicionadas de antioxidante sintético TBHQ e amostras livres de antioxidantes (controle), durante sete meses, simulando a comercialização em supermercados. Foram verificados também as propriedades antioxidantes dos extratos de especiarias produzidos nas condições selecionadas através das metodologias de DPPH e ABTS. O estudo do efeito da temperatura de extração e do grau de hidratação do etanol sobre o rendimento de compostos fenólicos totais dos extratos destas especiarias foi realizado com aplicação de planejamento experimental e metodologia de superfícies de resposta. As condições para uma extração eficiente dos compostos fenólicos do cravo, da canela e da pimenta foram o emprego de etanol a 49,5 % (v/v). As melhores temperaturas estiveram entre 45 a 50 °C para o cravo e canela, e 60 °C para a pimenta. Os extratos de cravo, canela e pimenta dedo-de-moça preparados nas condições otimizadas, foram adicionados nas proporções de 50 mg kg-1, 100 mg kg-1, 150 mg kg-1 e 200 mg kg-1 às amostras de óleo de soja refinado e submetido a um teste acelerado em estufa a 65 °C juntamente com amostras adicionadas nas mesmas proporções de TBHQ e amostras isentas de antioxidantes (controle), para verificação da concentração mais eficiente no retardar a oxidação. Em seguida, após os resultados do teste de estufa, os óleos adicionados de 100 mg kg-1 de extratos, TBHQ, e isento de antioxidantes foram acondicionados em embalagens de vidro transparente de 250 mL e armazenados sob condições de comercialização (incidência de luz fluorescente por 15 horas / 24 horas e 331,71 Lux). Os resultados de Índice de Peróxido, Acidez e Absortividade na faixa do ultravioleta evidenciaram que os extratos foram capazes de oferecer proteção antioxidante ao óleo de soja refinado em diferentes níveis, sendo que o tratamento adicionado de extrato de cravo foi o que mais se destacou na inibição da oxidação lipídica do óleo de soja, seguido do extrato adicionado de canela e pimenta (p<0,05). / Lipid deterioration is a major cause of shorter food shelf life, reducing its nutritional and organoleptical quality. The use of antioxidants during the manufacturing process can significantly decrease the extent of lipid oxidation reactions triggered by free radicals. The growing concern about the consumption of healthier foods and free from synthetic additives has received increased attention by the industry, which is currently looking for more natural alternatives, such as the use of antioxidants from herbs and spices, as a promising replacement of synthetic compounds. The objective of this work was to study the conditions for obtaining hydroalcoholic extracts of cloves (Syzygium aromaticum), cinnamon (Cinnamomum verum) and red pepper (Capsicum annuum) and its application in soybean oil refined, stored in glass containers, compared with samples added of synthetic antioxidant TBHQ and samples free antioxidant (control) during 7 months simulating marketing conditions in supermarkets. Extracts were analyzed by DPPH and ABTS methods. The study of the effect of extraction temperature and the degree of hydration of ethanol on the yield of total phenolic compounds of the extracts of these spices was carried out with application of experimental design and response surface methodology. The best solvent concentration for efficient extraction of phenolic compounds from clove, cinnamon and pepper was 49.5% ethanol (v / v). The best temperatures were between 45 and 50°C for cloves and cinnamon, and 60 ° C for pepper. The extracts of clove, cinnamon and red pepper prepared under optimized conditions were added in concentration of 50 mg kg-1 , 100 mg kg-1, 150 mg kg-1 and 200 mg kg-1 to samples of refined soybean oil and subjected to an accelerated storage test at 65°C with samples containing the same concentrations of TBHQ and samples free of antioxidant (control) in order to check the most efficient concentrations to slow the oxidation. The best extracts concentration 100 mg kg-1 from the Schaal oven test was added to oil packed in glass containers against oil with 100 mg kg-1 of TBHQ, and oils free of antioxidants and stored under normal commercialization conditions (fluorescence light exposure for 15 hours / 24 hours and 333,71 Lux). Peroxide, acid values and absorptivity in the ultraviolet range showed that the extracts were able to offer antioxidant protection to soybean oil at different levels. Clove extract, showed the best performance in the inhibition soybean oil oxidation, followed by cinnamon and pepper (p<0,05).
215

Efeito de extratos orgânicos de variedades de cebola sobre o quorum sensing bacteriano / Effect of organic extracts of onion varieties on bacterial quorum sensing

Quecan, Beatriz Ximena Valencia 13 June 2018 (has links)
Muitos genes bacterianos são regulados pelo mecanismo de comunicação denominado quorum sensing (QS). Neste sistema, moléculas sinalizadoras ativam um comportamento de grupo, conforme a densidade celular, permitindo o controle da expressão gênica. Estudos sugerem o potencial de compostos extraídos de plantas sobre o QS, a exemplo da quercetina, um flavonol presente em concentrações elevadas em algumas frutas e hortaliças. Este composto é o flavonoide majoritário presente em cebola (Allium cepa), mas não existem estudos que mostrem a atividade anti-QS de extratos orgânicos deste vegetal. Este trabalho avaliou o potencial antimicrobiano e anti-QS de extratos orgânicos de cebola branca e cebola roxa, assim como de alguns de seus componentes majoritários identificados, em fenótipos regulados pelo QS como a produção de violaceína em Chrormobacterium violaceum ATCC 12472, a motilidade tipo swarming e a formação de biofilmes em Pseudomonas aeruginosa PAO1 e Serratia marcescens MG1. Extratos de cebola branca e roxa foram obtidos por extração em fase sólida utilizando coluna de poliamida e seus compostos identificados e quantificados pelas técnicas de Cromatografia líquida- ionização por elétron spray-espectrometria de massas e cromatografia líquida de alta eficiência acoplada a detector de arranjo de diodo. A atividade antimicrobiana foi avaliada pelas curvas de multiplicação de cada micro-organismo. O efeito dos compostos quercetina aglicona (inibidor do QS já relatado na literatura e encontrado no extrato de cebola roxa) e quercetina-3-&#946;-D-glicosideo (um dos compostos majoritários encontrados em ambos extratos) sobre os micro-organismos utilizados neste estudo foi também avaliado. Foram obtidos três extratos: cebola branca em metanol (CB-MeOH), cebola branca em metanol amônia (CBMeOH/ NH4) e cebola roxa em metanol (CR-MeOH). Os compostos quercetina 3,4\'- diglicosídeio, quercetina-4-glicosídeo, quercetina-3-&#946;-D-glicosideo e quercetina aglicona foram os predominantes nos extratos das duas variedades de cebola. Cianidina-3-O-glicosideo também foi identificada no extrato de cebola roxa. A concentração inibitória mínima (MIC) dos extratos foi igual ou superior a 125 &#181;g/ml (p/v) de extrato seco. Não foi observada inibição significativa da produção de violaceína em C. violaceum pelos extratos orgânicos de cebola e nem pela quercetina-3-&#946;-D-glicosideo, nas concentrações sub-inibitórias avaliadas. No entanto, a quercetina aglicona inibiu significativamente a produção de violaceína em todas as concentrações. A glicosilação da quercetina pode ter afetado sua atividade sobre a inibição da produção de violaceina, já que estudos mostram menor atividade biológica deste composto quando glicosilado. Para a motilidade tipo swarming em P. aeruginosa PAO1 houve inibição significativa pelo extrato de cebola roxa, em todas as concentrações estudadas. Os demais extratos não apresentaram inibição contra este micro-organismo. Para S. marcescens MG1, foi observada inibição da motilidade swarming somente na concentração de 125 &#181;g/ml de CBMeOH/ NH4. As análises de comparação entre os dois tipos de quercetina revelaram que, embora para as duas bactérias testadas os dois compostos apresentaram atividade inibitória sobre a motilidade tipo swarming, a quercetina-3-&#946;-D-glicosideo foi menos eficiente que a quercetina aglicona na concentração de 125 &#181;g/ml. A formação de biofilmes não foi influenciada pelos extratos e, inesperadamente, não se detectou inibição da formação de biofilmes por ambos tipos de quercetina avaliados. De forma geral, os extratos orgânicos de cebola mostraram pouco efeito sobre os fenótipos controlados pelo quorum sensing e a glicosilação da quercetina provavelmente explica a baixa atividade antimicrobiana e anti-QS dos extratos. / Many bacterial genes are regulated by a communication mechanism called quorum sensing (QS). In this system, signaling molecules activate a group behavior according to cell density, allowing the control of gene expression. Studies suggest the inhibitory potential of compounds extracted from plants on the QS system, like quercetin, a flavonol present in high concentrations in some fruits and vegetables. This compound is the main flavonoid found in onion (Allium cepa); however, there are no studies showing the anti-QS activity of organic extracts of this plant. The objective of this work was to evaluate the antimicrobial and anti-QS potential of organic extracts of white and red onions, and their major components studied in QS-regulated phenotypes such as violacein production in Chromobacterium violaceum, swarming motility and biofilm formation in Pseudomonas aeruginosa PAO1 and Serratia marcescens MG1.White and red onion extracts were obtained by solid phase extraction using a polyamide column and its compounds were identified and quantified by Liquid Chromatography - Electron Spray-Mass Spectrometry and high performance liquid chromatography coupled to diode array detector. O The antimicrobial activity was evaluated by growth curves of each microorganism. The effect of non-glycosylated quercetin (a QS inhibitor already reported in the literature and found in red onion extract) and quercetin-3-&#946;-D-glycoside (one of the major compounds found in both extracts) on the microorganisms used in this study was also evaluated. Three extracts were obtained: white onion in methanol (CB-MeOH), white onion in methanol ammonia (CB-MeOH / NH4) and red onion in methanol (CR-MeOH). Our results showed that quercetin 3,4\'- diglycoside, quercetin-4-glycoside, quercetin-3-&#946;-D-glycoside and non-glycosylated quercetin were predominant in the extracts of the two onion varieties. Cyanidin-3-O-glycoside has also been identified in the purple onion extract. The minimum inhibitory concentration (MIC) of extracts was equal or greater than 125 &#181;g / ml (w / v) of dry extract. There was no significant inhibition of violacein production in C. violaceum by organic onion extracts or by quercetin-3-&#946;- D-glycoside at the sub-inhibitory concentrations evaluated. However, non-glycosylated quercetin showed a significant inhibition of violacein production in all tested concentrations. The glycosylation of Quercetin could have altered its inhibition activity towards violacein production, and in fact, some studies have shown less biological activity of some phenolic compounds when they have been glycosylated. For swarming motility in P. aeruginosa PAO1 there was significant inhibition by red onion extract, in all studied concentrations. The other extracts did not present inhibition against this microorganism. For S. marcescens MG1, inhibition of swarming motility was observed only at the concentration of 125 &#181;g / ml of CB-MeOH / NH4. Comparative analyses between the two types of quercetin showed that, although for the two bacteria tested the two compounds showed inhibitory activity on swarming motility, quercetin-3-&#946;-D-glycoside was less efficient than non-glycosylated quercetin in the concentration of 125 &#181;g / ml. Biofilm formation was not influenced by the extracts and unexpectedly, both types of quercetin evaluated did not show inhibition towards biofilm formation. In general, organic onion extracts showed little effect on quorum sensing controlled phenotypes and glycosylation of quercetin probably explains the low antimicrobial and anti-QS activity of the extracts.
216

Caracterização química, avaliação da atividade antioxidante in vitro e in vivo, e identificação dos compostos fenólicos presentes no Pequi (Caryocar brasiliense, Camb.) / Chemical characterization, in vitro and in vivo antioxidant activity evaluation, and identification of the phenolic compounds present in the pequi fruit (Caryocar brasiliense, Camb.)

Lima, Alessandro de 23 April 2008 (has links)
O estresse oxidativo produzido no organismo relaciona-se com o aparecimento e/ou desenvolvimento de uma série de doenças crônico-não transmissíveis. Os compostos fenólicos, presentes nos vegetais, são capazes de neutralizar as estruturas radicalares; diminuindo, portanto, o risco de surgimento de patologias a elas associadas. O objetivo do presente trabalho foi avaliar a atividade antioxidante do fruto e da amêndoa do pequi e a participação desta atividade na prevenção do processo oxidativo em ratos. Foram obtidos, de forma seqüencial, os extratos etéreo, alcoólico e aquoso, bem como as frações de ácidos fenólicos livres (AFL), esterificadas solúveis (AFS) e insolúveis (AFI) da polpa e da amêndoa do pequi. Todos os extratos e frações foram avaliados quanto à atividade antioxidante in vitro pelos ensaios de co-oxidação do &#946;-caroteno/ácido linoléico, DPPH (radical 1,1-diphenil-2-picrilhydrazil), ABTS (radical 2,2\'azinobis-(3-ethylbenzthiazoline-6-sulfonic acid), ORAC (Capacidade de Absorção de Radicais Oxigênio) e Rancimat; e apresentaram expressiva atividade antioxidante. Entre os extratos, o aquoso da polpa apresentou maior atividade; entre as frações, a AFL da polpa se destacou nos ensaios &#946;-caroteno/ácido linoléico, DPPH e ABTS. Os extratos e frações foram também avaliados quanto à composição em ácidos fenólicos, por HPLC. Encontraram-se os ácidos elágico, gálico, 4-OH benzóico, p-cumárico e procianidina B2. O ácido elágico esteve presente em todos os extratos e/ou frações, sempre em maior concentração; a procianidina B2, apenas no extrato aquoso da amêndoa. Na avaliação da atividade antioxidante in vivo, em ratos normais, foi administrado, por gavagem, extrato aquoso (100 e 300 mg/kg v.o.) e AFL (40 e 100 mg/kg v.o.) obtidos da polpa do pequi. Evidenciaram-se redução da lipoperoxidação e elevação da atividade das enzimas antioxidantes catalase (CAT), superóxido dismutase (SOD), glutationa peroxidase (GPx) e glutationa redutase (GR) no cérebro e no fígado dos animais que receberam o extrato aquoso a 300 mg/kg e a fração AFL a 100 mg/kg. Isso demonstra que o pequi possui propriedades antioxidantes tanto in vitro como in vivo. / The oxidative stress produced in live organisms is related to the appearance and/or development of a series of non-transmissible chronic diseases. Phenolic compounds present in vegetables are able to neutralize these substances, thus reducing the risk of development of free radicals associated to pathologies. The aim of this work was to evaluate the antioxidant activity in the pulp and almond of the pequi fruit and its effects in preventing the oxidative process in rats. Extracts were obtained by means of sequential extraction in which solvents with different polarities (ether, ethanol and water) were used, as well as free phenolic acid fraction (and) soluble esters and insolublebound compounds from the pulp and almond of the pequi. The total antioxidant capacity was estimated through the following methods: &#946;-carotene bleaching, DPPH (1,1- diphenyl-2-picrylhydrazyl radical), ABTS (2,2\'azinobis-(3-ethylbenzthiazoline-6-sulfonic acid), oxygen radical absorbance capacity (ORAC), and Rancimat assays. All extracts and fractions of phenolic acids showed a significant antioxidant activity. Among the extracts, the pulp aqueous extract showed higher activities than the others. Free phenolic acids fraction from the pulp of the pequi was better compared to other fractions in &#946;-carotene bleaching, DPPH and ABTS assays. Phenolic acids composition was identified by HPLC. It was found ellagic, gallic, 4-Hydroxybenzoic, p-coumaric and procyanidin B2 acid being ellagic acid presents at larger amounts in all extracts and fractions, whereas procyanidin B2 was found only in the aqueous extract of the almond from pequi. For evaluating the antioxidant activity in vivo, aqueous extract (100 and 300 mg/kg b.w.) and free phenolic acids (40 and 100 mg/kg b.w.) obtained from pequi pulp were administered in rats by oral gavage. It was observed a decrease in the levels of lipid peroxidation and an increased activity of antioxidant enzymes catalase (CAT), superoxide dismutade (SOD), glutathione peroxidase (GSHPx), and glutathione reductase (GSSGr) in the brain and liver of animals that received aqueous extract at 300 mg/kg b.w. and free phenolic acids fraction at 100 mg/kg, which demonstrate that pequi fruit has both in vitro and in vivo antioxidative properties.
217

Obtenção, caracterização, encapsulação e aplicação do extrato de vitex (Vitex agnus castus L.) / Obtention, characterization, encapsulation and application of chasteberry extract (Vitex agnus castus L.)

Echalar Barrientos, Mariana Alejandra 25 April 2017 (has links)
O fruto de vitex (Vitex agnus castus L.) é muito aromático, picante e amargo pelo alto teor de compostos fenólicos. É utilizado como pimenta na gastronomia e seu extrato como medicamento fitoterápico para combater os sintomas da tensão pré-menstrual (TPM), síndrome que acomete cerca de 80% das mulheres na idade reprodutiva. Assim, para a aplicação do extrato, com vistas à obtenção de um chocolate funcional para o público feminino, foi proposta sua encapsulação por spray drying visando mascarar ou atenuar o seu sabor desagradável e proteger os compostos fenólicos da oxidação. Portanto, o objetivo deste projeto foi à obtenção em condições otimizadas, caracterização, encapsulação por spray drying e aplicação em chocolate meio amargo do extrato concentrado dos frutos secos e maduros de vitex. O extrato foi obtido por maceração com solução 60 % etanol, a 60 °C e 12 h. Após a concentração do extrato, este foi encapsulado por spray dryer com 4 concentrações de carreador goma arábica e 2 temperaturas de ar de entrada diferentes. Os pós foram caracterizados fisicamente e em relação ao teor dos compostos bioativos. O tratamento com melhores propriedades (T6) foi aplicado em chocolate meio amargo e foi realizada a caracterização do produto. (I) Foi possível obter um extrato rico em compostos fenólicos, com alta atividade antioxidante. (II) A encapsulação foi possível, protegeu os compostos fenólicos da degradação, porém não foi eficiente para mascarar o sabor do extrato. Contudo, (III) a aplicação desse extrato, na forma livre e encapsulada, em chocolate meio amargo foi bem sucedida, pois os produtos obtidos tiveram uma boa aceitação sensorial e a casticina, um dos compostos bioativos responsáveis pela ação terapêutica do extrato, (IV) manteve-se estável durante o período de estocagem. Neste contexto, este trabalho representou uma (V) inovação na área de alimentos funcionais com apelo à manutenção da qualidade de vida de mulheres em período reprodutivo. Ainda, destaca-se a relevância deste trabalho devido à escassez de trabalhos acadêmicos que abordam a encapsulação e aplicação deste extrato em alimentos. / Chasteberry (Vitex agnus castus L.) is very aromatic, spicy and bitter by the content of phenolic compounds. It is used as pepper in gastronomy and its extract as an herbal medicine to combat the symptoms of premenstrual syndrome (PMS), syndrome that affects 80% of women in reproductive age. Thus, for an application of the extract, with goal to obtain a functional chocolate for the female public, its encapsulation was proposed by spray-drying in order to mask or attenuate its unpleasant taste and to protect the phenolic compounds from oxidation. Therefore, the aim of this project was to obtain an extract of chasteberry in optimized conditions, its characterization, encapsulation by spray drying and application in semisweet chocolate. The extract was obtained by maceration with a 60% ethanol solution, at 60 ° C for 12 h. After the extract concentration, it was encapsulated by spray drier with 4 different concentrations of gum arabic charcoal and 2 different inlet air temperatures. The powder was characterized physically and in relation to the content of the bioactive compounds. The treatment with better properties (T6) was applied to the semisweet chocolate and a characterization of the product was carried out. (I) It was possible to obtain an extract rich in phenolic compounds, with high antioxidant activity. (II) Encapsulation was possible, it protected the phenolic compounds from degradation, but was not efficient to mask the flavor of the extract. However, (III) the application of the extract in the free and encapsulated form in semisweet chocolate was successful, the products obtained had a good sensory acceptance and casticina, one of the bioactive compounds responsible for the therapeutic action of the extract, (IV) remained stable during the storage period. In this context, this work represents an (V) innovation in the area of functional foods with maintenance in the quality of life of women in the reproductive period. Still, a relevance of this work is highlighted due to the lack of academic papers that approach the encapsulation or application of chasteberry extract in foods.
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Downstream Processing of Recombinant Proteins from Transgenic Plant Systems: Phenolic Compounds Removal from Monoclonal Antibody Expressing Lemna minor and Purification of Recombinant Bovine Lysozyme from Sugarcane

Barros, Georgia 2012 May 1900 (has links)
Transgenic plant systems have been proposed as bioreactors in the production of pharmaceutical and industrial proteins. The economic benefits of inexpensive plant production systems could be erased if the downstream processing ends up being expensive. To avoid monoclonal antibody (mAb) modification or fouling of chromatography resins, removal of phenolics from plant extracts is desirable. Removal of major phenolics in Lemna extracts was evaluated by adsorption to PVPP, XAD-4, IRA-402 and Q-Sepharose resins. Analysis of phenolics adsorption to XAD-4, IRA-402 and Q-Sepharose showed superior dynamic binding capacities at pH 4.5 than at 7.5. The economic analysis using SuperPro Designer 7.0 indicated that addition of a phenolics adsorption step would increase mAb production cost only 20% by using IRA-402 compared to 35% for XAD-4 resin. The overall mAb processing cost can be reduced by implementing a phenolics removal step. To understand phenolics-resin interactions, adsorption isotherms of phenolic compounds (chlorogenic acid, ferulic acid, rutin, syringic acid and vitexin-2-O-rhamnoside) from different phenolic classes on three resins (IRA-402, PVPP, XAD-4) at pH 4.5 and 7.5 were determined. Differences in adsorption with the type of phenolics were observed, and PVPP was not efficient for phenolics removal. Screening of sugarcane lines for bovine lysozyme (BvLz) accumulation indicated that expression levels are still inadequate for commercial development. To maximize BvLz extraction, pH and ionic strength were evaluated; five conditions resulted in equivalent BvLz/TSP ratio. Membrane filtration process using BvLz extracts attained partial removal of native proteins by the 100 kDa membrane step, but also BvLz loss (21-29%). Regardless of the extraction condition, at least 47% of the starting BvLz was lost during the membrane processing. None of the evaluated extraction conditions caused a substantial recovery of BvLz in the concentrate. Alternative purification options for the IEX+HIC process, which achieved 95% BvLz purity, were tested. Direct loading of sugarcane extract concentrate on HIC and XAD-4 pretreatment of juice did not recovered BvLz as effectively as the IEX chromatography. Pure BvLz was obtained by the XAD+HIC process, but higher purification fold and HIC yield were achieved by the IEX+HIC process, due to the complete separation of BvLz and 18-kDa protein.
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Skystųjų preparatų iš Juglans nigra L. lapų gamyba, biologiškai aktyvių junginių kiekio įvertinimas ir antioksidacinio aktyvumo tyrimas / Biologically active compounds and antioxidant activity evaluation of liquid Black walnut (Juglans nigra L.) leaf preparations

Keturakytė, Vytautė 18 June 2014 (has links)
Tyrimo tikslas - pagaminti vandenines ir etanolines ištraukas iš Junglans nigra L. lapų ir įvertinti bendrą fenolinių junginių, bendrą flavonoidų, juglono kiekį bei nustatyti antioksidacinį aktyvumą. Metodika: 1. Tyrimo objektai: 70% etanolinė juodojo riešutmedžio tinktūra, vandeninė juodojo riešutmedžio lapų ištrauka bei gamyklinis “Black Walnut” 1:1 ekstraktas (gamintojas „Nature's Answer”, JAV). 2. Ištraukų iš J. nigra lapų gamyba. 1) Etanolinės tinktūros gamyba. Pritaikius perkoliacijos metodą iš juodojo riešutmedžio lapų žaliavos, naudojant 70% etanolį, buvo pagaminta tinktūra (santykis 1:10). 2) Vandeninė ištrauka. 10 g smulkintos lapų žaliavos buvo užpilta 120 ml verdančio vandens ir kaitinta 1 val. Ištrauka nufiltruota pro 4 nr. Vatmano filtrą. 3. Kokybinės flavonoidų įvertinimo reakcijos. 4. Bendras fenolinių junginių nustatymas naudojant Folin – Ciocalteu metodą (standartas – galo r.) 5. Bendras flavonoidų kiekio nustatymas spektrofotometriniu būdu, naudojant AlCl3 tirpalą (standartas - rutinas). 6. Juglono kiekio nustatymas spektrofotometriniu būdu. 7. Antioksidacinio aktyvumo įvertinimas fluorimetriniu būdu, naudojant 10-acetil-3,7-dihidroksifenoksazinas (AMR) ir krienų peroksidazę (HPR). Rezultatai. Bendram fenolinių junginių, bendram flavonoidų bei juglono išekstrahuoto kiekio palyginimui buvo pagamintos J. nigra lapų etanolinė ir vandeninė ištraukos. Tiriamų objektų biologiškai aktyvių komponentų kiekiai buvo palyginti su gamykliniu „Black Walnut“ ekstraktu... [toliau žr. visą tekstą] / Aim of the work - produce aqueous and ethanolic extracts of Junglans nigra leaves, evaluate the total phenolic and total flavonoids content, juglone concentration and identify antioxidant activity. Methods: 1. Objects of study: ethanolic tincture and aqueous extract of black walnut leaves, “Black Walnut” extract, 1:1 („Nature's Answer”, USA). 2. Liquid preparations of J. nigra leaves production: 1) Ethanolic tincture production. Tincture was produced of black walnut leaves applying the method of percolation. The 70% ethanol was used. Tincture ratio is 1:10. 2) Aqueous exract production. 10 g shredded leaves of black walnut were extracted with 120 ml of boiling wather for 1 hours. After boiling extract was filtered throught the Whatman paper no. 4. 3. Qualitative evaluation of flavonoids. 4. Total phenolic content was determined by spectrophotometric (Folin - Ciocalteau) method. 5. Total flavonoids content was measured with an aluminum chloride colorimetric assay using spectrophotometer. 6. Juglone determination by spectrophotometric method. 7. Fluorimetric antioxidant activity assay by using N-Acetyl-3,7-dihydroxyphenoxazine (Amplex Red) and horseradish peroxidase (HPR). Results. Ethanolic and aqueous extracts of J. nigra leaves were made to compare total phenolic, total flavonoids content, juglone concentration. Biologically active components study results of ethanolic and aqueous extracts were compared with “Black Walnut” extract. The highest total phenolic and total... [to full text]
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MĖLYNIŲ UOGŲ PREPARATŲ TYRIMAS IR VERTINIMAS / THE RESEARCH AND EVALUATION OF BLUEBERRY PREPARATION

Baliūtytė, Eglė, Krivickienė, Eglė 18 June 2014 (has links)
Darbo tikslas: atlikti Lietuvoje registruotų mėlynių uogų pasirinktų preparatų sudėčių ir technologijos palyginamąją analizę, įvertinti kiekybiškai ir nustatyti antioksidacinį aktyvumą. Darbo uždaviniai: Ištirti Lietuvoje registruotų mėlynių uogų preparatų pasiūlą. Atlikti šių preparatų palyginamąją analizę vertinant sudėtis. Pasirinktuose preparatuose nustatyti fenolinių junginių ir antocianinų kiekį spektrofotometriniu metodu. Nustatyti pasirinktų preparatų antioksidacinį aktyvumą DPPH metodu. Tyrimo objektai ir metodai: Preparatai su mėlynių uogų ekstraktu ir mėlynių uogų milteliais. Spektrofotometrinis metodas naudotas analizei: bendras fenolinių junginių kiekis – pagal Galo rūgšties kalibracinę kreivę; bendras antocianinų kiekis – pH diferenciniu metodu; antioksidacinis aktyvumas – DPPH laisvojo radikalo inaktyvavimo kreivė. Tyrimo rezultatai ir išvados: Iki 2013 m. birželio mėn. nustatyti 47 Lietuvoje registruoti mėlynių uogų preparatai. Į 97 proc. šių preparatų sudėtį įeinančių mėlynių uogų žaliavos forma – ekstraktas. 19 proc. visų tirtųjų sudaro kompleksiniai ir 9 proc. vienkomponenčiai preparatai. Spektrofotometriškai nustačius fenolinius junginius, didžiausias jų kiekis yra ,,Mėlynių ekstraktas“, kapsulėse (,,Vitaforce“, Jungtinė Karalystė), mažiausias - ,,Visioblue strong“, kapsulėse (,,Hankintatukku Oy“, Suomija). Preparatas ,,Mėlynių uogų ekstrakto tabletės su cinku forte 0,25 g”, („Elit-farm", Ukraina) eksperimentinio tyrimo metu nedavė apčiuopiamo rezultato... [toliau žr. visą tekstą] / Purpose of the work: To make the comparable ingredients and technology analysis of selected blueberry preparations registered in Lithuania, evaluate quantitatively and determine the antioxidant activity. Tasks: to investigate the supply of blueberry preparations registered in Lithuania. To make the comparable ingredients analysis of preparations mentioned above. Determine the phenolic compounds and anthocyanins quantity using the spectrophotometry method. Measure the antioxidant activity of selected preparation using DPPH method. Research objects and methodology: Preparations with blueberry extract and blueberry powder. Spectrophotometric methods were used for analysis: total phenolic content according calibration curve of galic acid; total anthocyanins - pH differential method; antioxidant activity - DPPH free radical inhibition. Results and conclusions: Until June, 2013 y. Lithuania set 47 record Blueberry fruit preparations. There was noticed that in 97 percent composition of the preparation, blueberry raw material shape - extract. 91 percent of explored preparations are multicomponent and just 9 percent - one-component. Determined by spectrophotometry, that the highest levels of the phenolic compounds are in ”Mėlynių ekstraktas“, capsules of (“Vitaforce”, United Kingdom) and the lowest – “Visioblue strong’’, capsules of (”Hankintatukku Oy’’, Finland). The quantity of Anthocyanins per recommended daily dose in the preparation was studied by spectrophotometry method. The... [to full text]

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