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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.
21

MINIMUM INHIBITORY CONCENTRATIONS OF TWO COMMON FOOD PHENOLIC COMPOUNDS AND THEIR EFFECT ON THE MICROBIAL ECOLOGY OF SWINE FECES IN VITRO

Zaffarano, Jennifer I. 01 January 2003 (has links)
Feeding sub-therapeutic levels of antibiotics to livestock has been associated withdevelopment and spread of antibiotic resistant bacteria. The present experiment was conductedto investigate the effect of antibiotic alternatives (caffeic acid, chlorogenic acid, and carbadox)on the microbial ecology of swine feces in vitro.Minimum inhibitory concentrations of caffeic and chlorogenic acids were determined forseveral pathogens using macrobroth and agar dilution techniques. Gram-negative bacteria werenot inhibited. Caffeic acid inhibited four Staphylococcus aureus strains at 200 ppm or less, andtwo Clostridium perfringens strains at 300 ppm. Chlorogenic acid inhibited all S. aureus strainsat 500 ppm, and one C. perfringens strain at 400 ppm.Effects of antibiotic alternatives on fecal microbial ecology were determined using an invitro incubation. Caffeic acid lowered total anaerobes, Bifidobacteria, Escherichia coli, andpercent E. coli (pandlt;0.01). Chlorogenic acid lowered total anaerobes, Bifidobacteria, andlactobacilli (pandlt;0.01), and increased acetate concentration (pandlt;0.0001). Carbadox lowered totalanaerobes, Bifidobacteria, E. coli, and coliforms (pandlt;0.01), and lowered acetate, propionate,butyrate, valerate, and total volatile fatty acid concentrations (pandlt;0.01). It can be concluded thataddition of caffeic acid, chlorogenic acid, or carbadox effected bacterial and chemicalcomponents of the microbial ecology of swine feces.
22

Pretreatment and enzyme hydrolysis of canola meal (Brassica napus L.) and oriental mustard bran (Brassica juncea): production of functional oligosaccharides and impact on phenolic content

Yuan, Lin 19 April 2014 (has links)
Canola meal (Brassica napus L.) and oriental mustard bran (Brassica juncea) were subjected to alkali and acid pretreatment to expose pentosan, for enhancing further enzymatic hydrolysis by endo-1,4-β-xylanase from Trichoderma longibrachiatum for the production of oligosaccharides. Pretreatment especially with alkali, effectively increased the relative content of pentosan to about ~ 41% and ~ 72%. Alkali pretreated canola meal and mustard bran resulted in a pentose content of 2.28 ± 0.15 g and 3.20 ± 0.11 g per 100 g substrates at 18 h and 24 h of reaction respectively, which corresponded to ~ 26% and ~ 28% conversion of original pentosan in substrates. UPLC-MS data showed xyloglucuronic acid (XGlcA) as the major oligosaccharide in the hydrolyzates. Reversed-phase HPLC-DAD indicated the principal phenolic compound in the hydrolyzates was sinapine. DPPH radical scavenging assay showed that endoxylananse hydrolyzates of acid pretreated substrates had strong antioxidant activities in comparison to alkali pretreated samples.
23

Phenolic profile and carbohydrate digestibility of durum spaghetti enriched with buckwheat flour and bran

Biney, Kuuku 09 September 2013 (has links)
There is growing demand for functional foods and ingredients as a result of their health-promoting properties. In this work, the potential of common buckwheat flour (Supreme) and bran (Farinetta) in improving upon the phenolic and antioxidant properties of durum spaghetti was investigated. The effects of processing and cooking on these properties were also studied in addition to the cooking quality and carbohydrate digestibility of spaghetti products. Among uncooked spaghetti samples, there were huge increments of between 114 and 522% for TPC, 50 and 242% for TFC, 359 and 1000% for DPPH antioxidant activity, and 101 and 197% for ORAC values of the experimental spaghetti samples over the control. Farinetta contributed more phenolic and antioxidant compounds than Supreme flour. Processing resulted in losses ranging from 1.2 to 33.7% in TFC and 42.0 to 55.3% in DPPH antioxidant activity. Cooking also resulted in significant losses (p < 0.05) of up to 39% in TPC, 40% in DPPH antioxidant activity, 22% in rutin content, and 55% in TFC in experimental samples. Cooking losses of up to 8.82% were recorded for the experimental samples and were higher in Farinetta-substituted products. These were generally higher than that of the control (6.33%). The introduction of buckwheat increased carbohydrate digestibility of products, but at the same time resulted in an overall lower release of reducing sugars after of 120 min of in vitro hydrolysis. Results show that the phenolic and antioxidant properties of durum spaghetti fortified with buckwheat milling fractions can compare favourably with those of 100% whole buckwheat pasta, and at the same time, maintain a higher cooking quality due to the presence of semolina.
24

Functional food-related bioactive compounds: effect of sorghum phenolics on cancer cells in vivo and conversion of short- to long-chain omega-3 polyunsaturated fatty acids in duck liver in vivo

Chen, Xi January 1900 (has links)
Doctor of Philosophy / Department of Human Nutrition / Weiqun Wang / Many functional food related bioactive compounds have been discovered and draw the attention of scientists. This dissertation focused on sorghum phenolic compounds and omega-3 polyunsaturated fatty acids. Study 1: phenolic agents in plant foods have been associated with chronic disease prevention, especially cancer. However, a direct evidence and the underlying mechanisms are mostly unknown. This study selected 13 sorghum accessions and was aim to investigate: (1) the effect of extracted sorghum phenolics on inhibiting cancer cell growth using hepatocarcinoma HepG2 and colorectal adenocarcinoma Caco-2 cell lines; (2) and the underlying mechanisms regarding cytotoxicity, cell cycle interruption, and apoptosis induction. Treatment of HepG2 and Caco-2 cells with the extracted phenolics at 0-200 M GAE (Gallic acid equivalent) up to 72 hrs resulted in a dose- and time-dependent reduction in cell number. The underlying mechanism of cell growth inhibition was examined by flow cytometry, significant inverse correlations were observed between the decreased cell number and increased cell cycle arrest at G2/M or induced apoptosis cells in both HepG2 and Caco-2 cells. The cytotoxic assay showed that the sorghum phenolic extracts were non-toxic. Although it was less sensitive, a similar inhibitory impact and underlying mechanisms were found in Caco-2 cells. These results indicated for the 1st time that a direct inhibition of either HepG2 or Caco-2 cell growth by phenolic extracts from13 selected sorghum accessions was due to cytostatic and apoptotic but not cytotoxic mechanisms. In addition, these findings suggested that sorghum be a valuable functional food by providing sustainable phenolics for potential cancer prevention. Study 2: omega-3 polyunsaturated fatty acids (ω-3 PUFAs) especially long-chain ω-3 PUFAs, have been associated with potential health benefits in chronic disease prevention. However, the conversion rate from short- to long-chain ω-3 PUFAs is limited in human body. This study was aim to assess the modification of fatty acid profiles as well as investigate the conversion of short- to long-chain ω-3 PUFAs in the liver of Shan Partridge duck after feeding various dietary fats. The experimental diets substituted the basal diet by 2% of flaxseed oil, rapeseed oil, beef tallow, or fish oil, respectively. As expected, the total ω-3 fatty acids and the ratio of total ω-3/ ω-6 significantly increased in both flaxseed and fish oil groups when compared with the control diet. No significant change of total saturated fatty acids or ω-3 fatty acids was found in both rapeseed and beef tallow groups. Short-chain ω-3 α-linolenic acid (ALA) in flaxseed oil-fed group was efficiently converted to long-chain ω-3 docosahexaenoic acid (DHA) in the duck liver. This study showed the fatty acid profiling in the duck liver after various dietary fat consumption, provided insight into a dose response change of ω-3 fatty acids, indicated an efficient conversion of short- to long-chain ω-3 fatty acid, and suggested alternative long-chain ω-3 fatty acid-enriched duck products for human health benefits. In conclusion, the two studies in this dissertation provided a fundamental understanding of anti-cancer activity by sorghum phenolic extracts and the conversion of short- to long-chain ω-3 PUFAs in duck liver, contribute to a long term goal of promoting sorghum and duck as sustainable phenolic and ω-3 PUFAs sources as well as healthy food products for human beings.
25

Estudo da mutagenicidade de metabólitos secundários liquênicos, utilizando o teste smart e ensaio cometa em células somáticas de Drosophila melanogaster

AMORIM, Érima Maria de 23 February 2016 (has links)
Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-08-02T18:27:23Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação ÉRIMA.pdf: 1439027 bytes, checksum: fdf84cb299bbcf04b46e42fe907f5130 (MD5) / Made available in DSpace on 2016-08-02T18:27:23Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação ÉRIMA.pdf: 1439027 bytes, checksum: fdf84cb299bbcf04b46e42fe907f5130 (MD5) Previous issue date: 2016-02-23 / Capes / Liquens, organismos simbiontes notáveis, produzem metabólitos secundários amplamente citados por suas atividades biológicas. Entretanto, pouco se sabe a respeito do potencial tóxico ao DNA destes fenóis. Este trabalho avaliou o perfil mutagênico e genotóxico dos ácidos úsnico e divaricático, através do teste de Mutação e Recombinação Somática (SMART) e ensaio Cometa, utilizando Drosophila melanogaster como modelo experimental. Organismos descendentes dos cruzamentos entre as linhagens de D. melanogaster mwh e flr3, foram submetidos a diferentes concentrações do ácido úsnico (0,63, 1,26, 2,53, 5,05 e 10,11 mg/mL) e do ácido divaricático (0,32, 0,63, 1,26, 2,53, 5,05 e 10,11 mg/mL). Os resultados foram comparados com o controle positivo, mitomicina a 1,0 mg/mL e negativo, solventes de diluição. Os ensaios cometa foram realizados em hemócitos de D. melanogaster, linhagem Oregon-R. As células foram expostas às doses 0,63, 1,26, 2,53, 5,05 e 10,11 mg/mL do ácido úsnico e 0,32, 0,63, 1,26, 2,53 mg/mL do ácido divaricático. Os resultados foram comparados aos controles positivo de ciclofosfamida à 1mg/mL e negativo, mistura dos solventes. No ensaio de antigenotóxicidade foram utilizadas as mesmas concentrações de ácido úsnico acrescidas de mitomicina a 1mg/mL. Os resultados mostraram que as larvadas submetidas o ácido úsnico no teste SMART apresentaram uma sobrevivência superior a 70% dos indivíduos demonstrando, com níveis não significativos de genotoxicidade. Resultado semelhante ao ensaio Cometa. O ácido úsnico apresentou redução da mutagenicidade, em todas as concentrações quando associado à mitomicina, caracterizando efeito antigenotóxico. O ácido divaricático, no teste SMART, apresentou efeito tóxico nas concentrações 5,05 e 10,11 mg/mL e efeito genotóxico no ensaio cometa nas doses 0,32, 0,63, 1,26, 2,53. / Lichens are notable symbiontic organisms. They can produce phenolic compounds widely described because its biological properties. However a little bit is known about the mutagenic and genotoxic potential of these molecules. This study evaluated the mutagenic and genotoxic profile of the usnic and divaricatic acids through the Somatic Mutation and Recombination test (SMART) and the comet assay using the Drosophila melanogaster as experimental model. Organisms descendants of the crossing between strains of D. melanogaster mwh and flr3 were submitted to different concentrations of usnic (0,63, 1,26, 2,53, 5,05 and 10,11 mg/mL) and divaricatic acid (0,32, 0,63, 1,26, 2,53, 5,05 and 10,11 mg/mL). The results were obtained by comparation with the positive and negative standards, mitomicine (1,0 mg/mL) and the dilution solvent respectively. The comet assay were realized using hemocites of D. melanogaster from the Oregon – R strain. The cells were exposed to the different concentrations of the usnic and divaricatic acids. The results were obtained byu comparation with the positive and negative standards, cyclophosphamide (1,0 mg/mL) and the dilution solvent. The antigenotoxicity assay used the same concentrations of the usnic acid with the addition of the mitomicyn (1,0 mg/mL). The results demonstrated that the larvae submitted to usnic acid exhibit a higher survival rate of 70%, with no significant levels of genotoxicity. The same result was observed to the comet assay. The usnic acid showed a significant reduction of the mutagenicity in all the tested concentrations with the addition of mitomicyn characterizing an antigenotoxic effect. The divaricatic acid in the SMART test showed a toxic effect at the concentrations of 5,05 and 10,11 mg/mL and a genotoxic effect ant the concentrations of 0,32, 0,63, 1,26, 2,53 mg/mL.
26

Constituintes polifenolicos e propriedades antioxidantes da polpa do fruto da palmeira Juçara (Euterpe edulis) / Polyphenolic Constituents and antioxidant properties of the Juçara Palmtree (Euterpe edulis) fruit pul

Arce Saavedra, Thony 29 July 2008 (has links)
Orientador: Jaime Amaya-Farfan / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-11T09:09:32Z (GMT). No. of bitstreams: 1 ArceSaavedra_Thony_M.pdf: 919411 bytes, checksum: bf66a4e887ab85861d6e11dc7fc25ff8 (MD5) Previous issue date: 2008 / Resumo: Introdução. Inúmeras pesquisas têm demonstrado a importância para a saúde de um enorme conjunto de substâncias fitoquímicas contidas nos alimentos, incluindo os polifenóis, que se destacam pelas propriedades antioxidantes e moduladoras do metabolismo. O fruto da palmeira juçara (Euterpe edulis Mart.) que possui grande similaridade composicional e sensorial com o açaí, tem sido apontado como uma fonte de macronutrientes e uma das mais ricas fontes de substâncias fenólicas, capaz de competir nutricional e comercialmente com um produto que se tornou quase um símbolo brasileiro. Objetivo. Determinar a composição polifenólica e avaliar a capacidade antioxidante da polpa integral do fruto da juçara. Métodos. A composição polifenólica foi determinada mediante a técnica de fracionamento por extração em fase sólida (SPE) e espectrometria de massas, nos modos MS e MS-MS. Para a atividade antioxidante in vitro foram utilizados os métodos de radicais livres, baseados no descoramento de uma solução composta de radicais estáveis, ácido 2,2-azino-bis (3-etilbenzotiazolin)-6-sulfónico (ABTS) e 2,2-difenil-1-picrilhidrazila (DPPH), utilizando três padrões analíticos em cada sistema. Resultados. Treze antocianinas e doze outros compostos, entre ácidos fenólicos e outros flavonóides, foram identificados. O extrato metanólico da polpa fresca integral, e a fração antociânica, apresentaram expressiva capacidade antioxidante in vitro. Conclusão: A polpa integral do fruto da juçara mostrou ser uma rica fonte de substâncias polifenólicas, apresentando maior poder antioxidante que o já conhecido para o açaí / Abstract: Introduction. A large number of studies have pointed out the importance for human health of an enormous variety of phytochemicals occurring in foods because of their role as antioxidants and metabolic signalers. The fruit of the palmtree jussara (Euterpe edulis Mart.) shares both compositional and sensory properties with assai (Euterpe oleraceae Mart.), and has been recently recognized as being a rich source of macronutrients and phenolic substances. This fruit is capable of nutritionally and commercially competing with assai, one of the Amazonian products that has become almost a symbol of Brazil. Objective. To determine the polyphenolic composition and the antioxidant capacity of the whole extract of the jussara fruit pulp. Methods. The polyphenolic composition was determined by a combination of solid phase fractionation and mass spectrometry in the MS and MS/MS modes. For the antioxidant capacity, in vitro tests were employed based on the bleaching of colored solutions containing the stable free radicals, 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) and three different analytical standards in each system. Results. Thirteen anthocyanins and twelve other compounds, including phenolic acids and flavonoids, were identified. The methanolic extract of the whole, fresh pulp, and the anthocyanin fraction, exhibited substantial in-vitro antioxidant capacities. Conclusion. The fresh jussara palmtree fruit showed to be a rich source of polyphenols and to possess greater antioxidant capacity than that already known for assai / Mestrado / Consumo e Qualidade de Alimentos / Mestre em Alimentos e Nutrição
27

\"Compostos fenólicos em madeiras brasileiras\" / \"Phenolics compounds in brazilian woods\"

Alexandre Ataide da Silva 24 November 2006 (has links)
A maturação em tonéis de carvalho é uma prática importante amplamente empregada na produção de uma bebida de alta qualidade. Porém, apesar da biodiversidade no Brasil, o envelhecimento da cachaça em tonéis de madeira não é uma prática comum. Os tonéis de carvalho são usualmente mais empregados para o processo de maturação da cachaça. Estes tonéis foram usados previamente por produtores para maturação de vinho, conhaque, e envelhecimento de whisky na Europa e América do Norte. Os apontamentos de alternativa para o carvalho apresentados neste trabalho reportam o perfil fenólico dos extratos de cachaça de espécies de madeira brasileiras em comparação com o carvalho. O método de HPLC foi usado para a análise simultânea de 16 compostos fenólicos de relevância para o sabor e aroma de bebidas envelhecidas. As separações cromatográficas foram realizadas usando uma coluna Shimadzu de C18 (2 mm x 3&#956;m x 250 mm) com gradiente de eluição. As eluições dos compostos foram monitoradas em seu máximo de absorção especifico através de um espectrofotômetro de arranjo de diodo com exceção de catequina e epicatequina, as quais foram monitoradas usando um detector espectrofluorométrico com emissão fixada a 280 nm e excitação a 313 nm. Os 16 compostos fenólicos seguintes foram analisados: (ácido gálico, (+)catequina, ácido vanílico, vanilina, (-)epicatequina, ácido seríngico, seringaldeído, escopoletina, cumarina, sinapaldeído, coniferaldeído, trans-resveratrol, ácido elágico, mirecetina, quercetina e o eugenol) em extratos de cachaça de diferentes espécies de madeira. Os principais compostos fenólicos identificados e quantificados foram: ácido de vanílico (média 0.18 mg/L), seringaldeído (média 0.048 mg/L) e vanilina (média 0.47 mg/L). A cumarina apresenta maior concentração nos extratos de madeira brasileira do que nos extratos de carvalho nos níveis do composto supracitado. Nas amostras de carvalho o teor médio foi de 0,0054 mg/L e nas espécies de madeira brasileiras o teor médio foi de 1,2 mg/L. Também foi analisada a presença de compostos fenólicos em cachaça, rum e whisky onde o seringaldeído e a vanilina foram os compostos majoritários. / Maturation in oak barrels is an important widely spread pratice in the production of a high quality spirit. However, despite the biodiversity in Brazil, the cachaça aging in wodden barrels is not a commun pratice. The use mostly imported oak barrels for the cachaça maturation process. This producers barrel had been usual maturation previously for wine, cognac, and whisky aging in Europe and North America. The aiming to present alternative to oak the present work report the phenolics profile of cachaça extracts of Brazilian wood species in comparation with oak. A HPLC method was used for the simultaneous analysis of 16 phenolic compounds of importance for the flavor and aroma of aged spirits. The chromatographic separations were carried out using a Shimadzu C18 column (2 mm x 3&#956;m x 250 mm) with for elution gradient. The eluting compounds were monitored at their specific maximum of absorption through a diode array spectrophotometric detector with exception of catechin and epicatechin which were probed using a spectrofluorometric detector with emission set at 280 nm and excitation at 313 nm. Follow 16 phenolics compounds have been analisys: ( gallic acid, (+)cathechin, vanillic acid, vanilin, (-)epicathechin, seringic acid, seringaldehyde, escopoletin, coumarin, sinapaldehyde, coniferaldehyde, trans-resveratrol, ellagic acid, mirecetin, quercetin and the eugenol) in cachaça extracts of different wood species. The major phenolic compounds identified and quantified are vanillc acid (medium 0.18 mg/L), seringaldehyde (medium 0.048 mg/L) and vanillin (medium 0.47 mg/L). The coumarin is on higher concentration in Brazilian wood extract then in oak the levels of the supracited compounds. In oak samples with medium values of 0.0054 mg/L and 1.2 mg/L for oak and Brazilian wood species respectively. Furthemore, the presence of phenolics were Abstract IQSC-USP iv investiged in cachaça, rum, and whisky revealing seringaldehyde and vanillin as the major components.
28

Desenvolvimento e validação de método para a extração e quantificação de compostos fenólicos em sedimento. Estudo de caso: Reservatório Guarapiranga, SP / Development and validation method for extraction and quantification of phenolics compounds in sediment. Case study: Reservoir Guarapiranga, SP

Gisele Adame 16 September 2016 (has links)
Compostos fenólicos vêm despertando preocupação nos últimos anos e incitando grande atenção em todo o mundo ao desenvolvimento de métodos de determinação e monitoramento contínuo no ambiente devido a sua elevada toxicidade e persistência no meio ambiente, principalmente no sedimento, que devido sua característica em acumular compostos faz desse um dos compartimentos mais importantes na avaliação do nível de contaminação de ecossistemas aquáticos continentais. Neste estudo foi desenvolvido um método analítico utilizando cromatografia a gás acoplada ao detector de espectrometria de massas (GC/MS) para a determinação de seis compostos fenólicos e foi avaliada a presença dos mesmos em amostras de sedimento do Reservatório Guarapiranga, um reservatório de usos múltiplos da água, destinado principalmente para abastecimento público de água potável da Região Metropolitana de São Paulo. Para garantir a reprodutibilidade do método de forma confiável atendendo aos objetivos e qualidade propostos, a metodologia desenvolvida foi submetida ao processo de validação, em que os parâmetros seletividade, linearidade, faixa de trabalho, limite de detecção, limite de quantificação, tendência/recuperação, precisão (repetitividade, precisão intermediária e reprodutibilidade) e robustez foram avaliados. A metodologia aqui proposta mostrou ser adequada para alcançar o objetivo de avaliar os compostos em estudo, e pela sua aplicação foi constatada a presença dos compostos fenol e 3-metilfenol no sedimento do reservatório. Nas amostras de sedimento coletadas em 2011, o fenol foi o composto encontrado com maior frequência, com alguns resultados acima do LQ, principalmente em pontos com maior influência urbana, em concentrações de 0,09 a 0,19 &mu;g g-1. Também foi encontrado o 3-metilfenol com resultados acima do LQ em dois pontos de coleta, G-11 e G-13, nas concentrações de 0,10 e 0,19 &mu;g g-1 respectivamente. Já na coleta realizada em outubro de 2014, o composto 3-metilfenol foi quantificado em dois pontos de coleta, G-02 e G-07, nas concentrações de 0,07 e 0,08 &mu;g g-1 respectivamente, sendo detectado abaixo do LQ em diversos pontos ao longo do reservatório. A presença destes compostos mesmo em baixas concentrações pode indicar uma contaminação decorrente de atividades industriais nas margens do reservatório e considerando-se que os compostos em sedimento com o tempo podem ser liberados na coluna dágua e causar contaminação na água de abastecimento este estudo fornece subsídios para revisão da legislação vigente que não estabelece limites para os compostos fenólicos na matriz de estudo. / Phenolic compounds are molecules with increased toxicity and persistence in the environment, mainly in the sediment. Furthermore, these molecules are capable of accumulate compounds, making them one of the most important at the evaluation of the contamination level on aquatic ecosystems in the continent. These features increased the preoccupation in the last years, inciting great attention around the globe about the development of methods to determine and continuously monitor these compounds in the environment. In this study, a new analytical methodology was developed using gas chromatography mass spectrometry system (GC/MS) at the determination and evaluation of six phenolic compounds in sediment samples of the Guarapiranga Reservoir, a water reservatory with multiple uses, intended primarily for public drinking water supply in the Metropolitan Region of São Paulo, Brazil. This methodology was submitted to the validation process, to ensure the reproducibility of the method in a trustworthy way, according to the objectives and quality proposed. Selectivity, linearity, working range, detection limit, quantification limit, trend/recovery, precision (repeatability, intermediate precision and reproducibility) and robustness are the parameters evaluated in this process. This methodology revealed itself adequate to achieve the goal of evaluating the compounds studied. Through this method, it was verified that the compounds phenol and 3-methylphenol are present at the reservoir´s sediment. In sediment samples collected in 2011, phenol was the compound found most frequently, with some results above LQ, especially on points with greater urban influence, in concentrations from 0.09 to 0.19 &mu;g g-1. It was also found 3-methylphenol with results above LQ on two collected points, G-11 and G-13 at concentrations of 0.10 and 0.19 &mu;g g-1 respectively. In 2014, the 3-methyl phenol compound was quantified in two collected points, G-02 and G-07 at concentrations of 0.07 and 0.08 &mu;g g-1 respectively, being detected below the LQ at various points along the reservoir. The presence of these compounds, even in low concentrations, can indicate a contamination from industrial activities at the reservoir margin. Considering that these compounds in the sediment can, with time, be released in the water column and contaminate the water supply, this study provides subsidies for a review of the current legislation, that do not sets limits to the concentration of phenolic compounds on sediment matrix.
29

Atividade antioxidante, caracterização química e botânica de mel amargo proveniente do município do Cantá-RR

Iolete do Nascimento Araújo Maciel 08 October 2013 (has links)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / No município do Cantá-RR a produção de mel amargo é atribuída pelos apicultores da região ao período de floração das plantas do gênero Vochysia. Esta pesquisa tem como objetivo investigar a existência de marcadores químicos que possam confirmar a origem botânica deste mel, bem como verificar sua composição química e atividade antioxidante. Para tanto, foram elaborados extratos de mel amargo por XAD-2, C18, líquido-líquido e mel bruto liofilizado. Para comparação da constituição foram obtidos também os extratos etanólicos das flores sem anteras e das anteras das flores (ricos em pólen). Os extratos de mel por XAD-2 e etanólicos das flores foram fracionados, sendo obtidos extratos hexânico, clorofórmico, acetato de etila e metanólico. Análises por espectrometria de massas foram realizadas com os diversos extratos e verificou-se uma grande semelhança entre os espectros. Por meio de padrões autênticos, foram identificados a crisina e o ácido cafeico nos extratos do mel amargo. Nas análises dos extratos hexânicos, por meio de cromatografia a gás acoplada à espectrometria de massas (CG-EM), foram identificados diversos n-alcanos e n-alcenos com tempos de retenção e índices de retenção idênticos no mel e nas flores. Para determinar a posição da dupla ligação realizou-se uma derivatização com dimetildissulfeto. Os n-alcenos semelhantes nos extratos do mel e das flores apresentaram insaturação na posição 1. Análises espectrofotométricas foram realizadas para quantificar os compostos fenólicos e foram obtidos 94,64 mg ácido gálico/100g de mel e os flavonoides com 86,23 g quercetina/100g de mel. O mel apresentou uma coloração branca, com base na escala de Pfund e a atividade antioxidante, um IC50 de 16,94 mg/mL, determinado por meio do método do DPPH. Este trabalho permitiu confirmar a origem botânica do mel obtida por melissopalinologia e por dados químicos, além de caracterizar quimicamente o mel através da quantificação de algumas classes de produtos naturais e sua atividade antioxidante. / The bitter honey production in the city of Cantá-RR has been attribute by beekeepers in the region to the period of flowering plants of the genus Vochysia. This research aims to investigate the existence of chemical markers that can confirm the botanical origin of the honey, as well as verify their chemical composition and antioxidant activity. Thus, we prepared extracts of bitter honey by XAD-2, C18, liquid-liquid (dichloromethane) and lyophilized honey. For comparison of the constitution were also obtained the extracts ethanol of the flowers without anthers and of the anthers of the flowers, rich in pollen. The extracts of honey XAD-2 and ethanol flowers were fractionated, obtaining extracts with hexane, chloroform, ethyl acetate and methanol. Mass spectrometric analyzes were performed with the different extracts and there was a great similarity between the spectra. By using authentic standards, chrysin and caffeic acid were identified in the extracts of bitter honey. In hexanic extract analyzes, through gas chromatography coupled to mass spectrometry (GC-MS), several n-alkanes and n- alkenes were identified with times of retention and identical retention index in the honey and in the flowers. To determine the position of the double bond, a derivatization with dimethuldisulfide was performed. The similar n-alkenes in extracts of honey and flowers presented unsaturation at position 1. Spectrophotometric analyses were performed to quantify the phenolic compounds getting to result of 94,64 mg of gallic acid /100 g of honey and flavonoids with 86,23 g/100g honey. The honey presented a white coloration, based on the Pfund scale and antioxidant activity one IC50 of 16,94 mg / mL,determined by means of the DPPH method. This work confirmed the botanical origin of honey obtained by melissopalynology and chemical data, and also contributed to the chemical characterization of the honey through quantification of some classes of natural products and their antioxidant activity.
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Studium vybraných aktivních látek v českém pivu / Study some active substances in Czech beer

Pařilová, Kateřina January 2009 (has links)
The aim of this work was to study phenolics and other active compounds in 22 kinds of lager beer and especially to find some differences between Czech beer and beers made in foreign countries. In theoretical part the most useful methods for phenolic and protein analysis are discussed. Further, basic steps of brewery technology are introduced and main beer components with regard to Czech beer specificity are presented. Analysis of total phenolics, total flavonoids, antioxidant activity and most of basic technological characteristics was performed spectrophotometrically. To identification and quantitative analysis of individual phenolics on-line liquid chromatography with photo-diode array (PDA) and mass spectrometry (MS) detection was used. Protein analysis was performed by vertical electrophoresis SDS-PAGE and by Experion microfluidic electrophoresis (BioRad). From the total of 22 samples, 15 Czech beers and 7 beers of foreign marks were enrolled into this study. In these samples levels of brewery characteristics, group antioxidants and individual phenolics were compared. Flask and can beers as well as alcoholic and non-alcoholic beers were compared too. As a model comparative sample the Czech hop of Sládek variety was used. Finally, usefulness of tested parameters to differentiation composition and technology of individual beer samples was evaluated and parameters suitable for Czech beer authenticity analysis were proposed.

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