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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.
1

Análise de ácido clorogênico em amostras de pêssego - Prunus persica (l.) Batsch : otimização e validação de método / Chlorogenic acid analysis in peach – Prunus persica (L.) Batsch : method optimization and validation

Souza Júnior, Dimas Henrique January 2007 (has links)
O pêssego é o nome popular do fruto produzido por Prunus persica (L.) Batsch, e é amplamente cultivado na região sul do Brasil. Seu cultivo é economicamente muito importante para o local, e o desenvolvimento de técnicas que garantam o controle de qualidade desta matéria-prima e seus produtos industriais são interessantes. No presente trabalho foi feita uma revisão de literatura acerca de análises realizadas por CLAE-UV com o pêssego, realizada uma otimização das técnicas de extração do ácido clorogênico e do sistema cromatográfico, validado este método e utilizado para quantificar 13 diferentes cultivares de pêssegos fornecidos pela EMBRAPA Clima Temperado, cultivados em Pelotas, RS. O resultado é um método rápido, econômico e prático que foi otimizado e validado, excelente para análises rotineiras de controle de qualidade deste material. As quantidades de ácido clorogênico foram comparadas entre si, e identificou-se que as cultivares Morro Redondo e Sunblaze apresentaram os maiores teores desta substância, sendo promissoras para serem empregadas pela indústria como alimento funcional. / Peach is the common name of the fruit produced by Prunus persica (L.) Batsch, widely cultivated in the southern of Brazil. Its cultivation is economically important to the local market, and the development of techniques that assure the quality control of the raw material as well as the industrial products made of this fruit are very useful. In this work, a literature review of the HPLC-UV analysis of peach was done, a technique of extraction and chromatographic system were optimized and validated, and 13 cultivar varieties supplied by EMBRAPA Clima Temperado, grown in Pelotas, RS were analyzed. The result is an optimized and validated method of HPLC-UV to quantify chlorogenic acid in peaches, excellent for routine analysis. The average amount of this phenolic compound in the selected cultivars was quantified and compared among them. It was identified that Morro Rendondo and Sunblaze varieties presents the highest amounts of this substance, and both are promising cultivars to be explored by the industry as functional food.
2

Análise de ácido clorogênico em amostras de pêssego - Prunus persica (l.) Batsch : otimização e validação de método / Chlorogenic acid analysis in peach – Prunus persica (L.) Batsch : method optimization and validation

Souza Júnior, Dimas Henrique January 2007 (has links)
O pêssego é o nome popular do fruto produzido por Prunus persica (L.) Batsch, e é amplamente cultivado na região sul do Brasil. Seu cultivo é economicamente muito importante para o local, e o desenvolvimento de técnicas que garantam o controle de qualidade desta matéria-prima e seus produtos industriais são interessantes. No presente trabalho foi feita uma revisão de literatura acerca de análises realizadas por CLAE-UV com o pêssego, realizada uma otimização das técnicas de extração do ácido clorogênico e do sistema cromatográfico, validado este método e utilizado para quantificar 13 diferentes cultivares de pêssegos fornecidos pela EMBRAPA Clima Temperado, cultivados em Pelotas, RS. O resultado é um método rápido, econômico e prático que foi otimizado e validado, excelente para análises rotineiras de controle de qualidade deste material. As quantidades de ácido clorogênico foram comparadas entre si, e identificou-se que as cultivares Morro Redondo e Sunblaze apresentaram os maiores teores desta substância, sendo promissoras para serem empregadas pela indústria como alimento funcional. / Peach is the common name of the fruit produced by Prunus persica (L.) Batsch, widely cultivated in the southern of Brazil. Its cultivation is economically important to the local market, and the development of techniques that assure the quality control of the raw material as well as the industrial products made of this fruit are very useful. In this work, a literature review of the HPLC-UV analysis of peach was done, a technique of extraction and chromatographic system were optimized and validated, and 13 cultivar varieties supplied by EMBRAPA Clima Temperado, grown in Pelotas, RS were analyzed. The result is an optimized and validated method of HPLC-UV to quantify chlorogenic acid in peaches, excellent for routine analysis. The average amount of this phenolic compound in the selected cultivars was quantified and compared among them. It was identified that Morro Rendondo and Sunblaze varieties presents the highest amounts of this substance, and both are promising cultivars to be explored by the industry as functional food.
3

Análise de ácido clorogênico em amostras de pêssego - Prunus persica (l.) Batsch : otimização e validação de método / Chlorogenic acid analysis in peach – Prunus persica (L.) Batsch : method optimization and validation

Souza Júnior, Dimas Henrique January 2007 (has links)
O pêssego é o nome popular do fruto produzido por Prunus persica (L.) Batsch, e é amplamente cultivado na região sul do Brasil. Seu cultivo é economicamente muito importante para o local, e o desenvolvimento de técnicas que garantam o controle de qualidade desta matéria-prima e seus produtos industriais são interessantes. No presente trabalho foi feita uma revisão de literatura acerca de análises realizadas por CLAE-UV com o pêssego, realizada uma otimização das técnicas de extração do ácido clorogênico e do sistema cromatográfico, validado este método e utilizado para quantificar 13 diferentes cultivares de pêssegos fornecidos pela EMBRAPA Clima Temperado, cultivados em Pelotas, RS. O resultado é um método rápido, econômico e prático que foi otimizado e validado, excelente para análises rotineiras de controle de qualidade deste material. As quantidades de ácido clorogênico foram comparadas entre si, e identificou-se que as cultivares Morro Redondo e Sunblaze apresentaram os maiores teores desta substância, sendo promissoras para serem empregadas pela indústria como alimento funcional. / Peach is the common name of the fruit produced by Prunus persica (L.) Batsch, widely cultivated in the southern of Brazil. Its cultivation is economically important to the local market, and the development of techniques that assure the quality control of the raw material as well as the industrial products made of this fruit are very useful. In this work, a literature review of the HPLC-UV analysis of peach was done, a technique of extraction and chromatographic system were optimized and validated, and 13 cultivar varieties supplied by EMBRAPA Clima Temperado, grown in Pelotas, RS were analyzed. The result is an optimized and validated method of HPLC-UV to quantify chlorogenic acid in peaches, excellent for routine analysis. The average amount of this phenolic compound in the selected cultivars was quantified and compared among them. It was identified that Morro Rendondo and Sunblaze varieties presents the highest amounts of this substance, and both are promising cultivars to be explored by the industry as functional food.
4

Ecodynamique des composés poly- et perfluoroalkylés dans les écosystèmes aquatiques / Environmental fate of poly- and perfluoroalkyl compounds in aquatic ecosystems

Munoz, Gabriel 16 December 2015 (has links)
Les tensioactifs poly- et perfluoroalkylés (PFAS) sont des composés d’origine anthropique produits à partir des années 1950 et qui sont désormais considérés comme des polluants ubiquistes. La première partie de ce travail a consisté à optimiser et valider des procédures pour l’analyse ultra-trace des PFAS. Ces méthodes ont ensuite été utilisées afin d’apporter de nouveaux éléments de réponse sur l’occurrence et la dynamique des PFAS dans les environnements aquatiques. Une attention particulière a été accordée aux valeurs censurées (<LD). Dans les eaux de surface et les sédiments, à l’échelle nationale, le perfluorooctane sulfonate (PFOS) s’est avéré prédominant parmi les acides perfluoroalkylés (PFAA) considérés ; la fraction organique du sédiment est apparue un facteur de contrôle clé des teneurs sédimentaires. L’utilisation des cartes auto-organisatrices de Kohonen a facilité la synthèse des résultats et les comparaisons entre sites. A une échelle plus locale, ces travaux ont permis de cartographier la contamination sédimentaire d’un estuaire macrotidal et d’étudier les facteurs de contrôle de leur distribution. La dynamique spatio-temporelle des PFAS et leur transfert aux premiers maillons trophiques ont été évalués en milieu fluvial urbain (la Seine) et en milieu estuarien (la Gironde). La détermination des facteurs d’amplification trophique en estuaire de Gironde confirme le caractère bioamplifiable du PFOS et de certains PFAA à longue chaîne. Le dernier axe de ces travaux concernait la recherche de PFAS d’intérêt émergent zwittérioniques et cationiques ; des résultats préliminaires semblent dissiper les inquiétudes concernant leur potentiel de bioaccumulation. / Poly- and perfluoroalkyl surfactants (PFAS) are anthropogenic compounds that have been used sincethe 1950s in a variety of applications and that have emerged as ubiquitously distributed contaminants.The first aim of this work was to optimize and validate analytical procedures for the trace-leveldetermination of PFAS. These methods were then applied to various sets of environmental samples,providing new elements to document the occurrence and environmental fate of PFAS in aquaticecosystems. In terms of statistical analyses, a special care has been devoted to incorporate nondetects(data <LOD). In French surface waters and sediments, perfluorooctane sulfonate (PFOS) wasthe prevailing perfluoroalkylated acid (PFAA); sediment organic carbon fraction was a key controllingfactor of PFAS sedimentary levels. Kohonen self-organizing maps were used to highlight similaritiesand differences between sites, providing evidence for distinctive features, sometimes at watershedscale. A mapping of PFAS in sediments was established in a macrotidal estuary, along with theirpartitioning behavior in the water column. The spatio-temporal dynamics of PFAS and transfer to thefirst trophic levels were investigated in an urban freshwater hydrosystem (the Seine River) and in anestuarine environment (Gironde estuary). In the Gironde estuary, trophic magnification factors (TMF)were significantly >1 for PFOS and several long-chain PFAA, providing new evidence for theirbiomagnification. The last theme addressed in this work was the analysis of newly-identified cationicand zwitterionic PFAS ; preliminary evidence seem to dispel concerns about the bioaccumulationpotential of the latter.

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