Fertilizantes minerais derivados de rochas fosfáticas podem ser uma fonte de contaminantes, como As, Cd, Cr, Pb e Hg. Além disso, resíduos de indústrias metalúrgicas e químicas podem ser adicionados à composição de fertilizantes para fornecer micronutrientes, atuando como uma fonte adicional de contaminantes. Desta forma, o controle de qualidade de fertilizantes e matérias-primas é importante para evitar danos ao meio ambiente e garantir uma produção segura de alimentos. Neste trabalho, procedimentos de digestão assistida por radiação micro-ondas de um fertilizante mineral formulado e uma mistura de micronutrientes foram desenvolvidos para a determinação simultânea de Al, As, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, P, Pb e Zn por ICP OES, avaliando doze misturas ácidas contendo HNO3, HCl, H3PO4, HF e H3BO3. A PCA foi aplicada para auxiliar a escolha de três procedimentos de digestão que exibiram os resultados com maior exatidão. O protocolo de extração sequencial do BCR foi aplicado para investigar a mobilidade e a bioacessibilidade dos elementos. As e Cd foram extraídos principalmente na primeira etapa, portanto estão fracamente ligados à matriz e, consequentemente, estão mais móveis e bioacessíveis. O Cr permaneceu quase que completamente na fração residual. O Pb apresentou maior mobilidade e bioacessibilidade na mistura de micronutrientes do que no fertilizante mineral formulado, possivelmente, devido a precipitação de Pb3(PO4)2, causado pela alta concentração de P no fertilizante. Os nutrientes (P, Ca, Mg, Cu, Mn e Zn) apresentaram boa bioacessibilidade, exceto Fe, que permaneceu quase totalmente na fração residual. Além disso, análises por DRX e MEV-EDS foram empregadas para caracterizar os resíduos sólidos das extrações, mostrando que os elementos podem ser cobertos por estruturas cristalinas (quartzo), que inibem a sua lixiviação e os tornam menos móveis e bioacessíveis. Um sistema de extração em fluxo foi proposto para avaliar a mobilidade e a bioacessibilidade de As, Cd, Cr e Pb em fertilizantes, que foi mais eficiente que os procedimentos em batelada, pois o sistema em fluxo simula a constante lixiviação que ocorre no solo, com a infiltração das águas de chuva ou irrigação das plantações. Além disso, essas análises foram realizadas no modo transiente do ICP OES, que permitiu avaliar a cinética de extração dos elementos. O procedimento foi empregado para misturas de fertilizante com solo, onde foram observados sinais que demoravam a retornar a linha base, demonstrando a interação dos elementos com a matriz do solo. Um estudo de especiação por XANES também foi realizado e possibilitou a identificação das espécies As(V), Fe2-xCrxO3 e PbCl2 no fertilizante e na mistura de micronutrientes. Ensaios realizados com brotos de milho foram realizados para avaliar a translocação de As, Cd, Cr e Pb. Além disso, a partir das análises de especiação de As por HPLC-ICP-MS, foi observado que exsudatos promoveram a redução do As(V) para As(III), sendo esta a espécie absorvida e translocada pela planta. / Mineral fertilizers derived from phosphate rocks can be a source of contaminants, such as As, Cd, Cr, Pb and Hg. In addition, metallurgical and chemical industry residues can be added to the fertilizer composition to provide micronutrients, acting as an additional source of contaminants. In this way, the quality control of fertilizers and raw materials is important to avoid damages to the environment and ensure a safe food production. In this work, microwave-assisted digestion procedures of a formulated mineral fertilizer and a mixture of micronutrients were developed for simultaneous determination of Al, As, Ca, Cd, Cr, Cu, Fe, Mg, Mn, Ni, P, Pb and Zn by ICP OES, evaluating twelve acidic mixtures containing HNO3, HCl, H3PO4, HF and H3BO3. PCA was applied to assist in the choice of three digestion procedures that exhibited the more accurate results more. The BCR sequential extraction protocol was applied to investigate the elements mobility and bioaccessibility. As and Cd were extracted mainly in the first step, thus they are weakly bound to the matrix and, consequently, are more mobile and bioaccessible. The Cr remained almost completely in the residual fraction. Pb presented higher mobility and bioaccessibility in the mixture of micronutrients than in the formulated mineral fertilizer, possibly due to the precipitation of Pb3(PO4)2 caused by the high concentration of P in the fertilizer. The nutrients (P, Ca, Mg, Cu, Mn and Zn) presented good bioaccessibility, except Fe, which remained almost totally in the residual fraction. In addition, XRD and SEM-EDS analyzes were employed to characterize the solid residue from extractions, showing that the elements can be covered by crystalline structures (quartz), which inhibit their leaching and make them less mobile and bioaccessible. A flow extraction system was proposed to evaluate the mobility and bioaccessibility of As, Cd, Cr and Pb in fertilizers, which was more efficient than batch procedures, because the flow system simulates the constant leaching occurring in soil, with infiltration of rainwater or irrigation of plantations. In addition, these analyses were performed in the transient mode of ICP OES, which allowed evaluating the kinetics of elements extraction. The procedure was applied to mixtures of fertilizer with soil, where a slow return to baseline of signal was observed, demonstrating the interaction of the elements with the soil matrix. XANES speciation study was also carried and allowed the identification of the species As(V), Fe2-xCrxO3 and PbCl2 in the fertilizer and mixture of micronutrients samples. Bioassays performed with maize sprouts were carried out to evaluate the translocation of As, Cd, Cr and Pb. In addition, from As speciation analysis by HPLC-ICP-MS, it was observed that exudates promoted the reduction of As (V) to As (III), being this the species absorbed and translocated by the plant.

Submitted by Eunice Novais (enovais@uepg.br) on 2018-05-07T18:21:20Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Bruna de Fatima P Schmite.pdf: 1583341 bytes, checksum: 0cbad71cd214749ae6e87e91447ced22 (MD5) / Made available in DSpace on 2018-05-07T18:21:20Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Bruna de Fatima P Schmite.pdf: 1583341 bytes, checksum: 0cbad71cd214749ae6e87e91447ced22 (MD5) Previous issue date: 2018-02-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O chá-mate é uma bebida muito consumida nos estados do Sul do Brasil, não só devido ao seu sabor e aroma, mas também por suas propriedades terapêuticas. Tais propriedades estão associadas à presença de diversos constituintes químicos em sua composição, como polifenóis, flavonoides, vitaminas e minerais. Esses minerais podem ser essenciais ao organismo humano, ou altamente tóxicos, dependendo da forma e concentração. Nesse sentido, o presente trabalho teve como objetivos determinar as concentrações totais de Cd, Cu, Pb e Al em chá-mate comercial, bem como o conteúdo desses elementos em infusões preparadas à temperatura ambiente (frio) e a quente. As concentrações de fenólicos em infusões também foram determinadas utilizando o método Folin-Ciocalteu. Além disso, avaliar as frações bioacessíveis desses elementos e, ainda verificar se a adição de alguns ingredientes as infusões (canela, limão, mel e açúcar) pode influenciar na biodisponibilidade do alumínio. As quantificações foram realizadas por espectrometria de absorção atômica com atomização eletrotérmica em forno de grafite e em chama. Para os teores totais a abertura de amostra, por via úmida (otimizada por planejamento fatorial) apresentou os melhores resultados, em relação a via seca. As concentrações totais para as quatro marcas estudadas variaram: Cd (0,08 à 0,320 μg g-1); Pb (0,36 à 0,44 μg g-1); Cu (10,3 à 12 μg g-1) e Al (347 à 526 μg g-1). Para as infusões os teores superiores de Al e Cd foram encontrados nas infusões a quente, enquanto que para o Cu e o Pb os maiores teores foram nas infusões a frio. Com isso, a ordem de extração nas infusões tanto a quente quanto a frio foi Cd>Pb>Al>Cu. Com relação aos teores de fenólicos, as maiores concentrações foram obtidas nas infusões a quente variando de 13 a 17 mg g-1. Nos estudos de bioacessibilidade in vitro empregando o método de simulação gástrica (PBET) os elementos Cd e Cu foram os metais mais bioacessíveis, enquanto o Al foi encontrado em forma relativamente inerte (baixa bioacessibilidade). Verificou-se também que o consumo diário de 100 mL da bebida, por um adulto, não ultrapassa os limites de ingestão diária desses metais recomendável pela Organização Mundial da Saúde. Por fim, verificou-se que a adição de ingredientes às bebidas, como o açúcar e mel podem diminuir os teores biodisponíveis de Al. / Yerba mate tea is a widely consumed drink in the southern states of Brazil, not only because of its flavor and aroma, but also due to its therapeutic properties. Such properties are associated with the presence of several chemical constituents in its composition, such as polyphenols, flavonoids, vitamins and minerals. These minerals may be essential to the human body, or highly toxic, depending on their form and concentration. In this sense, this study aimed to determine the total concentrations of Cd, Cu, Pb and Al in commercial mate tea, as well as the content of these elements in infusions prepared at room temperature (cold) and hot; to determine phenolic concentrations in infusions using the Folin-Ciocalteu method; to evaluate the bioaccessible fractions of these elements and to verify whether the addition of some ingredients to the infusions (cinnamon, lemon, honey and sugar) may influence the bioavailability of aluminium. The quantifications were performed using atomic absorption spectrometry with electrothermal atomization in graphite and flame furnace. For total content analyses, the wet route (optimized by factorial planning) showed the best results when compared to the dry route. The total concentrations for the four brands studied varied: Cd (0.08 to 0.320 μg g-1); Pb (0.36 to 0.44 μg g -1); Cu (10.3 to 12 μg g -1) and Al (347 to 526 μg g -1). Regarding infusions, the highest contents of Al and Cd were found in the hot infusions, while cold infusion presented the highest levels of Cu and Pb. Thus, the order of extraction in hot and cold infusions was Cd> Pb> Al> Cu. With respect to the phenolic contents, the highest concentrations were obtained in the hot infusions ranging from 13 to 17 mg g-1. In the in vitro bioaccessibility studies using the gastric simulation method (PBET) the Cd and Cu elements were the most bioaccessible metals, while Al was found in relatively inert (low bioaccessibility) form. It was also found that the daily consumption of 100 ml of the drink by an adult does not exceed the limits of daily intake of these metals recommended by the World Health Organization. It was also verified that the addition of ingredients such as sugar and honey to these beverages may decrease the bioavailable levels of Al.

La valorisation des déchets par digestion anaérobie conduit à la production d’un résidu, appelé digestat, qui est composé de la matière organique non biodégradée et présente une forte teneur en azote ammoniacal et organique. De par cette richesse en azote, les digestats présentent un intérêt grandissant pour la substitution aux engrais minéraux. L’objectif de cette thèse est de comprendre les transformations de l’azote en digestion anaérobie afin de prédire la qualité azotée des digestats. Cette compréhension des processus de transformation de l’azote ouvrira la possibilité de dimensionner et piloter le procédé de digestion anaérobie pour une substitution optimisée des engrais minéraux par les digestats. Pour cela, deux approches ont été développées: (i) une approche compréhensive centrée sur la compréhension de la bioaccessibilité de l’azote organique en lien avec sa biodégradabilité, et la compréhension des transformations de l’azote en digestion anaérobie en conditions de laboratoire et pilote; et ; (ii) une approche numérique où les processus identifiés ont été intégrés à des outils de modélisation à bases statistiques et biocinétiques permettant de prédire les propriétés azotées des digestats en fonction des cocktails de substrats et du temps de séjour dans le digesteur. / Energetic recovery of waste by anaerobic digestion leads to the production of a residue called digestate, which is composed of non-biodegraded organic matter and has a high content of ammoniacal and organic nitrogen. Due to this high nitrogen content, digestates are growing interest for the substitution of mineral fertilizers. The objective of this thesis is to understand the transformations of nitrogen that occur during anaerobic digestion in order to predict the nitrogen quality of digestates. This understanding of nitrogen transformation processes will allows the design and management of anaerobic digestion plants aiming at the optimization of the substitution of mineral fertilizers by digestates. To this end, two approaches were used in this work: (i) an experiment approach focused on the understanding of the bioaccessibility of organic nitrogen in relation to its biodegradability, and the understanding of the transformations of nitrogen in anaerobic digestion under laboratory and pilot conditions; and; (ii) a numerical approach where previously developed knowledge has been integrated in statistical and biokinetic modeling tools to predict the nitrogen properties of digestates according to substrate cocktails and residence time in the digester.

As rações comerciais devem ser um alimento balanceado que supra todas as exigências nutricionais nas diferentes fases da vida do animal. Sua formulação deve conter ingredientes de qualidade, em proporções adequadas. É de fundamental importância o conhecimento do valor nutricional das rações, para assegurar que o cão esteja ingerindo diariamente quantidades corretas dos nutrientes. O desbalanço de elementos essenciais e a presença de elementos tóxicos podem causar desequilíbrios nutricionais, doenças e, até mesmo, consequências fatais aos cães. O cobre é um dos vários elementos de importância a ser estudado quanto aos defeitos metabólicos nos cães. O acúmulo de cobre no fígado pode ocasionar lesões progressivas nas organelas dos hepatócitos, resultando em hepatite crônica e cirrose. Diante disso, este trabalho teve como objetivos (I) quantificação dos elementos químicos com função nutricional e com potencial tóxico presentes nas rações para cães adultos e filhotes, (II) avaliação da composição centesimal das rações amostradas, (III) avaliação da variação dos elementos químicos entre as amostras de ração de um mesmo lote de produção (IV), estudo da representatividade de pequenas porções-teste, (V) avaliação da bioacessibilidade de cobre em rações, com experimento in vitro. Os elementos químicos Al, As, Br, Ca, Cl, Co, Cr, Cs, Cu, Fe, I, K, La, Mg, Mn, Na, P, Rb, Sb, Sc, Se, Ti, U e Zn foram determinados pela análise por ativação neutrônica instrumental (INAA). A composição centesimal foi avaliada de acordo com os métodos recomendados da AOAC. A homogeneidade de distribuição dos elementos químicos nas rações foi avaliada pela análise de amostras grandes (LS-NAA). A bioacessibilidade de cobre nas rações foi estimada por meio da simulação da digestão gastrointestinal in vitro. Foi possível determinar por INAA todos os nutrientes minerais, isto é, Ca, P, K, Na, Cl, Mg, Fe, Cu, Mn, Zn, I e Se, com limites estabelecidos pela Association of American Feed Control Officials. Foram notadas em algumas rações altas concentrações de Al, Sb e U, elementos com grande potencial tóxico. Cerca de 16 % das amostras de ração apresentaram, pelo menos, um parâmetro não conforme quanto à composição centesimal. Os resultados obtidos por LS-NAA e NAA convencional mostraram variação na composição entre os sacos de ração para Br, Ca, Na e Zn, com boa concordância entre ambos os métodos. O emprego da LS-NAA combinada com NAA convencional permitiu observar que pequenas porções-teste (350 mg) de ração são representativas comparadas com aquelas de 1 kg para Br, Ca, K, Na e Zn. Em todas as rações para cães, 50 % do cobre presente estava sob a forma bioacessível / Commercial dog foods should be a balanced diet that meets all nutritional requirements at different stages of the animal\'s life. Its formulation should contain quality ingredients in suitable proportions. The knowledge of the nutritional value of dog food is fundamental to ensure that the animal is ingesting daily right amounts of nutrients. The imbalance of essential elements and the presence of toxic elements can cause nutritional problems, diseases, and even fatal consequences for dogs. Copper is one of several important factors to be studied for metabolic defects in dogs. Copper accumulation in the liver may cause progressive lesions in the organelles of hepatocytes, resulting in chronic hepatitis and cirrhosis. Thus, this study aimed to (I) determine essential and potentially toxic chemical elements in the dog food for puppies and adults, (II) assess the proximate composition of the sampled dog food, (III) evaluate the between-bag variation of chemical elements in dog food within the same production lot of one brand, (IV) study the representativeness of small test portions of dog food collected from regular 1 kg packed bags, (V) assess the in vitro bioaccessibility of copper in dog food. The chemical elements Al, As, Br, Ca, Cl, Co, Cr, Cs, Cu, Fe, I, K, La, Mg, Mn, Na, P, Rb, Sb, Sc, Se, Ti, U and Zn were determined by instrumental neutron activation analysis (INAA). The proximate composition was evaluated by AOAC recommended methods. The homogeneity of chemical elements distribution in the dog food was evaluated by analysis of large samples (LS-NAA). The bioaccessibility of copper was estimated by in vitro simulated gastrointestinal digestion. INAA was a suitable analytical tool for characterizing the profile of mineral nutrients, i.e., Ca, P, K, Na, Cl, Mg, Fe, Cu, Mn, Zn, I and Se in dog food with reference values set by Association of American Feed Control Officials. High concentrations of the toxic elements Al, Sb and U were observed in some dog food samples. Approximately 16% of dog food samples presented, at least, one value outside the reference limits from proximate composition. The results obtained by LS-NAA and conventional NAA showed between-bag compositional variability for Br, Ca, Na and Zn, with a good agreement between both methods. The use of LS NAA combined with conventional NAA allowed to observe that the small 350 mg portions of dry dog food taken for analysis is representative of one kilogram bag for Br, Ca, K, Na and Zn. In all dog foods, 50 % of the copper was present in bioaccessible form

<div>Zein is major nitrogen storage protein that accounts for nearly half of the protein content of the corn grain. As a byproduct of starch and ethanol processing, it is generally recognized as safe (GRAS) and soluble in up to 70% ethanol. Historically, zein has been used for films and coatings. However, usage of the corn protein has diminished in recent years. New advances in food nanotechnology has renewed interest in zein. By forming the protein into stable nanoparticles capable of being dispersed in aqueous solution, zein can be used in many applications ranging from improving stability and digestion of functional ingredients or active biodegradable packaging. Developing novel applications for this protein would then add value to a waste product during the processing of corn.</div><div><br></div><div>The formation of hydrophobic zein nanoparticles (ZNPs) would allow for easier dispersion in aqueous systems without further modification to increase hydrophilicity. However, their dispersibility and subsequent stability in aqueous systems is important for its functionality in food. Addition of sufficient ι-carrageenan (ι-CGN) prevented aggregation in the pH range of 5.25 to 6.75 and limited aggregation at pH 7.0. Enhanced stability was attributed to the adhesion of ι-CGN to the nanoparticle surface, as the ZNPs surface charge became significantly negative with introduction of ι-CGN. These particles remained stable for up to 30 days with significantly lower turbidity and greater resistance to gravitational separation when compared to ZNPs alone.</div><div><br></div><div>Lutein was encapsulated in zein nanoparticles, and the bioaccessibility was determined by quantifying lutein content after exposure to in vitro gastric and intestinal conditions. It was found that ZNPs provided a protective environment for lutein in aqueous dispersions and would release the carotenoid into the small intestine by rapid breakdown of ZNP structure during intestinal digestion. However, the process or residual components must have limited uptake of lutein into mixed micelles. ZNPs can be a promising encapsulating agent to improve the digestive stability of lutein.</div><div><br></div><div>Composite films composed of methylcellulose (MC) and zein nanoparticles (ZNPs) were prepared as a potential biodegradable alternative for synthetic packaging. The effects of ZNP aggregation on mechanical and moisture barrier properties as affected by drying temperature, pH, and stabilizers were tested. The phase separation of composite films was determined to be detrimental to both its mechanical and moisture barrier properties. The drying temperature, pH, and composition of the solvent casting solution all affected the distribution of ZNPs dispersed in MC films. Drying films at 23°C or setting the pH to 6.5 resulted in ZNP aggregation and weaker, brittle films that were poor moisture barriers. The presence of CGN was able to provide stability to ZNPs at both pH 4 and 6.5, thus improving its mechanical and moisture barrier properties.</div>

As rações comerciais devem ser um alimento balanceado que supra todas as exigências nutricionais nas diferentes fases da vida do animal. Sua formulação deve conter ingredientes de qualidade, em proporções adequadas. É de fundamental importância o conhecimento do valor nutricional das rações, para assegurar que o cão esteja ingerindo diariamente quantidades corretas dos nutrientes. O desbalanço de elementos essenciais e a presença de elementos tóxicos podem causar desequilíbrios nutricionais, doenças e, até mesmo, consequências fatais aos cães. O cobre é um dos vários elementos de importância a ser estudado quanto aos defeitos metabólicos nos cães. O acúmulo de cobre no fígado pode ocasionar lesões progressivas nas organelas dos hepatócitos, resultando em hepatite crônica e cirrose. Diante disso, este trabalho teve como objetivos (I) quantificação dos elementos químicos com função nutricional e com potencial tóxico presentes nas rações para cães adultos e filhotes, (II) avaliação da composição centesimal das rações amostradas, (III) avaliação da variação dos elementos químicos entre as amostras de ração de um mesmo lote de produção (IV), estudo da representatividade de pequenas porções-teste, (V) avaliação da bioacessibilidade de cobre em rações, com experimento in vitro. Os elementos químicos Al, As, Br, Ca, Cl, Co, Cr, Cs, Cu, Fe, I, K, La, Mg, Mn, Na, P, Rb, Sb, Sc, Se, Ti, U e Zn foram determinados pela análise por ativação neutrônica instrumental (INAA). A composição centesimal foi avaliada de acordo com os métodos recomendados da AOAC. A homogeneidade de distribuição dos elementos químicos nas rações foi avaliada pela análise de amostras grandes (LS-NAA). A bioacessibilidade de cobre nas rações foi estimada por meio da simulação da digestão gastrointestinal in vitro. Foi possível determinar por INAA todos os nutrientes minerais, isto é, Ca, P, K, Na, Cl, Mg, Fe, Cu, Mn, Zn, I e Se, com limites estabelecidos pela Association of American Feed Control Officials. Foram notadas em algumas rações altas concentrações de Al, Sb e U, elementos com grande potencial tóxico. Cerca de 16 % das amostras de ração apresentaram, pelo menos, um parâmetro não conforme quanto à composição centesimal. Os resultados obtidos por LS-NAA e NAA convencional mostraram variação na composição entre os sacos de ração para Br, Ca, Na e Zn, com boa concordância entre ambos os métodos. O emprego da LS-NAA combinada com NAA convencional permitiu observar que pequenas porções-teste (350 mg) de ração são representativas comparadas com aquelas de 1 kg para Br, Ca, K, Na e Zn. Em todas as rações para cães, 50 % do cobre presente estava sob a forma bioacessível / Commercial dog foods should be a balanced diet that meets all nutritional requirements at different stages of the animal\'s life. Its formulation should contain quality ingredients in suitable proportions. The knowledge of the nutritional value of dog food is fundamental to ensure that the animal is ingesting daily right amounts of nutrients. The imbalance of essential elements and the presence of toxic elements can cause nutritional problems, diseases, and even fatal consequences for dogs. Copper is one of several important factors to be studied for metabolic defects in dogs. Copper accumulation in the liver may cause progressive lesions in the organelles of hepatocytes, resulting in chronic hepatitis and cirrhosis. Thus, this study aimed to (I) determine essential and potentially toxic chemical elements in the dog food for puppies and adults, (II) assess the proximate composition of the sampled dog food, (III) evaluate the between-bag variation of chemical elements in dog food within the same production lot of one brand, (IV) study the representativeness of small test portions of dog food collected from regular 1 kg packed bags, (V) assess the in vitro bioaccessibility of copper in dog food. The chemical elements Al, As, Br, Ca, Cl, Co, Cr, Cs, Cu, Fe, I, K, La, Mg, Mn, Na, P, Rb, Sb, Sc, Se, Ti, U and Zn were determined by instrumental neutron activation analysis (INAA). The proximate composition was evaluated by AOAC recommended methods. The homogeneity of chemical elements distribution in the dog food was evaluated by analysis of large samples (LS-NAA). The bioaccessibility of copper was estimated by in vitro simulated gastrointestinal digestion. INAA was a suitable analytical tool for characterizing the profile of mineral nutrients, i.e., Ca, P, K, Na, Cl, Mg, Fe, Cu, Mn, Zn, I and Se in dog food with reference values set by Association of American Feed Control Officials. High concentrations of the toxic elements Al, Sb and U were observed in some dog food samples. Approximately 16% of dog food samples presented, at least, one value outside the reference limits from proximate composition. The results obtained by LS-NAA and conventional NAA showed between-bag compositional variability for Br, Ca, Na and Zn, with a good agreement between both methods. The use of LS NAA combined with conventional NAA allowed to observe that the small 350 mg portions of dry dog food taken for analysis is representative of one kilogram bag for Br, Ca, K, Na and Zn. In all dog foods, 50 % of the copper was present in bioaccessible form

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-09-05T20:11:17Z No. of bitstreams: 1 2016 - Fernanda Marques Peixoto.pdf: 14003225 bytes, checksum: 89c95a9ad22b1e74cdf2bda273665230 (MD5) / Made available in DSpace on 2017-09-05T20:11:17Z (GMT). No. of bitstreams: 1 2016 - Fernanda Marques Peixoto.pdf: 14003225 bytes, checksum: 89c95a9ad22b1e74cdf2bda273665230 (MD5) Previous issue date: 2016-12-08 / A lot of interest in the consumption of anthocyanins increased after the association of their intake and reduced risk of chronic diseases. Despite of in vitro evidences of anthocyanins benefits to health, there is still a gap in the knowledge of the mechanisms of absorption of anthocyanins by the human body. It is known that concentration of food anthocyanins doesn't reflect the amount of these compounds which are absorbed, metabolized, distributed and biologically active in humans. Some in vitro models have been developed to evaluate the steps of cell release and transport ( uptake) of these compounds from food. The objective of this study was to evaluate the in vitro absorption of food anthocyanins using the in vitro digestion followed by uptake and transport in Caco-2 human intestinal cell line and MKN-28 human gastric cell line. Initially, anthocyanins bioaccessibility of diverse fruits was evaluated in order to select the better sources for transport assays. The bioaccessibility assays were performed using an in vitro digestion model, which mimics the human oral, gastric and intestinal stages. Quantification and characterization of anthocyanins profile were performed by high-performance liquid chromatography (HPLC) with Thermo Scientific? C1s 2.4 (4.6 x 10mm) column. After selection of the most promising fruits, the bioaccessibility tests were followed by transport assays. To assess gastric absorption, the product from gastric digestion was applied on the MKN-28 cell monolayer, which was obtained after 7 days of culture of 2.5 x 10^5 MKN-28 cells seeded in RPMI culture media in transwell? plates. The permeate was collected after 30, 60, 120 andl80 minutes oftransport. For evaluation of intestinal absorption after digestion, the digesta from the intestinal phase was applied on the Caco-2 cell monolayer, which was obtained after 21 days of culture of 2.5 x 105 Caco-2 cells seeded in DMEM culture media in TRANSWELL? plates. The permeate was collected after 30, 60 and 120 minutes of transport. All analyses were made by forming CLUE / photodiode array detector (Thermo? Scientific) at 520nm. Peel powder from jabuticaba, jambo and Jamel?o were the most promising sources. The bioaccessibility of anthocyanins after gastric digestion was 13% for jabuticaba, 45 % for jambo and 65 % for jamel?o. In addition, the intestinal bioaccessibility was 1 O % for jabuticaba, 15 % for jambo and 45 % for jamel?o. The transport assay with the MKN-28 gastric cell line, revealed 19.7%, 9.7 % and 14.1 % of transport efficiency, respectively, for jambo, jabuticaba and jamel?o digestion products. While Caco-2 intestinal cell model showed 0.8 %, 0.2 % and 0.3 % oftransport efficiency, respectively, for jambo, jabuticaba and jamel?o. These results suggest food anthocyanins are preferentially absorbed by the human gastric mucosa and to a lesser extent by the human intestinal epithelium. / O interesse pelo consumo das antocianinas aumentou ap?s o surgimento da rela??o entre o seu consumo e a redu??o do risco de doen?as cr?nicas. Apesar das evid?ncias in vitro quanto a esses beneficios ? sa?de, ainda h? uma lacuna que permanece sob investiga??o: o mecanismo de absor??o das antocianinas pelo organismo humano. Sabe-se que a quantidade desses compostos, nos alimentos, n?o reflete a quantidade absorvida, metabolizada, distribu?da e biologicamente ativa em humanos. Alguns modelos in vitro t?m sido desenvolvidos para avaliar as etapas de digest?o e transporte celular (absor??o) de compostos dos alimentos. Assim, o objetivo deste trabalho foi avaliar o transporte in vitro de antocianinas em alimentos utilizando modelos de digest?o in vitro seguido do transporte em c?lulas intestinais Caco-2 e c?lulas g?stricas MKN-28. Na 1? etapa, oito frutos foram analisados quanto aos valores de bioacessibilidade (BCSS) fornecidos pelas antocianinas presentes, para posterior sele??o para os ensaios de transporte. Os ensaios de BCSS foram realizados com um modelo de digest?o in vitro, para simula??o das fases oral, g?strica e intestinal humana. A quantifica??o e determina??o do perfil de antocianinas foram realizadas por Cromatografia l?quida de alta efici?ncia (CLAE), com coluna Thermo? Scientific C1s 2,4 (4,6 x 100mm). Na 2? etapa, realizou-se os ensaios de BCSS, anteriormente aos ensaios de transporte, nos frutos potencialmente mais promissores. Para a avalia??o do transporte g?strico, na sequ?ncia, o digerido g?strico foi aplicado sobre a monocamada de c?lulas MKN-28, com 2,5 x 10^5 c?lulas, em meio RPMI, em placa transwell? e, ap?s 7 dias de cultivo, o permeado foi coletado nos tempos 30, 60, 120, 180 minutos. Para o transporte intestinal, sequencial, o digerido intestinal foi aplicado sobre a monocamada celular Caco-2, com 2,5 x 105 c?lulas, em meio DMEM, em placas transwell? e, ap?s 21 dias de cultivo, o permeado foi coletado nos tempos 30, 60 e 120 minutos de transporte. Todas as an?lises foram realizadas por CLUE/detector de arranjo fotodiodo (Thermo? Scientific), a 520 nm. Os p?s da casca da jabuticaba, jambo e jamel?o foram as matrizes mais promissoras. A BCSS das antocianinas, ap?s a digest?o g?strica, foi de 13 % parajabuticaba, 45 % parajambo e 65 % parajamel?o, enquanto a BCSS intestinal foi de 10% para jabuticaba, 15 % para jambo e 45 % para jamel?o. Os ensaios de transporte (ET) com os modelos de c?lula MKN-28 resultaram em 19,7; 9,7 e 14,1 % de ET, respectivamente, para os p?s do jambo, jabuticaba, e jamel?o, enquanto que o modelo Caco-2, resultaram em 0,8, 0,2 e 0,3 % de ET, respectivamente. Estes resultados sugerem que as antocianinas s?o preferencialmente absorvidas pela mucosa g?strica.

Les vitamines D et K sont des micronutriments liposolubles qui participent au bon fonctionnement de l’organisme. Elles jouent des rôles clés dans la prévention de trouble de l'hémostase et de la coagulation, des pathologies osseuses, métaboliques et cardiovasculaires. Cependant, même si ces vitamines sont apportées en quantités suffisantes par notre alimentation, leurs effets bénéfiques sont étroitement conditionnés par leur biodisponibilité. Or, mieux connaitre les mécanismes d’absorption permettrait d’appréhender leur biodisponibilité. Nous avons tout d’abord montré que l’absorption de la vitamine K implique des transporteurs du cholestérol, SR-B1 et CD36. Nous avons également montré que l’entérocyte est non seulement capable d’effluer les vitamines D et K néo-absorbées mais également d’excréter ces vitamines du compartiment sanguin vers la lumière intestinale. Ce phénomène bien connu pour le cholestérol (excrétion transintestinale du cholestérol) implique des transporteurs communs, dont ABCB1 et ABCG5/G8. Dans un second temps, dans le cadre de la relance de la consommation des légumineuses, nous avons mis en évidence que la présence de légumineuses dans un repas limite la biodisponibilité de ces vitamines. En effet, les fibres, phytates, saponines et tanins diminuent leur bioaccessibilité et/ou leur captage. La méthode de cuisson des légumineuses, en affectant leur composition nutritionnelle, peut moduler l’incorporation des vitamines D et K au sein des micelles mixtes et donc affecter leur biodisponibilité. Ces données soulignent ainsi le fait que les légumineuses doivent être cuites de manière appropriée et consommés dans des repas riches en micronutriments. / Vitamin D and K are fat-soluble micronutrients that participate to the proper functioning of the organism. They are essential to prevent bleeding, bone, metabolic and cardiovascular disorders. However, even if those vitamins are provided in sufficient quantities in our diet, their health effects are closely linked to their bioavailability. A better knowledge of their absorption mechanisms would help to optimize their bioavailability.Firstly, we showed that vitamin K absorption involves the cholesterol transporters SR-B1 and CD36. We also showed that enterocytes can not only efflux newly absorbed vitamins D and K but also excrete vitamin D and K from the blood compartment to the intestinal lumen. This phenomenon of transintestinal excretioninvolves the cholesterol membrane transporters ABCB1 and ABCG5/G8.Secondly, we showed that the presence of pulses within a meal limits vitamin D and K bioavailability. Indeed, fibers, phytates, saponins and tannins can decrease bioaccessibility and/or uptake of vitamin K. By modulating the nutritional profile of pulses, the cooking method can impact on fat-soluble vitamin transfer to mixed micelles, and in turn affect their bioavailability. These data suggest that pulses must be cooked in an appropriate manner and consumed in micronutrient-rich meals.Keywords: vitamin D, vitamin K, bioaccessibility, intestinal absorption, pulses.

The potential of a soil to immobilize heavy metal ions is dependent on the presence of adsorption sites, and the stability of metal species over the range of geochemical conditions present in the soil over time. Lead (Pb) is a cumulative toxin that is enriched in much of the urban pedosphere due to historical use of Pb-based paint and Pb-amended gasoline. Because in-situ remediation of Pb is possible if the bioavailable fraction can be rendered inert, understanding Pb-sorbent interactions is necessary to accurately and efficiently alter Pb speciation in soils. The objectives of this study are to 1) determine efficient ways to predict Pb behavior at the field scale, and 2) characterize microscale controls on Pb speciation. A combination of geospatial and analytical tools has been used across a variety of spatial scales to provide the first multiscale analysis of microenvironment impact on Pb speciation in soils. This research investigated Pb distribution at the field scale (in Burlington, VT), and mobility at the microscale. The field-scale study has shown that the relationship between total Pb and bioaccessible Pb is not linear, in stark contrast to the existing conceptual model of this relationship. It was determined that the disproportional influence of fine-fraction Pb in low total-Pb soils results in elevated bioavailability. Microscale investigations determined that there is a positive correlation between the density of reactive microenvironments and the release of Pb from contaminated soil, and that altered distributions of microenvironments significantly alters the rate of Pb release. This research identifies specific mechanisms controlling Pb behavior in soils at both the field and the microscale, which can be used to inform improvements to implementation of remediation.

Les études épidémiologiques récentes montrent une consommation insuffisante d’acides gras polyinsaturés (AGPI) dans les pays occidentaux. Cependant, la sensibilité des AGPI à l’oxydation est l’une des premières causes de détérioration des qualités organoleptique et nutritionnelle dans les produits alimentaires. Parallèlement, les lipides présents dans les produits alimentaires se trouvent le plus souvent sous forme émulsionnée. Ainsi, les entreprises désirant formuler des produits alimentaires enrichis en AGPI adoptent des stratégies technologiques pour les stabiliser chimiquement et physiquement, tout en assurant leur biodisponibilité. Une de ces stratégie consiste à rechercher, dans la nature, des systèmes émulsifiés stables afin d’en extraire des molécules tensioactives d’intérêt et de mimer l’organisation des lipides. C’est dans ce contexte que des études portent, depuis quelques années, sur les corps lipidiques (Oil Bodies, OB), structures végétales naturelles de stockage des lipides des plantes oléagineuses, composées de phospholipides (PL) et de protéines (OBP).L’objectif général de ce projet de thèse vise à maitriser la formulation d’émulsions préparées uniquement à base de colza (huile, PL et OBP) par une meilleure connaissance des interactions PL : OBP, d’étudier la stabilité des émulsions d’un point de vue physicochimique en conditions de stockage et dans des conditions mimant les conditions gastro-intestinales et, enfin, d’évaluer l’influence de la composition de l’interface des émulsions sur la bioaccessibilité des acides gras insaturés in vivo chez le rat.Les études spectroscopiques des interactions PL modèles : OBP ont mis en évidence des interactions favorables à la stabilisation des émulsions entre les PL anioniques, les PL insaturés et les OBP. Ces résultats ont orienté le choix vers une lécithine de colza spécifique. Les interactions PL : OBP, modulées par le pH et le rapport PL : OBP, influencent la réalisation des émulsions, la quantité d’OBP adsorbées à l’interface et la stabilité physique des émulsions, avec un crémage prononcé pour les émulsions riches en protéines. La synergie PL : OBP à l’interface semble être un facteur décisif pour ralentir l’oxydation de l’huile de colza émulsifiée. Le comportement des émulsions, dans des conditions mimant celles du milieu gastro-intestinal, montre que la présence d’OBP à l’interface favorise la floculation des émulsions à pH acide (mimant celui de l’estomac), mais que cette floculation est réversible lorsque le pH est ramené à des valeurs proches de celle de l’intestin. La présence des OBP favorise l’activité de la lipase pancréatique in vitro. Finalement, l’interface composée de PL et d’OBP améliore la bioaccessibilité lymphatique des AGPI in vivo chez le rat.En conclusion, nous avons montré qu’il est possible de formuler des émulsions uniquement à base de colza. Elles pourraient présenter une alternative intéressante aux émulsions stabilisées par des émulsifiants d’origine synthétique (politique clean label) ou d’origine animale (alimentation végane). / Recent epidemiologic studies show an insufficient intake of polyunsaturated fatty acids (PUFA) in occidental countries. Besides, the sensibility of PUFA to oxidation is one of the major causes of organoleptic and nutritional quality deterioration in food products. Moreover, lipids in food products are often in an emulsified stage. Therefore, industrials that care to formulate PUFA enriched food products adopt technological strategies to protect and stabilize the lipids while improving their bioavailability. One of those strategies consists in looking for stable emulsified systems that already exist in nature, extract tensioactive molecules of interest and mimic the lipid state. In this context, several studies deal with oil bodies (OB), that are natural occurring structures for lipid storage in oleaginous plants, composed of proteins (OBP) and phospholipids (PL).Therefore, the main objective of this PhD work is to manage emulsion formulation only based on canola (oil, PL and OBP). This goes through: 1) an understanding of the interactions between PL and OBP; 2) a study of the stability of the emulsions under storage and gastrointestinal conditions, and finally, 3) an investigation of the influence of the emulsion interfacial composition on the bioavailability of PUFA in rats.The spectroscopic studies of the model PL:OBP interactions showed favorable interactions for stabilizing the emulsions based on anionic PL, unsaturated PL and OBP. These results allowed choosing an adequate canola lecithin. The PL:OBP interactions, modulated by the pH and the PL:OB ratio, influences the formation of the emulsions, the quantity of OBP adsorbed at the interface and the physical stability of emulsions with a pronounced creaming in emulsions rich in proteins. The PL:OBP synergy at the interface seems to be a decisive factor to slow down the oxidation of the emulsified canola oil. The emulsion behavior in conditions that mimic that of the gastrointestinal track, shows that the presence of OBP at the interface favored the emulsion flocculation at acid pH (mimicking that of the stomach). However, the flocculation was reversible when the pH was adjusted to a value close to that of the intestine. OBP also increased the activity of the pancreatic lipase in vitro. Finally, the presence of PL and OBP at the interface increased the lymphatic bioaccessibility of the PUFA in rats.On the whole, we showed that it is possible to manage emulsion formulation only based on canola products. This could be of peculiar interest for clean labeling or vegan nutrition by subtracting synthetic emulsifiers or emulsifiers from animal origin, respectively.