Aujourd'hui, la gestion des sites et sols pollués apparaît comme un enjeu majeur des politiques environnementales et sanitaires. Pour ce faire, des outils d'aide à la décision doivent être développés et validés afin de faciliter l'identification et la compréhension des risques induits. Dans ce contexte, l'objectif de cette étude est d'améliorer les connaissances quant aux liens existants entre la nature des contaminants, leurs comportements géochimiques, la nature des phases porteuses et la bioaccessibilité. In fine, de cette compréhension fine en découlera une évaluation plus spécifique des risques environnementaux et sanitaires leur étant imputable, et une remédiation plus cohérente. Pour ce faire, deux sites contaminés à la typologie différente (minier vs industriel) ont été étudiés mais à contamination semblable (As, Pb, Zn et Cd). Après un échantillonnage représentatif en adéquation au type de site et à sa géomorphologie, une caractérisation physico-chimique fine a été effectuée sur chaque échantillon avant de déterminer leur stabilité environnementale et physiologique (bioaccessibilité). Le couplage avec de la minéralogie environnementale a permis d’expliquer le comportement des éléments dans les différents milieux. Dans un second temps, afin de s'affranchir des contraintes d'un milieu complexe comme le sol et de définir l'impact réel de chaque phase porteuse sur les risques, des phases pures ont été synthétisé et soumises aux mêmes tests que les échantillons naturels. Un retour sur le solide est alors systématiquement effectué mettant en évidence les modifications minéralogiques subies par l'échantillon. Des mélanges ont également été effectué afin d’appréhender et de mieux comprendre les effets cocktails d’éléments métalliques et metalloïdes. Cette approche intégrée, multi-analytique et multi-échelle est alors la première étape d'un long processus de compréhension et de prédiction des risques basé sur le couplage géochimie et minéralogie environnementale. / Today, the management of polluted sites and soils appears to be a major challenge for environmental and health policies. To do this, decision support tools must be developed and validated to facilitate the identification and understanding of the risks involved. In this context, the objective of this study is to improve knowledge of the links between the nature of contaminants, their geochemical behavior, the nature of carrier phases and bioaccessibility. Ultimately, this understanding will lead to a more specific assessment of the environmental and health risks attributable to them, and to a more coherent remediation. To do this, two contaminated sites with different typologies (mining vs. industrial) were studied but with similar contamination (As, Pb, Zn and Cd). After a representative sampling in accordance with the type of site and its geomorphology, a fine physico-chemical characterization was carried out on each sample before determining their environmental and physiological stability (bioaccessibility). The coupling with environmental mineralogy made possible to explain the behavior of the elements in the various environments. In a second step, in order to overcome the constraints of a complex environment such as the soil and to define the real impact of each bearing phase on the risks, pure phases were synthesized and subjected to the same tests as the natural samples. A return to the solid is then systematically carried out, highlighting the mineralogical changes undergone by the sample. Mixtures have also been made to understand and better understand the cocktail effects of metallic and metalloid elements. This integrated, multi-analytical and multi-scale approach is then the first step in a long process of understanding and predicting risks based on geochemistry and environmental mineralogy coupling.

Pollution et agriculture urbaine (AU) sont deux mondes interconnectés soumettant les villes au défi de la durabilité, dans un contexte où la pollution aux metalloïdes augmente au moins autant que l'intérêt pour l'agriculture urbaine. Les biofertilisants / bioamendements utilisés en AU (champignons mycorhiziens à arbuscules, compost, biochar) peuvent influencer la mobilité des polluants du sol. Cette étude vise à mieux comprendre le devenir de contaminants inorganiques géogéniques et anthropiques, majeurs (Cd, Pb) ou émergents (Sb), dans des systèmes sol-plante-biofertilisant et leur bioaccessibilité pour l'homme. Si la mobilité des polluants est modifiée par les biofertilisants, le type de source influence aussi leur bioaccessibilité. La communauté fongique semble cruciale dans ces phénomènes mais est impactée par l'ajout de compost. Ainsi, l'utilisation de ces biofertilisants sur sol pollué est à raisonner du fait des interactions multiples affectant la phytodisponibilité des polluants. / Urban agriculture (UA) and pollution are two worlds more inter-connected every day, creating one of the main challenges of sustainable cities as persistent metal(loid) contamination increases as much as the interest for urban agriculture. Biofertilizers and bioamendments used in UA (arbuscular mycorrhizal fungi, compost, and biochar) can influence the mobility of contaminants in soil. This study aims to better understand the fate of anthropic or geogenic, major (Cd, Pb) and emerging (Sb), inorganic contaminants in soil-plant-biofertilizer systems and their human bioaccessibility. While contaminant mobility in soil is affected by biofertilizers, their origin influences also their bioaccessibility. The fungal community seems crucial in this phenomenon but is impacted by compost addition. Hence, using these biofertilizers in contaminated soils has to be thought wisely because of the multiple interactions affecting contaminant's phytoavailability.

Au cours de leur élevage, les animaux sont exposés à divers contaminants chimiques, qui peuvent s’accumuler au niveau des tissus animaux et être retrouvés in fine dans les produits carnés consommés par l’Homme, représentant alors un risque pour la santé des consommateurs. L’évaluation de ce risque repose classiquement sur la mesure de teneur en contaminants de la viande fraîche alors que plusieurs travaux suggèrent que seule une fraction de ces contaminants est effectivement assimilée par le consommateur du fait des transformations technologiques comme la cuisson et physiologiques comme la digestion. L’objectif de cette thèse est d’étudier ces effets modulateurs de la cuisson et de la digestion sur les contaminants chimiques de la viande et leur bioaccessibilité. En s’appuyant sur le développement d’une méthode multirésidus GC×GC-TOF/MS pour le suivi de 206 polluants environnementaux et sur des collaborations avec des Laboratoires Nationaux de Référence, le premier objectif de ce travail était d’étudier l’impact de la cuisson sur un large spectre de contaminants chimiques d’une viande intentionnellement contaminée. Les résultats montrent que la cuisson n’a pas d’impact significatif sur la teneur en PCDD/F et en métaux lourds de la viande alors que des pertes significatives (d’autant plus importantes que l’intensité de cuisson est élevée) en PCB, antibiotiques et pesticides ont pu être détectées. Ces pertes ont pour origine soit une libération dans le jus de cuisson des contaminants thermorésistants, soit une dégradation sous l’effet de la cuisson des contaminants thermosensibles, comme cela a été observé pour un antibiotique, le sulfaméthoxazole, pour lequel un schéma de dégradation thermique est proposé. Le second objectif de ce travail était d’évaluer la bioaccessibilité des contaminants chimiques de la viande en s’appuyant sur un protocole standardisé de digestion in vitro statique. Dans le cas des PCB, les résultats obtenus indiquent que la bioaccessibilité dans la viande est relativement faible (26%). La teneur initiale de la viande en matière grasse et les variations physiologiques liées à l’âge du consommateur influencent significativement ces valeurs de bioaccessibilité alors que la cuisson de la viande a moins d’influence sur la bioaccessibilité. A terme, les résultats obtenus durant ce travail devraient conduire à proposer de nouvelles procédures d’évaluation des risques liés aux contaminants chimiques de la viande, prenant en compte les modulations induites par la cuisson et la digestion. / Livestock animals are exposed to various chemical contaminants during breeding. These contaminants are rapidly transferred from the environment to animal edible tissues, thus representing a public health risk. This risk is classically assessed based on the level of contaminants in raw meat. However, due to technological processes such as cooking or physiological transformations such as digestion, only a fraction of meat contaminants can be absorbed by the body. The purpose of this PhD thesis is to investigate the modulating effect of cooking and digestion on chemical contaminants in meat and on their bioaccessibility. Thanks to a GC×GC-TOF/MS multiresidue method developed in this study for the analysis of 206 environmental pollutants and to collaborations with French National Reference Laboratories, the first aim of this work was to assess the effects of pan cooking on a broad range of chemical contaminants in spiked meat. Cooking did not impact the level of PCDD/Fs and heavy metals in meat whereas significant losses (more important as cooking conditions were more intense) of PCBs, antibiotics and pesticides were observed. These losses may originate from juice expelling of heat-resistant compounds or from degradation by breakdown of thermolabile compounds such as the sulfamethoxazole antibiotic. The second aim was to assess the bioaccessibility of chemical contaminants in meat based on a standardized in vitro static digestion. For PCBs, results showed that their bioaccessibility was low (26%). Both the meat fat content and the age of consumer significantly affect this bioaccessibility value. In contrast, meat cooking was shown to have less influence on PCB bioaccessibility. The ultimate goal of the project will be to improve chemical risk assessment procedures taking into account the changes induced by cooking and digestion on micropollutants in meat.

No description available.

No description available.

No description available.

L'arsenic est un élément présent dans tous les compartiments de l'environnement, et les produits de la pêche représentent une source majeure d'exposition à l'arsenic par le biais de l'alimentation. Même s'il n'existe pas à ce jour de législation sur les teneurs en arsenic dans les aliments en France, les agences gouvernementales évaluent généralement les risques liés à la présence d'arsenic dans les produits de la pêche en se basant essentiellement sur la concentration totale de l'élément, sans tenir compte des différentes espèces présentes ni de leur bioaccessibilité. Par conséquent, le développement de méthodes d'analyse de spéciation revêt un intérêt particulier dans le cadre de l'évaluation des risques. La première partie de ce mémoire présente des informations générales sur les propriétés de l'arsenic, son occurrence dans les différents compartiments de l'environnement et sa toxicité, ainsi qu'une étude bibliographique des méthodes analytiques existantes pour étudier la spéciation de l'arsenic dans les matrices alimentaires, en particulier les produits de la pêche (extraction et séparation/détection). Les différentes approches pour l'évaluation de sa bioaccessibilité et de celle d'autres éléments traces métalliques d'intérêt sont également présentées. La deuxième partie de ces travaux porte sur la validation d'une méthode d'analyse de spéciation des principales espèces d'arsenic dans les produits la pêche (As(III), MA,DMA, As(V), AsB, TMAO, AsC) par couplage entre la chromatographie d'échange d'ions (IEC) et la spectrométrie de masse à plasma induit (ICP-MS) après extraction assistée par micro-ondes (MAE). L'évaluation des performances analytiques de la méthode, les contrôles qualités internes et externes mis en place et les différentes applications, en particulier les données d'occurrence des différentes espèces d'arsenic dans les produits de la pêche les plus consommés par la population française sont présentés et discutés. Dans la troisième partie, la bioaccessibilité maximale de l'arsenic et d'autres éléments d'intérêt est estimée à l'aide d'une méthode de lixiviation en ligne (impliquant la mesure en temps réel par ICP-MS de la fraction libérée par les différents fluides digestifs artificiels). La combinaison de ce procédé avec la méthode d'analyse de spéciation validée permet ainsi d'estimer la bioaccessibilité des différentes espèces d'arsenic. / Arsenic is an element present in all compartments of the environment, and seafood constitutes a major source of exposure to arsenic through human consumption. Although there is currently no legislation on arsenic in food in France, government agencies generally assess the safety of food items based solely on the total concentration of the element, without taking into account its different species or their bioaccessibility. Therefore, the development of speciation analysis methods is particularly relevant in the context of risk assessment. The first part of this thesis focuses on the properties of arsenic, its occurrence in the different compartments of the environment and its toxicity, and a literature review of existing analytical methods to study the speciation of arsenic in food matrices, especially seafood products (extraction and separation / detection). Different approaches for evaluating its bioaccessibility and that of other trace metals of interest are also presented.The second part of this work concerns the validation of a speciation analysis method for major arsenic species in seafood (As (III), MA, DMA, As (V), AsB, TMAO, AsC) by coupling ion exchange chromatography (IEC) with inductively coupled plasma mass spectrometry (ICP-MS) after microwave-assisted extraction (MAE). Evaluation of the analytical performance of the method, internal and external quality controls in place and applications of the method, particularly occurrence data of arsenic species in seafood most consumed by the French population are presented and discussed. In the third part, the maximum bioaccessibility of arsenic and other elements of interest is assessed using a continuous leaching method (involving the real-time measurement by ICP-MS of the fraction released by the different artificial digestive fluids). By coupling this leaching method with the above validated speciation analysis method, the bioaccessibility of different arsenic species is also assessed.

Introdução: O café é a segunda bebida mais consumida do mundo. O grão de café é uma das mais importantes \"commodities\" alimentares, sendo o principal produto de exportação agrícola. A produção mundial de café na safra 2016-2017 alcançou 153,869 milhões de sacas de 60 quilos. A bebida de café é consumida sob diversos métodos e preparações e a adição de açúcar e/ou leite são as mais comuns. O crescente consumo de cápsula de café expresso vem ganhando os lares da população brasileira com aumento de 29 % de 2010 a 2015, com estimativa de crescimento na ordem de 18 % de 2015 até 2020. A busca por diferentes tipos de café está relacionada com os efeitos sensoriais que o café pode exercer para os humanos. Entretanto, o café é considerado uma bebida bioativa com efeito antioxidante que atua como anticancerígeno, anti-obesidade, antidiabético, anti-hipertensivo e hepatoprotetor. Deste modo faz-se necessário avaliar a atividade antioxidante das cápsulas de café expresso de acordo com sua intensidade (torra) e avaliar o efeito da adição de ingrediente sobre os compostos fenólicos, a atividade antioxidante e sua bioacessibilidade. Objetivo: Avaliar o efeito de diferentes intensidades de torra e da adição de ingrediente sobre os compostos fenólicos e a atividade antioxidante das cápsulas de café expresso e sua bioacessibilidade. Material e Métodos: O presente projeto foi dividido em dois ensaios. O primeiro ensaio contou com quatorze cápsulas comerciais de café expresso, sendo treze tradicionais e uma descafeinada. O segundo ensaio contou com três cápsulas, sendo duas tradicionais e uma descafeinada. Todas foram adquiridas em estabelecimentos comerciais da cidade de São Paulo. No primeiro ensaio as bebidas foram preparadas como descrito na embalagem usando uma cafeteira doméstica e água. No segundo ensaio, às bebidas (preparadas de acordo ao primeiro ensaio), foram adicionados 40 mL leite e/ou 5 g de açúcar. A atividade antioxidante foi investigada pelo ensaio de eliminação de radicais ABTS, pela capacidade de absorção de radicais peroxila de oxigênio pelo (ORAC) e a capacidade de eliminação de radicais DPPH. O teor total de fenólicos foi determinado pelo método de Folin-Ciocalteau, as melanoidinas foram avaliadas pela absorbância a 420 nm e a digestão in vitro foi realizada por hidrólise assistida por enzimas digestivas. O perfil fenólico foi avaliado por CLAE/DAD. A capacidade de inibição da peroxidação lipídica foi determinada pela medição de substâncias reativas ao ácido tiobarbitúrico (TBARS). Resultados: No primeiro ensaio, todas as bebidas de café em cápsula apresentaram atividade antioxidante de acordo os métodos ORAC, DPPH e ABTS, variando de acordo a intensidade (torra) de cada cápsula. O teor de fenólicos variou de 191,41 a 374,36 mg equivalentes de ácido clorogênico/dose de café e as melanoidinas variaram entre 0,197 nm e 0,372 nm. No segundo ensaio, os fenólicos totais variaram de 129,40 a 541,81 mg equivalentes de ácido clorogênico/dose nas bebidas digeridas e não digeridas, respectivamente. A atividade antioxidante foi maior nas bebidas com adição de leite. O teor total de fenólicos foi maior nas amostras não digeridas. O perfil fenólico encontrado nas amostras não digeridas e digeridas, foi cafeína, ácido clorogênico, ácido cafeico, ácido p-cumárico e ácido ferúlico. Após a digestão in vitro, os ácidos fenólicos e a cafeína estavam mais bioacessíveis nas bebidas de café com adição leite e com leite e açúcar em comparação com as bebidas de café puras. As bebidas não digeridas apresentaram menor produção de TBARS em relação àquelas digeridas. Conclusão: Todas bebidas de café expresso em cápsulas estudadas apresentaram atividade antioxidante. A maior intensidade da torra pode influenciar a quantidade de fenólicos totais e atividade antioxidante. O conteúdo de ácidos fenólicos e cafeína e a atividade antioxidante das bebidas dependem dos ingredientes adicionado à preparação. Os compostos são mais bioacessíveis em bebidas com leite com açúcar e com leite, em comparação com bebidas puras. Os resultados sugerem que existem interações entre ácidos fenólicos e componentes do leite por meio de interação hidrofóbicas e/ou hidrofílicas que afetam a biodisponibilidade de ambos. / Introduction: Coffee is the second most consumed drink in the world. Coffee beans are one of the most important food \"commodities\" being the main agricultural export product. World coffee production in the 2016-2017 harvest reached 153,869 million bags of 60 kilos. The coffee drink is consumed of several methods and preparations, the addition of sugar and / or milk is the most common. The increasing consumption of espresso capsules has been gaining the homes of the Brazilian population with a 29% increase from 2010 to 2015, with an estimated growth of around 18% from 2015 to 2020. The search for different types of coffee is related to the sensory effects that coffee can exert on humans. However, coffee is considered a bioactive beverage with antioxidant effect that acts as anticancer, anti-obesity, antidiabetic, antihypertensive and hepatoprotective Thus, it is necessary to evaluate the antioxidant activity of the espresso capsules according to their intensity (roast) and to evaluate the effect of the addition of the ingredient on the phenolic compounds, the antioxidant activity and its bioacessibilide. Objective: To evaluate the effect of different roast intensities and the addition of the ingredient on the phenolic compounds and the antioxidant activity of the espresso capsules and its bioaccessibility. Material and Methods: The present project was divided into two trials. The first trial included: Fourteen commercial espresso capsules, thirteen traditional and one decaffeinated. The second trial had three capsules, two traditional and one decaffeinated. Both were purchased at food stores in the city of São Paulo. In the first assay the beverages were prepared as described on the package using a domestic kettle and water. In the second assay, the beverages were prepared according to the first test, but 40 ml of milk and / or 5 g of sugar. The antioxidant activity was investigated by the ABTS radical scavenging assay, oxygen radical scavenging ability (ORAC) and the DPPH radical scavenging ability. The total phenolic content was determined by the Folin-Ciocalteau method, as melanoidins were evaluated for absorbance at 420 nm and an in vitro digestion was performed by digestive enzyme assisted hydrolysis. The phenolic profile was evaluated by HPLC / DAD. Lipid peroxidation was determined by the action of thiobarbituric acid reactive substances (TBARS). Results: In the first trial, all capsule coffee beverages presented antioxidant activity according to the ORAC, DPPH and ABTS methods, varying according to the intensity (roast) of each capsule. The phenolic range ranged from 191.41 to 374.36 mg of chlorogenic acid equivalent / mL of coffee and the melanoidins ranged from 0.197 nm to 0.372 nm. In the second assay, total phenolics ranged from 129.40 to 541.81 mg equivalents of chlorogenic acid / dose in the digested and undigested beverages, respectively. The antioxidant activity was higher in beverages with milk addition. The total phenolic content was higher in the undigested samples. The phenolic profile found in the undigested and digested samples was caffeine, chlorogenic acid, caffeic acid, p-coumaric acid and ferulic acid. After in vitro digestion, phenolic acids and caffeine were more bioaccessible in coffee drinks with added milk and with milk and sugar compared to pure coffee beverage. Undigested beverages presented lower TBARS production in relation to those digested. Conclusions: All espresso drinks in capsules studied have antioxidant activity. The intensity can influence the amount of total phenolics and antioxidant activity. The content of phenolic acids and caffeine and the antioxidant activity of the beverages depend on the ingredients added to the preparation. The compounds are more bioavailable in milk and sugar milk beverages compared to pure beverages. The results suggest that there are interactions between phenolic acids and milk components through hydrophobic and / or hydrophilic interaction that affects the bioavailability of both.

Brazil is the country with the greatest biodiversity on the planet and a major producer of food. Tropical fruits, especially natives from Brazil, may contain considerable amounts of carotenoids that have antioxidant, anti-inflammatory, provitamin A and anticancer actions, such as β-carotene and lycopene. The food structure design concept aims to manipulate the food matrix for specific purposes, e.g. the preservation and manipulation of carotenoid bioaccessibility. The aim of this thesis was to explore tropical fruits, native and exotic from Brazil in the development of delivery systems for carotenoids. A screening step was carried out with 11 fruits, among which 2 were selected, the pitanga (Eugenia uniflora) and buriti (Mauritia flexuosa) fruits that were used for the production of microemulsions. At the screening were evaluated the proximate composition, fiber contents, carotenoid profiles and bioacessibilities. The nutritional value demonstrated that these fruits have high potential as raw-materials for healthy products due to their high fiber, minerals and carotenoid contents in addition to low energy value. Analysis by HPLC-DAD allowed the identification of 14 carotenoids in the 11 fruits studied for the screening. Results demonstrated the superiority of the bioaccessibility of xanthophylls (ranging 10 % - 52 %) in relation to carotenes, and the low bioaccessibility of lycopene from pitanga (1.1 %) and average bioaccessibility of β-carotene from buriti (26 %). Pitanga and buriti had their carotenoid profiles analyzed and monitored throughout an in vitro simulation of the digestion coupled with caco-2 cell cultures. Although xanthophylls are more bioaccessible, the intestinal ephitelium absorb preferentially the provitamin A carotenoids, such β-carotene and β-criptoxanthin. In order to produce these microemulsions, high-speed homogenization (HSH) and ultrasound (US) were studied in combination with the use of surfactants (Whey Protein Isolate and Tween 80), and addition of corn oil as carotenoid carrier. The experiments have shown that the interaction of US and HSH is capable to break cell walls and release carotenoids with higher efficiency. Optical and fluorescence microscopy, as well as carotenoid analysis demonstrated that it was possible to manipulate the food matrix structure releasing the carotenoids from the plant cells and encapsulating them inside the oil droplets, what increased their retention after processing. The microemulsion were affected by time of processing and by surfactant related to their rheology, final structure, stability of emulsion and carotenoid stability to processing. Finally, a dynamic gastrointestinal system was used to compare the behavior of carotenoids from whole fruit pulps and selected microemulsions (2% Tween 80, 5% corn oil, processed by HSH-US 4 min -4 min). The results demonstrated that it was possible to increase the stability to digestion and bioaccessibility of total carotenoids, lycopene and β-carotene from the microemulsions. / O Brasil é o país detentor da maior biodiversidade do planeta e um grande produtor de alimentos. Frutas tropicais, em especial as nativas brasileiras, podem conter quantidades consideráveis de carotenoides que possuem ação antioxidante, anti-inflamatória, provitamina A e anticâncer, como β-caroteno e licopeno. O desenho estrutural dos alimentos (food structure design), visa manipular a matriz alimentar com fins específicos, por exemplo, a preservação e manipulação da bioacessibilidade de carotenoides. Na presente tese buscou-se explorar frutas brasileiras não-convencionais no desenvolvimento de sistemas de entrega de carotenoides. Foi realizada uma etapa de triagem com 11 frutas, dentre as quais, 2 foram selecionadas, a pitanga (Eugenia uniflora) e o buriti (Mauritia flexuosa), e utilizadas na produção de microemulsões. Nesta triagem foram avaliadas a composição centesimal, o teor de fibras, o perfil de carotenoides e a bioacessibilidade destes carotenoides. O valor nutricional das frutas demonstrou seu potencial para utilização em produtos saudáveis, devido a seus teores eleveados de fibras, minerais e carotenoides além do baixo teor calórico. A análise por HPLC-DAD permitiu identificar até 14 carotenoides nas amostras das 11 frutas estudadas na triagem. O estudo da bioacessibilidade dos carotenoides das 11 frutas demonstrou principalmente a superioridade da bioacessibilidade de xantofilas (variando de 10 a 52 %) em relação aos carotenos, e portanto a baixa bioacessibilidade de licopeno da pitanga (1,1%) e média bioacessibilidade de β-caroteno do buriti (26%). Pitanga e buriti tiveram o perfil de carotenoides detalhadamente acompanhados através da simulação in vitro da digestão associada à absorção intestinal por culturas de células Caco-2. Neste estudo, observou-se que embora as xantofillas sejam mais bioacessíveis, o tecido epitelial do intestino absorve preferencialmente carotenoides provitaminicos A, como o β-caroteno e a β-criptoxantina. Para produzir as microemulsões foram estudados processamentos (homogeneização de alta-velocidade - HSH e ultrassom - US) em combinação com uso de surfactantes (Whey Protein Isolate e Tween 80) e adição de óleo de milho como carreador dos carotenoides. Os experimentos mostraram que a interação entre US e HSH é capaz de romper as paredes celulares e liberarem os carotenoides com maior eficiência. Ficou demonstrado através de microscopia ótica e de fluorescência, tanto quanto pela análise de carotenoides, que foi possível manipular estruturalmente a matriz alimentar liberando os carotenoides de dentro das células vegetais e encapsulando-os dentro das gotículas de óleo, além de aumentar sua retenção após o processamento. As microemulsões obtidas sofreram efeito do tempo de processamento e do surfactante em relação à reologia, estrutura final da matriz, estabilidade ao armazenamento e estabilidade dos carotenoides ao processo. Por fim, foi utilizado um sistema dinâmico de simulação da digestão gastrointestinal para comparar o comportamento dos carotenoides oriundos das polpas integrais das frutas e das microemulsões selecionadas (Tween 80 a 2%, óleo de milho a 5% e processado por HSH-US 4 min-4 min). Os resultados demonstraram que foi possível aumentar a estabilidade à digestão e a bioacessibilidade dos carotenoides totais, do licopeno e do β-caroteno.

Potentially harmful elements (PHE) are found naturally in soils, usually in low concentrations. However, due to the intensity of the anthropic activities, the concentrations of these elements may increase and have negative effects on the environment and human health. Methods for risk assessment may predict or indicate the level of exposure to contamination of an area. In addition to the total or pseudo-total concentration of PHE, generally extracted with acidic solutions, it is possible to determine the reactive, bioavailable and bioaccessible levels of these elements in order to evaluate the degree of soil contamination. Urban soil samples located in residential areas were collected in Piracicaba, State of São Paulo (SP) and in Santo Amaro, State of Bahia, including soils collected near a primary lead smelter area (COBRAC/Plumbum), where researchers detected elevated levels of PHE. Soils samples in an old lead metallurgy plant (Usina do Calabouço / IPT), which today belongs to the Centro Integrado de Ensino Multidisciplinar (CIEM/ Companhia de Pesquisa de Recursos Minerais (CPRM) - Geological Survey of Brazil) in Apiaí, located in the Upper Ribeira Valley (SP) were also collected. In vitro methods have been used in several countries to assess the bioaccessibility of PHE in humans. In this study, procedures based on ingestion and inhalation of soils using the Unified BARGE Method (UBM) and Artificial Lysosomal Fluid (ALF) methods were used to obtain the bioaccessible concentration in the gastrointestinal and pulmonary tract, respectively. As the bioaccessible fraction does not estimate the concentration absorbed and transported into the bloodstream, the in vitro method using Caco-2 cells, which are derived from human colon adenocarcinoma, was used to assess the amount of PHE that intestinal cells can absorb. The mineralogical data was obtained, and the sequential extraction of As, Cd, Cu, Mn, Pb and Zn was carried out to evaluate their interaction with lung fluid and gastric/gastrointestinal fluids. As expected, mine tailing samples had the highest pseudo-total concentrations of PHE in comparison to soil and sediment samples, both in the bulk soil (2 mm) and in the 250 &mu;m and 10 &mu;m sizes. Both respiratory and oral bioaccessibility of PHE varied widely among matrices, indicating that they were influenced by matrices´ chemistry, physical and mineralogical characteristics. The respiratory bioaccessible fraction, calculated as a percentage of the PHE pseudo-total concentrations, ranged from 13 - 109% for As; 14 - 98% for Cd; 21 - 89% for Cu; 46 - 140% for Pb, 35 - 88% for Mn and; 21 - 154% for Zn. Gastric bioaccessibility was greater than gastrointestinal bioaccessibility, ranging from 0-33% and 0-26% for As; 0-69% and 0-40% for Cd; 18-75% and 12-89% for Cu; 24-83% and 7-50% for Pb; 43-105% and 27-97% for Mn; 14-88% and 6-46% for Zn. Pseudo-total concentration provided a good estimate of respiratory and oral bioaccessibility, but the in-vitro methods provided more accurate results. Caco-2 cell line (in vitro test) was a good model for evaluating the effect of PHE exposure, but further studies on the transport and bioavailability of PHE in intestinal cells are needed. / Elementos potencialmente nocivos (EPN), dentre eles os metais pesados, são encontrados naturalmente nos solos, geralmente em baixas concentrações. Porém, devido à intensidade das atividades antrópicas, as concentrações destes elementos podem aumentar e ocasionar efeitos negativos ao meio ambiente e à saúde humana. Métodos para a avaliação de risco podem prever ou indicar o nível da exposição de uma área à contaminação. Além do teor total ou pseudototal de EPN, geralmente extraídos com soluções ácidas, pode-se determinar os teores nas frações reativa, biodisponível, bioacessível destes elementos para avaliação do grau de contaminação do solo. Por sua vez, métodos in vitro têm sido utilizados em vários países para avaliar a bioacessibilidade de PHE em seres humanos. Neste trabalho foram utilizadas amostras de solo urbano coletadas em Piracicaba e solos coletados em áreas de uma antiga usina de metalurgia de chumbo (Usina do Calabouço/IPT) na cidade de Apiaí, ambas localizadas no Estado de São Paulo; e na cidade de Santo Amaro, Bahia, onde foram coletadas amostras de solos urbanos localizados em áreas residenciais, principalmente próximas a uma antiga área de refino de chumbo, onde foram detectados níveis elevados de EPN. Foram avaliados procedimentos baseados na ingestão e na inalação de solos coletados por meio dos métodos Unified BARGE Method (UBM) e do Artificial Lysosomal Fluid (ALF) para obtenção do teor bioacessível nos fluidos gastrointestinais e nos fluidos pulmonares, respectivamente. Como a fração bioacessível não estima a concentração absorvida e transportada para a corrente sanguínea, o método in vitro, utilizando células Caco-2, que são extraídas de adenocarcinoma do cólon humano, foi usado para avaliar a quantidade de EPN que as células intestinais podem absorver. As características mineralógicas das amostras e a extração sequencial de As, Cd, Cu, Mn, Pb e Zn foram obtidas para avaliar a interação com fluido pulmonar e do o suco gástrico e gastrointestinal. Como esperado, as amostras de rejeito de mineração apresentaram as maiores concentrações pseudototais de EPN em comparação com as amostras de solo e sedimento, tanto nas amostras < 2mm, como nas amostras de tamanho < 250 &mu;m e < 10 &mu;m. A bioacessibilidade respiratória e oral dos EPN variou amplamente entre as matrizes, indicando que foram influenciadas por características químicas, físicas e mineralógicas das matrizes. A fração bioacessível respiratória, calculada como porcentagem das concentrações de EPN pseudototal, variou de 13 a 109% para As; 14 - 98% para Cd; 21 - 89% para Cu; 46 - 140% para Pb, 35 - 88% para Mn e; 21 - 154% para Zn. A bioacessibilidade gástrica foi maior que a bioacessibilidade gastrointestinal, variando de 0 a 33% e 0 a 26% para As; 0-69% e 0-40% para Cd; 18-75% e 12-89% para Cu; 24-83% e 7-50% para Pb; 43-105% e 27-97% para o Mn; 14-88% e 6-46% para Zn. A concentração pseudototal forneceu uma boa estimativa para bioacessibilidade respiratória e oral, mas os métodos in vitro fornecem resultados mais precisos. A linhagem celular Caco-2 foi um bom modelo para avaliar o efeito da exposição ao PHE, mas são necessários mais estudos sobre o transporte e biodisponibilidade de PHE em células intestinais.