La génération, propagation et la réception d’informations (bio/chimiques) entre les organismes individuels sont la clé de voûte de nombreux systèmes communicants intelligents et sont omniprésents dans la nature. Les colonies de lucioles synchronisent leurs flashs, et la contraction et l’expansion des muscles cardiaques sont quelques exemples parmi d’autres, où les signaux bio / chimiques générés par des sources synchronisées produisent un comportement coopératif. L’objectif final de cette thèse est de développer une plateforme fiable pour générer des réseaux de communication de liposomes, en encapsulant la réaction de Belousov-Zhabotinsky (BZ) en tant que source d’information ou un signal transmis, et d’étudier la dynamique d’un tel système. Pour atteindre cet objectif, plusieurs questions ont été abordées par une approche “bottom-up” et multi-échelle. Tout d’abord, nous avons étudié l’interaction entre des liposomes de DMPC dopés et non-dopés avec le cholestérol, l’acide myristique, tétradécylsulfate, tétradécylamine, et les espèces impliquées dans la reaction BZ en utilisant la diffusion de rayons X aux petits angles et par spectrophotométrie UV-visible. Des rangées 1D de micro-gouttelettes ont été fabriquées en encapsulant la réaction BZ en microgouttelettes au moyen de la microfluidique et la communication entre les gouttelettes adjacentes a été étudiée. Plus tard, nous avons démontré un système microfluidique facile à monter / démonter avec une conception robuste et une géométrie modulable pour générer des emulsions doubles d’eau dans l’huile dans l’eau (E/ H / O). Enfin, le comportement de ces doubles emulsions générées dans système microfluidique en utilisant des phosphoplipides comme tensioactif et du chloroforme comme phase huileuse, est rapporté. Nous avons montré, avec cette composition de la phase d’huile, que le comportement dynamique des émulsions doubles sous écoulement donne lieu à des phénomènes riches incluant la déformation et du “tip-streaming”. / Generation, propagation and reception of (bio/chemical) information between individual organisms are the keystone of many intelligent communicating systems, and are ubiquitous in Nature. Colonies of fireflies synchronize their flashes, and contraction and expansion of heart muscles are few examples among others, where bio/chemical signals generated by synchronized sources produce a cooperative behaviour. The final objective of this thesis is to develop a reliable platform for generating communicative networks of liposomes, encapsulating the Belousov-Zhabotinsky (BZ) reaction as source of information or transmitted signals, and to study the dynamics of such a system. To reach this goal, several issues were addressed by following bottom-up and multi-scale approaches. First we investigated the interaction between both bulk DMPC liposomes, and liposomes doped with cholesterol, myristic acid, tetradecylsulfate, tetradecylamine, and the species involved in the BZ-reaction by using small angle X-ray scattering (SAXS) and UV-visible spectrophotometry. Than 1D arrays of micro-droplets were fabricated by encapsulating the BZ reaction into microdroplets by means of microfluidics, and the communication between adjacent droplets was studied. Later, we demonstrated an easy to assemble/disassemble and robust design for a microfluidic device with adjustable geometry, for generating monodisperse water-in-oil-in-water (w/o/w) double emulsions. Finally, the behavior of w/o/w double emulsions generated in a microfluidic device, using phospholipids as surfactant and chloroform as the oil phase, was reported. We showed, with this composition of the oil phase, that the dynamic behaviour of the double emulsions under flow gave rise to different phenomena, such as deformation and tip-streaming.

[pt] A produção de petróleo é geralmente acompanhada pela produção de água, que pode estar presente sob forma livre e emulsionada. As emulsões podem ser encontradas em quase todas as fases de produção: nos reservatórios, nos poços produtores, nas facilidades de produção, nos dutos de transporte, no processamento e no armazenamento O sistema de Bombeio Centrifugo Submerso (BCS) é um dos métodos utilizados na indústria para a elevação de petróleo para campos localizados tanto em terra como em mar. Ainda que seja o método de elevação artificial mais apropriado para a produção de petróleo quando há elevada produção de água, a eficiência da bomba é bastante reduzida quando há manuseio de misturas de água e óleo e a formação de emulsões. Este trabalho teve como objetivo o estudo do cisalhamento aos quais os fluidos estão expostos durante a passagem por um estágio de uma Bomba Centrífuga Submersa e seus efeitos no grau de emulsificação da mistura de água e óleo. Foi construído um aparato experimental composto por dois discos, um giratório e um fixo. Ao escoar através destes a mistura de fluidos sofre deformação cisalhante e extensional e seu grau de emulsificação, isto é, tamanho médio e distribuição dos diâmetros de bolhas, é medido a montante e a jusante do dispositivo. / [en] Oil production is usually associated with the production of water, which may be found as a continuous phase or as a dispersed phase, in emulsions. Emulsions may be found in almost all the production stages: in reservoirs, production wells, production facilities, pipelines, in processing and in storage. The Electric Submersible Pump (ESP) is one of the methods employed in the industry to lift oil from fields located on land as well as at sea. Though this is the most appropriate artificial lift method for oil production when a considerable amount of water is produced, a pump’s efficiency is a greatly reduced when mixtures of water and oil are handled and emulsions begin to form. This paper intends to study the shearing imposed to fluids when flowing through a stage in a Electric Submersible Pump, and its effects in the degree of emulsification of the water and oil mixture. An experimental device was assembled consisting in two disks, one that spins and the other fixed. When flowing through them, a mixture of fluids is subjected to shearing and extensional deformation, and its degree of emulsification, i.e.: the average size and the bubble diameter distribution, may be measured upstream and downstream from the device.

Tuberculosis(TB) was declared to be a global emergency in 1993, with South Africa declaring it to be the country’s top health priority in 1996, but ineffective treatment strategies have led to fewer than half of all treated patients in South Africa being cured. At present,paediatric treatment remains a problem, as the antitubercular preparations of rifampicin, isoniazid and pyrazinamide, that are currently available, were not initially designed for the treatment of paediatric TB patients, providing a motivation for this project. The aim of this project is thus the development of a microemulsion dosage form for the oral delivery of RIF(Rifampicin), INH(Isoniazid) and PZA(Pyrazinamide) in combination. RIF, INH and PZA were adequately characterised with reference to the monograph standards referenced and were found to be sufficiently pure to be used in subsequent work. A chromatographic system and conditions were selected and validated as being optimal for HPLC analysis of RIF, INH and PZA in combination, with a drug partitioning method for miglyol 812 developed and validated. Ternary and pseudo-ternary phase diagrams were constructed and reported, all employing miglyol 812 as the lipid. It was undoubtedly the imwitor 308 and crillet 3 combination o/w microemulsion system that proved most successful, maintaining homogeneity on dilution. The microemulsion used in formulation comprised imwitor 308 (27.63%), crillet 3 (27.63%), miglyol 812 23.68%) and water (21.06%). The stability of RIF, INH and PZA was investigated in aqueous solution, miglyol 812, corn oil, 10%m/v cremophor RH, 5%m/v imwitor 308, 10%m/v crillet 3 and 70%m/v sorbitol solution. Trends in the stability assessments conducted on RIF, INH and PZA were noted, with slight variation depending on the formulation component being evaluated. RIF invariably demonstrated temperature and oxidation dependent degradation in all vehicles, with a definite distinction possible between samples stored at 25, 40 and 600C over a 7 day trial period. A definite advantage of storing RIF solutions under nitrogen was observed, with these solutions showing less degradation over the course of the trial, than those stored under air. INH produced a pronounced increase in the degree of degradation of RIF, whereas PZA had a negligible effect on it’s stability. INH proved to be most stable in the 70%m/v sorbitol solution with no significant oxidation or temperature dependent degradation indicated. Temperature dependent degradation was only noticable when INH was in combination with RIF, most significant in crillet 3 solution. PZA was the most stable of the three drugs, remaining relatively unaffected by temperature and the presence of air, independent of the vehicle employed, although the drug remaining did decrease slightly in the presence of RIF.Due to drug dose specifications and solubility limitations, the final formulation assessed, only contained RIF and INH, despite INH and PZA having no significant effect on the stability of each other. The solubility of PZA in the lipid and aqueous components of the microemulsion was not great enough to achieve the required 500 mg/10ml dose, while RIF and INH could achieve the respective 150mg/10ml and 100mg/10ml dose. RIF stability was improved, as anticipated, with the incorporation of RIF into the internal phase decreasing contact with INH which has been shown to affect it’s stability. RIF behaved as predicted, possessing greater stability than shown in the individual formulation components, however, INH did not, being less stable in formulation in the absence of antioxidant, than in it’s presence. A novel microemulsion formulation capable of delivering the incompatible RIF and INH in combination, with numerous microemulsion systems mapped,with the ability of being used for the delivery of other lipophilic drugs and drug combinations, was produced.The final formulation provided valuable information into possible future improvements of the microemulsion to improve drug stability.

Dans cette these nous avons étudié la dynamique de colloides aux interfaces fluides. Dans une première partie nous avons étudié la dynamique de drainage de films minces liquides contenant des particules de microgels de PNiPAM. Ces systèmes sont de plus en plus utilisés pour stabiliser et déstabiliser des émulsions sur demande en jouant sur la température. Nous avons montré que la dynamique de drainage et l'épaisseur des films dépend de la concentration et du degré de réticulation des particules. Nous avons pu à partir des épaisseurs des films remonter à la conformation des particules. Les microgels moins réticulés s'étalent davantage aux interfaces à basse concentration que les particules ayant un taux de réticulation plus élevé. En revanche à haute concentration, les particules moins réticulées forment des couches plus compactes, ce qui induit des films moins stables. Dans la deuxième partie nous avons étudié la dynamique d'adsorption de particules colloidales dans des systèmes eau dans eau, obtenus par la séparation de phase de deux solutions de polymères. A temps courts, la position de la particule varie exponentiellement avec le temps alors qu'aux temps plus longs l'évolution est logarithmique. De façon surprenante, nous trouvons que dans le régime exponentiel, le temps caractéristique, qui résulte théoriquement d'un équilibre entre les forces de tension interfaciale et la friction visqueuse est trop lent par rapport à la théorie. De plus l'existence d'un régime logarithmique (habituellement attribué à un piégeage/dépiégeage de la ligne de contact) est également surprenante puisque notre système présente des tensions interfaciales très faibles, de l'ordre de 100 µN/m. / This thesis examines interfacial colloidal dynamics in two separate aqueous systems. The first part aims to improve understanding of thermoresponsive microgel-stabilised emulsions. Many emulsion properties are determined by the behaviour and drainage dynamics of the thin films that form between droplets. This study reveals these drainage dynamics, achieved through observing a model thin film of PNiPAM microgel solution in air. We explore why, as other studies have shown, less cross-linked microgels stabilise emulsions more effectively than more cross-linked microgels, concluding that both adsorption dynamics and particle rearrangement under pressure play a role. Through a simple calculation, we are able to estimate the conformation of microgels at the interface, showing that microgel concentration in bulk determines the concentration at interface due to differences in adsorption kinetics, and microgel excess does not play a role. The second part of the thesis investigates behaviour of spherical colloidal particles within an Aqueous Two-Phase System (ATPS) composed of non-mixing polymer solutions of fish gelatin and dextran, with applications in low-fat foods. Additionally, the very low surface tension of these systems allows studing fast interfacial processes at experimentally accessible timescales. In this work, we examine adsorption dynamics of spherical particles, observing for the first time the theoretically-predicted exponential ‘snap-in’ stage of particle adsorption. Surprisingly, even at this low surface tension, a slower logarithmic relaxation is subsequently observed which at the oil/water interface is ascribed to pinning of the contact line on surface defects.

Nous étudions le comportement rhéologique de suspensions de bulles dans un fluide à seuil. Des suspensions modèles sont formulées par l'incorporation de bulles d'air monodisperses dans un fluide à seuil modèle, qui se comporte comme un solide visco-élastique pour de faibles déformations et s'écoule en suivant une loi de Herschel-Bulkley si la contrainte appliquée est supérieure à sa contrainte seuil. Nous caractérisons le module complexe, la contrainte seuil et la loi de comportement en écoulement de ces fluides à seuil aérés modèles. Pour des fractions volumiques en gaz inférieures à la fraction critique de percolation des bulles dans le fluide à seuil, la réponse macroscopique des suspensions de bulles est le résultat d'un couplage entre la rhéologie du fluide à seuil interstitiel et la capillarité qui s'exerce à la surface des bulles. Les grandeurs rhéologiques mesurées sur les suspensions décroissent d'autant plus avec la fraction volumique en gaz que les effets capillaires sont faibles. L'introduction de plusieurs nombres capillaires permet de quantifier ce couplage et de comparer les résultats expérimentaux obtenus à une estimation micro-mécanique. Au-delà de la fraction volumique critique de percolation des bulles, le matériau aéré devient une mousse de fluide à seuil dans laquelle le fluide à seuil interstitiel est confiné dans les bords de Plateau. Ce confinement entraîne l'apparition d'effets de taille finie lorsque la mousse de fluide à seuil est cisaillée, et la réponse macroscopique de la mousse dépend de la microstructure du fluide à seuil interstitiel / The rheological behaviour of suspensions of bubbles in yield stress fluids is investigated through experiments on model systems. Model foamed yield stress fluids are prepared by adding monodisperse bubbles in model yield stress fluids, which behave as soft visco-elastic solids for small deformation and flow with a Herschel-Bulkley law above their yield stress. The complex modulus, yield stress and flow curve of those model foamed yield stress fluids is characterised by rheometrical measurements. For gas volume fractions lower than the percolation threshold of the bubbles in the suspending yield stress fluid, the macroscopic behaviour of the bubble suspensions results from the coupling of the fluid rheology to capillarity acting on the surface of the bubbles. The rheological properties of the suspensions decrease all the more with the gas volume fraction as capillarity is weak. This coupling is quantified through capillary numbers which also allow us to compare our experimental results to micro-mechanical estimates. For higher gas volume fractions, beyond the percolation threshold of the bubbles, the aerated material turns into an actual foam of yield stress fluid in which the interstitial fluid is confined in the Plateau borders. This confinement leads to the onset of finite-size effects as the foam is sheared, and the macroscopic behaviour of the foam depends on the micro-structure of the interstitial yield stress fluid

Orientadores: Rosiane Lopes da Cunha, Ana Carla Kawazoe Sato / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Almentos / Made available in DSpace on 2018-08-18T17:56:49Z (GMT). No. of bitstreams: 1 Costa_AlineAlvaresdaSilva_M.pdf: 2383816 bytes, checksum: 2af9fcfd4c4efd286c4471da25aa7226 (MD5) Previous issue date: 2011 / Resumo: Proteínas são os biopolímeros mais amplamente utilizados nas formulações de emulsões alimentícias como agentes emulsificantes, por serem um aditivo seguro. Com o intuito de entender e melhorar as propriedades emulsificantes das proteínas, inicialmente foram estudadas as macroemulsões óleo-água (O/A) estabilizadas por caseinato de sódio (CN-Na), obtidas em um sistema rotor-estator, sob diferentes concentrações de proteína e condições de pH. Todas as macroemulsões apresentaram separação de fases, devido ao mecanismo de cremeação. Este processo de desestabilização foi reduzido quando existiu o aumento da viscosidade dos sistemas, obtido pela adição de maiores concentrações de proteína e pela redução do pH em direção ao ponto isoelétrico da proteína. Já a utilização da homogeneização a altas pressões promoveu a formação de emulsões cineticamente estáveis, não sendo observada separação de fases com 4% de CN-Na em nenhuma das condições de pH. De modo geral, as emulsões apresentaram comportamento pseudoplástico, com exceção das emulsões estabilizadas com 1% de proteína em pH 5, que se comportaram como fluido dilatante, e em pH 7, como fluido Newtoniano. A redução do pH para os sistemas com 1% de CN-Na levou à desestabilização das emulsões, devido à menor concentração de proteínas adsorvidas não permitirem uma estabilização eletrostática. Foi realizado um tratamento enzimático para melhorar a estabilização das emulsões que separaram de fases em pH ácido. Assim, géis de caseinato de sódio foram reticulados com lacase e ácido ferúlico e as propriedades mecânicas desses géis foram avaliadas. A adição de lacase mediada por ácido ferúlico resultou em géis mais rígidos, firmes e menos deformáveis. As melhores combinações foram selecionadas para o preparo de emulsões O/A estabilizadas com CN-Na com o objetivo de aumentar a estabilidade em pH ácido. O uso desse tratamento enzimático levou a modificações na estrutura da proteína e, com isso, mudanças nas suas propriedades funcionais, o que permitiu o aumento na estabilidade das emulsões. Em geral, essas emulsões tratadas enzimaticamente apresentaram-se mais estáveis, com distribuição de gotas menos polidispersa e com comportamento mais estruturado, apesar do aumento no diâmetro médio das gotas, variando entre 11,79 e 20,17 µm para emulsões em pH 3 contra 6,14 µm medido na emulsão controle (sem tratamento enzimático). Assim, o aumento na estabilidade dessas emulsões deve estar associado ao aumento da viscosidade, que promoveram estabilidade estérica aos sistemas. Portanto, os resultados mostram que foi possível a produção de emulsões ácidas com maior estabilidade a partir do caseinato de sódio, através do tratamento enzimático, originando emulsões com estruturas e propriedades reológicas diferenciadas em comparação com a proteína não reticulada / Abstract: Proteins are biopolymers widely used as a safe additive in the formulation of food emulsions as emulsifying agents. To understand and improve the emulsifying properties of sodium caseinate, initially oil-in-water macroemulsions (O/W) were studied. The emulsions were stabilized by sodium caseinate prepared using a rotor-stator device at different concentrations of protein and pH. All macroemulsions showed phase separation due to the creaming mechanism. This mechanism of destabilization was reduced with the increase of system viscosity, either due to the increase on the concentrations of protein and by the reduction of pH towards to the protein¿s isoelectric point. The use of high-pressure homogenization promoted the formation of stable microemulsions, with no phase separation observed in emulsions with 4% CN-Na. In general, the emulsions exhibited a shear-thinning behavior, except the emulsion containing 1% protein at pH 7, which exhibited Newtonian behavior, and at pH 5, which tended to show a shear-thickening behavior. The reduction of pH in emulsions with 1% CN-Na led to phase separated emulsions, which was attributed to the amount of adsorbed protein, which was insufficient to promote a strong electrostatic repulsion. In order to improve the stabilization of phase separated emulsions at acidic pH, an enzymatic treatment was carried out. Thus, sodium caseinate gels were crosslinked with laccase and ferulic acid and the mechanical properties of these gels were evaluated. The addition of laccase and ferulic acid resulted in gels with increased hardness, firmness and less deformable. The best treatments were selected for the preparation of O/W emulsions stabilized with CN-Na, in order to increase in their stability in acidic pH. The enzymatic treatment caused modifications in the protein structure, resulting in changes of functional properties, which led to an increase in the emulsion stability. In general, these enzymatically treated emulsions were more stable, composed by droplets with lower size distribution and more structured behavior, despite the increased mean droplet diameters (between 11.79 and 20.17 µm for emulsions at pH 3). Thus, the stability increase of these emulsions could be associated to the increase in viscosity, which resulted in steric stability. Results showed that it was possible to produce more stable emulsions containing sodium caseinate in acidic pH using enzymatic treatment, resulting in emulsions with different structures and rheological properties when compared with the non-cross-linked protein / Mestrado / Engenharia de Alimentos / Mestre em Engenharia de Alimentos

Extracting and producing heavy oil presents many difficulties, promoted by the nature of the constant quantities involved, such as viscosity of the oil, the means through where it moves the salinity of water, oil composition, the temperature and so forth. In the pumping, the amount of oil which is drawn is not enough to meet the expenses, that is, the cost-effectiveness has not been satisfactory. This work (Collection and Characterization of Emulsion to the correction of Heavy Oil Flow) sought to analyze the physical and chemical behavior and rheology of emulsions regarding the mobility and displacement of Heavy Oil. With the prior characterization of heavy oil from a study in the wells of the regions and UN-SEAL using sodium dodecyl sulfate (SDS) emulsion type water and oil were obtained (W / O). To the obtainment and the formulation of the oil-water emulsion type, the use of surfactant was essential to the choice of the anionic SDS, since this surfactant is widely used in the petroleum industry. The developments made in this work, in other words, obtaining the w / o emulsions, showed a decrease in viscosity, the shear stress with increasing shear rate with the behavior of a pseudo plastic fluid. It follows that achieving the w / o emulsions, in the micellar concentrations such as 6.67 x 10-2 g.mL-1, 1.0 x 10-1 g.mL-1 and 3.75 g.mL-1 to obtain the w / o emulsions were satisfactory, compared to concentrations of ions present in the oil sample, the pH, the levels of aromatics, resins and asphaltenes, the API gravity, the density, the shaking time, 6 min , the rotation speed of 1000 RPM ± 50, the temperature of 27 ° C, with the breaking time o the emulsion 300 min observed that the viscosity of emulsified oil, tension and shear rate were reduced. Therefore, emulsion water / oil (W / O), obtained in this study achieved the goal of working to reduce the parameters that affect the mobility of heavy oil. / Extrair e produzir óleo pesado apresentam muitas dificuldades, promovidas pela natureza das constantes grandezas envolvidas tais como: viscosidade do óleo, meio por onde este se desloca, a salinidade da água presente no meio, a composição do óleo, a temperatura do meio e outras. No bombeamento a quantidade arrastada de óleo não é bastante para fazer frente aos gastos, isto é, o custo-benefício, não tem sido satisfatório. O presente trabalho (Obtenção e Caracterização de Emulsão para Correção de Escoamento de Óleo Pesado) buscou analisar o comportamento físico-químico e reológico de emulsões quanto à mobilidade e o deslocamento do Óleo Pesado. Com a caracterização prévia do óleo pesado em estudo proveniente de poços da região UN-SEAL e utilizando o Dodecil Sulfato de Sódio (SDS) foram obtidas emulsões tipo Água e Óleo (A/O). Para formulação e obtenção de emulsão tipo água-óleo, o uso de surfactante foi imprescindível. A escolha do aniônico SDS, uma vez que, este surfactante é muito utilizado na indústria do petróleo. Os desenvolvimentos realizados nesse trabalho, ou seja, a obtenção das emulsões A/O, mostrou uma diminuição da viscosidade, da tensão de cisalhamento com o aumento da taxa de cisalhamento com um comportamento de um fluido pseudo-plástico. De onde se conclui que a obtenção das emulsões A/O, nas concentrações micelares tais como: 6,67x 10-2 g.mL-1, 1,0x 10-1g. mL-1 e 3,75 g.mL-1 para a obtenção das emulsões A/O, foram satisfatórias, relativamente às concentrações de íons presentes na amostra de óleo, do pH, dos teores de aromáticos, resinas e asfaltenos, do grau API; da massa especifica,do tempo de agitação, 6 min, a velocidade de rotação 1000±50 RPM, a temperatura do meio 27 ºC, com tempo de quebra da emulsão 300 min observado que a viscosidade do óleo emulsionado, tensão e taxa de cisalhamento foram reduzidas. Portanto, emulsões água/óleo (A/O), obtidas neste estudo atingiram o objetivo do trabalho de reduzir os parâmetros que interferem na mobilidade do óleo pesado.

Orientador: Lireny Aparecida Guaraldo Gonçalves / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-27T06:01:36Z (GMT). No. of bitstreams: 1 Mascarenhas_MariaCristinaChiarinelliNucci_D.pdf: 11179206 bytes, checksum: 71bb9c37c16718133e785f77c3b3fa2a (MD5) Previous issue date: 2015 / Resumo: O uso de gorduras vegetais em alimentos é amplo e muitas matérias primas, tecnologias e ingredientes são continuamente pesquisados em busca de funcionalidade e aspectos nutricionais mais adequados, ampliando o uso destas gorduras e melhorando a qualidade dos produtos finais. Uma das técnicas utilizadas para adequar a lenta cristalização do óleo de palma é o uso do processo de semeadura com óleos totalmente hidrogenados (OTH). O presente trabalho se refere à obtenção de cristais de OTH de soja ou de palma microencapsulados em material de parede amido de milho ¿OSA (AMM) ou maltodextrina (MD), em diversas proporções por spray drying. Estas micropartículas apresentaram tamanho de partícula (7,8-9,7µm), eficiência de encapsulação (61,8-89,6%) e morfologia características de produtos por spray dryer, além de manterem o polimorfismo original do material de recheio. Os OTH microencapsulados com quantidade de material de recheio superior (60%) apresentaram maior dificuldade de produção. Na aplicação em óleo de palma puro foram observadas a indução de cristalização e a formação de uma rede homogênea, densa e com poucos aglomerados. Os OTH de soja (45%) microencapsulados em MD e AMM inibiram a formação de polimorfos ? na mistura de óleo de palma. Os OTH microencapsulados com menor quantidade de recheio (30%), apresentaram comportamento de não liberação total do material de recheio nas aplicações, porém, atuaram como sementes de cristalização e influenciaram na transição polimórfica para forma ?. O OTH de soja (30%) microencapsulado em AMM, em sistemas de óleo de palma e açúcar auxiliou na textura e na redução de exsudação de óleo. Os OTH de soja (45%) microencapsulados em AMM e MD aplicados em emulsão A/O desempenharam papel de estruturantes e estabilizantes. Em geral, as micropartículas produzidas com AMM e OTH de soja apresentaram melhores desempenhos. A forma de dispersão ao meio dos cristais de OTH presentes nas micropartículas permitiu a formação de uma rede cristalina mais homogênea, acelerando o processo de cristalização, aumentando a consistência do óleo de palma no meio aplicado. E aos meios específicos, favoreceu a estabilidade em relação à separação de fase de emulsões, como margarinas e cremes, e reduziu a exsudação de óleo em sistemas anidros hidrofóbicos, a exemplo de recheios de biscoitos e de bombons, problemas de processo e qualidade de produto muito indesejável. Além disto, o uso destas micropartículas promove valores de consistência adequados e resistentes a oscilações térmicas, com ausência de ácidos graxos trans. Estas micropartículas podem servir como carreadoras de compostos lipofílicos com caráter nutracêutico se estes forem microencapsulados conjuntamente com o OTH, desempenhando função tecnológica e nutricional com facilidade de manuseio, estocagem e aplicação por estarem na forma de pó / Abstract: The technique of seeding is a option for the oils and fats industry to adapt to the physical characteristics of oils adding nutritional improvements and desirable consistency, expanding its application. This research refers to production of fully hydrogenated oils (FHO) by spray drying with maltodextrina (MD) and modified corn starch¿OSA (MCS) as wall materials to obtain possible seeds of crystallization. FHO of palm and soybean were used in different proportions. These particles were evaluated by mean diameter (7.8-9.7?m), efficiency of encapsulation (61.8-89.6%), polymorphism (maintained the original polymorphism corresponding material filling) and morphological characteristics (spherical form with some surface depression). In palm oil application, these particles induced crystallization and formed an homogeneous and dense crystal network with few agglomerates. FHO of soybean microencapsulated (45%) in MD and MCS inhibited the formation of the ? polymorph in palm oil. The FHO microencapsulated with smaller amount of filled material (30%) acted as seeding and polymorphic transition to influence the ? form, although it partially released the filled material in applications. FHO of soybean microencapsulated (30%) in MCS was applied in palm oil with sugar systems, enhancing the texture and the reduction of oil exudation. FHO of soybean microencapsulated (45%) with MCS and with MD were applied in W/O emulsion, in which these particles were structural network and stabilizers. In general, the particles produced using MCS as wall material and FHO of soybean as filling material showed better performance. The arrangement of the dispersion throughout the FHO crystals present in the particles allowed the formation of a more homogeneous crystal lattice, accelerating the crystallization process, increasing palm oil consistency in the applied mean. In specific means, it favored stability in relation to the separation of emulsions phase, such as margarines and creams, reducing exudation oil in hydrophobic anhydrous systems, such as fillings of cookies and candies, which is a very undesirable product quality problem. Furthermore, the use of these particles promotes consistency and temperature variation stability containing no trans fatty acids. These particles can serve as a carrier for nutraceutical lipophilic compounds if they were microencapsulated together with the FHO. Therefore these particles, which are in the powder form, can perform technological and nutritional functions allowing ease handling, storage and application / Doutorado / Tecnologia de Alimentos / Doutora em Tecnologia de Alimentos

Orientadores: Rosiane Lopes da Cunha, Fabiana Perrechil Bonsanto / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-27T07:04:27Z (GMT). No. of bitstreams: 1 Gomes_Andresa_M.pdf: 2606689 bytes, checksum: d42f6cece06eb1f758731050fdc49b30 (MD5) Previous issue date: 2015 / Resumo: Os polifenóis possuem alta capacidade antioxidante, sendo o seu uso associado à prevenção e a redução de doenças, estabilização de alimentos e antienvelhecimento. No entanto, estes compostos são instáveis na presença de luz, calor e em determinadas condições de pH, apresentam sabor amargo e adstringente, baixa biodisponibilidade e solubilidade em água, o que pode limitar sua utilização em alimentos. Neste contexto, este trabalho teve como objetivo estudar a encapsulação do ácido gálico (AG) pelo método de emulsificação. As emulsões foram formuladas utilizando-se óleo de soja como fase oleosa, monolaurato de polioxietileno de sorbitana (Tween 20) e polirricinoleato de poliglicerol (PGPR) como surfactantes e ácido gálico como bioativo de interesse. Foram estudadas emulsões do tipo óleo em água (O/A) e água em óleo (A/O) com razão de fases de 25:75 (móleo+Tween20:msoluçãodeácidogálico) e 75:25 (msoluçãodeácidogálico:móleo+PGPR), respectivamente. A concentração de surfactante (1, 2 e 4% m/m) e ácido gálico (0 ou 0,5% m/m) foi variado, de forma a identificar o sistema mais estável e que conferisse maior proteção ao ativo. O AG foi solúvel em água a 25 ºC nas concentrações de 0,1 - 1,3% (m/m). O aumento da concentração de AG (0 - 1,3% m/m) não exerceu efeito na tensão interfacial inicial (22 mN/m) e de equilíbrio (13 - 14 mN/m) dos sistemas óleo de soja/solução de AG, porém na presença dos surfactantes Tween 20 ou PGPR esta propriedade diminuiu para valores menores que 10 mN/m. As emulsões A/O apresentaram distribuição de tamanho de gota bimodal, comportamento pseudoplástico e a presença de AG resultou em menor separação de fases e diâmetro médio da fase dispersa na emulsão. As emulsões O/A apresentaram estabilidade cinética, distribuição monomodal e comportamento de fluido Newtoniano, sendo que a presença de AG também reduziu o diâmetro médio das gotas nas emulsões. O processo de emulsificação se apresentou como um método eficiente de encapsulação, protegendo o ativo da oxidação. A emulsão O/A apresentou maior teor de fenólicos totais e capacidade antioxidante quando comparada à emulsão A/O. Porém, ambas as emulsões apresentaram altas eficiências de encapsulação do bioativo (? 86,75%), podendo ser utilizadas como ingredientes em processos para fabricação de produtos de diversas naturezas, devido às diferentes propriedades físicas das emulsões O/A e A/O / Abstract: Polyphenols have high antioxidant capacity, and its use is associated with the prevention and reduction of diseases, stabilization of food and anti-aging. However, these compounds are unstable in presence of light, heat and some pH conditions, exhibit bitter and astringent taste, low bioavailability and solubility in water, which could limit its use in food systems. In this context, this work is aimed to study the encapsulation of gallic acid (GA) by emulsification method. Emulsions were formulated using soybean oil as oil phase, polyoxyethylene sorbitan (Tween 20) and polyglycerol polyricinoleate (PGPR) as surfactants and gallic acid as bioactive. The systems evaluated were oil-in-water (O/W) and water-in-oil (W/O) emulsions with 25:75 (woil+Tween20:wgallicacidsolution) and 75:25 (wgallicacidsolution:woil+PGPR) ratio, respectively. The surfactant concentration (1, 2 and gallicacidsolution oil+ PGPR 4% w/w) and gallic acid (0 or 0.5% w/w), was evaluated in order to identify the more stable system and greater protection to the bioactive. GA was soluble in water at 25 °C for concentration ranging from 0.1 up to 1.3% (w/w). The GA concentration increase (0 - 1.3% w/w) had no effect on the initial interfacial tension (22 mN/m) and equilibrium (13- 14 mN/m) in GA solution/soybean oil systems, however, in presence of Tween 20 or PGPR this property decreased to less than 10 mN/m. The W/O emulsions showed bimodal droplet size distribution, pseudoplastic behavior and the presence of GA decreased the phase separation and the average diameter of the emulsion dispersed phase. The O/W emulsions exhibited kinetic stability, monomodal droplet size distribution, Newtonian fluid behavior, and the presence of AG also reduced the average diameter of the droplets in emulsions. Results showed that the emulsification process was an efficient encapsulation method, protecting the bioactive against oxidation. The O/W emulsion showed content higher of totals phenolic and antioxidant capacity in comparison to the W/O emulsion. However, both emulsions exhibited high efficiencies of encapsulation of bioactive (? 86.75%) and can be used as ingredients in different products, due to the different physical properties of the O/W and W/O emulsions / Mestrado / Engenharia de Alimentos / Mestra em Engenharia de Alimentos

Orientadores: Maria Angela de Almeida Meireles Petenate, Diego Tresinari dos Santos / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-27T12:15:27Z (GMT). No. of bitstreams: 1 Rosa_MariaTherezadeMoraesGomes_D.pdf: 4902896 bytes, checksum: aef7e5c464da3869257ebd47ad538611 (MD5) Previous issue date: 2015 / Resumo: O presente trabalho de doutorado está dividido em dois temas principais, um sobre o uso da tecnologia supercrítica para a formação de partículas e outro sobre o uso do ultrassom para a formulação de emulsões. A revisão da literatura sobre o estado da arte do emprego do CO2 supercrítico para formação de micro e nanopartículas e encapsulação mostrou as potencialidades do uso desta tecnologia. A unidade usada para os experimentos de micronização via tecnologia supercrítica foi desenvolvida pelo grupo de pesquisa e validada utilizando uma substância modelo, o sal de ibuprofeno sódico. Esse fármaco foi selecionado devido às informações sobre o sistema CO2-Ibuprofeno encontradas na literatura. O efeito das condições operacionais (temperatura, pressão, vazão da solução, vazão do CO2, tipo de injetor e concentração de ibuprofeno sódico na solução etanólica) no rendimento de precipitação, teor de solvente residual, morfologia das partículas e consumo energético por unidade de produto processado foi investigado utilizando o método split-plot. Sal de ibuprofeno sódico foi micronizado com sucesso via Antissolvente Supercrítico (SAS) utilizando a unidade construída. A vazão de CO2 influenciou estatisticamente no rendimento de precipitação, enquanto que, não houve influência das condições operacionais no teor de solvente residual das partículas micronizadas. Com a apropriada seleção das condições operacionais, foi possível a obtenção de partículas de ibuprofeno sódico com morfologia de folha, sendo ideal para os processos de compressão do fármaco, com baixo teor de solvente residual e alto rendimento de precipitação. Neste trabalho também foi explorado o uso do ultrassom para a formulação de emulsões, contendo extrato rico em 'delta'-tocotrienol, com o intuito de aumentar o valor agregado deste extrato obtido das sementes de urucum por extração supercrítica com dióxido de carbono. As sementes de urucum já são valiosas pela característica de produzir pigmentos, a bixina e a norbixina. Contudo, essas sementes também vêm adquirindo notoriedade por conter outras substâncias de importância para a saúde do homem, como tocoferóis, tocotrienóis e geranil geraniol. Devido à importância desses compostos bioativos, que apresentam propriedades antioxidade, hidratante e fotoprotetora, este estudo visou o desenvolvimento de métodos para formação de emulsões permitindo a proteção desses compostos instáveis às condições adversas, aumentando assim o valor agregado dos extratos obtidos das sementes de urucum. Extrato de raiz de ginseng brasileiro, rico em saponinas, foi utilizado como biossurfactante. Adicionalmente, emulsões foram obtidas utilizando um homogeneizador tipo dispersor de fase múltipla na mesma densidade energética que foi aplicada no ultrassom. A influência do processo de emulsificação, densidade energética, concentração do biosurfactante, tipo de óleo e de biosurfactante no tamanho de gota e estabilidade da emulsão foi investigada. Os resultados indicaram que o extrato rico em saponinas pode ser uma boa opção para formulação de emulsões para aplicação em produtos alimentícios. Miniemulsões, com tamanho de gota variando entre 0,35 e 0,83 µm, foram obtidas, sendo que os menores tamanhos de gota foram observados empregando o extrato de raiz de ginseng e o ultrassom. O processo de emulsificação influenciou estatisticamente a estabilidade das emulsões / Abstract: The presented doctoral work is divided into two main themes under which one is about the use of supercritical technology for particle formation and the another one about the use of ultrasound for emulsion formulation. A literature review about the state of the art in using supercritical CO2 for micro and nanoparticles formation and encapsulation showed the potential of this technology. A homemade experimental apparatuses constructed by our research group and used for micro and nanoparticles formation has been validated using a model substance, the ibuprofen sodium salt. This drug was selected due to the literature information of the CO2-Ibuprofen system. The effect of operational conditions (temperature, pressure, CO2 flow rate, solution flow rate, injector and concentration of ibuprofen sodium in the ethanol solution) on the precipitation yield, energy consumption per unit of manufactured product, residual solvent content and particle morphology have been investigated using split-plot designs. Ibuprofen sodium salt was successfully micronized by Antisolvent Supercritical (SAS) using the constructed unit. The CO2 flow rate influenced the precipitation yield at statistically significant levels meanwhile none operating parameters did influence the residual solvent content in the micronized particles. Selecting appropriate process conditions, it has been shown to facilitate the production of homogeneous sheet-like microparticles of ibuprofen particles, the best for tableting purposes, with low residual solvent and high precipitation yield. In this work, the use of ultrasound has been also explored for fabricating microemulsion of 'delta'-tocotrienol-rich oil in order to add value to these extracts obtained from annatto seeds using supercritical extraction (SFE). The main pigments of annatto seeds are bixin and norbixin, wich are valuable natural colorants. However, these seeds have acquired notoriety by containing other important substances for human health, such as tocopherols, tocotrienols and geranylgeraniol. Due to the bioactive compounds importance, which have moisturizers, sunscreens and antioxidant properties, this study aimed to develop methods for emulsion formulation enabling the protection of these unstable compounds to adverse conditions, thus increasing the value of extracts from annatto seeds. Saponin-rich extract from Brazilian ginseng roots was used as biosurfactant. Additionally, emulsion was generated through mechanical stirring by dispax Reactor at the same energy density than ultrasound. The influence of the emulsification process, energy density, oil type, biosurfactant type and biosurfactant concentration on the size and stability of the resulting droplets was investigated. The results indicated that saponin-rich extract might be an attractive biosurfactant choice for emulsion formulations for use in food and beverage products. Mini-emulsions were obtained in this work; their droplet sizes ranged from 0.35 to 0.83 µm, saponin-rich extract and ultrasound gave the smallest droplet size. The emulsification process significantly affected the emulsion stability values / Doutorado / Engenharia de Alimentos / Doutora em Engenharia de Alimentos