Dans une logique d’éco-conception et de développement durable, de nombreux travaux ont pour objectif l’étude de polymères biosourcés. Parmi les recherches menées à ce jour, une piste d’étude consiste à les structurer aux échelles micro et nanoscopiques tout en valorisant certaines de leurs propriétés spécifiques, l’objectif étant la création de matériaux à propriétés fonctionnelles originales et performantes. Dans ce contexte, une attention particulière a été portée sur l’utilisation du dioxyde de carbone supercritique (CO2-sc). En effet, sa capacité à se solubiliser en grande quantité dans de nombreux polymères et donc d’en modifier les propriétés (viscosité, tension interfaciale, …) peut permettre une amélioration des matériaux composites fabriqués. Ce projet s’intéresse plus particulièrement à l’élaboration d’assemblages de biopolymères nanostructurés et revêt deux enjeux principaux : (1) la synthèse de nanoparticules de biopolymères (dans notre cas, du chitosane), (2) l’élaboration d’assemblages de biopolymères nanostructurés. La première étape a consisté à concevoir et développer de nouveaux procédés de génération de nanoparticules de chitosane par des procédés utilisant le CO2-sc soit comme antisolvant soit comme agent de dissolution et d'atomisation. Pour la deuxième étape, des films composites à base de poly (acide lactique) PLA et de poly (hydroxybutyrate-co-valérate) PHBV ont été préparés par la voie hot-melt par extrusion bi-vis. Des analyses thermiques, moléculaires et structurales, morphologiques et de granulométrie ont permis de caractériser les films biocomposites ainsi produits. / In a logic of eco-design and sustainable development, many works aim to study the bio-sourced polymers. Among these studies, a promising concept consists in structuring materials at micro and nanoscales while enhancing some of their properties, the objective being the creation of original materials with improved functional properties and performance. In this context, particular attention has been paid to the use of supercritical carbon dioxide (sc-CO2). Its ability to dissolve into many polymers in large quantities and thus to change their properties (viscosity, interfacial tension, ...), can improve both the composite material and its manufacturing process. This project focuses on the development of nanostructured biopolymers and addresses two main issues: (1) the synthesis of biopolymer nanoparticles (in this case, chitosan), and (2) the development of nanostructured biopolymers. The first step consisted in designing and developing new processing methods to generate biopolymer nanoparticles, using sc-CO2 as antisolvent agent or as dissolving and atomizing agent. For the second step, poly (lactic acid) PLA and poly (hydroxybutyric-co-hydroxyvaleric acid) PHBV based composite films were prepared by a hot-melt process by twin-screw extrusion of the nanoparticles and the matrix. Thermal, molecular and structural analysis, as well as morphological and particle size distribution studies allowed a good characterization of the biocomposite films.

Supercritical fluid chromatography (SFC) is an expanding chromatographic technique that is part of the evolving field of green chemistry due to its short run times and use of non-toxic solvents in combination with recycled CO2. The use of a suitable column is essential for separation science in general and there is a wide variety of SFC compatible columns available on the market. In collaboration with the AstraZeneca Gothenburg Separation Science Laboratory (SSL), an investigation of 25 stationary phases in combination with four different mobile phases was conducted in order to evaluate interactions between the mobile phase, stationary phase and analytes. The aim was to find a new column set, able to operate with a wide range of molecules at both analytical and preparative scale. The 36 compounds analysed were chosen to represent the chemical space suitable for current and foreseen compounds of interest within AstraZeneca. Furthermore, to mitigate the risk of degradation of sensitive compounds in basic conditions, different combinations of basic stationary phases and neutral mobile phases were investigated.The study was performed using a Waters Acquity UPC2 system equipped with a photodiode array (PDA) detector and a single quadrupole detector (SQD). The data was gathered by Empower 3 and analysed using statistical methods to evaluate corelations and orthogonality with the help of Python. Visualisations were produced using Pandas, XLstat and SIMCA.The results evaluated retention time, symmetry factor, distribution of retention times of compounds over the columns, and DMSO retention. The results showed that MeOH and the basic additive NH3 included in the mobile phase composition provided the shortest retention times, best peak symmetry and distribution of compounds. It was concluded that Kromasil 2EP, Kromasil Diol, DC Pak PBT, and Kromasil NH2 columns represent a diverse set for the intended chemical space. They all also operate with good results without additive, for the compounds used. / Superkritisk vätskekromatografi (SFC) är en växande kromatografisk teknik som tack vare sina snabba analyser, användandet av icke toxiska lösningsmedel, samt återvinningsbar CO2 utgör en del av den allt mer populära “gröna” kemin. Det finns en mängd kolonner utvecklade för SFC på marknaden, och att använda rätt sorts stationär fas är en viktig del för separationen av olika ämnen. I samarbete med Separation Science Laboratory på AstraZeneca i Göteborg, har 25 olika stationära faser i kombination med fyra mobila faser studerats för att analysera interaktionerna mellan faserna och analyterna. Målet är att hitta en uppsättning av kolonner som kan användas vid upprening av substanser med en stor variation av kemiska egenskaper/deskriptorer. För den här studien har 36 molekyler som representerar den kemiska rymd som AstraZeneca jobbar i använts. För att minimera risken av nedbrytning av känsliga molekyler i basiska miljöer, är även basiska kolonner med neutrala mobilfaser inkluderade. Under studien användes SFC systemet Acquity UPC2, utrustad med en Diode array detektor, en Single quadrapole detektor samt Empower 3 för insamling av data. Den statistiska analysen utfördes i Python och visualiseringen gjordes med hjälp av Pandas, Xlstat och Simca.Resultaten utvärderades med avseende på retentionstid, symmetrifaktorn, fördelningen av substanser över kolonnerna och retention av DMSO. Resultaten visade att MeOH med NH3 som additiv i mobilfasen gav kortast retentionstid, bäst symmetri och bredast fördelning av substanser. Slutsatserna var att kolonnerna Kromasil 2EP, Kromasil Diol, DC Pak PBT, and Kromasil NH2 tillsammans representerar den diversa uppsättning av kolonner som passar den kemiska rymnd som användes i studien. Samtliga kolonner kan även köras med goda resultat i neutrala mobila faser, med de betingelser som använts.

Amid growing environmental concern and continuous depletion of natural resources (such as water), the textile industry is constantly searching for sustainable production process. Traditional dyeing processes, notorious for their enormous water consumption, have led society to search alternative dyeing method. Super critical carbon dioxide (scCO2), emerging as a promising dyeing medium shows a potential solution to mitigate water utilization, consequently raising sustainable textile material wet processing. As this innovative technology characterize by its waterless nature, no effluents are generated and conserves enormous amount of water, energy while increasing productivity. Although it has attained commercial focus in polyester fabric dyeing, the imperative remains to reduce energy demand during dyeing process including commercially available dyes. As a result, the optimization of dyeing conditions assumes crucial importance, broadening the feasibility of these eco-friendly dyeing techniques. The objective of this thesis work is to find out the optimum dyeing conditions of polyester (PET) fabric dyeing with an azo disperse dye (Corangar orange PE3330) utilizing supercritical carbon dioxide (scCO2) as a dyeing medium. The investigation aims to unravel the dynamic correlation withing scCO2 dyeing conditions and dye performance. To conduct this study, comprehensive methodology employing a statistical design of two-level three-factor (23) full factorial design was adopted. The studied factors enclose temperature, pressure and dyeing durations, enclosing ranges of 80-1200C, 10-25Mpa and 1-2 hours respectively. Dye concentration was kept constant at 0.2%. The study looks for individual conditions of studied parameters and their impacts on color strength (K/S). Moreover, an analysis of color fastness attributes, comprising washing, sublimation, rubbing and extraction, is carried out. The statistical analysis shows that the prominence of pressure and temperature as the principal factors in scCO2 dyeing medium. Differential scanning calorimetry (DSC) analysis proves the negligible morphological transition in PET fabric following dyeing (crystallinity % for dyed and undyed fabric is 28.80 and 28.42% respectively). Findings also shows that comparable color properties to the traditional standard of PET fabric can be obtained by adapting dyeing pressure (20Mpa) and time (1 hour) while keeping the dyeing temperature (1200C). The findings concluded that satisfactory color strength (K/S) and color fastness related to the standard scCO2 dyeing process can be obtain with reduced energy and pressure. The outcome of this study subtle the relationship between temperature, pressure, and time towards color strength (K/S) and color fastness properties. Nonetheless, investigation of this study remained confined to laboratory-scale and for the purpose to upscale this finding for commercial use, it is crucial to carry out rigorous industrial trials.

No description available.

This thesis aims at a deeper understanding of Supercritical Fluid Chromatography (SFC). Although preparative SFC has started to replace Liquid Chromatography (LC) in the pharmaceutical industry - because of its advantages in speed and its less environmental impact - fundamental understanding is still lacking. Therefore there is no rigid framework to characterize adsorption or to understand the impact of changes in operational conditions.   In Paper I we demonstrated, after careful system verification, that most methods applied to determine adsorption isotherms in LC could not be applied directly in SFC. This was mainly due to operational differences and to the fact that the fluid is compressible which means that everything considered constant in LC varies in SFC.   In Paper II we showed that the most accurate methods for adsorption isotherm determination in LC, the so called plateau methods, do not work properly for SFC. Instead, methods based on overloaded profiles should be preferred.   In Paper III a Design of Experiments approach was successfully used to quantitatively describe the retention behavior of several solutes and the productivity of a two component separation system. This approach can be used to optimize SFC separations or to provide information about the separation system.   In Paper IV severe peak distortion effects, suspected to arise from injection solvent and mobile phase fluid mismatches, were carefully investigated using experiments and simulations. By this approach it was possible to examine the underlying reasons for the distortions, which is vital for method development.   Finally, in Paper V, the acquired knowledge from Paper I-IV was used to perform reliable scale-up in an industrial setting for the first time. This was done by carefully matching the conditions inside the analytical and preparative column with each other. The results could therefore provide the industry with key knowledge for further implementation of SFC. / This thesis aims at a deeper understanding of Supercritical Fluid Chromatography (SFC). Although preparative SFC has started to replace Liquid Chromatography (LC) in the pharmaceutical industry - because of its advantages in speed and its less environmental impact - fundamental understanding is still lacking. Therefore there is no rigid framework to characterize adsorption or to understand the impact of changes in operational conditions.   In Paper I-II it was demonstrated why most methods applied to determine adsorption isotherms in LC could not be applied directly for SFC. Methods based on extracting data from overloaded profiles should be preferred.   In Paper III a Design of Experiments approach was successfully used to quantitatively describe the behavior of several solutes in a separation system. This approach can be used to optimize SFC separations or to provide information about the separation system.   In Paper IV severe peak distortion effects often observed in SFC were carefully investigated and explained using experiments and simulations.   Finally, in Paper V, the prerequisites for performing reliable and predictable scale-up of SFC were investigated by small and large scale experiments. / <p>Paper 4 ("Evaluation of scale-up from analytical to preparative...") ingick som manuskript med samma titel i avhandlingen. Nu publicerad. </p>

The behaviour and impact of pharmaceuticals in the environment are still poorly understood. Pharmaceuticals are widely used and continually released into the environment causing increasing concerns about their impact on the environment beyond the intended human or veterinary use. Prescribed pharmaceuticals, typically, enter the environment either through excretion after human use or disposal of surplus medication. Sewage treatment plants do not completely remove pharmaceuticals and their metabolites and these have been detected in sewage treatment plant effluent and receiving waters. Land application of treated sewage effluent is widely practiced in New Zealand as an alternative to surface water discharge. Methods were developed to determine selected pharmaceuticals in environmental matrices such as sewage effluent, sewage solids, soil, and soil water. From these, pharmaceutical removal efficiencies were determined for three common sewage treatment processes; activated sludge, composting and land application of sewage effluent. The impacts of some common pharmaceuticals on soil microbial communities, together with the effect of prolonged exposure to sewage effluent on these communities were examined. Additionally, toxicity of sewage effluent, and toxicity mechanisms of specific pharmaceuticals were investigated using luminescent micro-organisms and lettuce seedlings. Pharmaceuticals were successfully detected in sewage effluent, sewage solids, compost, soil and soil water. The sewage treatment processes investigated, including land application, were able to remove or reduce pharmaceutical concentrations in sewage. In case of land application, volcanic soils were more efficient than sandy soils in pharmaceutical removal while irrigation rate and level of sewage pre-treatment also showed some effect on removal efficiency. Pharmaceuticals were not acutely toxic at environmental levels currently detected. Exposure of microbial communities to unnaturally high levels of pharmaceuticals did demonstrate that most pharmaceuticals were potentially able to induce stress in the microbial community although microbes were able to metabolise some of these pharmaceuticals. Twelve years of effluent irrigation resulted in microbial adaptation to aspirin, acetaminophen and tetracycline, indicating that these pharmaceuticals had an effect on microbial community. Presently, land application of treated sewage waste may be a suitable treatment for additional pharmaceutical removal provided that land application schemes are designed appropriately, and pharmaceutical accumulation in the soil is occasionally monitored. It would be prudent to recognise the potential risk that could be caused by chronic exposure to pharmaceuticals such that continued vigilance may lead to future indications of chronic effects at an early stage.

Contaminantes orgânicos há tempos são normalmente encontrados em baixíssimas concentrações no meio ambiente. Compostos orgânicos monoaromáticos, derivados dos subprodutos do petróleo, frequentemente são encontrados próximos a postos de combustíveis, onde há constantes vazamentos nos tanques de armazenamento. Poluentes emergentes, como exemplo os fármacos, também são temas constantes de pesquisas, devido à baixa taxa de degradação dos mesmos, mesmo após submetidos a sistemas de tratamento convencionais. Assim, a busca por técnicas de remediação, que visem a completa remoção de poluentes em baixas concentrações e metodologias analíticas que permitam o isolamento e detecção de tais compostos se torna essencial. Esse trabalho tem como uma de suas finalidades otimizar e aplicar um sistema de remoção de compostos orgânicos monoaromáticos presentes em solo, utilizando CO2 no estado supercrítico. A SPME-GC-MS foi otimizada e validada para a etapa de extração, com separação e quantificação por GC-MS dos contaminantes remanescentes após o solo ser submetido ao processo de remediação. Outro etapa do projeto, está relacionada com a determinação de sulfonamidas em lodo de esgoto. Para isso, um método rápido, fácil, barato e robusto de extração foi otimizado e validado, obtendo bons limites de quantificação (10-25 ng g-1) e detecção (4-9 ng g-1), com precisão e exatidão satisfatórios, de acordo com os valores estabelecidos pela ANVISA. Ainda com o propósito de determinar sulfonamidas em lodo de esgoto, um método LC online foi desenvolvido. A finalidade é promover o clean-up da matriz e extração dos analitos em um sistema de extração em fase sólida capilar online. Para isso, fez uso de duas colunas capilares (530 µm x 6,0 cm) dispostas em série, inseridas em um sistema cromatográfico capilar acoplado a detecção por espectrometria de massas. A primeira coluna teve como finalidade a retenção de interferentes presentes na amostra utilizando para isso, uma fase polimérica Strata-X. Já a segunda coluna, extraiu as sulfonamidas de interesse utilizando, para isso, uma fase polimérica aniônica Oasis Max. O extrato inserido no sistema de extração em fase sólida onlineera composto por 100 % solvente orgânico (acetonitrila); utilizando diferentes porcentagens de acetonitrila na etapa de carregamento, foi possível realizar clean-up adequado da amostra. A eluição dos analitos foi feita utilizando-se fase móvel acidificada. Com esse sistema, melhorou-se em até 30 % a extração de alguns compostos. Todos os métodos de preparo de amostra utilizados no trabalhos seguem a tendência atual sugerida pelo conceito do green chemistry. / The determination of organic contaminants in environmental matrices has long been a challenge for the scientific community, due to the very low concentrations they are present. Monoaromatic organiccompounds derived from petroleum sub-products are still a concern, because they are often found in environmental sites near gas stations, where there are constant leaks in storage tanks. Emerging pollutants,which include personal care products and pharmaceuticals, are also constant subject of research due to their low degradation rate, even after conventional treatment systems. Moreover, the research forremediation techniques aimed at complete removal of pollutants at low concentrations, as weel as new analytical methodologies for isolation and detection of such compounds are, both, essential. This workaims to optimize and apply a system to remove monoaromatic organic compounds present in soil, using CO2 in the supercritical state. As an analytical tool, SPME was optimized and validated with separation and quantification by GC-MS of selected contaminants remaining after the remediation process. Another research work developed is related to the determination of sulfonamides in sewage sludge.Firstly a methodology based on QuEChERS extraction method was optimized and validated, obtaining good results as limits of quantification, LOQ (10-25 ng g-1) and detection, LOD (4-9 ng g-1) withsatisfactory accuracy and precision, according to the values established by ANVISA. Still working to determine sulfonamides in sewage sludge, a new online sample preparation method was developed. Thepurpose of this method is to promote the matrix clean-up and concentration analytes in a capillary SPE system. It was used two capillary columns (500 µm x 6.0 cm) arranged in series in a capillarychromatographic system coupled to mass spectrometry. The first column was intended to retain interferences present in the sample, using a Strata-X polymer phase. The second column extracted sulfonamidesof interest, making use of an anionic polymer phase (Oasis MAX). The extract inserted in the online SPE system was composed of 100% organic solvent (acetonitrile); using different percentages of ACNwith appropriately pH at the loading stage, it was possible to achieve a satisfatory sample clean-up. The elution of the analytes was performed using an acidified mobile phase. This system improved by up to30% extraction yield of some compounds. All sample preparation methods used in the works follow the current trend suggested by the green chemistry concept.

Enquanto as amêndoas de babaçu são conhecidas por fornecer óleo rico em zinco, fósforo e potássio, seu mesocarpo possui propriedades anti-inflamatórias ainda pouco exploradas. Este estudo visou determinar a composição físico-química e o potencial de toxicidade in vivo do óleo de amêndoas de babaçu e da farinha de seu mesocarpo (ambos extraídos com CO2 supercrítico) bem como avaliar a atividade anti-inflamatória do mesocarpo (extraído com etanol pressurizado). Os extratos foram obtidos via técnicas inovadoras de extração que evitam a degradação de compostos termossensíveis e os resultados aqui alcançados apontam para a composição de extratos obtidos via tecnologia verde e sua caracterização. A extração com fluido supercrítico (SFE) é uma tecnologia limpa (pois não emprega solventes orgânicos) e promissora para obter extratos enriquecidos em compostos com atividade biológica como, por exemplo, fitosterois. Por sua vez, a extração com líquido pressurizado (PLE) é considerada rápida, eficiente e seletiva, sendo este trabalho o primeiro a isolar os flavonoides do extrato etanólico do mesocarpo de babaçu extraído via PLE. Os resultados indicaram que os maiores rendimentos de extração do óleo foram de 55,34 g/100g usando álcool isopropílico como solvente pressurizado e de 53,12 g/100g usando etanol. Tais rendimentos representam 92,4 e 88,7% do total de óleo nas sementes, respectivamente. Rico em ácidos láurico, mirístico, oleico e palmítico, o perfil de ácidos graxos foi o mesmo para os dois solventes nas condições operacionais utilizadas. Com uso de álcool isopropílico, o extrato apresentou a maior concentração de &beta;-sitosterol mediante 3 min de contato com o solvente (St) e 66% de volume de solvente (&cong; 7,48 mL, SV). Com uso de álcool etílico, a maior concentração de &beta;-sitosterol ocorreu para 3 min de tempo de contato (St) e 94% (&cong; 10,25 mL) de volume de solvente (SV). Em função da composição de ácidos graxos, os principais TAGs presentes no óleo foram COL, LOL, LOM, LOP e MOP. Na SFE, os maiores rendimentos do óleo de babaçu variaram de 51,94 a 57,71 g/100g (para 25 MPa) e de 53,65 a 59,93 g/100g (para 35 MPa), para temperaturas de 40, 50, 60, 70 e 80 °C. A maior concentração de &beta;-sitosterol (27,43 mg/100g de óleo) foi obtida na extração a 70 °C e 25 MPa. Os extratos do mesocarpo de babaçu também foram obtidos via PLE com etanol pressurizado. O maior rendimento (2,95%) e a maior concentração de fenólicos totais (1.257,25 mgGAE/100g) de pó dos extratos do mesocarpo de babaçu foram obtidos a 86 °C e 3 min (St). A maior atividade antimicrobiana na inibição de Staphylococcus aureus ocorreu extrações com menores tempos de contato (St) e elevadas temperaturas (na faixa supra), condições que também propiciaram os melhores rendimentos de extração e atividade antioxidante. O estudo de toxicidade foi feito para o óleo de amêndoas de babaçu obtido via SFE. Na dose aguda de 2.000 mg/kg e no estudo subagudo nas doses de 1, 3 e 5 mg/kg de óleo (doses repetidas), os resultados indicaram que este óleo não apresenta letalidade aos animais. Para avaliar a atividade anti-inflamatória foi utilizado o extrato do mesocarpo de babaçu obtido com etanol pressurizado a 86 °C e 3 min (St). Tal atividade foi confirmada para a dose de 30 mg/kg, administrada em ratos com processo inflamatório induzido com carragenina a 3%. Embora tenham sido constatadas a baixa toxicidade do óleo e a atividade anti-inflamatória do extrato do mesocarpo, mais estudos de avaliação toxicológica são necessários para aplicações do óleo de amêndoas e do extrato de mesocarpo de babaçu em produtos farmacêuticos, alimentícios e/ou cosméticos. / While babassu almonds are known for providing oil rich in zinc, phosphorus and potassium, its mesocarp has anti-inflammatory properties yet underexplored. The present study aimed at determining physical-chemical composition and in vivo toxicity potential of babassu almonds oil and its mesocarp flour (both extracted with supercritical CO2) as well as anti-inflammatory activity of babassu mesocarp (extracted with pressurized ethanol). Extracts were obtained using innovative extraction techniques that avoid the degradation of thermosensitive compounds and results here obtained point to the composition of extracts obtained via green technology and their characterization. Supercritical fluid extraction (SFE) is a promising clean technology (as organic solvents are not employed) to obtain extracts enriched in compounds with biological activity (e.g. phytosterols). In its turn, pressurized fluid extraction (PFE) is considered fast, efficient and selective, this work being the first to isolate flavonoids from ethanolic extract of babassu mesocarp extracted via PLE. Results indicated that highest extract yields of babassu oil were 55.34 g/100 g with isopropyl alcohol as pressurized solvent and 53.12 g/100 g with ethanol as solvent. Aforesaid extracts respectively represent 92.4% and 88.7% of total oil in seeds. Rich in lauric, myristic, oleic and palmitic acids, the fatty acid profile was the same for the two solvents and applied operating conditions. Using isopropyl alcohol, extract had the highest &beta;-sitosterol concentration for 3 min contact time with solvent (St) and 66% of volume of solvent, &cong; 22.44 mL (SV). Using ethyl alcohol as solvent, highest &beta;-sitosterol concentration occurred for St = 3 min and SV = 94% &cong; 31.96 mL. According fatty acids composition, main TAGs present in oil were COL, LOL, LOM, LOP and MOP. In SFE, highest yields of babassu oil ranged from 51.94 to 57.71 g/100 g (at 25 MPa) and from 53.65 to 59.93 g/100 g (at 35 MPa) at temperatures of 40, 50, 60, 70 and 80 °C. The highest concentration of &beta;-sitosterol (namely, 27.43 mg/100g-oil) was obtained for extraction at 70 °C and 25 MPa. Babassu mesocarp extracts were also obtained via PLE with pressurized ethanol. The highest yield (2.95%) and the highest total phenolic concentration (1,257.25 mgGAE/100g) of babassu mesocarp extract were obtained at 86 °C and 3 min (St). The highest antimicrobial activity in Staphylococcus aureus inhibition occurred for lower contact time (St) values and higher temperatures (in aforesaid values), which were conditions also providing the best extraction yields and antioxidant activity. Toxicity study was carried out for babassu almond oil obtained via SFE. At the acute dose of 2,000 mg/kg and in subacute dose study at 1, 3 and 5 mg/kg of oil (repeated doses), results indicated that this oil did not present lethality in animals. Anti-inflammatory activity was evaluated by using babassu mesocarp extracted with pressurized ethanol at 86 °C and 3 min (St). Such activity was confirmed at 30 mg/kg dose administered in rats with induced inflammatory process with carrageenan at 3%. While low toxicity of oil and anti-inflammatory activity of mesocarp extract were both observed, further evaluation studies are required for applications of almond oil and babassu mesocarp extracts in pharmaceutical, food and/or cosmetic products.

Orientadores: Mirna Lucia Gigante, Rafael Jimenez-Flores / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-09-11T21:12:34Z (GMT). No. of bitstreams: 1 Costa_MarceladeRezende_D.pdf: 1269005 bytes, checksum: be9b972dd7766eba5cc6917dd666c5f0 (MD5) Previous issue date: 2008 / Resumo: O leitelho de soro é um subproduto do processamento de manteiga a partir do creme de soro. Esse subproduto lácteo contém fragmentos da membrana do glóbulo de gordura do leite (MGGL), material rico em componentes com funções nutricionais e efeitos benéficos à saúde, destacando-se os fosfolipídeos. O objetivo desse trabalho foi obter um ingrediente lácteo enriquecido em fosfolipídeos da MGGL a partir do leitelho de soro utilizando a associação de duas tecnologias de fracionamento: ultrafiltração e extração com fluido supercritico (EFS). O leitelho de soro foi submetido à ultrafiltração e a cinco diafiltrações a 25 °C e o retentado obtido foi seco em spray-dryer, obtendo-se o leitelho de soro em pó (LSP), o qual foi submetido a três ciclos de extração a 50 °C com dióxido de carb ono supercrítico. As matériasprimas, produtos finais e uma amostra comercial de leitelho tradicional em pó (LTP) foram analisados quanto a sua composição centesimal, teor de fosfolipídeos, perfis lipídico e protéico. Os leitelhos de soro em pó, submetidos ou não à EFS, e o LTP foram avaliados quanto ao tamanho de partículas e suas propriedades funcionais (solubilidade protéica e capacidade emulsificante) em pH 5 e 7. A filtração em membrana reduziu em 74 e 96% os teores de lactose e cinzas no retentado e aumentou os de proteínas, lipídeos e fosfolipídeos em 91, 190 e 300%, respectivamente. A EFS reduziu em 55,4% o teor de lipídeos, removendo exclusivamente lipídeos apolares, com isso aumentou em 71% o teor de fosfolipídeos no leitelho de soro em pó, resultando em um produto com 73% de proteínas, 21% de lipídeos, 3% de lactose, 3% de cinzas e 12% de fosfolipídeos, em base seca. As propriedades funcionais dos leitelhos de soro em pó, submetidos à extração supercrítica (LSP-EFS) ou não (LSP), foram pouco ou não afetadas pelo pH, enquanto o abaixamento de pH prejudicou as características do LTP, devido ao alto teor de caseínas nesse tipo de pó em relação aos de leitelhos de soro. Os pós em soluções (5% de proteína) apresentaram de 69 a 84% de suas partículas, em % volumétrica, entre 10 e 100 µm. A solução de LTP em pH 5 foi a que apresentou a maior quantidade de partículas acima de 100 µm. LSP e LSP-EFS apresentaram solubilidades protéicas em torno de 86 e 84%, respectivamente, independente do pH. O LTP teve a solubilidade reduzida de 86 para 73% quando o pH foi reduzido de 7 para 5. Em pH 7, as emulsões (20% óleo de canola, 1% proteína) de LSP e de LSPEFS apresentaram melhor estabilidade (IC de 0,2 e 0,4%, respectivamente) do a emulsão de LTP (IC de 3,0%). Em pH 5, a emulsão de LSP-EFS foi a que mostrou melhor estabilidade, apresentando um IC de 7%, valor cerca de 82% menor do que os das emulsões de LSP e LTP. Os leitelhos de soro em pó obtidos podem ser considerados ingredientes com características promissoras, associando propriedades tecnológicas, especialmente para uso em alimentos de baixo pH, e conteúdo de compostos potencialmente benéficos à saúde, principalmente após o tratamento com extração supercrítica / Abstract: OBTENTION OF DAIRY INGREDIENT ENRICHED IN POLAR LIPIDS FROM WHEY BUTTERMILK. Whey buttermilk is a by-product from the whey cream processing into butter. This dairy by-product contains milk fat globule membrane (MFGM) fragments, a material rich in components with nutritional functions and beneficial health effects, especially phospholipids. The objective of this research was obtaining a dairy ingredient enriched in MFGM phospholipids from whey buttermilk using the association of two fractionation technologies: ultrafiltration and supercritical fluid extraction (SFE). Whey buttermilk was submitted to ultrafiltration and five diafiltrations at 25 °C. The retentate was spray-dried and later s ubmitted to three cycles of extraction at 50 °C with supercritical carbon dioxi de. Raw materials, final products and a commercial traditional buttermilk powder sample (BMP) were analyzed for gross composition, lipid and protein profiles, and phospholipids content. Whey buttermilk powders, before and after the SFE, and the BMP had particle size and some functional properties (protein solubility and emulsifying capacity) evaluated in pH 5 and 7. Membrane filtration reduced in 74 and 96% lactose and ash contents in the retentate and increased proteins, lipids and phospholipids in 91, 190 and 300%, respectively. SFE reduced in 55.4% the lipids content, removing exclusively non-polar lipids, while increased in 71% the phospholipids content in whey buttermilk powder, resulting in a product with 73% of proteins, 21% of lipids, 3% of lactose, 3% of ash and 12% of phospholipids, in dry matter basis. Functional properties of the whey buttermilk powders, treated (WBP-SFE) or not through SFE (WBP), were little or not affected by pH, while dropping the pH impaired the BMP features, due the high casein content in this type of powder in relation to the ones from whey buttermilk. The powders in solutions (5% protein) presented from 69 to 84% of the particles, in volume%, between 10 and 100 µm. The BMP solution in pH 5 was the one with the biggest amount of particles above 100 µm. WBP and WBP-SFE showed protein solubilities around 86 and 84%, respectively, independent of pH. BMP had the solubility reduced from 86 to 73% when pH was reduced from 7 to 5. In pH 7, the emulsions (20% canola oil, 1% protein) of the WBP and the WBP showed better stability (CI of 0.2 and 0.4%, respectively) than the BMP emulsion (CI of 3.0%). When in pH 5, WBP-SFE emulsion had the best stability, presenting CI of 7%, value about 82% smaller than the ones of WBP and BMP emulsions. Whey buttermilk powders obtained in this work can be considered ingredients with promising features, combining technological properties, especially for use in low pH foods, and content of components with potential health benefits, mainly after the supercritical extraction treatment / Doutorado / Doutor em Tecnologia de Alimentos

Este projeto de pesquisa, com o apoio dos pequenos produtores de café do Estado de São Paulo/Brasil, visou estudar e caracterizar o óleo de grãos de café verde obtido pela extração supercrítica e extração com fluido pressurizado. Foi feita a caracterização deste produto, considerando os componentes minoritários com atividade biológica demonstrada na literatura, como os componentes fenólicos e os diterpenos cafestol e kahweol. Com o objetivo de obter o óleo de café verde enriquecido, principalmente nestes dois principais diterpenos, componentes relevantes para as indústrias cosmética e farmacêutica, aplicaram-se como inovação tecnológica a extração supercrítica (SFE) e extração com fluido pressurizado (PFE). Os ensaios de extração foram realizados no Laboratório a Alta Pressão e Produtos Naturais (FZEA/USP/Brasil) para as SFE e no Laboratoire de Procédés (IUT/Université d\'Orléans/França) para PFE. No desenvolvimento da metodologia de análise dos diterpenos foram realizados estudos do método de saponificação do óleo de café verde Arabica (Coffea arabica) cv. Catuaí amarelo, obtido por prensagem (OP). E, concomitantemente a este estudo analítico, foram feitas as extrações do óleo dos mesmos grãos de café verde via SFE e PFE. Os diferentes óleos de grãos de café verde, obtidos pelos três métodos de extração foram analisados e comparados entre si considerando principalmente a concentração dos diterpenos. A metodologia analítica desenvolvida na primeira fase do trabalho constatou que para uma melhor análise dos diterpenos a reação de saponificação deve ser feita utilizando NaOH e a 70 °C. A fração insaponificável foi analisada para os diferentes extratos. Para os extratos obtidos via SFE, a cafeína teve que ser separada do óleo. A análise de quantificação dos diterpenos via cromatografia gasosa, utilizando o próprio cafestol e kahweol como padrão externo, indicou que o óleo obtido por SFE apresentou 50.180,41 mg cafestol/kg óleo e 63.764,32 mg kahweol/kg óleo na condição otimizada. Para a PFE as concentrações máximas obtidas foram de 65.876,29 mg cafestol/kg óleo e 53.328,47 mg kahweol/kg óleo e, no óleo de café verde obtido pelo método convencional a concentração dos diterpenos mostrou-se inferior com 7.508 mg cafestol/kg óleo e 12.822 mg kahweol/kg óleo. As propriedades físicas medidas visando a caracterização do óleo dos grãos de café verde obtido por SFE e prensagem dos grãos indicaram que tanto a densidade quanto a viscosidade diminuem com o aumento da temperatura. Para ambos os óleos, os comportamento da densidade foi semelhante, para aquele obtido pelo método convencional, os valores variaram de 0,94177 g/cm3 (25 °C) a 0,92143 g/cm3 (55 °C) e para o óleo obtido por SFE a variação foi de 0,93645 g/cm3 (25 °C) a 0,9157 g/cm3 (55 °C). A viscosidade dinâmica para o óleo obtido por prensagem variou de 127,8798 mPa×s (25 °C) a 35,0510 mPa×s (55 °C) e, para o óleo obtido por SFE, estes valores foram menores, entre 84,0411 mPa×s (25 °C) e 24,2555 mPa×s (55 °C). O índice de refração para ambos os óleos foi semelhante. Na extração com fluido pressurizado, (PFE), um valor ótimo de rendimento do extrato foi obtido quando se empregou metanol como solvente para uma temperatura de 100 °C e tempo de equilíbrio estático de 20 min. Este valor foi 183% superior a media dos resultados obtidos nos outros ensaios. Na concentração de diterpenos nestes extratos, nota-se também que o etanol foi menos eficiente que o metanol. Na comparação dos dois processos inovadores (SFE e PFE), a concentração de kahweol apresenta-se como o principal componente em quase todos os ensaios, com valores da relação cafestol/kahweol entre 0,73 e 0,96. No entanto, ao ser analisado o processo individualmente, percebe-se que a extração com fluido supercrítico indica que a maioria dos extratos obtidos teve uma concentração de kahweol superior ao cafestol. / This research project, with the support of small coffee producers in the State of São Paulo/Brazil, aimed to study and characterize the green coffee oil obtained by the supercritical fluid extraction and pressurized fluid extraction. Was made to characterize this authentic product, considering the minor components with biological activity demonstrated in the literature, such as phenolic compounds and diterpenes cafestol and kahweol. In order to get the green coffee oil enriched, mainly in these two major diterpenos, components relevant to cosmetic and pharmaceutical industries, applied technological innovation as the supercritical fluid extraction (SFE) and pressurized fluid extraction (PFE). The extraction tests were performed at the High Pressure Laboratory and Natural Products (FZEA/USP/Brazil) for SFE and the Laboratoire de Procédés (IUT/Université d\' Orléans/France) for PFE. In the development of methodology for analyzing diterpenes were conducted studies on the method of saponification of the green oil Arabica coffee (Coffea arabica) cv. yellow Catuaí, obtained by pressing (OP). And, concomitantly this analytical study were extracted from the oil of the same green coffee beans by SFE and PFE. Different green coffee beans oils, obtained by the three extraction methods were analyzed and compared with each other considering mainly the concentration of diterpenes. The analytical methodology developed in the first phase of the work found that for a better analysis of the diterpenes saponification reaction must be made using NaOH and 70 °C. The unsaponifiable fraction was analyzed for the different extracts. Specifically for extracts obtained by SFE, caffeine had to be separated from the oil. The analysis and quantification of diterpenes made by gas chromatography, using himself as cafestol and kahweol external standard, indicated that the oil obtained by SFE showed cafestol 50,180.41 mg/kg oil and kahweol 63,764.32 mg/kg oil in optimal condition. For the PFE maximum concentrations were obtained cafestol 65,876.29 mg/kg oil and kahweol 53,328.47 mg/kg oil and the green coffee oil obtained by the conventional method the concentration of diterpenes was lower than with 7,508 mg cafestol/kg oil kahweol and 12,822 mg/kg oil. The physical measures for the characterization of oil from green coffee beans obtained by SFE and pressing the grains indicated that both the density and the viscosity decrease with increasing temperature. For both oils, the density behavior was similar, to that obtained by the conventional method, the values ranged from 0.94177 g/cm3 (25 °C) to 0.92143 g/cm3 (55 °C) and the oil obtained by the SFE variation was 0.93645 g/cm3 (25 °C) to 0.9157 g/cm3 (55 °C). The dynamic viscosity for the oil obtained by pressing ranged from 127.8798 mPa×s (25 °C) to 35.0510 mPa×s (55 °C) and the oil obtained by SFE, these values were lower, between 84.0411 mPa×s (25 °C) and 24.2555 mPa×s (55 °C). The index of refraction for both oils was similar. In the extraction pressure, (PFE), an optimal value of the extract yield was obtained when methanol was used as solvent at a temperature of 100 °C and static equilibrium time of 20 min. This value was 183% above the average of the results obtained in other tests. At the concentration of these diterpenes extracts, note also that the ethanol was less effective than methanol. In comparing the two innovative processes (SFE and PFE), the concentration of kahweol presents itself as the main component in almost all tests, compared with values of cafestol/kahweol between 0.73 and 0.96. However, the process to be analyzed individually, it is clear that the supercritical fluid extraction indicates that most of the extracts had a concentration higher of kahweol than cafestol.