The environmental bioavailability of contaminants, rather than their total concentrations in the soil compartment play a decisive role for the risks associated with contaminated sites. Various soil constituents and abiotic conditions have strong influence on bioavailability, which may vary substantially between different locations. It is therefore necessary to site-specifically use tools that reflect the fractions of contaminants that are available to biota and pose the highest potential environmental risks. Bioassays provide integrated toxic responses which include effects from unknown contaminants or combinatory toxic effects from mixtures of contaminants. Thus, biological effect data greatly contribute to establish more realistic exposure and risk-scenarios at contaminated sites. The work underlying this thesis presents possible techniques for high capacity screening for site-specific hazards at contaminated areas. By combining rapid water extractions and cell-based in vitro designs measures of the toxic potential in soils was obtained. Toxicologically bioavailable fractions of mixed metal pollution, including arsenic, were primarily investigated in this thesis. In two of the studies, environmental availability and toxicological bioavailability of arsenic was explored in CCA-contaminated soils. Application of cell-based in vitro screening techniques was also conducted at a metal contaminated industrial site to obtain spatial distribution of toxicity. Multivariate association techniques were employed in the interpretation of environmental exposure and cytotoxicity data. It was shown that cell-based in vitro systems for both basal cytotoxicity and specific end-points targeting arsenic could assess the toxic potential from extracts obtained by several water-based extraction techniques including Pressurised Liquid Extraction (PLE). The cell-based in vitro systems were found to add important information on the site-specific differences in arsenics genotoxic potential from CCA-contaminated soils. The results highlight the importance of taking speciation and toxicological bioavailability into account in the risk analysis, rather than to base risk estimates on total load of contaminants. The presented screening approach was successfully applied at a metal polluted industrial site where spatial distribution of toxicity was obtained. PLE extraction also provided means for combined toxicological and chemical screening of explosives in soils from live-fire training ranges. Multivariate association techniques highly facilitated the interpretation of complex environmental data. The PLE was found to be a rapid extraction technique that has sufficient environmental relevance to be used in environmental impact analyses. It was also concluded that other cell-based in vitro systems that target specific toxic effects have large potential for being used in screening for a variety of environmental chemicals. Keywords: Environmental availability, Environmental bioavailability, Toxicological bioavailability, mixture toxicity, hazard screening, contaminated soils, heavy metals, arsenic, CCA, explosives, soil extraction, water extracts, cell-based in vitro tests, cytotoxicity, genotoxicity, PLE, MVDA, PCA, PLS. / Föroreningars biotillgänglighet snarare än deras totala koncentration i markmiljön styr den risk som kan förknippas med förorenade områden. Biotillgängligheten är ofta långt från 100% p.g.a. en rad olika bindningsytor och processer i jorden som reducerar biotillgängligheten. Således kan biotillgängligheten variera kraftigt mellan olika förorenade platser och även inom samma plats till följd av de specifika förhållanden som råder på respektive plats. Tillämpning av biologiska indikatorer som ger ett mått på den samlade giftigheten från biotillgängliga föroreningar är därför viktiga verktyg i platsspecifika exponerings- och farobedömningar. Många biologiska tester är ofta laborativt intensiva och dyra och lämpar sig mindre väl i testning av ett stort antal prover vilket är önskvärt om en tillräcklig geografisk täckning ska uppnås över ett förenat område. Testsystem som har kapacitet att hantera många prover till en rimlig kostnad är därför mycket användbart för screening i ett inledande skede av en miljöriskanalys av ett förorenat område. Föreliggande avhandlingsarbete presenterar möjliga lösningar i att kombinera snabb vattenextraktionsmetodik med cellbaserade in vitro system för platsspecifik toxikologisk faroscreening av metallförorenade områden. Metodiken erbjuder hög kapacitet för många jordprover. Tillämpning av metodiken har gjorts mot huvudsakligen metallföroreningar, inklusive arsenik. I två delarbeten studerades två modelljordar från CCA-förorenade fastigheter avseende tillgänglighet och giftighet av framför allt arsenik. Vidare studerades om det med applicerad metodik gick att illustrera geografisk utbredning av toxicitet, mätt i cellbaserade in vitro system, som biotillgängliga föroreningar uppvisar på ett metallförorenat industriområde. Slutligen studerades lämpligheten i att använda PLE för kombinerad kemisk och toxikologisk screening av jordar från militära skjutfält som var förorenade med explosivämnen. Cellbaserade in vitro system för mätning av både generell toxicitet och mer specifika effektmarkörer för arsenik visade sig användbara vid mätning från flera vattenbaserade extraktionsmetoder, inklusive PLE (trycksatt vätskeextraktion). Resultaten visade på PLEs tillämplighet som en snabb extraktionsmetod med bibehållen relevans för miljöanalyser. Applikation av cellbaserade in vitro system på vattenextrakt från förorenad jord gav värdefull information bl.a. om platsspecifik genotoxisk potential där specieringen av arsenik hade avgörande betydelse i en fallstudie med CCA-förorenade jordar. Vattenextraktion av jordprover kombinerat med cellbaserade in vitro system kunde också ge en geografisk bild av den omedelbara faran från biotillgängliga metallföroreningar inom ett industriområde. Vattenextraktion med PLE visade sig även användbart för screening av explosivämnen där extrakten direkt kunde användas för såväl kemisk karakterisering som för toxikologisk analys. Även andra typer av in vitro system än de som användes i detta arbete har stor framtida potential för tillämpning i faroscreening av ett stort antal olika typer av miljöföroreningar.

Made available in DSpace on 2014-06-11T19:22:16Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-09-06Bitstream added on 2014-06-13T18:07:57Z : No. of bitstreams: 1 biscaro_t_me_botfca.pdf: 707769 bytes, checksum: a5322c5ecf4e0883a2d95b9be40fdd31 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Em algumas condições não se têm obtido correlações entre os teores de B do solo, extraído com água quente, o teor de boro na planta e a produtividade da soja no Estado do Mato Grosso, mais precisamente na região de Campo Novo do Parecis. Sabe-se que o boro é um nutriente fortemente adsorvido nas partículas minerais do solo. Objetivou-se com este trabalho submeter amostras de solo de uma determinada área de estudo, na qual foi cultivada soja por três anos consecutivos e posteriormente cultivado algodão, a diferentes métodos de extração de boro, a fim de se estabelecer correlações entre a dose de boro na planta, a dose de nutriente aplicada e o teor de boro no solo disponível às plantas e, ainda, com a produtividade da soja. Amostras de solo, cultivadas com soja, coletadas por ocasião da condução do experimento no campo, foram analisadas quanto à concentração de B extraída pelos métodos: água quente modificado com solução de BaCl2 1,25 g L-1 (recomendado e chamado de método da água quente pelo IAC); água quente modificado com solução de CaCl2 0,01 mol L-1,a quente e água quente tradicional (o qual é preconizado por muitos autores como o método oficial) para dessa forma, tentar quantificar a real disponibilidade de boro neste solo, caracterizado como um LATOSSOLO VERMELHO AMARELO (LVA), possibilitando a determinação de um nível crítico. Ainda, durante o período de condução do trabalho, foi feito um estudo de adsorção de B nas amostras, e um estudo do comportamento da lixiviação do nutriente em colunas de solo, procurando verificar o efeito das adubações na dinâmica do nutriente. Em relação aos métodos de extração de boro no solo, o CaCl2 foi o que apresentou correlação positiva e significativa com o boro presente no tecido vegetal nos três anos agrícolas. Os métodos do BaCl2 e... / In some conditions, doesn't have obtained correlations among boron content in soil, boron extracted by hot water, boron content in plants and soybean productivity in a region (Campo Novo do Parecis) of the state of Mato Grosso/Brazil. This work was carried out to submit soil samples from determined area of study where was tillage soybean for three subsequent years and after tillage cotton, to differents extraction methods by boron with the aim to establish correlations among, amount of boron content in plants, amount of nutrient putted in soil, boron content in soil disponible to plants and the productivity. Soil samples obtained during the conduction of experiment on field were analyzed to predict the amount of boron in soil by the methods: hot water modified with BaCl2 solution (recommended and called by hot water from IAC - Instituto Agronômico de Campinas/SP-Brazil), hot water modified CaCl2 0,01 mol L-1 solution and hot water traditional (which is preconized by many authors like the official method) to this way try to quantify the real situation of boron disponibility in this soil, characterized like a Yellow Red Latossol, to take the determination of a critical level. During the conduction period of this work was made an adsorption study in the samples, and still a study of boron leaching behavior in soil columns, to verify fertilizer effect in nutrient dynamic. The extraction method with CaCl2 presented positive and significative correlation with boron present in soybean leaves on three subsequent farm work years. BaCl2 method and hot water traditional also presented positives and significatives correlations each one in two farm work years, this results were expected in function of similarity among three methods, it's an evidence that there is a method with capacity to predict boron disponibility in soils of Mato Grosso... (Complete abstract, click eletronic address below)

Filtration of grape juice was investigated. Effects of process parameters of filtration were examined. The usage of precoating material and filter aid were found to be necessary to prolong the filter life. Filter cake was found to be incompressible with the effect of increasing pressure. Increase in temperature caused increase in flow rate due to the reduction in viscosity. The influences of depectinization and clarification on filtration process were also examined. Depectinization and clarification decreased the resistance and increased the flow rate. Improvement in the quality of the grape juice was observed when these pretreatments were employed. The effects of temperature and soluble solid concentration on physical properties of clarified fruit juices were investigated. High temperature and soluble solid content dependencies of density, viscosity and heat capacity were detected. Experimental data were fitted as a function of temperature and soluble solid content. Models being valid for studied clarified fruit juices were achieved for density and viscosity with the regression coefficients (R2) higher than 0.90. Optimization of the solid-liquid extraction conditions for trans-resveratrol, trans-&amp / #949 / -viniferin, ferulic acid, and total phenolics from milled grape canes has been investigated. Temperature and ethanol concentration were found to be major process variables for all responses. Maximum yields of trans-resveratrol, trans-&amp / #949 / -viniferin, ferulic acid, and total phenolics were predicted as 4.25 mg/g dw, 2.03 mg/g dw, 1.05 mg/g dw, and 9.28 mg/g dw, respectively. Optimization of extraction conditions for antioxidant activity of grape cane extracts measured by the Trolox equivalent antioxidant capacity (TEAC) and the oxygen radical absorbance capacity (ORACFL) assays was carried out using solid-liquid extraction and response surface methodology. Ethanol concentration and temperature employed for the extraction of antioxidant agents from grape cane samples were found to be statistically significant process variables affecting antioxidant activity measured by the TEAC and ORAC methods. trans-Resveratrol and trans-&amp / #949 / -viniferin were extracted from milled grape canes using pressurized low polarity water (PLPW). The extraction temperature was significant for both compounds: extraction at 160oC resulted in a 40% loss of trans-resveratrol compared to 95oC while reduction of trans-&amp / #949 / -viniferin at both temperatures remained at 30%. Increasing ethanol concentration from 0 to 25% increased the extraction of total phenolics and trans-&amp / #949 / -viniferin by 44% and 489%, respectively. Solvent flow rate also influenced trans-&amp / #949 / -viniferin extraction. Effective diffusivities of trans-resveratrol increased by three times with increasing temperature. The modified Gompertz equation satisfactorily explained the extraction of the stilbenes investigated.

La présente thèse analyse les principaux aspects du défi de la durabilité des ressources en eau au Mexique avec l'objectif de contribuer à la littérature économique et d'alimenter par les faits l'élaboration de politiques. Elle est composée de trois chapitres. Le premier chapitre analyse la distorsion causée par les subventions à l'électricité et leurs effets sur la surexploitation des nappes phréatiques. Il contribue à la littérature en fournissant des estimations sur les élasticités prix-croisés liées à la demande d'eau d'irrigation au Mexique. Les résultats montrent que les changements dans le prix de l'eau souterraine affectent la quantité d'eau pompée ainsi que la répartition du travail et des engrais. Le deuxième chapitre étudie les effets des inspections environnementales sur l'extraction illégale de l'eau dans les municipalités mexicaines. Les résultats montrent que le programme d'inspection mené par l'agence de l'eau au Mexique a un impact sur le nombre d'irrigants ne possédant pas de concession valide. Toutefois, des efforts supplémentaires sont nécessaires pour améliorer la capacité des bureaux régionaux et permettre au programme d'avoir un effet substantiel sur la durabilité de l'eau. Enfin, le troisième chapitre aborde certaines des préoccupations liées au changement climatique en analysant les effets des périodes de sécheresse et des inondations sur la migration interne au Mexique. Les résultats montrent que la sécheresse comme les inondations agissent comme facteurs d'incitation à la migration interne. En outre, les écarts de revenu, les homicides, et le niveau d'éducation sont des facteurs clés pour la migration interne. / The sustainability or water resources in Mexico is challenged, among other things, by inadequate regulation tools, limited enforcement capacity, and the uncertainty related to climate change. This thesis analyses key aspects of these challenges with the overall objective of contributing to the economic literature and providing inputs for evidence based policy making. The thesis is composed of three chapters. The first chapter looks at the mechanisms regulating groundwater extraction. In particular, it analyses the distortion caused by electricity subsidies and their effects on groundwater overdraft. It contributes to the existing literature by providing estimates on cross-price elasticities related to irrigation water demand in Mexico. The results of this chapter show that changes in the price of ground water not only affect the amount of water pumped, but also the allocation of labour and fertilizers. The second chapter studies the effects of environmental inspections on illegal water extraction across Mexican municipalities. Results show that the main inspection program led by Mexico's water agency does have an impact on the number of irrigators extracting water without a valid concession. However, further efforts improving the capacity of regional offices are required for this program to have a substantive effect on water sustainability. Finally, the third chapter addresses some of the concerns related to climate change by analyzing the effects of droughts and floods on internal migration trends in Mexico. Results show that both droughts and floods act as push factors for internal migration. In addition, results also show that income differential, murders, and educational attainments are key drivers for internal migration in the country.

Ce travail a porté sur l'extraction de substances naturelles de sous-produits de la vigne en mettant en œuvre des procédés "verts" tels que l'extraction par eau sous-critique et la purification par filtration membranaire. Ces procédés représentent une alternative à l'extraction par solvant, traditionnellement utilisée dans la production de substances bio-sourcées. La majeure partie de cette étude a été menée sur des marcs de raisin de cépages variés, l'extraction a été optimisée et comparée sur la base du rendement, de la composition chimique et de l'activité antioxydante des extraits obtenus. De tous les cépages testés, les extraits de Dunkelfelder ont présenté l'activité antioxydante la plus élevée et la concentration en familles de molécules polyphénoliques la plus importante. En outre, ce marc de raisin de Dunkelfelder a été utilisé comme modèle afin d'optimiser les différents paramètres du procédé tels que la température, la pression et le temps de séjour hydraulique. Après la phase d'extraction par eau sous-critique, les extraits obtenus se sont révélés riches en de nombreuses familles de molécules. Ainsi, une étape de purification des composés cibles avant usage industriel s'est révélée indispensable. Le couplage de l'extraction par eau sous-critique avec des procédés membranaires représente une solution innovante pour la purification de ces extraits. Des essais de filtration tangentielle de l'extrait ont été menés avec onze membranes d'ultrafiltration (100 kDa à 2 kDa) et neuf membranes de nanofiltration (1000 Da à 150 Da). Le suivi du procédé s’est appuyé sur une détermination des paramètres opératoires optimisés et sur la détermination des coefficients de rétention des différentes familles des macro et micromolécules. Les résultats obtenus ont démontré que l'utilisation des technologies membranaires pourrait dans le futur, constituer une innovation technologique pour la purification des composés bio-actifs / This work has dealt with extraction of natural substances from winery by-products using "green" processes such as extraction by subcritical water and purification by membrane processes. These processes are an alternative to solvent extraction traditionally used in the natural products industry. Main part of the work was done on different grape pomace, extraction was optimized and compared in terms of yield, chemical composition, and antioxidant activity of extracts. Dunkelfelder extracts exhibited the strongest antioxidant activity and comparison of chemical compositions of the different extracts indicated. Furthermore this Dunkelfelder grape pomace was used as model in order to optimize the different process parameters such as temperature, pressure and hydraulic retention time. After the subcritical water extraction, extracts produced were found to be rich in several families of molecules. An essential purification step of target compounds prior to industrial use was indispensable. Coupling the subcritical water with membrane processes offers an innovative solution for the purification of these extracts. Thereby, the extract was assayed in a cross-flow apparatus against eleven membranes of ultrafiltration (100 to 2 kDa) and nine membranes of nanofiltration (1000 to 150 Da). The monitoring of the process was carried out by determining performance parameters and retention coefficients of different families of macro and micromolecules. The results obtained have demonstrated that the use of membrane technologies could bring innovative changes in the recovery of bioactive compounds for future industries.

Made available in DSpace on 2014-12-17T14:08:54Z (GMT). No. of bitstreams: 1 YasmineIFN_DISSERT.pdf: 3060416 bytes, checksum: 9c16a86ed5e6a8b081b1d3520826bad4 (MD5) Previous issue date: 2014-01-07 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The produced water is a byproduct formed due to production of petroleum and carries with it a high amount of contaminants such as oil particles in suspension, organic compounds and metals. Thus, these latter pollutants are very difficult to treat because of its high solubility in water. The objective of this work is to use and evaluate a microemulsioned system to remove metals ( K , Mg , Ba , Ca , Cr , Mn , Li , Fe ) of synthetic produced water. For the extraction of metals, it was used a pseudoternary diagram containing the following phases: synthetic produced water as the aqueous phase (AP), hexane as organic phase (OP), and a cosurfactant/surfactant ratio equal to four (C/S = 4) as the third phase, where the OCS (saponified coconut oil) was used as surfactant and n-butanol as cosurfactant. The synthetic produced water was prepared in a bench scale and the region of interest in the diagram for the removal of metals was determined by experimental design called. Ten points located in the phase Winsor II were selected in an area with a large amount of water and small amounts of reagents. The samples were analyzed in atomic absorption spectrometer, and the results were evaluated through a statistical assesment, allowing the efficiency analysis of the effects and their interactions. The results showed percentages of extraction above 90% for the metals manganese, iron, chromium, calcium, barium and magnesium, and around 45% for metals lithium and potassium. The optimal point for the simultaneous removal of metals was calculated using statistical artifact multiple response function (MR). This calculation showed that the point of greatest extraction of metals occurs was the J point, with the composition [72% AP, 9% OP, 19% C/S], obtaining a global extraction percentage about 80%. Considering the aspects analyzed, the microemulsioned system has shown itself to be an effective alternative in the extraction of metals on synthetic produced water remediation / A ?gua produzida ? um subproduto gerado na produ??o do petr?leo e possui uma grande quantidade de contaminantes, tais como part?culas de ?leo em suspens?o, compostos org?nicos e metais, sendo estes ?ltimos poluentes de dif?cil tratamento devido a sua alta solubilidade em ?gua. O objetivo deste trabalho ? utilizar e avaliar um sistema microemulsionado na extra??o de metais (K, Mg, Ba, Ca, Cr, Mn, Li, Fe) contidos na ?gua produzida. Utilizou-se um diagrama pseudotern?rio de um sistema contendo em sua composi??o: ?gua produzida sint?tica como fase aquosa (FA), hexano como fase org?nica (FO), e uma raz?o cotensoativo/tensoativo igual a quatro (C/T=4), sendo utilizado o OCS (?leo de coco saponificado) como tensoativo e n-butanol como cotensoativo. A ?gua produzida sint?tica foi preparada em escala de bancada e a regi?o de interesse para a remo??o dos metais foi determinada atrav?s do planejamento experimental de mistura, sendo escolhidos dez pontos localizados na fase de Winsor II, em uma ?rea com uma grande quantidade de ?gua e pouca quantidade de mat?ria ativa ou solvente. As amostras foram analisadas no espectr?metro de absor??o at?mica, e os resultados obtidos foram avaliados atrav?s de um tratamento estat?stico permitindo a an?lise da efici?ncia dos efeitos das vari?veis estudadas e suas intera??es. Os resultados apresentaram percentuais de extra??o acima de 90% para os metais mangan?s, ferro, cromo, c?lcio, b?rio e magn?sio, e em torno de 45% para o l?tio e o pot?ssio. O ponto ?timo para a remo??o simult?nea dos metais foi calculado atrav?s do recurso estat?stico de m?ltipla fun??o de resposta (MR). O c?lculo permitiu observar que o ponto onde ocorre o maior percentual de extra??o dos metais foi o ponto J com a composi??o [72% FA, 9% FO, 19% C/T], obtendo percentual de extra??o global em torno de 80% de todos os metais. Tendo em vista os aspectos analisados, o sistema microemulsionado estudado mostrou-se como uma eficiente alternativa na extra??o de metais de ?gua produzida sint?tica

I det här projektet extraherades värdefulla komponenter från äpple-pomace som är en restprodukt från cidertillverkning. Restprodukten var tillhandahållen av en svensk cidertillverkare. Extraktionen fokuserades mot pektin och fenolföreningar som uppvisar antioxiderande aktivitet. Extraktionsprocessen designades ur ett miljövänligt perspektiv, inga skadliga kemikalier användes. Fenolära substanser extraherades initialt från pomacen med en vattenlösning innehållande 50% etanol. Därefter studerades kompositionen och den antioxiderande aktiviteten i dessa extrakt. Fokuseringen i projektet låg främst på pektin. Pektin extraherades med subkritiskt vatten vid tre olika pH (3,5 och 7) samt vid två skilda temperaturer (120°C och 140°C) i antingen 5, 10 och 15 minuters sekvenser. Pektinet karakteriserades med avseende på extraktionsutvinningsgrad, sockerkomposition, molekylvikt och antioxiderande aktivitet. Resultaten jämfördes för att undersöka effekten av pH, temperatur och extraktionstid. Gelningsegenskapen hos olika pektin studerades som ett bevis på koncept i ett empiriskt experiment där hög-viskösa vätskor bestående av 5% pektin och 60% sackaros framställdes. Extraherade fenolföreningar har potential att fungera som naturligt utvunna antioxidanter i kosmetiska produkter och pektin kan tänkas användas som reologimodifierare i vattenbaserade formuleringar med låga pH-värden utan behov av kemiska modifieringar. / In this project, apple pomace from a Swedish cider making factory as a by-product was used as a raw material to extract valuable compounds. The extraction was focused on pectin and phenolic compounds with antioxidant activity. For the extraction procedures environmentally friendly processes were chosen without using any harsh chemicals. Phenolic compounds wereinitially extracted from the pomace using 50% aqueous ethanol and then the composition, total phenolic content and antioxidant activity were studied in these extracts. The main focus was on pectins, which were extracted by subcritical water at three different pH conditions (pH 3, 5 and 7) and two different temperatures (120°C and 140°C) in 5-, 10- and 15 minute sequences. Then the pectins were characterized in terms of extraction yield, sugar composition, molecular weight and antioxidant activity and the results were compared in terms of the effect of pH, temperatur eand extraction time. The gelling properties of the different pectins were also studied as a proof of concept in an empirical experiment, where highly viscous liquids were obtained at 5% pectinand 60% sucrose content. In summary, the extracted phenolic compounds have potential to function as naturally derived antioxidants in cosmetics and the pectin may be used as a rheology modifier in water-based formulations of low pH without any additional chemical modifications.

Enzymes and subcritical water can be used for the extraction of hemicelluloses from cereal by-products, making the processes eco-friendly. The polysaccharides extracted from cereal by-products can be used as matrices for development of materials for various applications. This includes bio-based materials such as films and hydrogels, which offer alternatives to existing materials produced from petrochemicals. The polymeric structure of cereal hemicelluloses contains functional groups which enable the modification of their structure by cross-linking, resulting in the formation of hydrogels. This project aims to use subcritical water extraction (SWE) to extract arabinoxylans (AXs) from corn and rye bran meanwhile the enzymatic treatment is done for purifying the samples during both pre- and post-treatment. AXs were further crosslinked by enzyme (laccase) for hydrogel preparation. During the whole project, the characterization included moisture and yield determination, starch and protein content which were tested using a spectrophotometer, monosaccharide content was analyzed by high performance anion exchange chromatography followed by pulsed amperometric detection (HPAEC-PAD) and phenolic acid content was quantified by high performance liquid chromatography (HPLC). The pretreatment for destarching and SWE process was successful. The result showed that arabinoxylans form corn bran were having higher content of arabino substituents, arabino toxylans ratio and ferulic acid content than rye samples. The enzymatic crosslinking could form strong gels in the condition that the AXs had high ferulic acid content. In terms of forming strong hydrogels or to improving the properties of AXs gel, the pre- and post-treatment should be optimized to increase the purity of the extracted feruloylated AX content. / Enzymer och subkritiskt vatten kan användas för extraktion av hemicellulosa från spannmålsbiprodukter, vilket gör extraktionen miljövänlig. Polysackariderna extraherade från spannmålsprodukter kan användas som matriser för utveckling av material för diverse applikationer. Detta inkluderar biobaserade material som filmer och hydrogeler, där petrokemikalier kan ersättas som råvara. Den polymera strukturen hos spannmålshemicelluloser innehåller funktionella grupper som möjliggör formation av tvärbindningar vilket resulterar i bildandet av hydrogeler. Syftet med detta projekt är extraktion av arbinoxylaner (AXs) från majs och rågkli genom att använda subkritiskt vatten-extraktion (SWE) där rening under för- och efterbehandling utförs enzymatiskt. AX modifierades därefter enzymatiskt (laccas) med tvärbindningar för hydrogelframställning. Under hela projektet karakteriserades hydrogelen utifrån fuktinnehåll, bestämmelse av utbyte, stärkelse och proteininnehåll som testades med en spektrofotometer, monosackaridhalten analyserades med högpresterande anjonsutbyteskromatografi följt avpuls-amperometrisk detektion (HPAEC-PAD), samt kvantifierades fenolsyrahalten med högupplöst vätskekromatografi (HPLC). Resultatet visade att arabinoxylaner från majskli hade högre innehåll av arabinosubstituenter, där förhållandet mellan arabino och xylans, samt arabino och ferulsyra innehållet var högre än för rågproverna. Den enzymatiska tvärbindningen kunde bilda starka geler i det tillståndet där AX hade en hög ferulsyrahalt. När det gäller att bilda starka hydrogeler eller att förbättra egenskaperna hos AXs-gel, bör för-och efterbehandlingen optimeras för att öka renheten fördet extraherade feruloylerade AX-innehållet.

The historical range of the Indus River dolphin has declined by 80% since the 19th century and has been fragmented into 17 river sections by construction of irrigation barrages. Dolphin sighting and interview surveys showed that river dolphins persist in six river sections, have been extirpated from ten, and are of unknown status in the remaining section. Logistic regression and survival modelling showed that low dry season river discharge was the primary factor responsible for the Indus dolphins range decline. Abundance of the three largest Indus dolphin subpopulations was estimated using tandem vessel-based direct counts, corrected for missed animals using conditional likelihood capture-recapture models. The entire subspecies was estimated to number between 1550-1750 in 2006. Dolphin encounter rates within the Guddu-Sukkur subpopulation (10.35/km) were the highest reported for any river dolphin and direct counts suggest that this subpopulation may have been increasing in abundance since the 1970s when hunting was banned. The dry season habitat selection of Indus dolphins was explored using Generalised Linear Models of dolphin distribution and abundance in relation to river geomorphology, and channel geometry in cross-section. Channel cross-sectional area was shown to be the most important factor determining dolphin presence. Indus dolphins avoided channels with small cross-sectional area <700m2, presumably due to the risk of entrapment and reduced foraging opportunities. The phylogenetics of Indus and Ganges River dolphins was explored using Mitochondrial control region sequences. Genetic diversity was low, and all 20 Indus River dolphin samples were identical. There were no haplotypes shared by Indus and Ganges River dolphins, phylogenetic trees demonstrated reciprocal monophyletic separation and Bayesian modelling suggested that the two dolphin populations diverged approximately 0.66 million years ago. Declining river flows threaten Indus dolphins especially at the upstream end of their range, and it is important to determine how much water is required to sustain a dolphin population through the dry season. Fisheries interactions are an increasing problem that will be best addressed through localised, community-based conservation activities.

<p>У оквиру ове докторске дисертације изведено је<br />испитивање различитих екстракционих поступака за<br />изоловање апигенина из цвета камилице, као и евалуација<br />биолошке активности добијених екстраката. Полазни<br />биљни материјал сачињавале су две групе латица<br />камилице: ферментисане и неферментисане (нативне).<br />Екстракција ферментисаних цветова је извођена применом<br />ултразвучне екстракције користећи етанол као екстрагенс,<br />а добијени екстракти су се одликовали изузетно високим<br />садржајем апигенина. Оптимизација екстракције је била<br />изведена применом методе одзивне површине. Применом<br />електрон-спин резонанце испитана је антирадикалска<br />активност екстраката. Додатно, фармаколошка вредност<br />добијених екстраката је потврђена и одређивањем њиховог<br />антимикробног и антипролиферативног потенцијала.<br />Нативни цветови камилице су екстраховани применом<br />различитих екстаркционих техника: микроталасне,<br />ултразвучне, Soxhlet екстракције као и екстракције<br />субкритичном водом. Eкстрaкција водом у субкритичном<br />стању се показала супериорнијом у односу на све остале<br />технике у погледу садржаја укупних фенола и флавоноида.<br />У циљу добијања екстраката са максималним садржајем<br />апигенина изведена је оптимизација овог екстракционог<br />процеса. Изоловање чистог апигенина је изведено из<br />екстракта добијеног под оптималним екстракцијом<br />условима (однос дрога:растварач 1:30, брзина мешања 3 Hz,<br />притисак 45 bar, температура 115&ordm;C, време 30 мин,<br />концентрација модификатора 0,001 М) применом поступка<br />колонске хроматографије на стубу полиамида. Хемијски<br />профил као и садржај појединачних полифенолних<br />компонената у екстрактима добијеним на различитим<br />притисцима, температурама и уз присуство модификатора<br />различитих концентрација одређен је применом UHPLCDAD-<br />HESI-MS/MS. У свим анализираним екстрактима<br />детектован је велики број полифенолних компонената, док<br />је апигенин у свима био доминантно једињење. Садржај<br />апигенина у екстракту добијеном под оптималним<br />екстракционим условима је износио 1.700,34 mg/kg.<br />Применом седам различитих тестова извршена је<br />евалуација антиоксидативног и антирадикалског<br />потенцијала екстраката. Антимикробни потенцијал<br />екстраката је одређен за осам различитих микробних<br />линија. in vitro тестовима испитана је способност<br />инхибиције &alpha;-амилазе, &alpha;-глукозидазе и тирозиназе.<br />Деловањем на раст три хистолошки различите ћелијске<br />линије, испитана је антипролиферативна активност<br />екстраката добијених субкритичном водом.<br />Антимотилитетна активност обе групе екстраката<br />(ферментисаних и неферментисаних цветова) одређена је у<br />in vitro условима.</p> / <p>U okviru ove doktorske disertacije izvedeno je<br />ispitivanje različitih ekstrakcionih postupaka za<br />izolovanje apigenina iz cveta kamilice, kao i evaluacija<br />biološke aktivnosti dobijenih ekstrakata. Polazni<br />biljni materijal sačinjavale su dve grupe latica<br />kamilice: fermentisane i nefermentisane (nativne).<br />Ekstrakcija fermentisanih cvetova je izvođena primenom<br />ultrazvučne ekstrakcije koristeći etanol kao ekstragens,<br />a dobijeni ekstrakti su se odlikovali izuzetno visokim<br />sadržajem apigenina. Optimizacija ekstrakcije je bila<br />izvedena primenom metode odzivne površine. Primenom<br />elektron-spin rezonance ispitana je antiradikalska<br />aktivnost ekstrakata. Dodatno, farmakološka vrednost<br />dobijenih ekstrakata je potvrđena i određivanjem njihovog<br />antimikrobnog i antiproliferativnog potencijala.<br />Nativni cvetovi kamilice su ekstrahovani primenom<br />različitih ekstarkcionih tehnika: mikrotalasne,<br />ultrazvučne, Soxhlet ekstrakcije kao i ekstrakcije<br />subkritičnom vodom. Ekstrakcija vodom u subkritičnom<br />stanju se pokazala superiornijom u odnosu na sve ostale<br />tehnike u pogledu sadržaja ukupnih fenola i flavonoida.<br />U cilju dobijanja ekstrakata sa maksimalnim sadržajem<br />apigenina izvedena je optimizacija ovog ekstrakcionog<br />procesa. Izolovanje čistog apigenina je izvedeno iz<br />ekstrakta dobijenog pod optimalnim ekstrakcijom<br />uslovima (odnos droga:rastvarač 1:30, brzina mešanja 3 Hz,<br />pritisak 45 bar, temperatura 115&ordm;C, vreme 30 min,<br />koncentracija modifikatora 0,001 M) primenom postupka<br />kolonske hromatografije na stubu poliamida. Hemijski<br />profil kao i sadržaj pojedinačnih polifenolnih<br />komponenata u ekstraktima dobijenim na različitim<br />pritiscima, temperaturama i uz prisustvo modifikatora<br />različitih koncentracija određen je primenom UHPLCDAD-<br />HESI-MS/MS. U svim analiziranim ekstraktima<br />detektovan je veliki broj polifenolnih komponenata, dok<br />je apigenin u svima bio dominantno jedinjenje. Sadržaj<br />apigenina u ekstraktu dobijenom pod optimalnim<br />ekstrakcionim uslovima je iznosio 1.700,34 mg/kg.<br />Primenom sedam različitih testova izvršena je<br />evaluacija antioksidativnog i antiradikalskog<br />potencijala ekstrakata. Antimikrobni potencijal<br />ekstrakata je određen za osam različitih mikrobnih<br />linija. in vitro testovima ispitana je sposobnost<br />inhibicije &alpha;-amilaze, &alpha;-glukozidaze i tirozinaze.<br />Delovanjem na rast tri histološki različite ćelijske<br />linije, ispitana je antiproliferativna aktivnost<br />ekstrakata dobijenih subkritičnom vodom.<br />Antimotilitetna aktivnost obe grupe ekstrakata<br />(fermentisanih i nefermentisanih cvetova) određena je u<br />in vitro uslovima.</p> / <p>In the frame of this thesis different extraction approaches for<br />apigenin isolation from chamomile ligulate flowers were<br />examined and biological activity of obtained extracts was<br />evaluated. Starting plant samples included fermented and<br />nonfermented (native) flowers.<br />Extraction of fermented flowers was performed by using<br />ultrasound-assisted extraction with ethanol. The concentration<br />of apigenin was high in obtained extracts. Optimization of the<br />extraction procedures was performed by response surface<br />methodology. Antiradical activity of observed extracts was<br />examined by electron-spin resonance spectroscopy.<br />Furthermore, pharmacological potential of obtained extracts<br />was confirmed by determining their antimicrobial and<br />antiproliferative activity.<br />Native chamomile flowers were extracted by different<br />extraction techniques: microwave, ultrasound, Soxhlet and<br />subcritical water extraction. Subcritical water extraction<br />showed to be superior in comparison to other applied techniques<br />in respect to total phenols and flavonoids content. Optimization<br />of the subcritical water extraction was directed to maximization<br />of apigenin content. Isolation of pure apigenin from extracts<br />obtained under optimal extraction conditions (sample-tosolvent<br />ratio 1:30, agitation rate 3 Hz, temperature 115&ordm;C,<br />pressure 45 bar, extraction time 30 min) was performed by<br />preparative chromatography. Chemical profiles and content of<br />individual polyphenolic components in extracts obtained at<br />different pressures, temperatures, and with different<br />concentrations of a modifier was determined by UHPLC-DADHESI-<br />MS/MS. In all analyzed extracts the great number of<br />polyphenolic components was detected while apigenin was the<br />dominant compound in all extracts. Content of apigenin in the<br />extract obtained under optimal extraction condition was<br />1,700.34 mg/kg. Antioxidant and antiradical potential of<br />extracts was evaluated according to different mechanisms.<br />Antimicrobial potential of extracts was determined against eight<br />different microbial strains. Ability of extracts to inhibit &alpha;-<br />amylase, &alpha;-glucosidase and tyrosinase was determined by in<br />vitro assays. Antiproliferative activity of subcritical water<br />extracts was defined by testing their influence on the growth of<br />three histologically different cell lines.<br />Anti-intestinal motility activity of both group of extracts (native<br />and fermented) was determined by in vivo experiments.</p>