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Le présent travail de thèse porte sur l’étude de l’impact de la texturation par DIC (Détente Instantanée Contrôlée) sur les deux opérations d’extraction d’huile et de transestérification in-situ appliquées aux graines de colza et fèves de Jatropha Curcas. Une analyse fondamentale a prouvé l’importance de la diffusion du solvant ou réactif dans la matrice solide, et permis d’identifier les processus d’intensification au travers des trois caractéristiques physiques de diffusivité effective, d’accessibilité initiale et de rendement d’extraction ; ainsi que la cinétique de transestérification in-situ et le rendement d’ester méthylique d’acides gras. Une étude phénoménologique a permis de déterminer les diverses valeurs de ces caractéristiques en fonction des paramètres opératoires DIC (pression de vapeur d’eau saturée P et temps de traitement t).Dans le cas d’extraction, la diffusivité effective (Deff) de produits traités par DIC peut atteindre 8,01 10-12 m2/s contre 0,715 10-12 m2/s pour le colza non traité et 5,90 10-12 m2/s contre 2,42 10-12 m2/s pour le jatropha non traité. Le taux d’accessibilité initiale de produits traités par DIC peut atteindre 80,53% contre 26,71% pour le colza non traité et 92,58% contre 75,91% pour le jatropha non traité. Au plan du rendement, la DIC a pu impliquer un rendement de 153% pour le colza et 112% pour le jatropha.Dans le cas de la transestérification in-situ, les rendements d’esters méthyliques d’acides gras totaux (FAME total) obtenus pour les produits traités par DIC sont systématiquement supérieurs à ceux de la matière première non traitée par DIC pour les deux cas de colza et de jatropha. Le temps de réaction a été réduit à 30 - 45 minutes contre 120 minutes pour le produit non traité par DIC (cas de colza) et à 15 minutes au lieu de 60 minutes pour le produit non traité par DIC (cas de fèves de jatropha). / The present work has concerned the impact of Instant - Controlled Pressure Drop (DIC) texturing on both operations of oil extraction and in-situ transesterification, carried out with the rapeseed and the kernels of Jatropha Curcas. A fundamental analysis proved the importance of the reactive or solvent diffusion within the solid matrix. By texturing the natural product, the whole operation can be intensified. The process is revealed through three characteristics, which are the effective diffusivity, the starting accessibility, and the yields of extraction. Also, the kinetics and yield of fatty acid methyl ester of in-situ transesterification are discovered. A phenomenological study allowed determining the value of these characteristics versus DIC operating parameters (saturated steam pressure P and treatment time t).A 2 h solvent extraction of DIC treated material allowed the total oil yields to be improved by 153% for colza and 112% for jatropha, the effective diffusivity (Deff) can reach up to 8.014*10-12 m2/s as against 0.715*10-12 m2/s for colza untreated by DIC, and up to 5.90*10-12 m2/s as against 2.42*10-12 m2/s for the untreated jatropha. The rate of initial accessibility of products treated by DIC can reach up to 80.53% as against 26.71% for untreated colza and can reach up to 92.58% as against 75.91% for the product untreated jatropha. In the case of in situ transesterification, the total yield of fatty acid methyl esters (FAME total) obtained from the DIC treated products is systematically higher than that of untreated colza and jatropha raw material. The reaction time was decreased to 30 - 45 min instead of 120 min in the case of colza, and to 15 min instead of 60 min in the case of jatropha kernel.

Si les lipides contribuent à la valeur nutritionnelle et sensorielle de nombreux aliments, ils sont particulièrement sensibles aux réactions d'oxydation. Les principaux mécanismes mis en jeu lors de l'oxydation des acides gras insaturés sont relativement bien connus. En revanche, il est aujourd'hui quasiment impossible de prédire l'avancement des réactions et souvent nécessaire de recommencer une nouvelle étude de stabilité oxydative pour tout nouveau couple produit alimentaire / procédé de transformation. L'objectif de la thèse est donc de construire un modèle mécanistique couplé à un modèle de transfert de l'oxygène dans le but de prédire l'avancement des réactions d'oxydation dans un milieu lipidique continu et dans des conditions expérimentales définies et contrôlées (température, oxygénation, composition en acides gras, composition en antioxydants). Pour cela, un schéma réactionnel visant à détailler l'ensemble des réactions impliquées dans le phénomène d'auto-oxydation des lipides a été proposé puis un modèle stoechio-cinétique a été construit à partir des valeurs des paramètres cinétiques issues de la littérature. La réactivité des acides gras insaturés présents dans trois huiles végétales d'usage courant (colza, tournesol, tournesol oléique), purifiées de leurs antioxydants naturels, a été étudiée entre 80 et 180°C, en suivant différents marqueurs d'oxydation (diènes conjugués, hydroperoxydes, aldéhydes, polymères). Comme attendu, les cinétiques d'oxydation se sont avérées dépendantes de la composition des huiles en acides gras, de la température et des conditions d'oxygénation. L'ajout d'antioxydant(s) a confirmé l'effet protecteur de l'α-tocophérol, qui n'a pas été amélioré par un enrichissement en acide chlorogénique, acide phénolique naturellement présent dans les graines de tournesol. Les résultats obtenus ont été utilisés pour valider le modèle développé, dont les prédictions permettent de reproduire les tendances expérimentales. Deux limitations ont été mises en évidence au cours de cette phase de validation dont la première concerne la description fiable et précise du mécanisme d'oxygénation du milieu, qu'il sera nécessaire de mesurer dans une huile à haute température pour valider le modèle d'oxydation. Par ailleurs, compte tenu du nombre important de réactions prises en compte, il sera indispensable de disposer d'un jeu de données expérimentales plus important, pouvant inclure des intermédiaires radicalaires. Pour cela, les potentialités de la résonance paramagnétique électronique ont été étudiées au cours de ce travail, à la fois pour suivre les radicaux lipidiques et pour accéder à des paramètres cinétiques pour des réactions radicalaires, peu disponibles dans la littérature. / If lipids contribute to nutritional and sensorial properties of many foodstuf, they are particularly sensitive to oxidation reactions. The main mechanisms involved in the oxidation of unsaturated fatty acids are already well-known. However, it is almost impossible to predict the progress of oxidative reactions and often necessary to develop new studies of oxidative stability for each new food product / processing. The aim of this study is to develop a mechanistic model coupled to oxygen transfer in order to predict the evolution of oxidation reactions in a bulk lipid system and in defined and controlled experimental conditions (temperature, oxygenation, fatty acids' composition, antioxidants' composition). Thus, a reaction scheme detailing all the reactions involved in the oxidation phenomenon was proposed and a stoichio-kinetic model was built on the basis of conservation equations and kinetic parameters available in literature. The reactivity of unsaturated fatty acids contained in three usual edible oils (rapeseed, sunflower, high oleic sunflower), previously stripped of their natural antioxidants, was studied between 80 and 180 °C, following several oxidation markers (conjugated dienes, hydroperoxides, aldehydes, polymers). As expected, oxidation kinetics depended on fatty acids' composition of oils, on temperature and on oxygen availability. The addition of antioxidant(s) confirmed the protective effect of α-tocopherol, which was not improved by the enrichment in chlorogenic acid, a phenolic acid naturally occurring in sunflower seeds. The experimental data were used to validate the model which predictions reproduce experimental tendencies. Two limitations were identified during model validation. The first is the accurate description of the oxygenation mechanism of the medium which need to be measured in oil at high temperatures. Moreover, given the large number of reactions taken into account, it is essential to have a set of more important experimental data which include radical intermediates. For this, the potential of electron spin resonance spectroscopy was evaluated in this in order to follow lipid radical species and access to kinetic parameters of radical reactions, few available in literature.

Depuis une trentaine d’années, l’élément soufre (S) est devenu un des éléments les plus limitants pour la croissance des cultures du fait de nombreux facteurs, comme les nouvelles pratiques de gestion des sols et la limitation des pollutions anthropiques. Ainsi, des carences en S apparaissent au sein des cultures et particulièrement en Europe de l’Ouest. Nos objectifs ont été d’appréhender la communauté bactérienne fonctionnelle du sol qui, de par son activité arylsulfatase, permet la minéralisation de la forme majoritaire du S en sulfate (forme de S assimilée par les plantes). D’après nos résultats, la densité de cette communauté bactérienne fonctionnelle est plus importante dans les environnements où le S est potentiellement plus limitant (rhizosphère de colza vs orge). De plus, cette communauté fonctionnelle apparaît diversifiée et est notamment composée de divers genres bactériens affiliés à de nombreuses classes taxonomiques (Actinobactéries, Firmicutes, a-, ß-, d-, ?-protéobactéries et aux Planctomycètes). De plus, au sein de la rhizosphère du colza, des variations temporelles de structure et de diversité de cette communauté fonctionnelle ont également été mises en évidence. En conclusion, l’ensemble des expérimentations semble mettre en évidence, que la communauté bactérienne fonctionnelle minéralisant les esters de sulfate apparaît stimulée sous colza comparée à celle présente sous orge. Ces résultats laissent présager le rôle potentiel de cette communauté fonctionnelle dans le turn-over du S dans les sols agricoles et la mise en place d’approches d’écologie fonctionnelle supplémentaires permettrait de mieux cerner son implication dans la nutrition soufrée des cultures / Over the past thirty years, Sulfur (S) has become one of the most limiting element for crop growth due to many factors, such as new soil management practices and depletion of the anthropogenic pollution. Thus, S deficiencies increase in crops, particularly in Western Europe. Our objectives were to apprehend the soil functional bacterial community which, by its arylsulfatase activity, allows the mineralization of the majority form of S to sulfate (form of S assimilated by plants). Based on our results, the density of the functional bacterial community are higher in environments where S is potentially limiting (rapeseed rhizosphere vs. barley rhizosphere). Moreover, this functional community appeared diverse and belonging to several taxonomic classes (Actinobacteria, firmicutes, a-, ß-, d-, ?-proteobacteria and Planctomycetea). In addition, in the rapeseed rhizosphere, temporal variations of the structure and diversity of this functional community have also been highlighted. In conclusion, our experiments appear to demonstrate that this functional bacterial community mineralizing sulphate esters appeared stimulated in rapeseed rhizosphere compared to that present in barley rhizosphere. However, the establishment of new approaches to allow additional functional ecology bases for this community should be made to allow a better understanding of its potential involvement in sulfur nutrition of crops

Les tourteaux de colza et de tournesol, principalement utilisés en alimentation animale pour leur forte teneur en protéines, représentent des sources d’acides phénoliques aux propriétés antioxydantes et bioacives variées mais peu valorisées à ce jour. Par ailleurs, les procédés de séparation de ces composés sont basés sur des extractions par solvants qui génèrent des effluents et impactent l’intégrité des autres composants des matières premières.La première partie de ce travail de thèse a été consacré au développement de nouveaux procédés de séparation de la fraction phénolique des tourteaux de colza et de tournesol. Après un broyage adéquat des tourteaux, le fractionnement par tri électrostatique et turbo-séparation a permis d’obtenir des fractions enrichies en protéines et les composés phénoliques. Dans les deux cas, l’état granulométrique des tourteaux broyés a été déterminant. Le tri électrostatique a conduit au plus forts taux d’enrichissement en protéines et composés phénoliques (jusqu’à deux fois la concentration dans les tourteaux) avec des rendements de l’ordre de 30% après recyclages. Cette étape a été suivie par l’extraction de la fraction phénolique par des mélanges hydro-alcooliques « verts » à base d’éthanol, en substitution au méthanol.Dans la deuxième partie, nous nous sommes intéressés à la production enzymatique des acides sinapique et caféique, à partir des tourteaux ou de leurs extraits. Trois cinnamoyl estérases recombinantes d’A. niger aux activités et spécificités différentes ont été testées. L’hydrolyse des tourteaux non traités thermiquement s’est traduite par une dégradation des composés phénoliques par des enzymes endogènes. Le problème a pu être contourné en réalisant l’hydrolyse sur l’extrait phénolique des tourteaux avec néanmoins, dans le cas du colza, l’existence de réactions secondaires néfastes au rendement en acide sinapique.La dernière partie a consisté en la synthèse de mono- et di-esters d’acide sinapique et caféique avec différents α,ω-diols aliphatiques, puis l’évaluation de leur capacité antioxydante en milieu émulsionné et en milieu homogène. Un effet négatif de la mono-estérification des acides phénoliques a été observé en milieu hétérogène montrant ainsi l’influence négative du groupement hydroxyle situé à l’extrémité de la chaîne alkyle. Un effet de seuil a été observé, en revanche, avec les deux familles de di-esters d’acides phénoliques, indiquant une amélioration de la capacité antioxydante jusqu’à un optimum correspondant à une longueur de chaine alkyle particulière. Enfin, tous les mono- et di-esters testés en milieu homogène ont montré une capacité antiradicalaire plus faible que celle des acides phénoliques de départ correspondants. / Rapeseed and sunflower meals are highly abundant and protein-rich by-products mainly dedicated to animal feed. Besides, they also represent an interesting source of phenolic compounds with various bioactive and antioxidant properties, but widely untapped so far. In addition, the recovery processes of phenolic compounds are based on the use of solvents that generate effluents and may negatively affect the integrity of other meal constituents.The first part of this work was devoted to the development of new separation processes of rapeseed and sunflower meal phenolic fractions. After an appropriate milling of the meals, the dry fractionation by electrostatic sorting or air classification allows the recovery of proteins and phenolics enriched fractions. In both cases, the particle-size distribution of milled meals has been of paramount importance on process efficiency. Electrostatic sorting lead to the highest enrichments in proteins and phenolics (up to two times more than in starting meals) with recovery yields around 30% after recycling. This step was followed by the extraction of phenolics using green hydro-alcoholic mixtures based on ethanol as substitutes to methanol.In the second part, we investigated the enzymatic production of sinapic and caffeic acids from rapeseed and sunflower meals or their extracts. Three recombinant cinnamoyl esterases from A. niger exhibiting different activities and selectivities were tested. Owing to the presence of active endogenous enzymes, the hydrolysis of non-thermally treated meals has lead to a significant loss of phenolics. The issue was overcomed by performing hydrolysis on the corresponding phenolic extracts. However, in case of rapeseed extract, acyl transfer reactions were detrimental to sinapic acid formation and yield.Finally, in the last part, we synthesized mono- and di-esters of sinapic and caffeic acids with aliphatic α,ω-diols of increasing chain length, then we evaluated their antioxidant capacities in emulsion and in homogenous medium. A negative impact of the mono-esterification of the phenolic acid with the different aliphatic diols was observed in the heterogeneous media, implying the negative influence of the hydroxyl group at the end of the alkyl chain. Conversely, a “cut-off” effect was observed for the two di-esters series showing an improvement of the antioxidant capacity until an optimum was reached for a particular alkyl chain. Finally, all the esters showed lower antiradical capacities in the homogenous media compared to the corresponding starting phenolic acids.

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-08-09T17:41:31Z No. of bitstreams: 2 Tese - Patricia Antonio - 2016.pdf: 2346033 bytes, checksum: 5d733f10f72d4427f3e205bc5f8674ad (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-10T11:36:49Z (GMT) No. of bitstreams: 2 Tese - Patricia Antonio - 2016.pdf: 2346033 bytes, checksum: 5d733f10f72d4427f3e205bc5f8674ad (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-08-10T11:36:49Z (GMT). No. of bitstreams: 2 Tese - Patricia Antonio - 2016.pdf: 2346033 bytes, checksum: 5d733f10f72d4427f3e205bc5f8674ad (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-03-04 / The animal production potential grows fast and food production is always being challenged to meet this need in the nutrition as well as in the economic context. Forage plants are the basis of the diet of ruminants in most production systems in tropical regions. Forage availability varies during the year depending on weather conditions. It turns necessary to have stored forage to supplement the animals. Silage is the most widely used form of stored forage. The tropical grasses ensiling is an alternative to traditional silage crops because it can be used the surplus produced in the rainy season. However, the fermentation process can be altered by many factors, making difficult the production of good quality silage so there is the need of using additives as a means of improving the nutritional and fermentative quality of these types of silages. Thus, this study aimed to use moisture sequestering additives: soybean, canola, sunflower and cotton meal, in the production of B. brizantha silage in order to improve the nutritional value, fermentative value, degradability and digestibility of these silages, thus obtaining information about alternative materials for the production of good quality silage. The experiment was carried out a part in experimental PVC silos and estimated the bromatologic parameters, effluent and gas losses, N-NH3, pH, titratable acidity, protein fractions and silage degradability, and the other part in experimental silos with a capacity of 200 kg to evaluate the performance of sheep fed with these silages through intake and total tract digestibility of nutrients, metabolic and rumen parameters of these animals. The silages of Brachiaria brizantha with sequestering moisture additives were effective in keeping concentrations of plasma metabolic and ruminal profile parameters within the reference levels, increasing the readily soluble A fraction and decreasing the C protein fraction consequently improving the ruminal degradability, and reducing the silage losses. Therefore it is recommended its use as an alternative to ruminant nutrition. / O potencial de produção animal cresce num ritmo acelerado e a produção de alimentos está sempre sendo desafiada a suprir essa necessidade tanto no contexto nutricional quanto econômico. As plantas forrageiras constituem a base da dieta dos ruminantes na grande maioria dos sistemas de produção das regiões tropicais. A disponibilidade de forragem é variável durante o ano, dependendo de condições climáticas. Isto gera a necessidade de se ter forragem conservada sendo a silagem a forma mais utilizada. A ensilagem de capins tropicais é uma alternativa à ensilagem de culturas tradicionais podendo ser utilizada o excedente produzido na época das águas. No entanto, o processo fermentativo pode ser alterado por alguns fatores, dificultando a confecção de silagens de boa qualidade, havendo assim a necessidade do uso de aditivos como meio de melhora da qualidade nutricional e fermentativa desses tipos de silagens. Dessa forma, o presente trabalho visou utilizar aditivos sequestrantes de umidade: farelos de soja, canola, girassol e algodão, na confecção de silagens de Brachiaria brizantha com o objetivo de melhorar o valor nutritivo, valor fermentativo, degradabilidade e digestibilidade dessas silagens, obtendo assim, informações sobre materiais alternativos para a confecção de silagens de qualidade. O experimento foi realizado uma parte em silos experimentais de PVC e estimados os parâmetros bromatológicos, as perdas por efluentes, perdas por gases, N-NH3, pH, acidez titulável, frações proteicas e a degradabilidade da massa ensilada, e outra parte em silos experimentais com capacidade para 200 kg para avaliar o desempenho de ovinos alimentados com essas silagens, através de consumo e digestibilidade total dos nutrientes, parâmetros metabólicos e ruminais destes animais. As silagens de Brachiaria brizantha com aditivos sequestrantes de umidade foram eficientes em manter as concentrações dos metabólicos plasmáticos e parâmetros de perfil ruminal dentro dos níveis de referência, aumentar a fração A prontamente solúvel e diminuir a fração C da proteína consequentemente melhorando a degradabilidade ruminal, e diminuindo as perdas da silagem. Portanto sendo recomendado o seu uso como alternativa para a nutrição de ruminantes.

<p>På SSAB i Borlänge har man upptäckt att avgaser från färgen förorenar ugnarna vid härdning. Avgaserna består av lösningsmedel och andra flyktiga föreningar som sedan förkolnas och faller ner på lackerade plåtband. För att komma runt det här problemet har SSAB tillsammans med Akzo Nobel Industrial Finishes AB, i Gamleby, tillverkat en färg som inte ska ge ifrån sig något lösningsmedel och på så sätt minska bildandet av föroreningar i ugnarna. Färgen heter NOVA GreenCoat och innehåller rapsmetylester, RME, som är ett reaktivt lösningsmedel och ska binda till bindemedlet i färgen och på så sätt hindras från att avgå vid härdning.</p><p>Syftet har varit att undersöka om en viss metod fungerar bra för att samla upp avgaser vid härdning. Avgaserna analyserades med GC-MS och härdningen studerades med FTIR. Arbetet har utförts både i Borlänge och i Gamleby.</p><p>Metoden för uppsamling av avgaserna visade sig fungera, dock inte särskilt effektivt. Den skulle därför behöva optimeras.</p><p>Härdningen kunde till viss del följas med hjälp av FTIR. Förändring i IR-spektrumet syntes för hydroxyltoppen vid cirka 3500 cm^-1. En skillnad kunde ses för en topp vid 2858 cm^-1 som uppkom i det ohärdade materialet innehållande RME, men den försvann under härdning. Toppen ökade med ökad mängd RME och syntes inte alls för de prover som inte innehöll RME.</p><p>Samtliga gjorda analyser indikerade att RME avgick vid härdning. Vid analys med GC-MS kunde de föreningar som avgick från RME identifieras som: metyl-14-metyl pentadekanoat och/eller metyl hexadekanoat, olika former av metyl oktadekanoat samt olika former av metyl eikosanoat. Andra föreningar från klarlacken som avgick var lösningsmedel x och y samt i två av proverna hexametoximetylmelamin, HMMM.</p> / <p>Problems with exhaust gases from paint that contaminates the ovens have been discovered at SSAB in Borlänge.  The exhaust gases contain solvents and other volatiles that vaporize from the paint and later on carbonize and fall down on the next coming sheets. SSAB and Akzo Nobel Industrial Finishes AB have developed a paint that is not supposed to vaporize any solvents and therefore reduce the contaminations of the ovens. The paint is called NOVA GreenCoat and contains rapeseed methyl ester, RME. RME is a reactive solvent that is supposed to react with the binder in the paint and therefore be prevented from leaving during thermal cure.</p><p>The purpose was to investigate whether a specific method worked well, for collecting the exhaust gases during thermal cure, or not. The collected exhaust gases were analyzed by using GC-MS and the cure was studied with FTIR. The work was executed both in Borlänge and Gamleby.</p><p>The method for collecting the exhaust gases worked, unfortunately it wasn’t particularly effective. It therefore needs to be optimized.</p><p>The cure could partially be studied by using FTIR. Changes in the IR-spectrum could be followed by looking at the hydroxyl peak at approximately 3500 cm^-1. A certain difference was observed for a peak at 2858 cm^-1 that appeared in the uncured material containing RME. The peak disappeared during cure. It increased with increased amount of RME and could not be observed at all for the samples that did not contain RME.</p><p>All the analyzed samples indicated that RME vaporize during cure. When analyzed with GC-MS the volatiles that vaporize from RME were identified as: hexadecanoic acid methyl ester and/or penta decanoic acid methyl-14-methyl ester, different forms of octadecanoic acid methyl ester and different forms of eicosanoic acid methyl ester. Other volatiles that vaporize from NOVA GreenCoat were solvent x and solvent y and for two of the samples hexa metoxy methyl melamine, HMMM, was also found.</p>

<p>Lipid peroxidation is thought to be an important factor in the pathophysiology of a number of diseases and in the process of ageing, but its measurement <i>in vivo</i> has been difficult. The aim of this thesis was to evaluate methods for measurement of lipid peroxidation <i>in vivo</i> that are suitable for clinical investigations, and to apply these methods in animal and human studies investigating basal conditions and situations associated with increased lipid peroxidation.</p><p>The ferrous oxidation in xylenol orange assay for quantification of total plasma lipid hydroperoxides was re-evaluated regarding sample handling and storage. It was shown to be a useful tool for analyses of fresh but not stored plasma samples.</p><p>A methodology for measurement of the total amount (sum of free and esterified) of an F₂-isoprostane, 8-iso-prostaglandin F_2α, in tissues using alkaline hydrolysis in combination with an existing radioimmunoassay was developed. High levels of 8-iso-prostaglandin F_2α in rat liver tissue were quantified by this technique both at basal conditions and in an experimental model of increased lipid peroxidation induced by carbon tetrachloride.</p><p>Supplementation with vitamin E to rats decreased both non-enzymatic and enzymatic lipid peroxidation as measured by 8-iso-prostaglandin F_2α and a major prostaglandin F_2α metabolite. This was verified both in the urine at basal conditions, and in the urine and liver tissue after carbon tetrachloride induced lipid peroxidation.</p><p>In a randomised cross-over study in humans, a rapeseed oil-based diet with an increased proportion of easily oxidised polyunsaturated fatty acids was compared to a control diet rich in saturated fats. The rapeseed oil-based diet did not seem to increase the degree of lipid peroxidation in plasma and urine as measured by 8-iso-prostaglandin F_2α, hydroperoxides and malondialdehyde, presumably due to a sufficient content of antioxidants in the rapeseed oil diet.</p><p>In conclusion, the simultaneous measurement of several biomarkers of lipid peroxidation is a promising approach for future studies investigating the possible role of lipid peroxidation <i>in vivo</i> under basal conditions and in the pathology of diseases.</p>

Lipid peroxidation is thought to be an important factor in the pathophysiology of a number of diseases and in the process of ageing, but its measurement in vivo has been difficult. The aim of this thesis was to evaluate methods for measurement of lipid peroxidation in vivo that are suitable for clinical investigations, and to apply these methods in animal and human studies investigating basal conditions and situations associated with increased lipid peroxidation. The ferrous oxidation in xylenol orange assay for quantification of total plasma lipid hydroperoxides was re-evaluated regarding sample handling and storage. It was shown to be a useful tool for analyses of fresh but not stored plasma samples. A methodology for measurement of the total amount (sum of free and esterified) of an F2-isoprostane, 8-iso-prostaglandin F2α, in tissues using alkaline hydrolysis in combination with an existing radioimmunoassay was developed. High levels of 8-iso-prostaglandin F2α in rat liver tissue were quantified by this technique both at basal conditions and in an experimental model of increased lipid peroxidation induced by carbon tetrachloride. Supplementation with vitamin E to rats decreased both non-enzymatic and enzymatic lipid peroxidation as measured by 8-iso-prostaglandin F2α and a major prostaglandin F2α metabolite. This was verified both in the urine at basal conditions, and in the urine and liver tissue after carbon tetrachloride induced lipid peroxidation. In a randomised cross-over study in humans, a rapeseed oil-based diet with an increased proportion of easily oxidised polyunsaturated fatty acids was compared to a control diet rich in saturated fats. The rapeseed oil-based diet did not seem to increase the degree of lipid peroxidation in plasma and urine as measured by 8-iso-prostaglandin F2α, hydroperoxides and malondialdehyde, presumably due to a sufficient content of antioxidants in the rapeseed oil diet. In conclusion, the simultaneous measurement of several biomarkers of lipid peroxidation is a promising approach for future studies investigating the possible role of lipid peroxidation in vivo under basal conditions and in the pathology of diseases.

På SSAB i Borlänge har man upptäckt att avgaser från färgen förorenar ugnarna vid härdning. Avgaserna består av lösningsmedel och andra flyktiga föreningar som sedan förkolnas och faller ner på lackerade plåtband. För att komma runt det här problemet har SSAB tillsammans med Akzo Nobel Industrial Finishes AB, i Gamleby, tillverkat en färg som inte ska ge ifrån sig något lösningsmedel och på så sätt minska bildandet av föroreningar i ugnarna. Färgen heter NOVA GreenCoat och innehåller rapsmetylester, RME, som är ett reaktivt lösningsmedel och ska binda till bindemedlet i färgen och på så sätt hindras från att avgå vid härdning. Syftet har varit att undersöka om en viss metod fungerar bra för att samla upp avgaser vid härdning. Avgaserna analyserades med GC-MS och härdningen studerades med FTIR. Arbetet har utförts både i Borlänge och i Gamleby. Metoden för uppsamling av avgaserna visade sig fungera, dock inte särskilt effektivt. Den skulle därför behöva optimeras. Härdningen kunde till viss del följas med hjälp av FTIR. Förändring i IR-spektrumet syntes för hydroxyltoppen vid cirka 3500 cm-1. En skillnad kunde ses för en topp vid 2858 cm-1 som uppkom i det ohärdade materialet innehållande RME, men den försvann under härdning. Toppen ökade med ökad mängd RME och syntes inte alls för de prover som inte innehöll RME. Samtliga gjorda analyser indikerade att RME avgick vid härdning. Vid analys med GC-MS kunde de föreningar som avgick från RME identifieras som: metyl-14-metyl pentadekanoat och/eller metyl hexadekanoat, olika former av metyl oktadekanoat samt olika former av metyl eikosanoat. Andra föreningar från klarlacken som avgick var lösningsmedel x och y samt i två av proverna hexametoximetylmelamin, HMMM. / Problems with exhaust gases from paint that contaminates the ovens have been discovered at SSAB in Borlänge.  The exhaust gases contain solvents and other volatiles that vaporize from the paint and later on carbonize and fall down on the next coming sheets. SSAB and Akzo Nobel Industrial Finishes AB have developed a paint that is not supposed to vaporize any solvents and therefore reduce the contaminations of the ovens. The paint is called NOVA GreenCoat and contains rapeseed methyl ester, RME. RME is a reactive solvent that is supposed to react with the binder in the paint and therefore be prevented from leaving during thermal cure. The purpose was to investigate whether a specific method worked well, for collecting the exhaust gases during thermal cure, or not. The collected exhaust gases were analyzed by using GC-MS and the cure was studied with FTIR. The work was executed both in Borlänge and Gamleby. The method for collecting the exhaust gases worked, unfortunately it wasn’t particularly effective. It therefore needs to be optimized. The cure could partially be studied by using FTIR. Changes in the IR-spectrum could be followed by looking at the hydroxyl peak at approximately 3500 cm-1. A certain difference was observed for a peak at 2858 cm-1 that appeared in the uncured material containing RME. The peak disappeared during cure. It increased with increased amount of RME and could not be observed at all for the samples that did not contain RME. All the analyzed samples indicated that RME vaporize during cure. When analyzed with GC-MS the volatiles that vaporize from RME were identified as: hexadecanoic acid methyl ester and/or penta decanoic acid methyl-14-methyl ester, different forms of octadecanoic acid methyl ester and different forms of eicosanoic acid methyl ester. Other volatiles that vaporize from NOVA GreenCoat were solvent x and solvent y and for two of the samples hexa metoxy methyl melamine, HMMM, was also found.