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1
Gioielli, Luiz Antonio. "Desenvolvimento de bases gordurosas para margarinas cremosas por interesterificação." Universidade de São Paulo, 1985. http://www.teses.usp.br/teses/disponiveis/9/9131/tde-18032008-081014/.
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O trabalho teve por objetivo o desenvolvimento de bases gordurosas para margarinas utilizando o método de modificação por interesterificação, como alternativa ao processo de hidrogenação parcial, que forma isômeros trans.The aim of the study was to develop soft margarines by using intertesterification, as an alternative of hydrogenation, which forms trans isomers.
2
Fischer, Carol Lea. "Oral mucosal lipids are antimicrobial against Porphyromonas gingivalis, induce ultrastructural damage, and alter bacterial lipid and protein compositions." Diss., University of Iowa, 2013. https://ir.uiowa.edu/etd/2494.
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Periodontal disease is a chronic inflammation of the gingiva and periodontium that leads to progressive destruction and irreversible damage to the supportive structures of the teeth. It affects nearly half of the United States population and is a particular risk factor in adults older than 65 years of age. Oral microorganisms assemble in plaque as a polymicrobial biofilm and Porphyromonas gingivalis, an important secondary colonizer in oral biofilms, has been implicated in periodontal disease. Although the protective functions of various salivary molecules such as antimicrobial proteins have been delineated, lipids present in saliva and on the oral mucosa have been largely ignored and there is growing evidence that the role of lipids in innate immunity is more important than previously realized. In fact, recent studies suggest that sphingoid bases and fatty acids, which exhibit potent broad spectrum antimicrobial activity against a variety of bacteria and fungi, are likely important innate immune molecules involved in the defense against oral bacterial and fungal infections. However little is known about their spectrum of activity or mechanisms of action. In addition, the effects of these lipids that are endogenous to the oral cavity have not been explored against oral bacteria. In this study I hypothesized that oral mucosal and salivary lipids exhibit dose-dependent antimicrobial activity against P. gingivalis and alter cell morphology and metabolic events. To test this hypothesis, I first examined the effects of two fatty acids: sapienic acid and lauric acid, and three sphingoid bases: sphingosine, dihydrosphingosine, and phytosphingosine, against a variety of gram-positive and gram-negative bacteria including P. gingivalis. Using broth microdilution assays to determine minimum inhibitory and minimum bactericidal concentrations, I show that antimicrobial activity against bacteria is dose-dependent, lipid specific, and microorganism specific. Kill kinetics were also variable across each bacteria-lipid combination. Upon examination of select bacteria-lipid combinations via scanning and transmission electron microscopy, different morphologies were evident across all treatments, demonstrating differential activity of each lipid for a particular bacterium as well as for each bacterium across different lipids. In addition, all sphingoid bases and fatty acids were taken up and retained in association with P. gingivalis cells and could be extracted along with bacterial lipids and separated using thin layer chromatography. Using a combination of two-dimensional in-gel electrophoresis and Western blots followed by mass spectroscopy and n-terminus degradation sequencing, I show that sapienic-acid treatment induces a unique stress response in P. gingivalis, as evidenced by the ability of P. gingivalis to upregulate a set of proteins involved in fatty acid biosynthesis metabolism and energy production, protein processing, cell adhesion, and virulence. Finally, utilizing flow cytometry and confocal microscopy, I assessed the effects of oral antimicrobial lipids against a representative host cell and describe oral lipid concentrations that are both antimicrobial to P. gingivalis cells and non-cytotoxic to the representative host cells tested. Combined, these data strongly suggest that sphingoid bases and fatty acids found within the saliva and on oral mucosa likely do contribute to the innate antimicrobial activity of saliva, mucosal surfaces, and skin and this dose-dependent activity is both lipid specific and bacteria specific. This information adds to current knowledge of the innate functions of endogenous lipids in the oral cavity. With bacterial resistance to current antibiotics increasing, the exploration of new antimicrobial agents is important and these lipid treatments may be beneficial for prophylactic treatments or therapeutic intervention of infection by supplementing the natural immune function of endogenous lipids on skin and other mucosal membranes.
3
Kouakou, Cédric. "Etude approfondie de la cristallisation des carburants et des combustibles, impact des nouvelles bases." Thesis, Pau, 2014. http://www.theses.fr/2014PAUU3017/document.
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Les industries du raffinage et du transport doivent faire face à une conjoncture marquée par une demande croissante et importante de carburant gazole et à la fois par la Directive 2003/30/EC de l’Union Européenne imposant l'incorporation progressive de sources renouvelables dans les carburants (5,75 % en 2010 à 20 % en 2020, en terme de contenu énergétique). Dans ce contexte, les schémas de raffinage ont été orientés vers la valorisation de plus de coupes lourdes en bases pour la formulation des carburants gazoles et combustibles Fuel–Oil domestique, tandis que l’aspect réglementaire est satisfait en ayant recours à des bases alternatives de type Esters Méthyliques d’Huiles Végétales (EMHV). Cependant, les gazoles moteurs ainsi formulés sont d’avantage exposés aux problématiques de cristallisation en raison de l’accroissement de composés susceptibles de s’y solidifier lors de températures hivernales (principalement les n-alcanes et les Esters Méthyliques d’Acides Gras). Il est par conséquent important de se doter d’un outil d’optimisation de la formulation permettant de prédire la température d’apparition des premiers cristaux, soit leur point de trouble. Dans cette perspective, il a été nécessaire d’acquérir les données expérimentales de transition de phase liquide – solide des Esters Méthyliques d’Acides Gras composants les EMHV, mais également celles des fluides réels (gazoles fossiles, EMHV et leurs mélanges). Les données collectées ont par la suite été comparées aux prédictions résultantes de modèles thermodynamiques se proposant de décrire l’équilibre de phase liquide – solide des gazoles et des EMHV, afin de s’en inspirer pour établir une approche prédictive de calcul des températures de transition de phase des mélanges.En définitive, nous avons reliés les résultats de la modélisation thermodynamique et les mesures du point de trouble réalisées conformément aux normes pétrolières en vigueur en Europe (ASTM D5771et D7689), afin d’établir des corrélations aptes à la prédiction de cette propriété attestant de la tenue au froid des gazoles moteursThe concerns about greenhouse effect have encouraged the use of biodiesels to replace petroleum-derived diesel fuel. Indeed, the European Union has issued a Directive 2003/30/EC, which mandates the use of biofuels in a percentage ranging from 5.75% in 2010 to 20.00% in 2020 (calculated on the basis of energy content) for all transportation fuels marketed within the member states. First-generation biodiesels made from vegetable oils or animals fats are blended with petroleum diesel to fuel the engines. Besides, the refining schemes were modified to produce more heavy petroleum cuts in order to satisfy the growing demand of diesel fuel. However, the resulting diesel are more exposed to operability problems as the Fatty Acid Methyl Esters and the heavy normal paraffins may solidified in the tank and filters when the temperature drops down during the winter seasons. Thus the study of the solid-liquid phase equilibria of these blends may be useful to predict the temperature of apparition of the solidified material, known as the cloud point. In this work, we collected the melting data of the pure biodiesel components (Fatty Acid Methyl Esters) and we studied the phase change temperature of real diesel samples (petroleum diesel and biodiesel blends). Then, we have developed a thermodynamic model in order to compute the solid-liquid phase equilibria of all these kind of fluids involved in the diesel fuel formulation. Comparisons were made with the experimental phase change measurements and with the cloud point normalized measurement methods (ASTM D5771 et D7689). Finally, we have correlate the phase change temperature calculated by the thermodynamic model with the normalized cloud point, so as this important data could be obtain by a predictive tool
4
Pawlak, Michal. "Effets hépatoprotecteurs de PPARα : rôle physiopathologique et bases moléculaires des activités PPARα dans l'inflammation aiguë et la stéatohépatite non alcoolique." Thesis, Lille 2, 2013. http://www.theses.fr/2013LIL2S047/document.
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La stéatohépatite non alcoolique (NASH) est une maladie du foie à évolution clinique grave, dont la prévalence est en constante progression. La stéatohépatite non alcoolique est caractérisée par un dépôt excessif de lipides dans les hépatocytes (stéatose) associé à une inflammation chronique, au contraire de la stéatose hépatique (NAFLD), manifestation initiale mais bénigne d'un dérèglement métabolique. Le NASH augmente le risque de progression vers la fibrose, la cirrhose et le carcinome hépatocellulaire et ne peut être soigné que par une greffe hépatique. Le risque de développer un diabète de type est aussi significativement augmenté chez les patients atteints de NASH. PPAR⍺ est un récepteur nucléaire connu pour réguler l'utilisation des acides gras dans le foie et réprimer les voies de signalisation pro-inflammatoires. [...]Nous avons conçu mutant de PPAR⍺ dont l'activité de liaison à l'ADN est abolie. La comparaison de ses activités transcriptionnelles in vitro avec le PPAR⍺ non muté démontre que les activités de contrôle du métabolisme sont abolies pour ce mutant, alors que les activités anti-inflammatoires restent intactes. [...] Dans cette étude, nous montrons donc pour la première fois que PPAR⍺ inhibe la progression de la stéatose vers le NASH et la fibrose par un mécanisme anti-inflammatoire direct, indépendant de son effet sur le métabolisme lipidique hépatiqueNon-alcoholic fatty liver disease (NAFLD) is an increasingly prevalent liver condition characterized by excessive lipid deposition in the hepatocytes steatohepatitis (NASH) is hallamarked by chronic inflammation. NASH markedly increases the risk of progression towards liver fibrosis, cirrhosis ans hepatocellular carcinoma. The nuclear peroxisome proliferator-activated receptor alpha (PPAR⍺) regulates hepatic fatty acid utilization and represses pro-inflammatory signaling pathways. [...]Liver-specific expression of wild type or DNA binding-deficient PPAR⍺ in acute and chronic models of inflammation demonstrated that PPAR's anti-inflammatory, but not metabolic activities, result from DNA binding-independent mechanisms in vivo. We futher show that PPAR⍺ inhits the transition from steatosis toward NASH and fibrosis through a direct, anti-inflammatory mechanism independent of its effetc on hepatic lipid metabolism
5
Мазаєва, Вікторія Сергіївна. "Технологія жирових продуктів із заданими властивостями багатоцільового призначення." Thesis, Український науково-дослідний інститут олій та жирів НААН, 2018. http://repository.kpi.kharkov.ua/handle/KhPI-Press/39134.
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Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.18.06 – технологія жирів, ефірних масел і парфумерно-косметичних продуктів. – Національний технічний університет "Харківський політехнічний інститут", Харків, 2018.
Дисертаційну роботу присвячено науковому обґрунтуванню перспективної технології одержання жирових продуктів з наперед заданими властивостями. Визначено триацилгліцерольний склад найбільш поширеної жирової сировини. Показано, що при загальній кількості триацилгліцеролів від 11 до 20 у кожному компоненті визначальними (за вмістом) є 7 – 10 триацилгліцеролів, від яких і залежать фізико-хімічні властивості жирових сумішей. На діаграмах диференційної скануючої калориметрії проаналізовані фазові перетворення для процесів плавлення та кристалізації в широкому діапазоні температур для одинадцяти сумішей. Виконано порівняльний аналіз температури в характерних точках з температурами плавлення і застигання. В результаті проведених обчислень знайдені коефіцієнти апроксимації для обчислення вмісту твердих триацилгліцеролів в характерних точках на діаграмі диференційної скануючої калориметрії і отриманих за допомогою ядерного магнітного резонансу, що дозволяє зіставляти і перераховувати результати обох аналізів, а це, в свою чергу, дозволяє досягати більш достовірних результатів. За допомогою плану Шеффе отримані рівняння регресії на базі яких розраховано рівняння залежності фізико-хімічних властивостей від триацилгліцерольного складу, що підтверджує можливість створення жирових основ жировмісних продуктів за допомогою відомого триацилгліцерольного складу. Розроблена методологія дозволяє скорегувати рецептуру жирових сумішей згідно із заданими фізико-хімічними властивостями або відтворювати вже існуючі рецептури за допомогою іншої сировини, на стадії лабораторних досліджень, ще до початку технологічного процесу і мінімізувати втрати енергоресурсів та час роботи лабораторії.Thesis for a candidate Degree in Technical sciences, specialty 05.18.06 – technology of fats, essential oils and perfumery and cosmetic products. – National Technical University "Kharkiv Polytechnic Institute", of Ministry of Education and Science of Ukraine Kharkiv, 2018. The thiacylglycerol composition of the most common fatty material is determined. It is shown that in the total number of triacylglycerols from 11 to 20 in each component, the determinant (in content) is 7-10 triacylglycerols, on which the physical and chemical properties of fatty mixtures depend. In the diagrams of differential scanning calorimetry, phase transformations for melting and crystallization processes in a wide temperature range for eleven mixtures are analyzed. A comparative analysis of temperature at characteristic points with melting and freezing temperatures has been performed. As a result of the calculations, the coefficients of approximation were calculated for the calculation of the content of solid triacylglycerols in the characteristic points on the differential scanning calorimetry diagram and obtained with the help of a nuclear magnetic resonance, which allows to compose and recalculate the results of both analyzes, which in turn allows us to achieve more reliable results. Using the Scheffe plan, regression equations were derived on the basis of which the equation of the dependence of physical and chemical properties on the triatsilglycerol composition was calculated, which confirms the possibility of creating fatty bases of fat-containing products with the help of knowledge of the triacylglycerol composition. The developed methodology allows to adjust the formula of fat mixtures according to the given physical and chemical properties or to reproduce already existing recipes with the help of other raw materials, at the stage of laboratory research, before the beginning of the technological process and to minimize energy losses and the time of the laboratory.
6
Мазаєва, Вікторія Сергіївна. "Технологія жирових продуктів із заданими властивостями багатоцільового призначення." Thesis, Національний технічний університет "Харківський політехнічний інститут", 2018. http://repository.kpi.kharkov.ua/handle/KhPI-Press/39133.
Full textAbstract:
Дисертація на здобуття наукового ступеня кандидата технічних наук за спеціальністю 05.18.06 – технологія жирів, ефірних масел і парфумерно-косметичних продуктів. – Національний технічний університет "Харківський політехнічний інститут", Харків, 2018.
Дисертаційну роботу присвячено науковому обґрунтуванню перспективної технології одержання жирових продуктів з наперед заданими властивостями. Визначено триацилгліцерольний склад найбільш поширеної жирової сировини. Показано, що при загальній кількості триацилгліцеролів від 11 до 20 у кожному компоненті визначальними (за вмістом) є 7 – 10 триацилгліцеролів, від яких і залежать фізико-хімічні властивості жирових сумішей. На діаграмах диференційної скануючої калориметрії проаналізовані фазові перетворення для процесів плавлення та кристалізації в широкому діапазоні температур для одинадцяти сумішей. Виконано порівняльний аналіз температури в характерних точках з температурами плавлення і застигання. В результаті проведених обчислень знайдені коефіцієнти апроксимації для обчислення вмісту твердих триацилгліцеролів в характерних точках на діаграмі диференційної скануючої калориметрії і отриманих за допомогою ядерного магнітного резонансу, що дозволяє зіставляти і перераховувати результати обох аналізів, а це, в свою чергу, дозволяє досягати більш достовірних результатів. За допомогою плану Шеффе отримані рівняння регресії на базі яких розраховано рівняння залежності фізико-хімічних властивостей від триацилгліцерольного складу, що підтверджує можливість створення жирових основ жировмісних продуктів за допомогою відомого триацилгліцерольного складу. Розроблена методологія дозволяє скорегувати рецептуру жирових сумішей згідно із заданими фізико-хімічними властивостями або відтворювати вже існуючі рецептури за допомогою іншої сировини, на стадії лабораторних досліджень, ще до початку технологічного процесу і мінімізувати втрати енергоресурсів та час роботи лабораторії.Thesis for a candidate Degree in Technical sciences, specialty 05.18.06 – technology of fats, essential oils and perfumery and cosmetic products. – National Technical University "Kharkiv Polytechnic Institute", of Ministry of Education and Science of Ukraine Kharkiv, 2018. The thiacylglycerol composition of the most common fatty material is determined. It is shown that in the total number of triacylglycerols from 11 to 20 in each component, the determinant (in content) is 7-10 triacylglycerols, on which the physical and chemical properties of fatty mixtures depend. In the diagrams of differential scanning calorimetry, phase transformations for melting and crystallization processes in a wide temperature range for eleven mixtures are analyzed. A comparative analysis of temperature at characteristic points with melting and freezing temperatures has been performed. As a result of the calculations, the coefficients of approximation were calculated for the calculation of the content of solid triacylglycerols in the characteristic points on the differential scanning calorimetry diagram and obtained with the help of a nuclear magnetic resonance, which allows to compose and recalculate the results of both analyzes, which in turn allows us to achieve more reliable results. Using the Scheffe plan, regression equations were derived on the basis of which the equation of the dependence of physical and chemical properties on the triatsilglycerol composition was calculated, which confirms the possibility of creating fatty bases of fat-containing products with the help of knowledge of the triacylglycerol composition. The developed methodology allows to adjust the formula of fat mixtures according to the given physical and chemical properties or to reproduce already existing recipes with the help of other raw materials, at the stage of laboratory research, before the beginning of the technological process and to minimize energy losses and the time of the laboratory.
7
Aguiar, Prado Lucas De Ofeu. "Prédiction de la production et de la composition de la matière grasse du lait par modélisation : rôle des flux de nutriments absorbés." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLA015/document.
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La composition du lait en acides gras (AG) chez la vache laitière est la résultante du métabolisme lipidique au niveau du rumen et au niveau de la glande mammaire. Dans le cadre du renouvellement des systèmes d’unités d’alimentation INRA, l’objectif de ce travail est de prédire par une approche quantitative utilisant la méta-analyse de bases de données, les flux duodénaux d’AG chez les ruminants, le transfert des AG de l’intestin à la glande mammaire, et les flux d’AG sécrétés dans le lait.Des équations de prédiction des flux duodénaux et absorbés des AG saturés, des AG impairs et ramifiés, et d’un grand nombre d’isomères des AG insaturés ont été obtenues en intégrant les effets de facteurs expérimentaux tels que la nature du fourrage, le pourcentage de concentré, la supplémentation en huiles, graines végétales, et en produits marins, et leurs interactions. Ces équations sont fonction des AG ingérés et des facteurs interférents (mode de conservation et familles botaniques des fourrages, composition du régime alimentaire, caractéristiques des animaux).Pour le transfert des AG du duodénum à la glande mammaire, les équations privilégient comme prédicteur leur flux duodénal respectif, mais utilisent aussi des paramètres digestifs ruminaux (pH, acétate, butyrate) ou des caractéristiques des rations pour les AG impairs et ramifiés, ou les AG synthétisés de novo (C4:0 à C14:0).La validation de ces modèles a été faite à partir d’une base de données externe qui a permis de coupler les deux modèles et d’évaluer leur précision. Finalement, nous proposons des équations de prédiction des AG spécifiques ainsi que des groupes d’AG présentant un intérêt nutritionnel et qui peuvent fournir une approche aux systèmes d'unités d'alimentation pour prédire leurs réponses à différents types de rationsMilk fatty acids (FA) composition in dairy cows results from lipid metabolism in rumen and mammary gland. In the context of renewing the INRA feed unit system, the objective of this work is to predict, by a quantitative approach using metaanalysis, duodenal flows of FA in ruminants, FA transfer from the intestine to the mammary gland, and the secreted FA flows in the milk. Predictive equations for duodenal and absorbed saturated FA, odd and branched FA, and a large number of unsaturated FA isomers were obtained by integrating the effects of experimental factors such as the nature of the forage, the concentrate percentage, supplementation with oleaginous oils and seeds, and marine products, and their interactions.These equations are function of ingested FA and their interfering factors (forage conservation mode and botanical family, diet composition, animal factors).For the transfer of FA from duodenum to the mammary gland, the equations favor the prediction of their respective duodenal flows, but they also use ruminal digestive parameters (pH, acetate, butyrate) or dietary characteristics for odd and branched FA, or de novo synthesized FA (C4 :0 to C14 :0).Models validation was done with an external database, which allowed coupling the two models and evaluate their accuracy. Finally, we propose predictive equations for specific FA as well as FA groups of nutritional interest that can provide an approach to the INRA feed unit system to predict their milk yield responses according to different types of rations
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González, Paz Rodolfo Jesús. "Polyurethanes based on fatty acids with improved biocompatibility." Doctoral thesis, Universitat Rovira i Virgili, 2012. http://hdl.handle.net/10803/96663.
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El objetivo principal de esta tesis ha sido el desarrollo de nuevos poliuretanos a partir de ácidos grasos como fuentes renovables, utilizando química “click” en la síntesis de los dioles y polioles correspondientes. La primera parte del trabajo describe la preparación de los monómeros “vía” acoplamiento tiol-eno ó tiol-ino, su caracterización y las propiedades de los poliuretanos sintetizados. Como los polímeros a partir de ácidos grasos provienen de macromoléculas biológicas y pueden ser potencialmente biocompatibles, la segunda parte del trabajo está dirigida a incrementar la biocompatibilidad de los poliuretanos a través de diversas estrategias de funcionalización con moléculas bioactivas, para su implementación en ingeniería de tejidos. Tres metodologías fueron investigadas: mezclas con gelatina; inmovilización covalente de colágeno sobre la superficie mediante plasma; e inmovilización iónica de sulfato de condroitina sobre la superficie mediante aminólisis.The main objective of this thesis has been the development of new polyurethanes from renewable sources such as fatty acids, using "click" chemistry in the synthesis of the corresponding diols and polyols. The first part of this study describes the preparation of monomers "via" thiol-ene or thiol-yne coupling, characterization and properties of the synthesized polyurethanes. As the polymers from fatty acids derived from biological macromolecules and can be potentially biocompatible, the second part of this work is focused on the enhancement of polyurethanes biocompatibility through bioactive molecules functionalization strategies, for tissue engineering purposes. Three approaches have been investigated: blends of polyurethanes and gelatin; covalent surface modification of polyurethanes with collagen by plasma treatment; and ionic surface modification of polyurethanes with chondroitin sulfate by aminolysis treatment.
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Passet, Quentin. "Synthesis and functionalization of fatty acid-based hyperbranched polymers." Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0059.
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Ces travaux de thèse portent sur la valorisation de la biomasse oléagineuse, via la polymérisation de synthons, issus d’huiles végétales, en polymères hyper-ramifiés. Ces recherches ont conduit à la synthèse et à la purification d’un nouveau monomère biosourcé, le 10,11-epoxy undecan-1-ol (EUnd), dont la polymérisation par ouverture de cycle (ROMBP) a permis de générer des polyéthers hyper-ramifiés biosourcés. Les conditions de polymérisations ont été étudiées en laboratoire dans le but d’optimiser les rendements de synthèse mais aussi afin de contrôler la structure chimique, ainsi que leurs propriétés. La copolymérisation de l’EUnd avec le glycidol a permis d’atteindre de nouvelles propriétés, notamment en termes de solubilité. Une seconde partie fut consacrée à la fonctionnalisation de polyesters hyper-ramifiés biosourcés, développés au LCPO lors du projet HyPerBioPol. L’objectif étant de contrôler la solubilisation des composés dans différents milieux, polaires et apolaires, afin de créer des polymères pouvant être utilisés comme agents de réticulationThe aim of this thesis is to valorize oilseed biomass through the polymerization of building block, stemming from vegetable oils, into hyperbranched polymers. This research involves the synthesis and purification of a new bio-based monomer, coined as 10,11- epoxyundecanol (EUnd), which ring-opening multibranching polymerization (ROMBP) has generated bio-based hyperbranched polyethers (hbPEUnd). Conditions of polymerization have been studied in order to maximize yields of reaction and control both the chemical structure and the properties of hbPEUnd. Copolymerization of EUnd with glycidol has also been implemented, yielding hyperbranched copolyethers with varied properties (e.g. solubility). The second part of this work has been dedicated to the functionalization of bio-based hyperbranched polyesters, developed in the frame of a former project. Appropriate derivatizations have provided these modified polyesters with solubility in polar solvents and made them employable as curing agents
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Ramayo, Caldas Yuliaxis. "Dissecting the Genetic Basis of Pig Intramuscular Fatty Acid Composition." Doctoral thesis, Universitat Autònoma de Barcelona, 2013. http://hdl.handle.net/10803/120210.
Full textAbstract:
El cerdo (Sus scrofa domestica) constituye una de las principales fuentes de carne para la humanidad, y es también un excelente modelo animal para el estudio de enfermedades metabólicas en humanos. Los ácidos grasos (AG) juegan un papel importante actuando como moléculas de señalización celular en diversas rutas metabólicas asociadas a este tipo de patologías y además en la determinación de la calidad organoléptica y nutricional de la carne porcina. Como consecuencia, descifrar la base molecular del metabolismo de los AG podría contribuir al conocimiento de la base genética de las enfermedades metabólicas, además de favorecer el desarrollo tecnológico para mejorar la calidad de la carne porcina. El objetivo principal de esta tesis ha sido estudiar las bases genéticas del contenido intramuscular (IMF) de AG en cerdos.
Para ello hemos utilizado diferentes, pero complementarias aproximaciones analíticas. Inicialmente utilizamos los datos genotípicos del chip porcino de 62.612 SNPs (Illumina) e identificamos 49 regions con variación en el número de copias. Posteriores estudios de asociación masivos entre 32 fenotipos relacionados con el perfil IMF AG y los SNPs del chip de Illumina nos permitieron identificar 43 regiones significativamente asociados a 15 de los fenotipos analizados. Cabe destacar que el 53.5% de las regions identificadas contienen QTLs asociados a caracteres lipídicos. Al comparar el transcriptoma del hígado entre dos grupos de cerdos con fenotipos extremos para la composición IMF de AG se han identificado un total de 55 genes diferencialmente expresados. Análisis funcionales revelan que muchos de estos genes pertenecen a funciones biológicas, rutas metabólicas y redes génicas interconectadas relacionadas con el metabolismo los AG. La implementación de un enfoque holístico que basado en la co-asociación entre genes y/o SNPs a lo largo de varios fenotipos nos permitió identificar redes génicas, rutas metabólicas y factores de transcripción relevantes para el metabolismo de los AG. Por primera vez, interacciones génicas predichas en base a la co-asociación entre genes fueron válidadas mediante estudios de co-expresión génica en dos tejidos relevantes para el metabolismo de los AG en cerdos (hígado y tejido adiposo). Los resultados obtenidos muestran la utilidad de la biología de sistemas en el estudio de caracteres complejos. Sin embargo, serán necesarios estudios que integren diferentes disciplinas para establecer estrategias más eficientes que permitan mejorar la calidad de la carne de cerdo.Pigs (Sus scrofa) are relevance to humans, both as a source of food and as an animal model for scientific progress. Technological, nutritional and organoleptic properties of pork meat quality are highly dependent on lipid content and fatty acid (FA) composition. The molecular processes controlling FA composition and metabolism are highly interconnected and not fully understood. Elucidating these molecular processes will aid the technological development towards the improvement of pork meat quality and increase knowledge of FA metabolism underpinning metabolic diseases. This thesis deals with FA metabolism in pigs, analyzed from different perspectives. We have described for the first time a Copy Number Variant Regions map in swine based on whole genome SNP genotyping chips some of them may have an effect on FA. A Genome-Wide Association Study approach was carried out in a Iberian x Landrace backcross across 32 traits related to IMF FA composition and a total of 43 chromosomal regions were identified. Besides, 53.5% of these chromosomal intervals had been reported to contain QTL for lipid traits in previous studies. The liver transcriptome of two female groups of phenotypically extreme pigs for Intramuscular FA composition were sequenced using RNA-Seq. A differential expression analysis identified 55 protein-coding genes differentially-expressed between groups. Functional analysis revealed that these genes belong to biological functions, canonical pathways and three connected gene networks related to lipid and FA metabolism. Finally, a holistic gene network approach based on SNP-to-SNP co-association was employed. Supporting evidence for co-association network predictions were confirmed at tissue-specific manner by gene co-expression analysis in adipose and liver tissues. The analysis of the topological properties of both the co-association and co-expression predicted gene networks, allowed the identification of key transcription factors, candidate genes and metabolic pathways that are likely being determining meat quality and FA composition, as well as controlling energy homeostasis in pigs. Future studies targeting these genes, their pathways and interactions will continue to expand our knowledge of molecular control of FA metabolism and it might lead to discovery of functional relevant mutations, unfolding new strategies for improve pork meat quality.
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Meheust, Hélène. "New fatty acid-based polyesters as viscosity control additives for lubricants." Thesis, Bordeaux, 2018. http://www.theses.fr/2018BORD0291.
Full textAbstract:
L’objectif de ces travaux de thèse a été de développer des polyesters issus de ressources oléagineuses pour les utiliser comme additifs pour moduler la viscosité d’huiles lubrifiantes. Pour ce faire, l’approche par polycondensation de monomères de type hydroxy-acide a été privilégiée. Dans un premier temps, le poly(ricinoléate de méthyle) et son homologue saturé, le poly(12-hydroxystéarate de méthyle), ont été synthétisés dans une large gamme de masses molaires et leur utilisation comme épaississant d’huiles lubrifiantes a été démontrée. Dans un second temps, des polyesters dérivés du poly(ricinoléate de méthyle) et présentant des architectures de polymère en peigne ont été synthétisés par addition thiol-ène et polycondensation. Une étude de l’impact de l’architecture de ces polyesters sur leur comportement en solution a permis de prouver que les structures en peigne étaient les plus adaptées pour des applications visant, à la fois, un épaississement et une diminution du point d’écoulement de l’huile lubrifiante. Par la suite, des copoly(9-alkyl 12-hydroxystéarate)s en peigne possédant différentes chaînes pendantes ont été synthétisés afin de contrôler leur solubilité dans une huile minérale, la Yubase 4+, et ont permis de réduire la diminution de viscosité de cette huile avec la température. Finalement, l’étude dans le dodécane de deux copoly(9-alkyl 12-hydroxystéarate)s en peigne a révélé un phénomène d’agrégation des chaînes polymères lesquelles se désagrègent avec l’augmentation de la température, ce qui est en accord avec un des mécanismes d’action des additifs modulant la viscosité des huiles lubrifiantes décrit dans la littératureThe aim of this thesis was to promote the use of polyesters from oleaginous resources as viscosity control additives for lubricants. The hydroxyl-acid type monomers were polymerized through polycondensation route. First, poly(methyl ricinoleate) and its homologous poly(methyl-12-hydroxystearate) were synthesized in a large range of molecular weights and their use as thickeners of lubricant oils was demonstrated. Secondly, comb polyesters derived from poly(methyl ricinoleate) were designed via thiol-ene addition and polycondensation process. The effect of the polyester architecture on their behavior in solution was investigated and revealed that comb polymers are the most suitable for applications that required a thickening efficiency and a pour point depressant effect. Then, comb (co)poly(9-alkyl 12-hydroxystearate)s with various pendant alkyl chains were designed in order to control their solubility in a mineral oil, the Yubase 4+, and to limit the oil viscosity decrease of these oils with temperature. Finally, the behavior in dodecane of two comb (co)poly(9-alkyl 12-hydroxystearate)s revealed that the polymer chains tend to aggregate at low temperature and to disaggregate with the temperature increase. This phenomenon is in accordance with one of the oil Viscosity Index Improver behaviors, described in literature
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Tunedal, Kajsa. "Mathematical modeling of fatty acid metabolism during consecutive meals and fasting : New insights into fatty acid regulation based on arterio-venous data." Thesis, Linköpings universitet, Institutionen för medicinsk teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-177309.
Full textAbstract:
Obesity, type 2 diabetes, and cardiovascular diseases are major problems in today's society, causing millions of deaths every year. One of the main risk factors for these diseases is a dysregulation of the fatty acid metabolism, where the balance between release and uptake of fatty acids is disturbed. Thus, understanding how fatty acid metabolism works is of great importance in the battle against these diseases. The human fatty acid release and uptake can be unraveled by measuring the difference in metabolite concentrations between an artery before the adipose tissue and a vein draining the tissue. Such measurements are called arterio-venous. However, due to the complexity of the fatty acid mechanisms, the resulting measurements alone are not enough to understand all of the involved reactions governing the metabolism. One analytical tool to decipher such complex mechanisms is mathematical modeling. A few mathematical models have previously used arterio-venous data of the fatty acid metabolism, but none of the previous models describe a full day including several meals and nightly fast. In this project, I combine mathematical modeling and arterio-venous data to investigate the mechanisms of fatty acid metabolism during three consecutive meals and fasting. The resulting mathematical model can explain arterio-venous data of free fatty acids, triglycerides, and glycerol. The model predictions show that re-esterification of monacylglycerides, a mechanism that has not been considered before when analyzing arterio-venous data, is of importance to be able to accurately describe the fatty acid metabolism. Additionally, the model predicts that there is a hormonal regulation during the night. Finally, it is shown that many of the previous simple calculations used to approximate metabolic reactions do not capture the desired reactions but instead calculate more complex properties, while the use of the model allows for a more detailed analysis separating all of the different reaction rates. These results give new insights into the complex mechanisms of fatty acid metabolism and provide a new tool to analyze arterio-venous data more comprehensively. In the future, this can lead to a better understanding of metabolic diseases such as obesity, type 2 diabetes, and cardiovascular diseases.
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Bat, Erhan. "Synthesis And Characterization Of Hyperbranched And Air Drying Fatty Acid Based Resins." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606270/index.pdf.
Full textAbstract:
There has been a considerable effort in the last years to decrease the amount of volatile organic compounds (VOCs) present in organic coatings. The risks to human health and environmental hazards associated with VOCs, governmental directives, and economic factors are the main driving forces behind this effort. One way of achieving less or no VOC containing coating systems is to produce low viscosity resins. Hyperbranched resins owing to their globular structure have low viscosities and are promising materials for decreasing the VOCs. In this research hyperbranched resins having properties close to alkyds were synthesized. Dipentaerythritol, which was used as the core was esterified with dimethylol propionic acid. The hyperbranched polyester was then esterified with the castor oil fatty acids (Castor FA). The hydroxyl group of the ricinoleic acid present in the castor FA was modified with different amounts of linseed oil fatty acids (Linseed FA) and benzoic acid.
The chemical characterization of the resins was achieved by FTIR spectroscopy and the thermal properties were determined by DSC. Then, the physical and the mechanical tests were carried out. The resins containing the Castor FA only and 32.5 % Linseed FA in addition to the Castor FA had 24 and 68 Persoz hardness, respectively. The viscosity of the resins decreased from 17.3 Pa
s to 5.8 Pa&
#61655
s as the amount of the Linseed FA was increased. The resins showed excellent adhesion, gloss, flexibility and formability.
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Moore, Robert Lee. "Antioxidant Protection of an Omega-3 Fatty Acid Fortified Dairy-Based Beverage." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/36376.
Full textAbstract:
Skim, butter-derived aqueous phase, anhydrous milk fat, and fish oil were used to
formulate ultra high temperature (UHT) processed extended shelf-life omega-3 fatty acid
fortified dairy-based beverages with fat contents mimicking whole milk (3.25%).
Oxidation of the lipids in the formulated beverages was investigated during storage for 35
days at 4 °C using GC/MS analysis, conjugated diene analysis, and headspace solid phase
micro-extraction GC/MS (SPME-GC/MS) analysis of headspace. Omega-3 fatty acid
fortified dairy-based beverages were produced that mimicked the physical properties of
3.25% fat whole milk. Oxidation resulted in only small changes in omega-3 lipid content
and sensory analysis by an untrained panel indicated that the overall aroma was no
different than that of commercially available UHT processed milk. An omega-3 fatty acid
fortified dairy-based beverage was produced that delivered 440mg of omega-3 fatty acid
per 8oz serving. When consumed daily, the beverage could provide the equivalent
amount of omega-3 fatty acids recommended by the American Heart Association, and the
equivalent amount of omega-3 fatty acids found in two fatty fish meals over the period of
one week.
Antioxidants were added to the lipid phase, immediately prior to processing, of
additionally produced formulations to determine if a reduction in omega-3 lipid oxidation
was observed. No overall reduction in oxidation was observed, as indicated by GC/MS
and SPME-GC/MS analysis. Sensory analysis indicated that oxidative aromas increased
during storage for the antioxidant and omega-3 fatty acid fortified dairy-based beverage.
Ascorbyl palmitate was determined to have a pro-oxidative effect on the formulated
omega-3 fortified dairy-based beverages. Antioxidants present in the commercial grade
fish oil used for fortification were effective in controlling oxidation in the formulated
omega-3 fatty acid fortified dairy-based beverages.
Master of Science
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Alsharari, Zayed. "Dietary Intake, Fatty Acid Biomarkers, and Abdominal Obesity : Population-Based Observational Studies." Doctoral thesis, Uppsala universitet, Institutionen för folkhälso- och vårdvetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-327278.
Full textAbstract:
The aim of this thesis was to investigate the associations between fatty acid (FA) biomarkers, carbohydrate intake, and abdominal obesity (AO) and related anthropometric measures in a population-based cohort of men and women in Stockholm County. The overall hypothesis was that dietary fat quality assessed by serum and adipose tissue FA composition, and dietary intake of especially carbohydrates is associated with AO. FA composition was assessed by liquid gas chromatography, and AO was measured as waist circumference (WC), waist hip ratio (WHR) and sagittal abdominal diameter (SAD). Dietary intake was assessed by 7-day food records. Papers I, II, III, and IV were all observational studies based on a Swedish population in Stockholm County (n=5460). A sub-cohort of only men (n=301) was included in Papers II, III, and IV. In Paper I, serum proportions of the polyunsaturated FA (PUFA), linoleic acid (LA) (18:2n6), was inversely associated with AO in both men and women, whereas a positive association was observed between the saturated FA (SFA), palmitic acid (PA) (16:0) and AO measures. These findings support recent interventional studies suggesting that a higher relative intake of PUFA (LA) from vegetable oils as compared with 16:0 is associated with decreased abdominal adiposity. In Paper II, we investigated whether biomarkers of dietary fat quality were related to the corresponding FA intake from fat-rich foods reported in a short food frequency questionnaire (FFQ). Serum proportions of the long-chain n-3 PUFAs eicosapentaenoic acid (EPA) and docosahexanoic acid (DHA) were higher among men with higher total fish intake. Serum LA was higher among men who reported a consumption of more than 5 g/d of margarine. Absolute agreement between intakes assessed with FFQ of 60YO and 7-day food record of "Kost och Metabola syndromet"/"Diet and the Metabolic syndrome" (KOMET) was highest for alcohol, total fish, and eggs. Weighted Kappa statistics revealed the strongest agreement for alcohol, margarine, and fruits. In Paper III, carbohydrate intake was inversely associated with 16:0 in serum phospholipids (PL). Disaccharide and alcohol intake was positively and non-linearly associated with palmitoleic acid (16:1) and stearoyl-CoA-desaturase (SCD) activity in PL. Alcohol was consistently associated with higher SFA and monounsaturated FA (MUFA). Results of Paper IV indicated that total carbohydrate intake was inversely associated with measures of AO and central fat distribution, WHR and SAD, respectively. Likewise, monosaccharide intake was associated with lower AO. In contrast, alcohol intake was associated with AO prevalence and all anthropometric measurements. In conclusion, serum SFA (palmitic acid) was positively associated with AO, whereas n-6 PUFA (linoleic acid) was associated with lower AO. High intake of total carbohydrate and monosaccharides were associated with lower AO. Overall, these results support a beneficial role on adiposity of diets that are higher in polyunsaturated fat (vegetable oils) and total carbohydrates compared with saturated fat.
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Lewis, Heidi A. "IMPROVING LARVAL SUNSHINE BASS PRODUCTION THROUGH SUPPLEMENTATION OF FEMALE WHITE BASS BROODSTOCK DIETS WITH LONG-CHAIN POLYUNSATURATED FATTY ACIDS." OpenSIUC, 2010. https://opensiuc.lib.siu.edu/dissertations/118.
Full textAbstract:
Feeds that maximize reproductive potential are needed to ensure success of captive broodstock. Nutritional requirements for somatic growth of juvenile fishes differ from nutritional requirements of mature fishes and are largely species-specific. Broodstock nutritional research has focused primarily on lipid and fatty acid requirements and their effects on reproductive conditioning due to the importance of these nutrients in providing metabolic energy and structural elements, i.e. for phospholipids for embryonic development. Development of suitable broodstock feeds are limited by not knowing fatty acid requirements for many species. Once requirements are identified, plant, grain, marine, algal, and fungal lipid sources can be blended to develop least-cost diet formulations. The objectives of this dissertation are to (1) evaluate white bass Morone chrysops ovum fatty acid composition and reproductive performance after feeding maternal broodstock graded levels of squid to fish oil; (2) evaluate flax, canola, and corn oils as alternatives to marine oil(s) in white bass maternal broodstock diets; (3) determine extent to which grain oils can replace marine oils in female white bass broodstock diets in order to maintain reproductive performance and quantify fatty acid utilization of larvae with different initial fatty acid profiles; and (4) assess dietary supplementation of 20:4n-6, 20:5n-3, and 22:6n-3 concentrates to boost reproductive performance of female white bass fed primarily plant oil-based lipid sources. Of the marine and plant oils tested, menhaden fish oil provided female white bass broodstock the fatty acids (~3.9% n-3 long-chain polyunsaturated fatty acids; LC-PUFA; dry matter basis) necessary to maximize embryonic survival; however, flax oil, due to its low 18:2n-6 and high 18:3n-3 content, showed promise as a suitable plant oil candidate for partial if not complete marine oil substitution in female white bass broodstock feeds. Differential responses in embryonic and larval survival resulted in comparable total larval yields at 5 days post hatch (DPH) after feeding female broodstock graded levels (0, 33, 67, or 100%) flax to fish oils for 30 weeks prior to spawning. At the end of the endogenous feeding period, fatty acid compositions of flax and fish oil-fed broodstock progeny deviated from initial ova composition. Although n-3 LC-PUFA from menhaden fish oil are essential for embryonic survival, sunshine bass appear to have lower n-3 LC-PUFA requirements after hatch. Larval survival was highly dependent on the presence of C18 PUFA present due to flax oil inclusion in maternal diets. Embryonic survival of progeny produced from broodstock fed dietary saturated fatty acid-rich plant lipids supplemented with intact LC-PUFA concentrates (~3.4% n-3 LC-PUFA; dry matter basis) was similar to that of the broodstock fed the menhaden fish oil control diet containing 4.8% n-3 LC-PUFA. Although the dietary requirement for n-3 LC-PUFA was reduced by feeding these LC-PUFA concentrates in combination with plant lipids, menhaden fish oil is still the most viable option for least cost broodstock diet formulations intended for white bass.
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Kimmel, Tobias. "Kinetic investigation of the base catalyzed glycerolysis of fatty acid methyl esters." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=97339174X.
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Langevin, Karolanne. "Fatty Acids Profiles of Yellow Perch (Perca flavescens) in Lakes of the Outaouais Region with and without Largemouth Bass (Micropterus salmoides) and Smallmouth Bass (Micropterus dolomieu)." Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/35366.
Full textAbstract:
Fatty acids (FAs) are used as trophic markers in aquatic food web studies, but few studies have quantified individual variability in FAs profiles over several sites in a range of conditions. I investigated whether FAs profiles of yellow perch (YP), Perca flavescens, vary with body size and between lakes with and without largemouth (Micropterus salmoides), and smallmouth bass (Micropterus dolomieu), the most common and abundant piscivores in lakes of the region. I analyzed the FAs of YP as well as zooplankton, benthic invertebrates, and prey fish collected from eight lakes where bass were either present or absent in the Outaouais region over the summer of 2016. I compared the growth rate of YP between the lakes and the YP in lakes without bass exhibited a slower growth rate. I also compared the FA signatures of YP using redundancy analysis (RDA). 23 FAs could be identified and quantified. FAs profiles were dominated by palmitic- (16:0), oleic- (18:1), stearic- (18:0), and palmitoleic acid (16:1). The RDA analysis based on FAs profiles of YP revealed variation along two main gradients (the presence of bass and the date of capture). The first two eigenvectors accounted for 42.1% of the variation (RDA1=27.6% and 2=14.6%). Arachidonic (20:4) and docosatrienoic (22:3) were the most correlated FAs with RDA1. Due to the sampling period, it was impossible to determine if the observed effects were due to the date of capture, the presence of bass, or a change in metabolism, but the last two were deemed as the most plausible explanations. It was concluded that the utility of FA signatures to quantify diet in natural environments is limited and that FAs might be more successful as markers in primary consumers and other lower trophic levels. It is recommended that a combination of FAs, stable isotopes, and modelling should be used in the future.
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Lu, Qiang. "Potent short-chain fatty acid-based histone deacetylase inhibitors as anti-tumor agents." Connect to resource, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1117541292.
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Thesis (Ph. D.)--Ohio State University, 2005.Title from first page of PDF file. Document formatted into pages; contains xix, 116 p.; also includes graphics. Includes bibliographical references (p. 106-116). Available online via OhioLINK's ETD Center
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Wang, Yi, and 王毅. "Structural basis on human Sirt6 function of hydrolyzing long chain fatty acyl lysine." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/196481.
Full textAbstract:
Sirtuins, a class of enzymes known as nicotinamide adenine
dinucleotide-dependent deacetylases, have been shown to regulate a variety of biological processes, including aging, transcription, and metabolism. Severn human Sirtuins members (Sirt1-7) are involved in various kinds of severe diseases like aging, cancer development, autoimmune diseases and therefore are considered as potential drug targets for treatment. Among them, Sirt4-7 have very weak traditional deacetylation function in contrast to the others. So, investigation on the real functions of these sirtuins is a prerequisite for specific modulator (inhibitor or activator) design. Crystallography is a robust way to study the molecular basis of the catalytic function of these sirtuins. Here we show that the real function of Sirt6 is the de-long-chain-fatty acylase activity from lysine, such as the demyristoylase activity. The crystal structure of Sirt6 complex shows a large hydrophobic pocket accommodating the myristoyl group. Together with the biochemical and physiological data from our collaborators, we confirm that Sirt6 promotes the TNFα secretion via hydrolysis the myristoyl group on K19 and K20. Fatty acylation on lysine occurs in mammalian cells and had been found for years, however, the regulatory mechanism is still unclear. Our results provide the opportunities to understand the regulatory of the long chain fatty acyl modification on lysine via Sirt6, which has been little studied until now. More work will be focused on the structural based development of inhibitors to cure the Sirt6 regulated diseases in the near future.published_or_final_version
Physiology
Doctoral
Doctor of Philosophy
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Guc, Esra. "Synthesis And Characterization Of Fatty Acid Based Hyperbranched Polymers For Anti-cancer Drug Delivery." Master's thesis, METU, 2008. http://etd.lib.metu.edu.tr/upload/3/12609675/index.pdf.
Full textAbstract:
Conventional methods of chemotherapy requires novel therapy systems due to serious side effects and inefficiency of drug administration. In recent years many studies are carried out to improve drug delivery systems. Polymers are one of the most important elements for drug delivery research due to their versatility. By the discovery of dendritic polymers, drug delivery studies gained a new vision. Highly branched monodisperse structure, multiple sites of attachment, well-defined size and controllable physical and chemical properties make them efficient drug delivery systems.
In this research hyperbranched dendritic polymers were sythesized and characterized for hydrophobic drug delivery. Dipentaerythritol which was used as core molecule, esterified with dimethylol propionic acid. Ricinoleic acid was esterified with the end groups of dimethylol propionic acid and hyperbranched resin (HBR) was formed. By considering the properties of HBR, hydrophobic tamoxifen and idarubicin were used for drug delivery study. The most efficient loading was determined as 73% for tamoxifen and 74% for idarubicin. Drug-HBR interactions and changes in properties of HBR were determined by FTIR, zeta potential and particle size measurements. FTIR results indicated that idarubicin chemically interacted with HBR while tamoxifen physically loaded to HBR. Drug delivery profile of HBR was studied in the absence and presence of lipase from
Pseudomonas sp. and sodium dodecyl sulfate (SDS). Results revelaed that lipase and SDS increased the release rate of tamoxifen while idarubicin release rate was not affected. The effect of lipase was also tested for the degradation of HBR and it was indicated that lipase sustain a faster degradation. Finally toxicity of HBR and drug loaded HBR on MCF-7 breast cancer cell line was determined with XTT proliferation assay. Empty HBR did not cause significant toxicity on MCF-7 cells while drug loaded HBR was more toxic than free drug. By this study the efficiency of novel synthesized hyperbranched polymer in drug delivery was shown.
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Enns, Jennifer Emily. "The role of dietary fatty acids from plant-based oils in metabolic and vascular disease." Elsevier, 2012. http://hdl.handle.net/1993/30603.
Full textAbstract:
Dietary fat has long been implicated in the etiology of metabolic and cardiovascular disease, and both the amount of fat and the fatty acid composition of the diet play a role in disease progression. Although national health organizations have set guidelines for the recommended intake of dietary fats, questions remain regarding the optimal dietary lipid profile for maintaining health and improving disease conditions. Whether certain types of fatty acids from plant-based oils can improve metabolic and vascular disease has been studied and debated, but not fully determined. In this study, we investigated the role of dietary fatty acids from plant-based oils, and examined their effects on metabolic and vascular disease parameters.
Obese fa/fa Zucker rats were fed a diet containing flaxseed oil, which resulted in smaller adipocytes and decreased adipose tissue T-cell infiltration. Obese-prone Sprague Dawley rats were fed high-fat diets with different proportions of mono- and polyunsaturated fats. Changes were observed in adipose tissue levels of fatty acid synthase, adiponectin and fatty acid receptors GPR41 and GPR43, but other metabolic and inflammatory mediators in adipose tissue and serum remained stable.
A systematic review and meta-analysis on the impact of n3 fatty acids on major cardiovascular endpoints showed that little evidence exists to support their role in peripheral arterial disease. Then again, very few studies on this topic have been conducted. To address this research gap, a clinical trial was designed to investigate the effects of a dietary intervention on blood vessel properties in people with peripheral arterial disease. Participants in the Canola-PAD Study consumed 25 g/day of canola oil or a Western diet oil mixture as part of their usual diet for 8 weeks. Although the intervention altered phospholipid fatty acids, vascular function, the lipid profile and inflammatory markers stayed relatively stable.
Overall, this research demonstrates that dietary fatty acids from plant-based oils can be immunomodulatory, but at the physiological doses tested they are not potent mediators of functional changes in obesity or vascular physiology.October 2015
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Mina, Kym Deanne. "Measurement of fish consumption in population-based studies of cancer." University of Western Australia. School of Population Health, 2007. http://theses.library.uwa.edu.au/adt-WU2007.0093.
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[Truncated abstract] The role of fish consumption and omega-3 polyunsaturated fatty acids (PUFAs) in the prevention of disease has been the subject of much investigation in recent years. A clue that these factors might be of importance was the observation that populations consuming high levels of marine omega-3 PUFAs had lower rates of morbidity and mortality from cardiovascular disease. From there, research in this area has expanded to include a range of chronic diseases and their prevention. An area of particular interest is the role of fish consumption in the prevention of various cancers. In Australia, one in three men and one in four women are expected to be diagnosed with cancer by the age of 75. Identifying preventive factors that can be translated into constructive health promotional messages is of great importance in addressing this group of diseases that has such a large impact on the health and wellbeing of the population. ... Results and conclusions Analysis of the data from the population-based case-control study suggests a protective effect of preserved fish consumption, possibly due to the high oil content of these fish. The developed questionnaire is a valid and reliable tool for measuring fish and seafood consumption as determined by regression analysis with an independent biomarker and reliability analysis using intra-class correlation. Importantly, reliability can be maintained despite asking a high level of detail from participants. For ranking according to overall fish consumption, detailed questioning is probably not necessary, however inclusion of variables representing multiple categories of fish and seafood consumption in a regression model enables us to better account for variation in blood omega-3 PUFA levels than a single variable representing overall consumption. For the purpose of questionnaire validation, plasma phospholipid and erythrocyte membrane levels of EPA and DHA are equivalent biomarkers of fish and seafood consumption. The choice between them by future investigators will be based on more practical aspects such as convenience and the fasting state of subjects. The tangible product of this thesis is additional evidence to support a protective association between fish consumption and prostate and breast cancers, and a valid and reliable questionnaire v for measuring habitual consumption of fish and seafood in a West Australian population, that could also be applied to other populations after minor adjustment for local fish and seafood consumption patterns.
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Loehle, Sophie. "Understanding of adsorption mechanism and tribological behaviors of C18 fatty acids on iron-based surfaces : a molecular simulation approach." Phd thesis, Ecole Centrale de Lyon, 2014. http://tel.archives-ouvertes.fr/tel-00999372.
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The current requirements in automotive lubrication impose complex formulation. Among all the additives present in oil, the presence of molybdenum dithiocarbamate and zinc dithiophosphate, both tribological additives containing sulfur and phosphorous is found. For environmental reasons, it is important to reduce or eliminate the presence of these two elements contained in oil. Organic molecules based on carbon, oxygen and hydrogen seems to be good candidate. The lubrication mechanism of fatty acids (e.g. stearic, oleic and linoleic acids) is revisited with a new approach combining experimental and computational chemistry studies. First, the adsorption mechanisms of fatty acids on iron-based surfaces are investigated by Ultra-Accelerated Quantum Chemistry Molecular Dynamics simulations. The adsorption of fatty acids on iron oxide surface occurred through the acid group. Depending on the nature of the substrate, on the density of the film and on the tilt angle between the molecule and the surface, different adsorption mechanisms (physisorption and chemisorption) can occur. Stearic acid molecules form a close-packed and well-arranged monolayer whereas unsaturation acids cannot because of steric effects induced by double carbon-carbon bonds. The friction process favors the formation of carboxylate function. Results are confirmed by surface analysis (XPS and PM-IRRAS). Tribological properties of pure fatty acids, blended in PAO 4 and mixture of saturated/unsaturated acids are studied by MD simulations and tribotests. Low friction coefficient with no visible wear is reported for pure stearic acid and single stearic acid blended in PAO 4 at 1%w at high temperature. This lubricating behavior is inhibited in the presence of unsaturated acids, especially at 150 °C. MD simulation results show a faster diffusion toward the surface for unsaturated fatty acids than for stearic acid at all studied temperature.
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Wassell, Paul. "A multidisciplinary approach to structuring in reduced triacylglycerol based systems." Thesis, University of Chester, 2013. http://hdl.handle.net/10034/311252.
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This study (Wassell & Young 2007; Wassell et al., 2010a) shows that behenic (C22:0) fatty acid rich Monoacylglycerol (MAG), or its significant inclusion, has a pronounced effect on crystallisation (Wassell et al., 2010b; 2012; Young et al., 2008) and interfacial kinetics (3.0; 4.0). New interfacial measurements demonstrate an unusual surface-interactive relationship of long chain MAG compositions, with and without Polyglycerol Polyricinoleate (PGPR). A novel MAG synthesised from Moringa oleifera Triacylglycerol (TAG) influenced textural behaviour of water-in-oil (W/O) emulsions and anhydrous TAG systems (4.0: 5.0; 6.0). Emulsifier mixtures of PGPR and MAG rich in C18:1 / 18:2 and C16:0 / C18:0 do not decrease interfacial tension compared with PGPR alone. Only those containing MAG with significant proportion of C22:0 impacted interfacial behaviour. A mixture of C22:0 based MAG and PGPR results with decreasing tension from ~20°C and is initially dominated by PGPR, then through rearrangement, the surface is rapidly dominated by C22:0 fatty acids. A Moringa oleifera based MAG showed unusual decreased interfacial behaviour not dissimilar to PGPR. All other tested MAG (excluding a C22:0 based MAG), irrespective of fatty acid composition resulted with high interfacial tension values across the measured temperature spectrum (50°C to 5°C). A relative decrease of interfacial tension, with decreased temperature, was greater, the longer the chain length (Krog & Larsson 1992). Moreover, results from bulk and interfacial rheology showed that the presence of C22:0 based MAG has a pronounced effect on both elastic modulus (G’) and viscous modulus (G’’). Through a multidisciplinary approach, results were verified in relevant product applications. By means of ultrasonic velocity profiling with pressure difference (UVP-PD) technique, it was possible to examine the effect of a C22:0 based MAG in an anhydrous TAG system whilst in a dynamic non-isothermal condition (3.0). The non-invasive UVP-PD technique conclusively validated structural events. The application of a Moringa oleifera based MAG in low TAG (35% - 41%), W/O emulsions, results in high emulsion stability without a co-surfactant (PGPR). The bi-functional behaviour of Moringa oleifera based MAG is probably attributed to miscibility (Ueno et al., 1994) of its fatty acids, ranging ~30% of saturated fatty acids (SAFA), with ~70% of C18:1 (5.0). It is concluded that the surface-interactive behaviour of Moringa oleifera based MAG, is attributed to approximately 10% of its SAFA commencing from C20:0. When examined separately and compared, results showed that physical effect of a Moringa oleifera based MAG was not dissimilar to PGPR, influencing the crystallisation kinetics of the particular anhydrous TAG system. When either was combined with a C22:0 rich MAG, enhanced gelation onset and strong propensity to form dendrite structure occurred (5.0). Macrobeam and synchrotron radiation microbeam small angle x-ray diffraction (SR-μ-SAXD) was utilized (6.0) to assess behavior of C22:0 rich MAG, with and without PGPR (Wassell et al., 2012). The C22:0 based MAG combined with PGPR promoted TAG crystallisation as observed by differential scanning calorimetry (DSC). Polarised optical microscopy (POM) observations indicated that C22:0 based MAG eliminates formation of large crystal aggregates, resulting in the likely formation of tiny Pickering TAG / MAG crystals (6.0). It is concluded that the presence and interactive behaviour of Pickering surface-active MAG, is strongly linked to increased fatty acid chain length, which induce increased textural resilience owing to viscoelasticity (4.0; 5.0). A multidisciplinary approach was able to verify structuring behaviour (4.0; 5.0), using multiple analyses (Wassell et al., 2010b; 2012; Young et al., 2008). Novel structuring solutions in reduced TAG based systems have been provided (4.0; 5.0). This study both enhances current understanding of structuring in low TAG W/O emulsions and has led to novel MAG compositions, which address emulsification, structuring and texture in TAG based food systems (Wassell et al., 2010a; 2012a; 2012b; 2012c; 2012d; 2012e; Bech et al., 2013).
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Coursey, Andrew Richard. "ALTERNATIVE FEEDING STRATEGIES TO MAXIMIZE MARINE FEEDSTUFF REPLACEMENT IN LARGEMOUTH BASS Micropterus salmoides CULTURE WHILE MAINTAINING PRODUCTION PERFORMANCE." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/theses/648.
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ANDREW R. COURSEY, for the Master of Science degree in Zoology, presented 24 June 2011 at Southern Illinois University Carbondale TITLE: ALTERNATIVE FEEDING STRATEGIES TO MAXIMIZE MARINE FEEDSTUFF REPLACEMENT IN LARGEMOUTH BASS Micropterus salmoides CULTURE WHILE MAINTAINING PRODUCTION PERFORMANCE Advisors: Chris Kohler and Jesse Trushenski Harvest of marine resources for feedstuff production is at its maximum sustainable yield and alternative feedstuffs are needed to supply livestock production for an expanding human population having a growing desire for seafood. Aquaculture is currently the fastest growing sector of agriculture, but the high cost and limited supplies of marine feedstuffs for aquafeeds could ultimately limit production of foodfish. Replacement of marine feedstuffs poses a dilemma, however, as replacement of fish meal can affect animal growth, and replacement of fish oil in aquafeeds leads to altered fillet fatty acid profiles without the maximum benefit of high omega-3 (n-3) and long-chain polyunsaturated fatty acids (LC-PUFA) content. Two feeding trials were conducted to determine if poultry byproducts can replace fish meal and fish oil in diets for largemouth bass Micropterus salmoides without affecting production performance or fillet fatty acid composition. Poultry byproducts were able to replace fish meal and fish oil while maintaining production performance of largemouth bass, however, the altered fatty acid profiles of the feeds were reflected in the fillets. Finishing diets containing high levels of fish oil were implemented to restore n-3 and LC PUFA concentrations in the fillet. Twelve weeks of finishing proved suitable to partially restore n-3 and LC-PUFA concentrations while limiting the overall use of marine resources in the largemouth bass production cycle.
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Moruisi, Kgomotso Gini. "The effect of a fatty acid-based carrier on the bioavailability of epigallocatechin gallate / K.G. Moruisi." Thesis, North-West University, 2008. http://hdl.handle.net/10394/2031.
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Grigorakis, Kriton. "Quality of cultured and wild gilt-head sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax)." Thesis, University of Lincoln, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312889.
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Río, Nieto Enrique del. "New polyurethanes from vegetable oil-based polyols." Doctoral thesis, Universitat Rovira i Virgili, 2011. http://hdl.handle.net/10803/31904.
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Los poliuretanos son uno de los materiales poliméricos más usados debido a sus buenas propiedades. Tradicionalmente, los poliuretanos se han sintetizado a partir de derivados del petróleo, sin embargo, teniendo en cuenta motivos de sostenibilidad, se hace necesario desarrollar tecnologías más ecológicas y económicamente viables.
En esta tesis se han obtenido poliuretanos con buenas propiedades mecánicas y memoria de forma a partir de polioles basados en aceites vegetales, utilizando diferentes estrategias sintéticas: A partir de oleato de metilo epoxidado, mediante polimerización por apertura de anillo y posterior reducción; por polimerización vía metátesis de monómeros derivados de aceite de ricino y mediante polimerización por apertura de anillo de oxazolinas derivadas de ácidos grasos y posterior funcionalización vía acoplamiento tiol-eno con mercaptoetanolPolyurethanes are one of the most important polymeric materials, and exhibit versatile properties suitable for use in many fields. However, the synthesis of polyurethanes from renewable resources is still an important challenge for scientists. In the search for green routes for polyurethanes, fats and oils offer important alternatives for the production of polyols, thus enable substitute petrochemicals. In this thesis, polyurethanes with good mechanical and shape-memory properties have been synthesized. Three different ways have been exploited to obtain polyols from vegetable oil derivatives: Polyols obtained by ring opening polymerization of epoxidized methyl oleate and reduction of the ester groups. Two different families of polyols have been synthesized by metathesis polymerization of castor oil-based monomers. Polyoxazoline-polyols were achieved by ring opening polymerization of fatty acid-based oxazolines and functionalization of the obtained polyoxazolines by thiol-ene coupling with mercaptoethanol.
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Negi, Devender Singh. "Base catalyzed glycerolysis of fatty acid methyl esters: investigations towards the development of a continuous process." [S.l.] : [s.n.], 2006. http://deposit.ddb.de/cgi-bin/dokserv?idn=980493404.
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Bougouin, Adeline. "Identification of milk fatty acids as proxies of the enteric methane emissions in dairy cows." Thesis, Université Clermont Auvergne (2017-2020), 2018. http://www.theses.fr/2018CLFAC036/document.
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Le méthane (CH4) est un puissant gaz à effet de serre produit lors de la fermentation microbienne anaérobie des aliments dans le rumen. L’un des enjeux majeurs pour le secteur de l’élevage est de trouver des stratégies (alimentaires, génétique) pour réduire les émissions de CH4 tout en maintenant les performances animales. Les techniques de mesure de ces émissions sont coûteuses et difficilement utilisables à grande échelle sur le terrain, d’où la nécessité de trouver des alternatives de mesure ou biomarqueurs pour prédire ces émissions. Les acides gras (AG) du lait ont déjà été identifiés comme indicateurs intéressants de la méthanogenèse chez la vache laitière, mais il convient d’améliorer la précision des équations de prédiction du CH4 existantes ainsi que d'élargir leur domaine d'application à tous types de rations. L'objectif de mon travail de thèse a été de confirmer la pertinence des AG du lait comme indicateurs périphériques de la méthanogénèse chez la vache laitière avec diverses conditions nutritionnelles. Deux bases de données regroupant des données individuelles (issues d’une collaboration scientifique internationale) et moyennes (issues de la littérature) de CH4, de composition en AG du lait et d’autres performances et caractéristiques de l’animal, ainsi que des données de composition chimique des rations, ont été créées. Parallèlement, l’acquisition in vivo de données en conditions expérimentales contrôlées pour des rations mal connues ont permis d’incrémenter la base de données individuelles. Des équations de prédiction des émissions de CH4 [en g/jour, g/kg de matière sèche ingérée (MSI), et g/kg de lait] ont été développées à partir de certains AG du lait, utilisés seuls ou combinés à d’autres variables d’ingestion et de performances laitières, représentant alors des modèles complexes. Des relations entre les émissions de CH4 et la teneur de différents AG du lait (C10:0, iso C17:0 + trans-9 C16:1, iso C16:0, cis-11 C18:1, cis-15 C18:1, cis-9,cis-12 C18:2, et trans-11,cis-15 C18 :2) ont été mises en évidence, confirmant des voies métaboliques communes dans le rumen entre méthanogenèse et métabolisme lipidique. Les équations sont également liées aux types de régimes à partir desquels elles ont été développées. Les équations simples (AG du lait uniquement) sont moins précises que les complexes (erreurs résiduelles de prédiction, respectivement, de 58.6 g/jour, 2.8 g/kg MSI et 3.7 g/kg lait vs. 42.8 g/jour, 2.5 g/kg MSI et 3.3 g/kg lait). Une différence minimum de 16% de CH4 entre stratégies de réduction pourra être mise en évidence par la meilleure équation de prédiction développée. Des équations basées sur des AG bien déterminés par les méthodes infrarouges devront être testées pour évaluer, en routine et à grande échelle, de nouvelles stratégies de réduction des émissions de CH4 entérique chez la vache laitièreMethane (CH4) is a potent greenhouse gas coming from the anaerobic microbial fermentation of the diet in the rumen. One of the main current challenge for the dairy sector is to find CH4 mitigation strategies (diets or genetics) without altering animal performance. Enteric methane measurement methods are costly and very difficult to apply on a large scale on field. Thus, there is a need to develop alternative measurement methods, such as equations based on proxies to predict CH4 emissions. Milk fatty acids (FA) have been identified as potential predictors of the methanogenesis in dairy cattle, but the prediction ability of extant published CH4 equations must be improved, and their domain of applicability must be enlarged to a wide range of diets. The objective of this PhD thesis was to confirm the potential of milk FA as proxies to predict enteric CH4 emissions in dairy cows fed a wide range of diets. Two databases (based on individual and mean data, respectively) were built thanks to an international collaboration, and gathered data on CH4, milk FA composition, dairy performances, diet and animal characteristics. Two in vivo experiments were conducted with the aim to study the effect of dietary strategies poorly documented, on methanogenesis and milk FA. The data from these experiments were included in the created database. Firstly, simple CH4 prediction equations were developed [g/d, g/kg of DMI (DMI), and g/kg of milk] based only on milk FA, and secondly other variables related to cow intake or characteristics, and dairy performance were added and constituted complex equations. Relationships between CH4 and several milk FA (C10:0, iso C17:0 + trans-9 C16:1, iso C16:0, cis-11 C18:1, cis-15 C18:1, cis-9,cis-12 C18:2, and trans-11,cis-15 C18 :2) were found, confirming common rumen metabolic pathways between methanogenesis and lipid metabolism. Equations were also closely related to the diets included in the database used for their development. Simple equations were less accurate than complex ones (prediction error of 58.6 g/d, 2.8 g/kg DMI and 3.7 g/kg milk vs 42.8 g/d, 2.5 g/kg DMI and 3.3 g/kg milk, respectively). A minimum difference of 16% in CH4 emissions between mitigating strategies can be evidenced with the best prediction equation developed in this PhD. Methane prediction equations based on milk FA well determined by infrared spectrometry methods need to be developed in order to be used on a routine basis and on a large scale. These prediction equations would allow studying the effect of novel mitigation strategies of enteric CH4 emissions in dairy cows
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Schiebel, Johannes [Verfasser], and Caroline [Akademischer Betreuer] Kisker. "Structure-Based Drug Design on Enzymes of the Fatty Acid Biosynthesis Pathway / Johannes Schiebel. Betreuer: Caroline Kisker." Würzburg : Universität Würzburg, 2013. http://d-nb.info/111188675X/34.
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Hopkins, M. J. "Characterisation of the human intestinal microbiota based on community cellular fatty acid analysis and ribosomal RNA measurements." Thesis, University of Cambridge, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604222.
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Chemostat studies were undertaken to validate the correlation between bacterial growth rate and 16S ribosomal RNA content for intestinal isolates, and also to identify potential 'signature' cellular fatty acids (CFA) for use as markers of bacterial community structure. These two methods were then used, in conjunction with traditional techniques, to investigate changes in the human colonic microflora associated with carbohydrate metabolism, antibiotic administration, and the ageing process. Short chain carbohydrates (SCC) were used to manipulate the composition and activities of the intestinal microbiota. They showed considerable potential as prophylactic agents in the prevention C. difficile infection. Viable count and 16S rRNA methodologies indicated that these carbohydrates predominantly stimulated bifidobacteria, although the metabolism of other bacterial genera could be affected, and the suppressive effect they induced against C. difficile was not limited to a specific species or genus. However, administration of SCC to patients undergoing antibiotic therapy could result in further impairment of colonisation resistance, with more fermentable carbohydrates, and broad spectrum antibiotics being of highest risk. Bifidobacteria were found to exhibit SCC substrate preferences when growing as part of the normal colonic microflora, which could have important consequences if a particular bacterial strain is to be targeted, such as during probiotic or prebiotic therapy. In conclusion, CFA analysis was effective in detecting differences between environmental samples, although careful consideration is needed to attribute these changes to an altered bacterial community structure rather than modification of the composition of bacterial membranes in stable populations. Viable count methodology proved advantageous for analysing inhibition of bacterial populations, whilst 16S rRNA analysis was the technique of choice for investigating metabolically active samples since it precludes the subjective nature of bacterial identification.
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Chen, Rong. "Synthesis and characterization of tall oil fatty acid based thermoset resin suitable for natural fiber reinforced composite." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-16591.
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Biobased thermoset resins were synthesized by functionalizing the tall oil fatty acid with hydrogen peroxide and then methacrylic anhydride. The obtained resins were characterized by FTIR to confirm the conversions. The cross-linking ability of the resins were checked by curing experiments and followed by DSC analysis regarding the extent of cross linking. TGA analysis was conducted to identify the thermal degradation patterns of cured resins. The obtained resins (blended with or without 33wt% styrene) were used as matrix and knitted viscose fibers were used as reinforcements to make bio-based composites. Ten layers of knitted viscose fibers were stacked crosswise (0/90⁰С) and hand lay-up impregnation was performed. The fiber ratio of all composites was around 63-66%. The composites were characterized by flexural testing, dynamic mechanical thermal analysis and charpy testing. This work demonstrates that manufacture of composites with both matrix and reinforcement fiber coming from renewable resources is feasible, and the resulted composites have satisfied mechanical performance.Program: MSc in Resource Recovery - Sustainable Engineering
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Mu, Xiaohong. "In vitro characterisation of food effects on in vivo performance of a heterodisperse polysaccharide-based controlled drug delivery system in gastrointestinal tract." Thesis, University of Bath, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340927.
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Torella, Joseph Peter. "Synthetic biology approaches to bio-based chemical production." Thesis, Harvard University, 2014. http://nrs.harvard.edu/urn-3:HUL.InstRepos:13088835.
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Inexpensive petroleum is the cornerstone of the modern global economy despite its huge environmental costs and its nature as a non-renewable resource. While ninety percent of petroleum is ultimately used as fuel and can in principle be replaced by sources of renewable electricity, ten percent is used as a feedstock to produce societally important chemicals that cannot currently be made at a reasonable cost through alternative processes. In this dissertation, I will discuss my efforts, together with several colleagues, to apply synthetic biology approaches to the challenge of producing renewable petrochemical replacements. In Chapter 2, I discuss our efforts to engineer E. coli to produce fatty acids with a wide range of chain lengths at high yield, thereby providing an alternative platform for the production of diverse petrochemicals. In Chapter 3, I describe a novel method of DNA assembly that we developed to facilitate synthetic biology efforts such as those in Chapter 2. This method is capable of simultaneously assembling multiple DNA pieces with substantial sequence homology, a common challenge in synthetic biology. In Chapter 4, I discuss the development of a "bionic leaf": a hybrid microbial-inorganic catalyst that marries the advantages of photovoltaic-based light capture and microbial carbon fixation to achieve solar biomass yields greater than those observed in terrestrial plants. This technology offers a potentially low-cost alternative to photosynthesis as a source of biomass and derived chemicals and fuels. The work described in this dissertation demonstrates the capacity of synthetic biology to address the problem of renewable chemical production, and offers proof of principle demonstrations that both the scope and efficiency of biological chemical production may be improved.
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Ozkizilcik, Sureyya. "Nutrition and feeding in striped bass Morone saxatilis larvae: Lipid and fatty acid requirements and microencapsulated diets." W&M ScholarWorks, 1995. https://scholarworks.wm.edu/etd/1539616801.
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There has been a growing interest in the commercial aquaculture of striped bass, Morone saxatilis. Little is known, however, about the nutritional requirements and feeding physiology of striped bass larvae. The objectives of this study were (a) to evaluate the efficiency of the live food enrichment techniques in studying the nutritional requirements for polyunsaturated fatty acids (PUFA), phospholipids and free amino acids, (b) to determine the ontogenetic changes of lipolytic enzymes, and (c) to develop a microencapsulated diet for striped bass larvae as full or partial replacement of live food. Three enrichment techniques, namely, microencapsulated fish oil, yeast/fish oil emulsion and unicellular algae, Chlorella sp. were evaluated for their efficiency in improving the n-3 PUFA content of Artemia nauplii to striped bass larvae. The enrichment of the Artemia nauplii appeared to increase the eicosapentaenoic acid content and enhance the growth of the striped bass larvae. The uptake and metabolism of &\sp{14}&C-glycine or &\sp{14}&C-phosphatidylcholine labeled liposomes by freshly hatched Artemia nauplii were investigated as a new technique for amino acid and phospholipid. The results of this study suggest that liposomes may be used to enrich Artemia nauplii with phospholipids and free amino acids. Ontogenetic changes of triacylglycerol hydrolase, wax ester hydrolase and phospholipase A&\sb2& were determined in the fertilized eggs and premetamorphosed larvae of striped bass and the larval food Artemia using radioassays. It was estimated that first feeding striped bass larvae had the capacity to digest 47% of their daily lipid ingestion. A complex protein-walled microcapsule (CWC) was prepared by incorporating lipid-wall capsules containing highly water soluble nutrients along with other dietary materials in a cross-linked protein-wall microcapsule. In vitro experiments indicated that the CWC was digested by the crude enzyme extract from striped bass larvae or purified porcine pepsin and trypsin. Diet acceptability, growth and survival of striped bass larvae fed complex protein-walled microcapsules were investigated in two separate experiments. In both experiments, the acceptability of microencapsulated diets was high. Neither microencapsulated diet support growth when solely fed to the larvae. The results of this study suggested that CWC can be used for partial replacement (60%) of live food without any significant effect on growth and survival of striped bass larvae.
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Chan, Ka-yee, and 陳嘉儀. "Application of fatty acid profiles in field- and laboratory -based investigations of trophic relationships in Hong Kong wetland." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2012. http://hub.hku.hk/bib/B48199436.
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This study primarily aimed to evaluate the usefulness of fatty acids (FAs) in revealing trophic relationships in Hong Kong wetlands, through a combination of field studies and laboratory experiments.
A field-based study in Mai Po mangroves involved FA profiling of basal food sources (i.e., leaf litter from three mangrove species, diatoms and macroalgae, and sediments) and consumers (particularly crabs). FA composition of all mangroves was similar, and lacked some polyunsaturated FAs present in diatoms and macroalgae. Uca and Sesarma crabs, with different feeding mechanisms, had divergent FA profiles: Uca arcuata FAs reflected a diet of macroalgae and diatoms, while FAs of Sesarma spp. were typical of mangrove leaves. Temporal changes in consumer FA profiles between 2001 and 2007 appeared attributable to increased sedimentation at Mai Po and shifts in organic content of the substratum.
A second field-based study was conducted at Luk Keng marsh where a salinity gradient (0 to 30?) allowed investigation of the effects of salinity changes in FA profiles and stable isotope (carbon and nitrogen) signatures of the consumers and their foods. Basal food sources were leaf litter, including a fungal biomarker of decomposition (ergosterol), fine particulate organic matter (FPOM) and periphyton. Both FPOM and periphyton (but not leaf litter) contained 20:4 and 20:5 FAs, but their concentrations were affected by salinity. FA 20:4 occurred at higher levels in samples from fresh water, whilst FA 20:5 exhibited the opposite pattern and was more abundant under saline conditions, and thus the ratio of FA 20:4 to FA 20:5 decreased with increasing salinity. Combined application of FA biomarkers and isotopic signatures were able to elucidate trophic relationships between consumers and their food at Luk Keng confirming that FA 20:4 as a useful biomarker in the freshwater portion and FA 20:5 in the more saline area. FA 20:4 was particularly associated with predatory freshwater insects that had high δ15N values, but was scarce in primary consumers (snails, detritivorous beetles) with low δ15N values.
Two laboratory experiments were undertaken to investigate: 1) the effect of diet on FA profiles in the apple snail, Pomacea canaliculata, and 2) interacting effects of diet and salinity on FA profiles of the Indian medaka fish, Oryzias melastigma. The results of the apple snail study showed that dietary-mediated changes in FA profiles were only reflected in the snail tissues after at least three months, and FA profiles of digestive tissues and neutral lipids were first to respond to the dietary change. The results of the medaka study demonstrated that the ratio of FA 20:4 to FA 20:5 was affected by both diet and salinity, reflecting a similar finding in the Luk Keng field study, although diet had a stronger effect on this ratio.
The results of both field studies supported the use of FA profiles as food web tracers in wetlands and were complemented by laboratory results that yielded insights which will allow refinement of FA biomarker applications in food-web studies.published_or_final_version
Biological Sciences
Doctoral
Doctor of Philosophy
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Matzen-Fredel, Anna. "Immobilisation of metathesis catalysts on mesoporous materials for the conversion of bio sourced fatty compounds." Thesis, Lille 1, 2012. http://www.theses.fr/2012LIL10174.
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Alors que les ressources fossiles décroissent, le concept de bio-raffinerie est une approche très attrayante pour la production de produits chimiques à partir de ressources renouvelables. Dans ce contexte, les dérivés d’acides gras insaturés, obtenus par hydrolyse de triglycérides issus de végétaux, sont une catégorie importante de substrats. Leur conversion en composés à haute valeur ajoutée est un objectif majeur qui peut être atteint grâce à la catalyse, et plus particulièrement grâce à la métathèse des alcènes. De plus, dans un esprit de meilleure séparation entre produits et catalyseurs, et pour des questions de recyclage, l’emploi de catalyseurs hétérogènes est de grand intérêt. L’hétérogénéisation de catalyseurs commerciaux à base de ruthénium a été entreprise. Les matériaux hybrides ont été préparés en deux étapes: après une cationisation à l’aide de sels d’argent, les espèces organométalliques ont été immobilisées par échange ionique dans les aluminosilicates mésoporeuses de type MCM-41. Ces nouveaux catalyseurs ont été caractérisés par RMN du solide, IR, DRX, BET, analyse élémentaire et ATG. Ils ont été employés avec succès dans différentes réactions de métathèse impliquant le substrat-type, l’oléate de méthyle. Les réactions étudiées sont l’homométathèse, l’éthénolyse et la métathèse croisée avec des oléfines fonctionnalisées issues des acides acrylique et crotonique. Bien que le recyclage n’ait pas été couronné de succès, les catalyseurs supportés permettent de réaliser toutes ces réactions, ce qui représente dans certains cas le premier exemple de telles transformations par catalyse hétérogène avec des activités et sélectivités élevéesAs fossil resources constantly decrease, the concept of bio-refinery is a most attractive approach to generate chemicals from renewable resources. In this context, unsaturated fatty acids derived from the hydrolysis of crops extracted-triglycerides are a major class of substrates. These must be converted to high added-value derivatives: catalytic transformations can play a key role in this, by converting such compounds into other functionalized derivatives. A most attractive reaction to meet this challenge is olefin metathesis. Based on product/catalyst separation and catalyst recycling issues, use of heterogeneous catalysts is of high interest.We thus prepared heterogenized commercial ruthenium catalysts. The hybrid materials were prepared in a two-step procedure: after silver salt-mediated cationization, the organometallic species were immobilized by ion exchange on mesoporous aluminosilicates of the MCM-41 family. The novel catalysts were characterized by solid-state NMR, IR, XRD, BET, elemental analysis and TGA. They were successfully applied in several metathesis reactions involving the archetypic methyl oleate, a C18 unsaturated ester, with different grades of purity. The probed reactions were self-metathesis, ethenolysis and cross-metathesis with functionalized olefins derived from acrylic and crotonic acids. Though recycling was not completely successful, the supported catalysts were able to efficiently catalyze all these transformations, providing in some instances the first heterogeneously examples of such reactions with high activity and selectivity
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Junfeng, Shi. "The lipid sensor Ffar4 regulates muscle-based diet-induced thermogenesis." 京都大学 (Kyoto University), 2017. http://hdl.handle.net/2433/225536.
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Barry, Kelli. "REEVALUATING ESSENTIAL FATTY ACID REQUIREMENTS IN HYBRID STRIPED BASS Morone chrysops × M. saxatilis AND RAINBOW TROUT Oncorhynchus mykiss." OpenSIUC, 2017. https://opensiuc.lib.siu.edu/theses/2084.
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The aquaculture industry is expanding to supply the demand for sustainable protein, essential nutrients, and energy. Recent reports of worldwide fish production indicate a rise in aquaculture, coupled with near static capture fishery landings. Feed prices represent a major limiting factor for aquaculture as ingredients sourced from wild caught fisheries remains stagnant. Fish oil is included in the realm of expensive, marine sourced ingredients and is a highly nutritious commodity. Lipids are indispensable constituents of aquafeeds because they provide essential energy and nutrients. Some fatty acids are deemed essential because they must be obtained via dietary intake to avoid pathology and ultimately mortality. Depending upon the species, essential fatty acids may include C18 polyunsaturated fatty acids (C18 PUFA) or long chain polyunsaturated fatty acids (LC-PUFA). Despite many years of research, essential fatty acids requirements in aquaculture nutrition are still not fully understood. Therefore, the work described herein was intended to determine the essentiality of C18 PUFA or LC-PUFA (including n-3 and n-6 fatty acids) in diets of hybrid Striped Bass and Rainbow Trout through survival, growth performance, and fatty acid tissue analysis. The essentiality in the two taxa were examined through feeding fish experimental diets that met all other nutrient requirements, except for fatty acid nutrition, for a period of 8 weeks. Diets were created to isolate individual fatty acids with hydrogenated soybean oil, rich in saturated fatty acids (SFA), and the absence or addition of various C18 PUFA or LC-PUFA fatty acid concentrates. An ideal fatty acid nutrition diet was formulated with 100% fish oil. Hybrid Striped Bass are reported to require EPA (eicosapentaenoic acid, 20:5n-3) and/or DHA (docosahexanoic acid, 22:6n-3) at 0.5-1% dietary inclusion rate. For all vertebrates, ARA (arachidonic acid, 20:4n-6) may also be important when determining LC-PUFA requirements. Results of this study indicate that hybrid Striped Bass do have a dietary requirement for LC-PUFA and that provision of C18 PUFA alone is insufficient to avoid essential fatty acid deficiency and support optimal growth of this fish. Existing fatty acid requirements for Rainbow Trout are 0.7 – 1.0% 18:3n-3 (alpha linolenic acid, ALA) and/or 0.4 – 0.5% n-3 LC-PUFA. It is debated whether Rainbow Trout require C18PUFA or LC-PUFA. Results of this study indicate Rainbow Trout are physiologically able to synthesize LC-PUFA from C18PUFA. Therefore, Rainbow Trout do not require LC-PUFA-rich feeds, but providing preformed LC-PUFA in the diet may be energetically advantageous and support improved growth performance. Quantitatively assessing essential fatty acid requirements in representative finfish will allow for more accurate formulations, but aquaculture is incredibly diverse and it will not be possible to conduct requirement students in all cultured taxa. The traditional formulation conventions for fatty acid requirements failed to recognize that the cold-water and marine species that had been evaluated were largely top-level carnivores, whereas the warm-water and freshwater species were largely herbivores, omnivores, or low level carnivores. In more recent work, the use of trophic levels to predict and generalize essential fatty acid requirements is gaining credence. Utilizing the trophic hierarchy ideology to guide EFA requirements may provide more accurate formulation. However, more research on various taxa is needed to determine the exact threshold at which PUFA essentiality, specifically requirements for C18 PUFA vs. LC-PUFA, can be predicted.
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Kimura, Makoto, 眞人 木村, Susumu Asakawa, and 晋. 浅川. "Comparison of community structures of microbiota at main habitats in rice field ecosystems based on phospholipid fatty acid analysis." Springer, 2006. http://hdl.handle.net/2237/12083.
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Fakhouri, Farayde Matta. "Bioplasticos flexiveis e biodegradaveis a base de amido e gelatina." [s.n.], 2009. http://repositorio.unicamp.br/jspui/handle/REPOSIP/256348.
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Orientadores: Fernanda Paula Collares Queiroz, Lucia Helena Innocentini MeiTese (doutorado) - Universidade Estadual dse Campinas, Faculdade de Engenharia de Alimentos
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Resumo: O objetivo deste trabalho foi desenvolver um bioplástico flexível, biodegradável e comestível, à base de polímeros naturais de fontes renováveis (amido e gelatina) por processo de extrusão termoplástica seguido de sopro. Inicialmente, foi realizada a caracterização física e funcional de biofilmes à base de amido e gelatina elaborados pela técnica de solução (casting), visando a escolha das melhores formulações para serem utilizadas na produção destes bioplásticos por processo de extrusão e sopro. As soluções filmogênicas de amido de mandioca (nativo e modificado) e milho (nativo, ceroso, ceroso modificado e lipofílico) foram preparadas nas concentrações de 3 e 5% e a de gelatina, na concentração de 10%. Os biofilmes compostos de gelatina e amido (de mandioca ou de milho) foram elaborados nas proporções 4:1, 1:1 e 1:4, plastificadas com sorbitol ou glicerol, sendo 5% para as soluções de gelatina e 10% para as soluções de amido. Todos os biofilmes formados foram visualmente transparentes. A adição de gelatina provocou um aumento na espessura, na permeabilidade ao vapor de água (PVA) e na resistência à tração (RT), provocando também uma diminuição na opacidade dos mesmos. Posteriormente, diferentes ácidos graxos (palmítico, mirístico, cáprico, capróico e caprílico), nas concentrações de 5, 15, 25 e 50%, foram adicionados à mistura de amido lipofílico e gelatina. Esta adição causou, em geral, um aumento da opacidade, da espessura e da elongação, no entanto, ocorreu uma diminuição na RT e da PVA dos biofilmes formados. A melhor formulação de amido lipofílico, gelatina e plastificante (glicerol, sorbitol e ácido mirístico) foi utilizada para a produção de filmes por diferentes técnicas (prensados, prensados e soprados e extrudados). Bioplásticos prensados apresentaram menores valores de RT e maiores valores de solubilidade em água. Os filmes extrudados, obtidos nas mesmas concentrações de amido, gelatina e plastificante, apresentaram-se semi-rígidos, característica não desejável para o objetivo em questão. Com base nestes resultados, foram alteradas as concentrações dos componentes da mistura para permitir a obtenção de bioplásticos com propriedades adequadas pelo processo de extrusão termoplástica. Estes bioplásticos foram caracterizados quanto às propriedades físicas, fisico-químicas, morfológicas, mecânicas, de barreira e térmicas. Os bioplásticos elaborados foram flexíveis, apresentaram expansão durante o sopro e foram visualmente homogêneos, porém, os elaborados com sorbitol apresentaram-se quebradiços após o condicionamento. A adição de gelatina causou uma diminuição no valor de PVA, mas não influenciou a solubilidade em água nem a opacidade dos bioplásticos. A adição de lipídios ocasionou uma diminuição na RT dos bioplásticos, tanto no sentido transversal como no longitudinal em relação ao sentido de produção. Filmes compostos com 10 e 20% de gelatina, sem adição de ácido graxo apresentaram os menores valores de PVA e maiores valores de RT
Abstract: The goal of this research was to develop a flexible, biodegradable and edible film using natural polymers (starch and gelatin) from renewable sources through a process of thermoplastic extrusion followed by blowing. The first step of the research consisted on a physical and functional characterization of starch and gelatin based biofilms produced using the casting technique. The purpose was to select the solutions to be used on the production of these biofilms by extrusion and blowing. The filmogenic solutions of manioc starch (native and modified) and corn (native, waxy, waxy modified and lipofilic) were prepared at concentrations of 3 and 5%. The filmogenic solution of gelatin was prepared at a concentration of 10%. The gelatin and (manioc and corn) starch based biofilms were prepared at ratios of 4:1; 1:1 and 1:4. They were plasticized with sorbitol or glycerol at 5% for the the gelatin solutions and 10% for the starch solutions. All the biofilms obtained were visually transparent. The addition of gelatin resulted in an increase of the film thickness, an increase of the water vapour permeability (WVP), an increase of the tensile strength (TS) and a decrease in the opacity. Different fatty acids (palmitic, miristic, capric, caproic and caprilic) were added to the lipofilic starch and gelatin solution at concentrations of 5, 15, 25 and 50%. These additions resulted in an increase on opacity, thickness and elongation. However, there was a decrease on WVP and TS. The best solution of lipofilic starch, gelatin and plasticizer (glycerol, sorbitol and miristic acid) was used in the production of films by different techniques (pressed, pressed and blowed and extruded). Pressed biofilms showed lower values of strain at break and higher values of water solubility. The extruded films, obtained at the same concentrations of starch, gelatin and plasticizer were found to be semi-rigid, a characteristic not aligned with the objective of theresearch. Based on the results of this first assessment, the concentrations of the components were adjusted with the purpose of obtaining extruded films with the desired properties. The resulting biofilms were characterized for their physical, physico-chemical, morphology, mechanical, barrier and thermical properties. Biofilms in general were flexible, showed expansion during blowing and were visually homogeneous. However, biofilms prepared with sorbitol were cracking very easily after storage. The addition of gelatin resulted in a reduction of the WVP but did not have any influence on the water solubility nor on the opacity of the biofilms. The addition of lipids resulted in a reduction of the TS of the biofilms both in longitudinal and transversal directions. Biofilms with 10 and 20% of gelatin and no fatty acid added showed lower values of WVP and higher values of TS
Doutorado
Doutor em Tecnologia de Alimentos
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Lorenzen, Jan [Verfasser], Thomas [Akademischer Betreuer] Brück, Thomas [Gutachter] Brück, Thomas [Gutachter] Fässler, Uwe [Gutachter] Bornscheuer, and Wolfgang [Gutachter] Eisenreich. "Enzymatic functionalization of bio based fatty acids and algae based triglycerides / Jan Lorenzen ; Gutachter: Thomas Brück, Thomas Fässler, Uwe Bornscheuer, Wolfgang Eisenreich ; Betreuer: Thomas Brück." München : Universitätsbibliothek der TU München, 2019. http://d-nb.info/1201819997/34.
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Jin, Yuqin. "Biotechnological improvements of bio-based fuels and lubricants characterization of genes for branched chain fatty acids and mono-acyl esters /." [Ames, Iowa : Iowa State University], 2007.
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Lau, Clara Sueling. "Formulation and Physical, Chemical and Sensory Analysis of a Novel Flaxseed-enriched Milk-based Beverage to Deliver Omega-3 Fatty Acids." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/29396.
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An increased interest in functional beverages is occurring, and omega-3 fatty acids (FA) are one of the most commonly sought ingredients to fortify such beverages. Omega-3 FA produce beneficial health effects, likely due to their anti-inflammatory properties. The majority of current omega-3 FA-fortified products include marine-derived omega-3 FA sources, often producing undesired flavors due to lipid oxidation. Little research regarding incorporation of alpha-linolenic acid in functional beverage formulation has been conducted. Alpha-linolenic acid is less susceptible to oxidation and may be a candidate to deliver omega-3 FA into the diet via functional products.
Flaxseed is the richest plant source for alpha-linolenic acid; consumption may increase omega-3 FA intake and lower the omega-6:omega3 FA ratio, thereby, attenuating inflammation. Finely ground flaxseed was, therefore, incorporated into a chocolate milk foundation ("flaxmilk") to increase dietary omega-3 FA. An untrained consumer panel tasted and rated flaxmilk's palatability using a 9-point hedonic scale. A score of "6.0" ("like slightly") was targeted. A mean hedonic score of 6.35 was achieved, surpassing the targeted score and indicating an acceptable product.
Sensory and analytical analyses of flaxmilk were conducted and compared to standard chocolate milk. Flaxmilk was significantly different in most physical, chemical and sensory characteristics compared to chocolate milk.
A reduction in the omega-6:omega-3 FA ratio may attenuate inflammation; inflammation has been linked to osteoporosis. Thus, a secondary analysis of data collected from 202 women was conducted to estimate the dietary omega-6:omega-3 FA ratio and examine relationships between the omega-6:omega-3 FA ratio and total body and site-specific bone mineral density (BMD). The omega-6:omega-3 FA ratio had no appreciable association with any measure of BMD in the overall sample of women or in younger or older subsamples of women.
In summary, consumers found flaxmilk to be an acceptable product, despite sensory and compositional differences compared to chocolate milk. The relationship between the omega-6:omega-3 FA ratio and BMD remains unclear.Ph. D.
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Bertan, Larissa Canhadas. "Desenvolvimento e caracterização de filmes simples e compostos a base de gelatina, acidos graxos e breu branco." [s.n.], 2003. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255988.
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Orientador: Carlos Raimundo Ferreira GrossoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Pesquisas sobre filmes comestíveis à base de polímeros surgiram nos últimos tempos devido ao impacto ambiental aliado a necessidade de reduzir os resíduos sólidos. Estudo com proteínas animais, como gelatina, demonstraram a capacidade de formar filmes, além de possuir grande produção e baixo custo no Brasil. O objetivo deste trabalho foi desenvolver e caracterizar filmes simples e compostos feitos de gelatina, triacetina, ácidos graxos (esteárico, palmítico e láurico) e breu branco. Filmes de gelatina simples e compostos foram produzidos e caracterizados quanto às propriedades de barreira ao vapor de água, oxigênio, solubilidade, propriedades mecânicas (resistência à tração e elongação), opacidade e isotermas de sorção (25°C). Posteriormente foram realizadas análises microestruturais, através da microscopia eletrônica de varredura e microscopia confocal a laser de varredura, temperatura de transição vítrea (Tg) obtida por análise térmica mecânica dinâmica (DMTA) e temperatura de fusão por calorimetria diferencial de varredura (DSC). A adição de substâncias hidrofóbicas (ácidos graxos e breu branco) produziu filmes menos permeáveis ao vapor de água e menor resistência a tração comparando ao filme simples Os filmes compostos causaram aumento da elongação, da opacidade, e da permeabilidade ao oxigênio. Os resultados da microscopia eletrônica de varredura e microscopia confocal a laser, indicaram boa distribuição das substâncias hidrofóbicas e alterações na morfologia da matriz polimérica. O aparecimento de duas a três transições e temperaturas de fusão sugere heterogeneidade dos biofilmes compostos
Abstract: Recently, many researches have been developed on biodegrable and edible films based on biopolymers due to environmental considerations allied to the necessity of reduction residues. Studies involving animal proteins, such gelatin demonstrated the capacity to form films, besides large production with low cost in Brazil. So that, the objective of this work was the development and characterization of the sim pie and composite films produced from gelatin, triacetin, fatty acids (stearic, palmitic, blend of both and blend more lauric acid) and elemi resin. Simple and composite gelatin films were produced and characterized with respect to the water vapor (Wvp) and oxygen permeabilities, solubility, mechanical properties (tensile strenght and elongation), opacity and sorption isotherm determination (25°C). Morphological analysis were effected, by scanning electronic microscopy (SEM) and confocallaser scanning microscopy (CLSM), glass transition temperature (Tg) obtained by dynamic mechanical analysis (DMT A), and temperature of melting by differential scanning calorimeter (DSC) The addition of hidrofobic substances (fatty acid and elemi resin) decreased the WVP and mechanical resistance comparing to the simple film. The composite film increased on elongation, opacity and oxygen permeability. The results SEM and confocal laser scanning microscopy (CLSM) indicated good distribution of hidrofobic substances and alterations in the morphology of the polimeric matrix. The appearance of two Tg's and temperature of melting suggests the heterogeneity of composites biofilms
Mestrado
Mestre em Alimentos e Nutrição
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Singh, Suniti. "High rate anaerobic treatment of LCFA-containing wastewater at low temperature." Thesis, Paris Est, 2019. http://www.theses.fr/2019PESC2042.
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La hausse des prix des carburants et les incitations favorisant le marché des énergies renouvelables poussent le marché mondial de l'eau et les technologies des eaux usées vers la digestion anaérobie. Les gains financiers résultant de la réduction de l'empreinte de l'usine et du transport des boues constituent également des moteurs économiques importants. La croissance efficace des méthanogènes est la clé de la fonctionnalité AD, pour laquelle les températures mésophiles (30-35 ° C) ou thermophiles (48-55 ° C) et pH 6,8-7,2 sont optimales. Le goulot d'étranglement dans la polyvalence de la mise en œuvre de la DA est son inefficacité à des températures plus basses. Comme un énorme morceau de biosphère est en permanence à moins de 5 ° C, le développement du DLTA fournirait une meilleure efficacité énergétique pour le traitement des eaux usées dans les régions tempéréesFats, oil and grease (FOG) is a significant constituent in numerous wastewaters such as those in dairy industry. The hydrolysis of FOG results in the production of long chain fatty acids (LCFA) which destabilize the anaerobic treatment process due to their physico-chemical and microbial toxicity effects. Harnessing the high methanogenic potential of FOG necessitates effective treatment of high LCFA loads, wherein the feasibility of LCFA treatment at low temperatures has been not investigated up to now. The aim of this thesis was to study the feasibility of high-rate anaerobic treatment of LCFA-rich wastewaters at low ambient temperatures using a dairy wastewater matrix.The screening of mesophilic inocula for treatment of mixed LCFA containing synthetic dairy wastewater (SDW) in batch studies showed that granular sludge inoculum achieved faster and higher methane yields (76-82% of theoretical yield) than the two municipal digestates (1-72%) at both 20 and 10°C. The LCFA degradative capacity in the granular sludge inoculum was attributed to the presence of β-oxidizing bacteria from the family Syntrophaceae (Syntrophus and uncultured taxa), the acetotrophic activity from Methanosaeta and putative syntrophic acetate oxidizing bacteria (SAOB). Continuous high-rate treatment of SDW was found to be feasible in expanded granular sludge bed (EGSB) reactors at 20°C (hydraulic retention time (HRT) 24 h, LCFA loading rate (OLR) 670 mgCOD-LCFA/L·d, 33% COD-LCFA) with a COD removal of 84–91% and methane yield of 44–51%. SDW feeding for longer than two months resulted in LCFA accumulation, which led to granular sludge flotation (36-57%) and disintegration. To counter the LCFA induced granular sludge disintegration and flotation, a novel reactor type, dynamic sludge chamber-fixed film (DSC-FF), was designed and achieved sCOD removal of 87-98% at HRTs from 12-72 h (LCFA loading rate 220-1333 mgCOD-LCFA/L·d) at 20°C. Moreover, even at the 12 h HRT, the unsaturated LCFAs (linoleate and oleate) were treated and only part of saturated LCFAs (stearate, palmitate) remained after treatment in the DSC-FF reactors. An increased methanogenic activity was established in the reactor sludges during reactor runs; evidenced by a higher acetotrophic activity in the granular sludge (from DSC), and a higher hydrogenotrophic activity in the biofilm (from FF) indicating development of distinct metabolic capabilities in the different reactor compartments. High throughput 16S rRNA sequencing showed that the relative abundance of the acetoclastic methanogen, Methanosaeta increased in EGSB reactors when fed with increased LCFA concentrations. The relative abundance of Methanosaeta increased also in the active microbiomes of granules (from DSC) and biofilm (from FF) during the 150-d reactor operation, demonstrating acetoclastic methanogenesis as the predominant methanogenesis pathway for SDW and LCFA degradation at 20°C. Microbial communities with a high β-oxidizing along with high methanogenic activity were developed during SDW treatment in DSC-FF reactors at 20°C. In DSC-FF reactors, the biofilm microbiome (from FF) had a prominent presence of the β-oxidizing bacteria Syntrophus and the hydrogenotrophic methanogen Methanospirillum; in comparison to the presence of the acetogenic bacteria - Syntrophobacter, Desulfobulbus, and Geobacter in the granular sludge microbiome, suggesting a role of these taxa at different trophic levels during LCFA degradation. In summary, this work demonstrated successful inoculum selection at low temperatures (10 and 20°C), and high-rate anaerobic LCFA degradation at 20°C using combined approaches of inoculum mixture and novel reactor design (here, DSC-FF). The key bacterial and archaeal taxa involved in the anaerobic conversion of LCFA to methane at 20°C were also deduced
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Xiao, Suo. "Phagotrophic Algae Based Approaches for Advanced Wastewater Treatment." University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1542368310384856.
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Crouse, Curtis. "Use of Alternative Lipids and Finishing Feeds to Improve Nutritional Value and Food Safety of Hybrid Striped Bass." OpenSIUC, 2012. https://opensiuc.lib.siu.edu/theses/1066.
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Seafood represents the most important source of long-chain polyunsaturated fatty acids (LC-PUFAs) in the human diet. However, consuming fish can present risks from persistent organic pollutants (POPs) that bioaccumulate in edible tissues following dietary exposure. In farmed fish, POPs accumulate as a result of feeding diets based on fish oil (FO). Fish oil substitution can reduce POP accumulation, but also results in loss of beneficial LC-PUFAs. Fish oil-based finishing diets at the end of production can restore LC-PUFAs, but this strategy also increases POPs. The present study assessed the use of saturated fatty acid (SFA)-rich lipids to replace fish oil in grow-out feeds in conjunction with a fish oil-rich finishing diet to determine if this strategy could produce hybrid striped bass with equal production performance, equivalent LC-PUFA levels, and reduced POP concentrations. Triplicate tanks of hybrid striped bass were raised on diets containing fish oil (100% FO), fish oil spiked with additional POPs (100% FO Spike), or blends (50/50 or 25/75) of FO and coconut (CO) or palm (PO) oils (50% CO, 50% PO, 75% CO, 75% PO) with and without an eight week finishing period with the 100% FO diet prior to harvest. Production performance, fillet LC-PUFA, and POP content were assessed. Production performance was not adversely affected by any of the feeding regimens. However, fatty acid profile was altered, with fillets of fish consuming less fish oil having lower LC-PUFA and POP levels. Finishing yielded a modest increase in fillet LC-PUFAs and POPs, but POPs accumulated more readily than LC-PUFAs during finishing. However, harvest fillet POP and LC-PUFA levels in the experimental groups were lower relative to levels in the 100% FO group. Replacing fish oil in aquafeeds can produce fish with reduced LC-PUFAs, and also reduced POPs. Feeding fish oil results in more rapid accumulation of POPs than LC-PUFA. Overall, the 75% fish oil replacement feeds yielded fish with the highest ratio of LC-PUFAs to POPs. Despite lower LC-PUFA content, fillets of fish fed the 75% fish oil replacement feeds could be incorporated into a weekly meal plan with other dietary sources of LC-PUFAs to meet dietary recommendations for these essential nutrients.