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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Sorption of Cyclohexane on Oil Sands Tailings

Vagi, Lisa Unknown Date
No description available.
2

The Production of Protein Isolates from the Aqueous Extraction of De-hulled Yellow Mustard Flour and Determination of their Functional Properties

Hijar, Benjamin 12 July 2013 (has links)
Two types of protein isolates were prepared from de-hulled yellow mustard flour by aqueous extraction, membrane processing and acid precipitation of proteins at the isoelectric point (IEP 5.5). Their electrophoretic, main functional properties and protein composition were determined. The precipitated and acid soluble protein isolates had 83.0 and 96.0% protein content on a moisture and oil free basis, respectively. The acid soluble protein isolate had comparable functional properties to those of commercially available soybean and other protein isolates. The precipitated protein isolate exhibited less desirable functionality than the soluble isolate, due to its high lipid content (~25%); however, it was still comparable to soybean isolates. Storage temperature had limited effect on lipid oxidation, and hence the stability of the precipitated protein isolate at 25-45ºC. Taste and texture of wieners and bologna prepared with 1-2% of this isolate as binder were comparable to those prepared with soy protein isolates.
3

The Production of Protein Isolates from the Aqueous Extraction of De-hulled Yellow Mustard Flour and Determination of their Functional Properties

Hijar, Benjamin 12 July 2013 (has links)
Two types of protein isolates were prepared from de-hulled yellow mustard flour by aqueous extraction, membrane processing and acid precipitation of proteins at the isoelectric point (IEP 5.5). Their electrophoretic, main functional properties and protein composition were determined. The precipitated and acid soluble protein isolates had 83.0 and 96.0% protein content on a moisture and oil free basis, respectively. The acid soluble protein isolate had comparable functional properties to those of commercially available soybean and other protein isolates. The precipitated protein isolate exhibited less desirable functionality than the soluble isolate, due to its high lipid content (~25%); however, it was still comparable to soybean isolates. Storage temperature had limited effect on lipid oxidation, and hence the stability of the precipitated protein isolate at 25-45ºC. Taste and texture of wieners and bologna prepared with 1-2% of this isolate as binder were comparable to those prepared with soy protein isolates.
4

Extraction aqueuse d'huile de colza assistée par hydrolyse enzymatique : optimisation de la réaction, caractérisation de l'émulsion et étude de procédés de déstabilisation / Rapeseed oil extraction assisted by enzymes : reaction optimisation, emulsion, characterisation and destabilisation process study

Guillemin, Sandrine 08 November 2006 (has links)
En réponse aux attentes actuelles des consommateurs pour des produits de haute qualité nutritionnelle et environnementale, et face aux impératifs industriels conduisant à minimiser les risques et l’impact environnemental lors de l’extraction à l'hexane de l’huile de la graine de colza, l’étude de l’extraction aqueuse avec assistance enzymatique de cette huile a été reprise avec 2 objectifs principaux : déterminer les enzymes et mélanges d'enzymes adaptés à la meilleure déstructuration du tissu adipeux végétal, et d'autre part étudier les propriétés et la déstabilisation de l'émulsion formée. De l'optimisation de ces 2 séquences du process dépendent les rendements finaux en huile de l'extraction et les propriétés du tourteau, qui constituent les clés économiques de l'émergence de cette nouvelle technologie. Pour cela, après caractérisation physicochimique des constituants de la graine, protéases et polysaccharides hydrolases ont été testées seules ou en combinaison afin d’optimiser le rendement en huile libre et en huile contenue dans l’émulsion engendrée lors de l’extraction et obtenue par centrifugation. Après caractérisation de l’émulsion (rhéologie, diffusion statique de la lumière, pH, conductivité), des tests de déstabilisation physicochimiques ou thermo-mécaniques ont été mis en œuvre afin de séparer les constituants de l’émulsion formée, et obtenir ainsi la libération de l'huile. Les tests réalisés ont permis de retenir trois procédés de déstabilisation: l’addition de talcs, l’inversion de phase par addition d’huile exogène en présence de NaCl dans la phase aqueuse, et les cycles de congélation/décongélation. Afin d’apporter les premiers éléments de l’optimisation de ce dernier procédé, une étude par planification expérimentale a été mise en œuvre / Consumer's concerns about the quality and environmental impact of the products as well as the industrial requirements regarding the risk assessment and the environmental and health repercussions of the solvent extraction of rapeseed oil using hexane led us to work on the optimisation of the aqueous enzymatic extraction of this oil. The study has been carried out to determine the best combination of enzymes able to achieve the disruption of the vegetal adipose tissue, and to characterize the emulsion obtained after centrifugation. The final objective was to maximize the yields of the oil extraction and to obtain adequate nutritional properties of the cake. After the physicochemical characterization of the rapeseed raw material, several proteases and polysaccharide hydrolases have been tested individually and in combination in order to optimize the removal of free oil and the emulsion oil yield occurring during the aqueous extraction process. The physicochemical properties of the emulsion have been determined: rheological properties, pH, conductivity, spectroscopy by Short Angles Light Scattering). Thereafter some physicochemical and thermo-mechanical treatments have been carried out to destabilize the oil-in-water emulsion obtained after the centrifugation, which contained a large part of the total oil of the reaction mixture. Three destabilization processes appeared particularly interesting to increase the free oil removal from the emulsion: talc addition before centrifugation, phase inversion by addition of exogenous oil in presence of NaCl in the aqueous phase, and freezing/thawing cycles. Finally, an optimisation trial of the freezing/thawing process using a Doehlert experimental design has been done as an example
5

Etude de l'hydrolyse enzymatique des grains de colza et de tournesol : application à l'extraction de leurs huiles / Study of the enzymatic hydrolysis of rapeseed and sunflower : application to extraction of their oils

Ricochon, Guillaume 10 December 2009 (has links)
L'extraction d'huile de graines d'oléagineux en milieu aqueux a pour principal objectif la suppression des solvants utilisés dans les industries de trituration. Pour extraire l'huile des graines, les mélanges enzymatiques et de nombreux paramètres physico-chimiques ont été étudiés. Deux plans d'expériences consécutifs, réalisés sur le M.I.A. ont permis de formuler des mélanges d'enzymes efficaces, constitués de 3 ou 4 préparations enzymatiques commerciales parmi les 25 retenues initialement. Cette démarche permet de réaliser des mélanges optimaux pour la dégradation des parois des graines étudiées. Les extractions d'huile font apparaître 4 phases après séparation par centrifugation : résidu solide, émulsion, phase aqueuse et huile libre. Les effets de différents paramètres physico-chimiques ont été évalués (broyage, temps, température, agitation, séparation...). Au final, l'huile libérée des graines à l'aide des mélanges formulés (85% de l'huile totale pour le colza, 92% pour le tournesol), la quantité de sucres fermentescibles produite (entre 60 et 80 g/l en fonction des conditions) ou encore la concentration de protéines solubilisées (supérieure à 30g/l) sont les résultats marquants de cette étude. Cette étude décryptant les conditions à mettre en œuvre pour maximiser l'extraction d'huile en phase aqueuse constitue un socle de connaissances permettant d'envisager le développement futur d'un bioraffinage complet des graines de colza grâce à la valorisation de chacun des co-produits huiles, protéines (napines du colza) et sucres fermentescibles. / The extraction of oil from oilseed in an aqueous medium aims to remove the solvents used in the crushing industry. To extract oil from seeds, the enzymatic mixtures and numerous physico-chemical parameters have been studied. Two consecutive experimental designs, realized on the A.I.M. prepared from treated seeds, allowed to select effective enzyme mixtures, consisting of 3 or 4 commercial enzyme preparations out of the 25 originally selected. This original approach, based on the use of statistical tools, allows to achieve optimal mixtures for the degradation of the walls of studied seeds. The extraction of oil shows 4 phases after separation by centrifugation: solid residue, emulsion, aqueous phase and free oil. The effects of different physico-chemical parameters were evaluated (grinding time, temperature, agitation, separation...). Finally, the oil released from seeds using enzymatic mixtures made (85% of the total oil for rapeseed, 92 % for sunflower), the amount of fermentable sugars produced (60 and 80 g/l depending on conditions) or the concentration of solubilized protein (greater than 30g/l) are the landmark results of this study. This study, decrypting the conditions to implement the maximization of oil extraction in aqueous phase, is an important whole of knowledge to contribute the future development of a complete biorefining of rapeseed and sunflower with the use of each co-products : oils, proteins (napins from rape) and fermentable sugars.
6

Value-Added Opportunities for Tomato and Peach Seeds

Lavenburg, Valerie Michelle 01 April 2022 (has links) (PDF)
The food industry is increasingly concerned with operational sustainability and food waste reduction. In the United States, the tomato industry was worth $1 billion in 2020, and tomatoes are currently ranked second as the most consumed vegetable after potatoes. Tomato processors have striven to valorize pomace by-products, which contain seeds with valuable compounds such as 45% fiber, 30% oil, and 26% protein. The U.S. peach industry, which was worth $599 million in 2017, is also looking for alternative ways to utilize their seeds, made up of 52% oil. Both tomato and peach seeds are rich in bioactive compounds such as carotenoids and polyphenols, respectively. Meanwhile, global edible oil production is forecasted to reach 632 million tons in 2022, and there is increasing interest to produce specialty oils. Organic solvent extractions are commonly used to extract oils from various commodities in the food industry, but this method comes with some environmental concerns, such as toxicity and flammability. Enzyme-assisted aqueous extractions (EAEP) have been proposed as a green alternative to solvent extractions of oilseeds. However, research on the economic feasibility of this process has been limited. There is a need for a better understanding of the potential of EAEP and performing such analysis on peach and tomato seeds would be valuable based on the importance of these commodities in California and in the U.S. in general. To determine whether applying such a process to tomato and peach seeds would be valuable, data on oil yields from EAEP, quality of the extracted oils, and economics associated with EAEP is needed. The U.S. snack food industry was worth approximately $42 billion as of 2019, and this market continues to grow as an increasing number of people eat snacks as meal replacements. There is also growing consumer demand for natural and functional foods, which offer health benefits beyond basic nutritional value, such as reducing risk of disease. Therefore, this consumer landscape provides excellent opportunities for by-products from vegetable and fruit processing to be transformed into functional ingredients. With these key ideas in mind, the objectives of this research were 1) to determine the impact of various extraction factors on oil yields from EAEP of tomato and peach seeds; 2) to evaluate the effect of aqueous extractions on oil quality; 3) study whether these processing steps are economically feasible for industrial commercialization and 4) identify another potential use for tomato pomace as a functional ingredient in snack food application. Tomato and peach seeds were each isolated and ground into a flour, then analyzed for fiber, fat, protein, moisture, and ash content. The effects of pH (set to 3, 9, and sequential adjustment of 3 followed by 9), time (2–8 h), and addition of cellulase, protease, and 1:1 enzymatic cocktail at a concentration of 4% were evaluated during aqueous extractions of tomato oils. Peach oil extractions were evaluated for the same parameters except for time which was fixed at 2 h. The impact of the pH of aqueous extractions on the oxidative stability and nutritional composition of tomato and peach oils were also determined. Techno-economic analyses were conducted using Superpro software to estimate operational costs and profits from this process. To assess the value of tomato by-product as a functional ingredient, pomace flour was added to crisp snacks at usage levels of 0 and 7% (w/w flour basis). Crisp snacks were stored at ambient room temperature and frozen temperatures (-23 °C) for ten weeks. Proximate analyses on the crisp snacks were conducted. Sensory evaluation was performed over time using hedonic scoring surveys. For tomato seeds, the highest oil yield (41%) was obtained during 2 h extractions at pH 9, which were 68% higher than from 2 h extractions performed at pH 3. Enzyme addition was only beneficial during 8 h extractions of tomato seeds using 4% cellulase at pH 3, which led to 53% higher oil yield compared to the control performed in the same conditions without enzymes. Increasing incubation time from 2 to 8 h improved oil yields by 63% for cellulase extractions at pH 3 and 69% for protease extractions at pH 9. Peach oil yield of the controls at pH 9 (53%) and the yield obtained with protease extractions at pH 9 (45%) were approximately eight times higher than all extractions set to pH 3. Once extracted, some properties of the tomato and peach oils were determined. The pH of the aqueous extractions did not have a significant effect on quality parameters on both tomato and peach oils, except for polyphenol content, DPPH production, peroxide and TBARS values. Overall, both tomato and peach oils had peroxide and free fatty acid values comparable to other specialty oils, such as sunflower and sesame oils. From a techno-economic point of view, tomato oil production at flow rate of 1,752,000 kg pomace/yr garnered $13 million in profit (equivalent to $7.42/kg pomace) after a payback time of 1.6 years, which was more profitable than the industry’s current pomace disposal practice. Peach oil processing became profitable once the production scale reached 65,700,000 kg pits/yr, which led to $15.5 million in profit ($0.24/kg pits). Overall, production of tomato oil was more profitable than peach oil. When tomato pomace was added into crisp snacks at 7% concentration, fiber increased by 35.2% compared to the control. Moisture content and water activity for the control and pomace crisp snacks remained constant during room temperature and frozen storage for ten weeks. However, the addition of tomato pomace led to a bitter aftertaste of the crisp snacks and reduced overall liking scores by panelists compared to scores for the control crisp snacks. Overall, this research took multiple, innovative approaches to valorize tomato and peach seeds, while also studying the economic, environmental, and industrial implications of such approaches. It highlighted alternative, sustainable strategies of how tomato and peach by-products could be repurposed to reduce waste and make value-added food products.
7

Nouveau procédé de bioraffinage du tournesol plante entière par fractionnement thermo-mécano-chimique en extrudeur bi-vis : étude de l'extraction aqueuse des lipides et de la mise en forme du raffinat en agromatériaux par thermomoulage

Evon, Philippe 28 April 2008 (has links) (PDF)
L'extraction aqueuse des lipides de la graine de tournesol est étudiée en contacteur agité. La diffusion à l'intérieur des particules est le facteur limitant de l'échange de matière. Les protéines sont impliquées dans l'entraînement et la stabilisation des lipides par l'eau. Le fractionnement de la plante entière est également étudié avec l'eau en extrusion bi-vis. Un extrait et un raffinat sont obtenus séparément et en une seule étape continue. Des rendements d'extraction en huile de 55 % peuvent être obtenus sous forme d'émulsions huile/eau. Leur stabilité est assurée par la présence à l'interface de tensioactifs : les phospholipides et les protéines voire les pectines. Les extraits se composent aussi d'une phase hydrophile. Prépondérante, elle contient des composés hydrosolubles (protéines, pectines…). Riches en fibres, les raffinats présentent une teneur significative en protéines au comportement thermoplastique. Ils peuvent être transformés en agromatériaux par thermomoulage.
8

Valorisation chimique de la biomasse oléagineuse d’origine béninoise : Lophira lanceolata et Carapa procera / Chemical enhancement of the oleaginous biomass from Benin : Lophira lanceolata and Carapa procera

Nonviho, Guévara 22 April 2015 (has links)
Lophira lanceolata (Ll) et Carapa procera (Cp) sont des plantes oléagineuses, peu étudiées. Au Bénin, elles sont pourtant utilisées à des fins alimentaires, cosmétiques et thérapeutiques. Cette étude vise la caractérisation de leurs graines, coques et bois. Les huiles végétales de Ll ont été obtenues par différentes méthodes dont une aqueuse traditionnelle tandis que celle de Cp l’a été par utilisation d’hexane. De façon générale, les huiles de Ll montrent un profil nutritionnel riche en acides gras polyinsaturés (>50% m/m: masse pour masse). Outre ses propriétés chimiques meilleures, celle obtenue par le procédé traditionnel est plus riche en acides gras essentiels, en composés phytostéroliques comme le lupéol et en tocols. La torréfaction et l’utilisation d’enzymes ont également permis d’évaluer l’impact de ces méthodes sur la composition chimique des graines de Ll. Quant aux graines de Carapa p., elles présentent un profil plutôt abondant en acides gras monoinsaturés, en tocotriénols (85,56% m/m) et en lanostérols (28,03%, m/m). Les tourteaux, coques et bois des deux espèces montrent une variabilité chimique en composés pariétaux (extractibles, hémicelluloses, celluloses et lignines). Une caractérisation in fine des hémicelluloses de ces parties des deux plantes a permis de montrer qu’elles sont essentiellement de type glucuronoxylanes. Les extractibles de ces plantes ont également offert une large gamme de composés à connotations industrielles et pharmaceutiques positives. Enfin, les conditions optimales de la biosorbption du bleu de méthylène sur les coques de Lophira ont également été évaluées. Cette évaluation a permis de mettre en exergue la potentielle utilisation de ces résidus agroforestiers pour rendre potables les eaux usées industrielles / The chemical composition of wild oilseeds, such as Lophira lanceolata (Ll) and Carapa procera (Cp) of Benin is mostly unknown. Yet they undergo crafted transformations for food, cosmetic and therapeutic purposes. This study aims to characterize their seeds, hulls and woods. From these crops, different oils have been extracted. One of them has been produced in rural area according to aqueous ancestral method. On the whole, oils of Ll have presented an interesting nutritional profile. They are rich in polyunsaturated fatty acids (> 50% m/m: mass for mass), especially that extracted by artisanal process. Beyond its good chemical properties, it provides essential fatty acids, phytosterols such as lupeol and more tocols compounds. Roasting and the use of enzymes have also assessed the impact of these methods on the chemical composition of LI seeds. Differently, Cp oil’s has an abundant presence of MUFA, tocotrienols (85.56% w/w) and the richest composition in lanosterol (28.03%, m/m). The seeds cakes, hulls and wood of both species showed various distributions on chemical components (extractives, hemicellulose, cellulose and lignin). The characterization of hemicelluloses from different parts of plants has shown that they are essentially glucuronoxylans type. Extractives also offered a wide range of compounds mostly appreciated for industrial and pharmaceutical purposes. The chemical composition of the shells of Lophira was rich in organic compounds such as lignin (32.13%, dry weight) so their biosorbent capacity was evaluated. They showed methylene blue good adsorption capacity in aqueous solution, which highlighted their potential use in the purification of wastewater

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