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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.
11

Amphiphilic Phase-transforming Catalysts for Transesterification of Triglycerides

Nawaratna, Gayan I 03 October 2013 (has links)
Heterogeneous catalytic reactions that involve immiscible liquid-phase reactants are challenging to conduct due to limitations associated with mass transport. Nevertheless, there are numerous reactions such as esterification, transesterification, etherification, and hydrolysis where two immiscible liquid reactants (such as polar and non-polar liquids) need to be brought into contact with a catalyst. With the intention of alleviating mass transport issues associated with such systems but affording the ability to separate the catalyst once the reaction is complete, the overall goal of this study is geared toward developing a catalyst that has emulsification properties as well as the ability to phase-transfer (from liquid-phase to solid-phase) while the reaction is ongoing and evaluating the effectiveness of such a catalytic process in a practical reaction. To elucidate this concept, the transesterification reaction was selected. Metal-alkoxides that possess acidic and basic properties (to catalyze the reaction), amphiphilic properties (to stabilize the alcohol/oil emulsion) and that can undergo condensation polymerization when heated (to separate as a solid subsequent to the completion of the reaction) were used to test the concept. Studies included elucidating the effect of metal sites and alkoxide sites and their concentration effects on transesterification reaction, effect of various metal alkoxide groups on the phase stability of the reactant system, and kinetic effects of the reaction system. The studies revealed that several transition-metal alkoxides, especially, titanium and yttrium based, responded positively to this reaction system. These alkoxides were able to be added to the reaction medium in liquid phase and were able to stabilize the alcohol/oil system. The alkoxides were selective to the transesterification reaction giving a range of ester yields (depending on the catalyst used). It was also observed that transition-metal alkoxides were able to be recovered in the form of their polymerized counterparts as a result of condensation polymerization subsequent to completion of the transesterification reaction.
12

EFFECTS OF STEARIDONIC ACID-ENRICHED SOYBEAN OIL ON METABOLIC PROFILE AND FATTY ACID COMPOSITION IN LEAN AND OBESE ZUCKER RATS

Casey, John 01 December 2013 (has links)
Background, Consumption of marine-based oils high in omega-3 polyunsaturated fatty acids (n3PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is known to protect against obesity-related pathologies. It is less clear whether traditional vegetable oils with high omega-6 polyunsaturated fatty acid (n6PUFA) content exhibit similar therapeutic benefits. As such, this study examined the metabolic effects of a plant-based n3PUFA, stearidonic acid (SDA), in polygenic obese rodents. Methods, Lean (LZR) and obese Zucker (OZR) rats were provided either a standard westernized control diet (CON) with a high n6PUFA to n3PUFA ratio (i.e., 16.2/1.0) or experimental diet modified with flaxseed (FLAX), menhaden (FISH), or SDA oil that resulted in n6PUFA to n3PUFA ratios of 1.7/1.0, 1.3/1.0, and 1.0/0.8, respectively. Results, After 12 weeks, total adiposity, dyslipidemia, glucose intolerance, and hepatic steatosis were all greater, whereas n3PUFA content in liver, adipose, and muscle was lower in OZR vs. LZR rats. Obese rodents fed modified FISH or SDA diets had lower serum lipids and hepatic fat content vs. CON. The omega-3 index (i.e., ÓEPA + DHA in erythrocyte membrane) was 4.0, 2.4, and 2.0-fold greater in rodents provided FISH, SDA, and FLAX vs. CON diet, irrespective of genotype. Total hepatic n3PUFA and DHA was highest in rats fed FISH, whereas both hepatic and extra-hepatic EPA was higher with FISH and SDA groups. Conclusions, these data indicate that SDA oil represents a viable plant-derived source of n3PUFA, which has therapeutic implications for several obesity-related pathologies.
13

Processamento de oleo de soja utilizando ultrafiltração em miscela na etapa de degomagem e na obtenção de lecitina / Soybean oil processing using ultrafiltration in micelle in the degumming ste

Soares, Marinalda da Silva 26 May 2004 (has links)
Orientadores: Lireny Aparecida Guaraldo Gonçalves, Luiz Antonio Viotto / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-03T21:14:27Z (GMT). No. of bitstreams: 1 Soares_MarinaldadaSilva_D.pdf: 1635248 bytes, checksum: f576efc88ef55b05d1817c84d8468ee7 (MD5) Previous issue date: 2004 / Resumo: Tradicionalmente o óleo de soja bruto é degomado por adição de água ou solução ácida. A tecnologia de membranas aplicada ao processamento de óleos vegetais tem se tornado importante, pois utiliza baixas temperaturas, não necessita de tratamento de águas residuais, retém compostos indesejáveis, além de preservar compostos minoritários importantes no óleo. Os objetivos deste trabalho foram otimizar as condições de ultrafiltração de miscela de óleo de soja bruto como alternativa à degomagem clássica, avaliar as características físico-químicas e sensoriais do óleo degomado e desodorizado em escala piloto e obter lecitina de soja através da concentração do retentado. A ultrafiltração da miscela foi realizada à 40 ºC, em unidade piloto NETZSCH utilizando duas membranas cerâmicas em alumina, pré-condicionadas, com diâmetro de poro de 0,01mm, de 19 e 37 canais. O efeito da pressão transmembrana e do teor de fósforo na alimentação foram avaliados com relação ao fluxo de permeado e retenção de fosfolipídios. A faixa de pressão transmembrana utilizada nos tratamentos foi de 0,6 a 2,0 bar, sob velocidade tangencial de 3,5 m/s. Foi estabelecido um planejamento experimental fatorial 22 completo, com 3 pontos centrais e 4 pontos axiais, para cada membrana. O teor de fósforo na alimentação não exerceu efeito considerável no percentual de retenção, entretanto teve efeito negativo sobre o fluxo de permeado nas duas membranas. Valores maiores de pressão transmembrana favoreceram o aumento de fluxo e de retenção para membrana de 19 canais. Entretanto, para membrana de 37 canais, apenas a retenção foi favorecida pelo aumento da pressão, sendo que um grande aumento da pressão (acima de 1,5 bar) para esta membrana, teria efeito negativo sobre o seu fluxo. Os premeados obtidos nos tratamentos que apresentaram melhor retenção de fosfolipídios (>98%) para as duas membranas, ou seja, valores de fósforo abaixo do nível máximo exigido pela indústria de 10 mg.kg-1, foram desodorizados em unidade piloto de desodorização com vaso de inox encamisado de 3 litros, sob vácuo de 12 mmHg, a 230ºC, por 90 minutos, utilizando nitrogênio como gás de arraste. Após determinações físico químicas que asseguraram a qualidade, os produtos obtidos foram levados à analise sensorial de aceitação ao nível de consumidor e comparados com um óleo de soja refinado comercial. Os óleos desodorizados obtidos não apresentaram diferença significativa (p £ 0,05) entre si e comparados ao óleo de soja refinado comercial para os atributos aroma e sabor. A lecitina obtida a partir da ultrafiltração dos retentados estava de acordo com os padrões do Food Chemical Codex, com 53 % de insolúveis em acetona / Abstract: Crude soybean oil is traditionally degummed by water addition or phosphoric acid. The membrane technology applied to vegetable oils processing has become important because it allows to use temperatures, reduces waste water treatment, retains undesirable products, besides preserving important minor compounds in the oil. The objectives of this work were to optimize the conditions of crude soybean oil micelle ultra filtration as an alternative to the traditional degumming, evaluate the physical-chemical and sensorial characteristics of the degummed and deodorized oil in pilot plant scale and to obtain soy lecithin through retentate concentration. The ultrafiltration was accomplished at 40o C, in a NETZSCH pilot unit utilizing two pre-conditioned ceramic in alumina membranes with 0.01 mm pore diameter of 19 and 37 channels. The feed transmembrane pressure effect and the phosphorous content were evaluated regarding to the permeate flux and retention of phospholipids. The transmembrane pressure range used in the treatments was from 0.6 to 2.0 bar under tangential velocity of 3.5m/s. A complete 22 experimental design was established with 3 central points and 4 axial points for each membrane. The phosphorous content has not carried on considerable effect in the retention, nevertheless it had a negative effect over the permeate flux in the two membranes. Greater transmembrane pressure values favor the flux and retention increase in the 19 channels membrane. However in 37 channels membranes only the retention was favored by the increasing pressure while, a great pressure increase (above 1.5 bar), presented a negative effect on the its flux. The treatments that showed better phospholipids retention (>98%) for the two membranes, phosphorous values below the maximum level of 10 mg/kg required by the industry were deodorized in a deodorization pilot unity with stainless steel jacketed reactor with 3 liters capacity, under 12 mmHg vacuum, at 230 ºC, for 1.5 hours, using nitrogen as carrier gas. After physical-chemical determinations that assured the quality, the obtained products were analyzed regarding to the sensorial acceptance at the consumer level and compared with commercial soybean refined oil. The statistical analysis have not shown significative difference (p £ 0.05) among the two desodorized oils and commercial soybean neutrative-bleached-desodorized oil for the aroma and flavor atributes. The obtained lecithin was in accordance with the standards of Food Chemical Codex, with 53% of acetone insoluble / Doutorado / Doutor em Tecnologia de Alimentos
14

LOW TRANS FATTY ACID CONTAINING HYDROGENATED EDIBLE OILS

Xiao, Haiyi 27 November 2007 (has links)
No description available.
15

Rice Bran Wax Oleogel Water Holding Capacity and Its Effects on the Physical Properties of the Network

Cramer, Erica Danielle 24 October 2016 (has links)
No description available.
16

Influência da adição de óleo de soja no perfil oxidativo de concentrado para bovino / Influence of addition of soybean oil in the oxidative profile of concentrate for cattle

Bueno, Juliana Lisboa Biotto Carvalho 28 February 2012 (has links)
O objetivo deste trabalho foi estudar o perfil oxidativo de concentrados para bovinos adicionados de óleo de soja, refinado e degomado, em um período de armazenamento de 15 dias, sob as temperaturas de 25ºC e 40ºC. Foram formados cinco grupos de alimentos: controle (C) sem adição de óleo, tratamentos (T) 1, 2, 3 e 4 com adição de 2, 4, 6 e 8%, respectivamente, de óleo de soja refinado ou degomado. Para tal, foram avaliados os índices de peróxidos e de acidez. Com relação à influência da temperatura de estocagem, ao longo do período experimental à 25ºC, não houve alteração com relação aos valores de índice de peróxido quando se adicionou óleo de soja refinado aos concentrados, contudo, à 40ºC, houve aumento observando-se um valor máximo em torno de 0,9 mEq/kg de concentrado. O índice de acidez do óleo refinado extraído dos concentrados armazenados à 25ºC não foi alterado ao longo do período de armazenamento, e à 40ºC resultou em aumento de 19, 25, 44 e 44% para os respectivos T1, T2, T3 e T4 em relação ao controle. Quanto à influência do tipo de óleo processado na oxidação lipídica dos concentrados armazenados à 40ºC, a adição de óleo de soja refinado não alterou os índices de peróxidos dos concentrados ao longo dos 15 dias de experimento, e para o degomado observou-se um aumento no 3º dia de armazenamento em 57%, 44%, 123% e 93% para os respectivos T1, T2, T3 e T4, em relação ao controle. Também, o efeito da adição de óleo de soja degomado resultou em aumento do índice de acidez de 21%, 36%, 43% e 57% a partir do 5º dia de experimento, em relação ao 1º dia. Conclui-se que durante os 15 dias de armazenamento, houve diferença no perfil oxidativo dos concentrados adicionados de óleo de soja quando se comparou as temperaturas de 25ºC e 40ºC, mas se manteve inalterado quando se avaliou os tipos de óleo refinado e degomado em diferentes porcentagens. Assim, a adição de óleo de soja refinado ou degomado não altera o perfil oxidativo do concentrado para bovino sob as condições deste estudo. / The objective of this work was to study the oxidative profile of concentrates for cattle added soybean oil, refined and degummed in a storage period of 15 days, at temperatures of 25ºC and 40ºC. Were formed five food groups: control (C) without addition of oil, treatments (T) 1, 2, 3 and 4 with the addition of 2, 4, 6 and 8%, respectively, of refined or degummed soybean oil. For this purpose ware available index of peroxide and of acidic. Regarding the influence of storage temperature, the addition of refined soybean oil did not alter the values of the peroxide during the trial period at 25ºC, however, at 40ºC of storage of food alter this parameter and was shown a maximum value about 0.9 mEq/kg of concentrate. The acidity of refined oil extracted from concentrates stored at 25ºC was not changed during the storage period, and 40ºC resulted in an increase of 19, 25, 44 and 44% for the respective T1, T2, T3 and T4 compared the control. Regarding the influence of oil processed in lipid oxidation of concentrates stored at 40ºC, the addition of refined soybean oil did not alter the levels of peroxide concentrates over the 15 days of experiment, and the degummed observed an increase in 3rd day of storage in 57%, 44%, 123% and 93% for the respective T1, T2, T3 and T4, compared to control. Also, the effect of addition of crude soybean oil resulted in increased acid value of 21%, 36%, 43% and 57% from the 5th day of experiment, as compared to day 1. Thus, the addition of refined soybean oil or degummed not change profile for bovine oxidative concentrated under the conditions of this study.
17

Influência da adição de óleo de soja no perfil oxidativo de concentrado para bovino / Influence of addition of soybean oil in the oxidative profile of concentrate for cattle

Juliana Lisboa Biotto Carvalho Bueno 28 February 2012 (has links)
O objetivo deste trabalho foi estudar o perfil oxidativo de concentrados para bovinos adicionados de óleo de soja, refinado e degomado, em um período de armazenamento de 15 dias, sob as temperaturas de 25ºC e 40ºC. Foram formados cinco grupos de alimentos: controle (C) sem adição de óleo, tratamentos (T) 1, 2, 3 e 4 com adição de 2, 4, 6 e 8%, respectivamente, de óleo de soja refinado ou degomado. Para tal, foram avaliados os índices de peróxidos e de acidez. Com relação à influência da temperatura de estocagem, ao longo do período experimental à 25ºC, não houve alteração com relação aos valores de índice de peróxido quando se adicionou óleo de soja refinado aos concentrados, contudo, à 40ºC, houve aumento observando-se um valor máximo em torno de 0,9 mEq/kg de concentrado. O índice de acidez do óleo refinado extraído dos concentrados armazenados à 25ºC não foi alterado ao longo do período de armazenamento, e à 40ºC resultou em aumento de 19, 25, 44 e 44% para os respectivos T1, T2, T3 e T4 em relação ao controle. Quanto à influência do tipo de óleo processado na oxidação lipídica dos concentrados armazenados à 40ºC, a adição de óleo de soja refinado não alterou os índices de peróxidos dos concentrados ao longo dos 15 dias de experimento, e para o degomado observou-se um aumento no 3º dia de armazenamento em 57%, 44%, 123% e 93% para os respectivos T1, T2, T3 e T4, em relação ao controle. Também, o efeito da adição de óleo de soja degomado resultou em aumento do índice de acidez de 21%, 36%, 43% e 57% a partir do 5º dia de experimento, em relação ao 1º dia. Conclui-se que durante os 15 dias de armazenamento, houve diferença no perfil oxidativo dos concentrados adicionados de óleo de soja quando se comparou as temperaturas de 25ºC e 40ºC, mas se manteve inalterado quando se avaliou os tipos de óleo refinado e degomado em diferentes porcentagens. Assim, a adição de óleo de soja refinado ou degomado não altera o perfil oxidativo do concentrado para bovino sob as condições deste estudo. / The objective of this work was to study the oxidative profile of concentrates for cattle added soybean oil, refined and degummed in a storage period of 15 days, at temperatures of 25ºC and 40ºC. Were formed five food groups: control (C) without addition of oil, treatments (T) 1, 2, 3 and 4 with the addition of 2, 4, 6 and 8%, respectively, of refined or degummed soybean oil. For this purpose ware available index of peroxide and of acidic. Regarding the influence of storage temperature, the addition of refined soybean oil did not alter the values of the peroxide during the trial period at 25ºC, however, at 40ºC of storage of food alter this parameter and was shown a maximum value about 0.9 mEq/kg of concentrate. The acidity of refined oil extracted from concentrates stored at 25ºC was not changed during the storage period, and 40ºC resulted in an increase of 19, 25, 44 and 44% for the respective T1, T2, T3 and T4 compared the control. Regarding the influence of oil processed in lipid oxidation of concentrates stored at 40ºC, the addition of refined soybean oil did not alter the levels of peroxide concentrates over the 15 days of experiment, and the degummed observed an increase in 3rd day of storage in 57%, 44%, 123% and 93% for the respective T1, T2, T3 and T4, compared to control. Also, the effect of addition of crude soybean oil resulted in increased acid value of 21%, 36%, 43% and 57% from the 5th day of experiment, as compared to day 1. Thus, the addition of refined soybean oil or degummed not change profile for bovine oxidative concentrated under the conditions of this study.
18

Modification of Alkyd Resins and Seed Oil Based Reactive Diluents for High Performance Coatings

Pellegrene, Brittany Ann 29 August 2019 (has links)
No description available.
19

The effects of Low α-Linolenic fatty acid Soybean Oil and Mid Oleic acid Soybean Oil on the growth of Her-2/neu and Fatty acid synthase over-expressing human breast cancer (SK-Br3) cells

Bark, Jee Hyun 21 January 2011 (has links)
A variety of soybean oils (SOs) were developed with improved functional properties. Some of the modified SOs contain altered fatty acid (FA) composition by selective breeding methods. Currently, low α- linolenic acid soybean oil (LLSO) and low α- linolenic acid and mid oleic acid soybean oil (LLMOSO) are available FA modified SOs in the market. The consumption of FA modified SOs has been increased because the United States Food and Drug Administration required listing trans fat content in food products sold in U.S. as an effort to reduce possible health risks caused by trans fat beginning 2006. However, the effects of these FA modified SOs on human chronic diseases including breast cancer (BC) have not been studied. BC has become the most frequently diagnosed cancer and is the second leading cause of cancer death among American women. The type of dietary fat, FA composition, and n-6/n-3 ratio are known to influence BC development. Therefore, it is possible that the changed FA composition and n-6/n-3 ratio in the FA modified SOs may affect BC progression, and its critical health concern needs to be investigated. Increased human epithelial growth factor receptor 2 (Her-2/neu) and fatty acid synthase (FAS) are associated with BC progression. In fact, FAS activity and expression are affected by dietary FA composition and FA metabolism. Hypothesis of this research is that LLSO and LLMOSO may affect Her-2/neu and FAS expressing human BC (SK-Br3) cell growth in vitro and in vivo. To test our hypothesis, we investigated the potential adverse or beneficial effects of LLSO and LLMOSO in comparison with conventional SO and lard on human BC cells and then examined the possible mechanisms of action by evaluating the expression level of genes markers involved in growth factor mediated signal transduction pathway, specifically Her-2/neu PI 3-kinase (phophoinositide 3- kinase)-FAS signal transduction pathway. In vitro study demonstrated that all the tested oils at 0-2 μl/ml level have cytotoxic effects. LLMOSO had less cytotoxic effects on the growth of SK-Br3 cells compared to SO. However, there was no difference in SK-Br3 cell growth between LLSO and SO. The apoptotic protein markers (mutant p53 and caspase-3) analysis revealed that the cell growth inhibition by oil treatments was cytotoxic by triggering apoptosis. Western blot analysis demonstrated that LLSO- and LLMOSO- induced changes on cell growth involve Her-2/neu and FAS signaling transduction pathway and sterol regulatory element binding protein-1 (SREBP-1), mitogen activated protein kinase (MAPK), and phosphatidylinositol 3-kinase (PI 3-kinase) are possible down-stream effectors of Her-2/neu signaling pathway. We also evaluated the dietary effects of LLSO (20% fat of total calorie), SO (20%), and lard (20%) on the growth of SK-Br3 tumors implanted in athymic mice. Changes in tumor surface area, body weight, and food intake were monitored during the 6 months feeding study. After termination, tumor net weight, Her-2/neu and FAS mRNA expression in tumors, FAS protein expression in liver, lipid composition in diets, abdominal fat, and serum, as well as plasma total cholesterol and triglyceride levels were analyzed. In vivo study showed that there were no statistical differences in tumor size and tumor net weight among SO, LLSO, and lard groups. No differences in FAS mRNA and protein expression levels between the LLSO and SO groups were observed. Tumors from the lard group expressed higher Her-2/neu and FAS mRNA than those from the LLSO and SO group. The lipid analysis demonstrated that LLSO was not significantly distinct from SO in trans fat concentration after metabolism. Serum cholesterol and triglyceride levels were unchanged in LLSO fed compared to SO fed mice. In summary, LLSO which contained modification in αLA concentration showed similar effects on SK-Br3 as SO in both in vitro and in vivo. However, LLMOSO which contained more drastic modifications on FA composition exhibited less cytotoxicity compared to SO in vitro. / Master of Science
20

Investigation of High-Oleic Soybean Oil as an Extraction Solvent to Remove Hydrogen Sulfide from Natural Gas

Emma C Brace (9021866) 25 June 2020 (has links)
<div>Conventional soybean oil and high-oleic soybean oil offer opportunities as bio-solvents for sweetening sour natural gas, adding value to the soybean oil industry and the natural gas industry. The rise of fracking in the United States and changing economics in the energy industry have increased use of natural gas, which is often rendered sour by high concentrations of hydrogen sulfide (H2S), a toxic and corrosive impurity. The present work evaluates the viability of both conventional and high-oleic soybean oil to act as bio-solvents for removing gaseous H2S. Predictive in silico methods, experimental validation, and economic feasibility analysis are included to draw conclusions regarding the overall capability and feasibility of using soybean oils as bio-solvents for gas sweetening.</div><div><br></div><div>In silico predictive methods for sweetening were implemented to assess the relationship between fatty acid composition in the soybean oils and the ability to effectively partition H2S from methane or nitrogen gases. The Conductor-like Screening Model for Real Solvents (COSMO-RS) was used to predict the partition coefficient (K) of H2S in a bi-phasic liquid-vapor system made up of fatty acids in the liquid phase and methane or nitrogen gas in the vapor phase. The fatty acid mass fractions represented those found in soybean or high-oleic soybean oil. Methane represented gas and nitrogen was considered in order to compare to experimental conditions. This proof of concept work predicted K values for H2S below 0.0005 at temperatures from 10 to 100 °C at atmospheric pressure; K values near zero indicate near-complete removal of H2S from the gas phase.</div><div><br></div><div>Experimental validation included equilibrium extraction experiments as well as data collection for isotherm model development. Experimental equilibrium studies were carried out at residence times ranging from 0 – 60 minutes with mixing at ambient conditions. Experiments resulted in K values below 0.1 for H2S in soybean oil and high-oleic soybean oil at 25 °C with residence times less than 15 minutes and a 2:1 gas to oil ratio. More than 90% of the H2S was removed from the gas phase within 15 minutes. Isotherm models demonstrated the saturation limits of the soybean oils and compared them to saturation limits in water and heptane. </div><div><br></div><div>Economic feasibility experiments used graphical and algebraic methods to determine the number of equilibrium stages needed to remove 99.9% of H2S from feed gas with H2S concentrations ranging from 40 – 400 ppm. A gas flow rate equivalent to industrial levels was used to design an extraction column. Capital costs and operating costs were estimated, along with the revenues to be gained from selling methane and selling recovered elemental sulfur as a secondary product. Solvent regeneration would need to exceed 98% in order to keep the cost of treating a unit of natural gas equal to or less than existing industrial methods. Suggestions for cutting costs and improving process viability are made.</div><div><br></div>

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