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Castejon, Letícia Vieira. "Parâmetros de qualidade na clarificação da lecitina de soja." Universidade Federal de Uberlândia, 2015. https://repositorio.ufu.br/handle/123456789/17770.
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A lecitina de soja é um complexo de fosfolipídeos em óleo de soja, sendo denominada de
lecitina de soja comercial. Sua coloração é âmbar, apresenta alta viscosidade, cheiro e gosto
característicos. É bastante utilizada como emulsificante, possui características próprias devido
a modificações física, químicas ou de processos de obtenção. O presente trabalho teve por
objetivo avaliar fisico-quimicamente lecitinas de soja clarificadas, pela adição de peróxido de
hidrogênio a 35% (v/v), a temperatura e agitação controladas. Avaliar os aspectos qualitativos
e de coloração, para posterior aplicação em leite integral UHT e verificação das características
de pó (molhabilidade e insolubilidade). A etapa de clarificação foi planejada
experimentalmente, através de um Planejamento Composto Central, cuja lecitina de soja
comercial, sem tratamento com peróxido foi analisada quanto à reologia, apresentando
comportamento pseudoplástico a 25°C e newtoniano à 50°C. Sua composição de ácidos
graxos foi de elevado teor de insaturados conforme análise cromatográfica. A clarificação
produziu lecitinas mais claras do que a lecitina comercial e foi selecionada a lecitina
clarificada com maior valor de luminosidade (L*) para análise reológica, a qual mostrou
mesmos comportamentos reológicos da lecitina comercial, porém com ligeiros aumentos na
viscosidade aparente. Resultado das avaliações sobre a coloração foram realizadas, mostrando
os efeitos da temperatura, tempo de agitação sob rotação constante e concentrações de H2O2
(%, m/v), obtendo-se colorações mais vermelhas e amarelas, intensas e de tonalidade
tendendo ao amarelado. O ponto experimental em que se obteve maior luminosidade, cor
branca, foi a 50°C, 520 segundos de agitação e adição de 2,3% de peróxido de hidrogênio,
35% (m/v). Um modelo de cor foi elaborado para predizer quais parâmetros de cor
influenciam sobre a cor aparente, para isso foram analisados compostos carotenoides e
clorofilas, chegando-se à conclusão que outras substâncias, como substâncias marrons e
tocoferóis, se determinadas melhorariam o ajuste. Os resultados das avaliações da qualidade
oxidativa das lecitinas clarificadas, mostraram os efeitos das variáveis do planejamento sobre
as respostas de índice de saponificação, coeficiente de oxidação, índice de acidez e atividade
de água, os resultados mostraram que em condições extremas, foram mantidos bons estados
de oxidação lipídica. A aplicação da lecitina mais clarificada no leite mostrou que a cor do
leite em pó ficou mais clara. A melhor solubilidade e menor tempo de molhabilidade foram
obtidos para concentração adicionada de lecitina igual a 1,0% (m/m) sobre a massa aplicada e as micrografias dos pós mostraram que o aumento no teor de lecitina de soja deixa os
grânulos menores e o pó mais granuloso.Soy lecithin is a complex phospholipid in soybean oil, being called commercial soybean lecithin. Its color is amber, high viscosity, smell and taste characteristic. It is widely used as an emulsifier, has its own characteristics due to physical changes, chemical or production processes. This study aimed to assess physico-chemically clarified soy lecithins, by adding hydrogen peroxide to 35% (v / v), the controlled temperature and agitation. It was considered qualitative aspects and also in color, for later use in UHT whole milk and verification of powder characteristics (wettability and solubility). The clarification step is designed experimentally, using a central composite design, the commercial soybean lecithin without peroxide treatment rheology was analyzed, showing pseudoplastic behavior at 25°C and the Newtonian at 50°C, the composition of fatty acids was higher unsaturated content as chromatographic analysis. Clarification produced lighter than lecithin and commercial lecithin was clarified lecithin selected with higher brightness value (L*) to rheological analysis, which showed the same rheological behavior of commercial lecithin, but with slight increases in apparent viscosity. Reviews staining were performed, showing the effects of temperature under constant stirring rotation time and H2O2 concentration (% w/v) to give more red dyes and yellow, intense tint and tended to yellow. The experimental point was obtained in higher brightness, white color at 50°C was 520 seconds of stirring and addition of 2.3% hydrogen peroxide, 35% (w/v). A color model is designed to predict which color parameters influence on the apparent color, for that were analyzed carotenoids and chlorophyll compounds, coming to the conclusion that other substances, such as brown substances and tocopherols, if certain improve the fit. The evaluation of oxidative quality of clarified lecithins have shown the effects of the design variables on the saponification number of responses, oxidation rate, and acid value of water activity, the results showed that in axial conditions are maintained good oxidation states lipid. The application of more clarified lecithin in milk showed that the color of milk powder became clearer. The best solubility and shorter wettability were obtained for added lecithin concentration equal to 1.0% of the applied mass and the powders micrographs showed that the increase in soy lecithin content leaves the smaller beads and the most granular powder.
Tese (Doutorado)
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Svensson, B. Martin. "Lipase catalysis in lecithin-stabilised microemulsions." Thesis, University of East Anglia, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.406836.
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Beattie, Stuart Gavin. "Lecithin colesterol ACYL transferase gene transfer studies." Thesis, Royal Holloway, University of London, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409233.
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Ghazi, Samira. "Factors influencing expression of lecithin : cholesterol acyltransferase." Thesis, University College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.322763.
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Chamberlin, Richard Addison. "Light scattering studies on lecithin micellar solution." Thesis, Massachusetts Institute of Technology, 1991. http://hdl.handle.net/1721.1/13859.
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Stroppa, Valter Luís Zuliani. "Influência de lecitina e PGPR no processo de microestruturação de chocolate amargo." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266882.
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Orientadores: Lireny Aparecida Guaraldo Gonçalves, Priscila EfraimDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química
Made available in DSpace on 2018-08-18T18:52:26Z (GMT). No. of bitstreams: 1 Stroppa_ValterLuisZuliani_M.pdf: 1829992 bytes, checksum: 1eb19d94141314569616332614683d54 (MD5) Previous issue date: 2011
Resumo: Chocolates são produtos compostos por uma fase lipídica com predominância de manteiga de cacau, e que contem liquor, açúcar emulsificantes e eventualmente leite em pó (ou derivados lácteos) e aromas. As características físicas dos chocolates como brilho, dureza, fusão a temperaturas da boca e estabilidade térmica são conseqüências da estruturação cristalina induzida na manteiga de cacau. Os triacilgliceróis presentes na manteiga de cacau podem-se organizar em até seis formas polimórficas sendo que apenas duas são estáveis e geram produtos de melhor qualidade. A adição de emulsificantes ao chocolate visa melhorar o comportamento reológico durante o processamento diminuindo as tensões interfaciais entre a fase gordurosa e as partículas sólidas. Os emulsificantes promovem o recobrimento das partículas sólidas com a fase oleosa lubrificando as interfaces que, desta maneira, poderão servir de elementos ativos para a nucleação. Este trabalho avaliou o efeito da adição dos dois emulsificantes mais utilizados na indústria, lecitina de soja e PGPR (poliglicerol poliricinoleato), no processo de estruturação cristalina de chocolate amargo. Foram produzidos chocolates com diferentes teores de emulsificantes conforme um planejamento fatorial completo 2² rotacionado. O nível de lecitina variou de 0,08 a 0,92% e o de PGPR de 0,02 a 0,58%. Para caracterizar esta influência foram utilizadas técnicas de reometria (determinação das propriedades de escoamento), ressonância magnética nuclear (acompanhamento da cinética de cristalização), Índice de temperagem (quantificação da pré-cristalização), e ensaios de ruptura (avaliação da resistência estrutural). Os valores de viscosidade plástica de Casson do chocolate medidos a 40ºC variaram de 1,4 a 5,9 Pa.s enquanto que o limite de escoamento variou de zero a 34Pa. Os parâmetros cinéticos avaliados de isotermas de cristalização a 15ºC ajustadas ao Modelo de Avrami resultaram no expoente n variando de 2,598 a 2,956 e o parâmetro k entre 5,15.10-6 e 2,85.10-5 min-n para os diferentes teores de emulsificantes. Estes efeitos foram associados à capacidade da lecitina em aumentar o volume cristalino e ao potencial nucleador do PGPR
Abstract: Chocolates are confectionary products composed by a lipid phase based mainly on cocoa butter that contains cocoa mass, sugar, emulsifiers and eventually milk solids and aromas. Physical characteristics of chocolates like gloss, hardness, melting at mouth temperature and thermal stability result from the crystalline structuration accomplished by the fat phase. The triacylglycerols in cocoa butter can be organized in up to six different polymorphs but only two of them are stable and therefore yield better quality products. The addition of emulsifiers to chocolates intends to improve the rheological behavior during processing by the reduction of the interfacial tension between the fat phase and the solid particles. The emulsifiers promote the coating of the solid particles by an oily layer, lubricating the interfaces that then can serve as active elements for nucleation. This work examines the effects of the addition of the two most used emulsifiers in chocolate, namely soy lecithin and PGPR (polyglycerol polyricinolate) in the crystalline structuration of chocolates. Chocolates with different contents of the two emulsifiers were produced, following a 22 complete factorial rotational design. The lecithin level varied from 0.08 to 0.92% and the PRPG content from 0.02 to 0.58%. The influence of the additives was characterized by rheometry (determination of the flowing parameters), nuclear magnetic resonance (monitoring the crystallization kinetics), Temperindex (pre-crystallization level quantification), and snap test (structural resistance). The values of Casson's plastic viscosity of the chocolates, measured at 40ºC, varied from 1.4 to 5.9 Pa.s while the yield value ranged between zero to 34 Pa. The kinetic parameters evaluated from crystallization isotherms at 15ºC modeled by the Avrami equation resulted in the exponent n varying from 2.598 to 2.956 and k parameters between 5.15 10-5 min-n and 2.85 10-5 min-n when the different amount of emulsifiers were used. These effects are associated to the ability of lecithin to enlarge the crystal volume and to the nucleating potential of PGPR
Mestrado
Engenharia de Processos
Mestre em Engenharia Química
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Maivaldová, Iva. "Interakce fosfolipidů s polyelektrolyty ve vodném prostředí." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2010. http://www.nusl.cz/ntk/nusl-216675.
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This diploma thesis is focused on determination of aggregation behavior of selected phospholipids (lecithin; 1,2-dipalmitoyl-sn-glycerol-3-phosphocholine) in water and on the effect of native hyaluronan addition of various molecular weights and concentrations on this behavior. The behavior has been investigated with fluorescence spectroscopy using pyrene and perylene as fluorescence probes being able to penetrate into hydrophobic cavities of formed aggregates. Critical aggregation concentration and the concentration at which lecithin begins to aggregate have been determined. Regarding 1,2-dipalmitoyl-sn-glycerol-3-phosphocholine, it was possible to determine only the beginning of aggregation value. The values of this parameter for lecithin and for 1,2-dipalmitoyl-sn-glycerol-3-phosphocholine correspond in the order. It has been investigated, that the addition of native hyaluronan has only in some systems slight effect on the aggregate behavior of selected phospholipids.
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Viñado, Martínez Alberto. "Use of soybean lecithin in broiler chicken diets." Doctoral thesis, Universitat Autònoma de Barcelona, 2019. http://hdl.handle.net/10803/667795.
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La adición de grasas es una práctica habitual en la fabricación de piensos para avicultura, ya que son fuente de energía y ácidos grasos esenciales. La disponibilidad de ingredientes con alto contenido energético se puede ver reducida a causa del aumento de población mundial y la utilización de aceites vegetales para la producción de biodiesel. Por ello, la lecitina de soja (L), un coproducto del refinado del aceite de soja (S), puede ser una fuente de energía alternativa, ya que presenta un alto contenido en fosfolípidos, triacilgliceroles, ácidos grasos libres (AGL), fósforo, colina y compuestos antioxidantes. Por todo ello, el objetivo de la tesis fue estudiar el uso potencial de L como fuente de energía para piensos de pollos de carne.
Para ello, se realizaron varios ensayos con el objetivo de estudiar el uso de L como fuente de energía en la alimentación de pollos y evaluar su influencia sobre el rendimiento productivo, digestibilidad de los ácidos grasos (AG), utilización de la energía y perfil de AG de la grasa abdominal. Una dieta base fue suplementada al 3% con S o aceite ácido (A), que fueron sustituidos por niveles crecientes (1%, 2% y 3%) de L (cruda o con alto contenido en AGL en el Capítulo Tres y Cuatro, respectivamente). En relación con la sustitución de S por L, aunque durante la fase de iniciación no se observaron efectos sobre el rendimiento productivo, los balances de digestibilidad demostraron que la incorporación de L disminuyó la digestibilidad de los AG y el contenido en energía metabolizable aparente del pienso. Sin embargo, en la fase de crecimiento-acabado, la sustitución parcial de L (hasta un 2%), no dio lugar a modificaciones en el rendimiento productivo ni la utilización de la energía y de AG. Respecto a la sustitución de A por L, tanto en fase de iniciación como en la de crecimiento-acabado, se observó que la combinación de ambos coproductos dio lugar a una mayor utilización de la energía y los nutrientes. Finalmente, el perfil de AG de la grasa abdominal estaba directamente relacionado con el perfil de AG del pienso, y no se observaron modificaciones importantes al sustituir S por L.
En el último ensayo (Capítulo Cinco) se desarrolló una prueba de campo bajo condiciones experimentales con el objetivo de estudiar, diferentes niveles de inclusión de L en sustitución de S en dietas de pollos de crecimiento y de acabado, y su efecto sobre el rendimiento productivo. Además, se estudió el efecto sobre la digestibilidad ileal de los AG, el perfil de AG de la grasa abdominal y la salud intestinal. La sustitución total del S (2% de inclusión) por L, en dietas que también contenían aceite de palma y A (3,25% y 4,5% de grasas añadidas en crecimiento y acabado, respectivamente) no modificó el rendimiento productivo, la digestibilidad ileal de los AG totales y la morfología yeyunal. Por otro lado, se observó una reducción de la digestibilidad ileal de los AG poliinsaturados y un incremento en los recuentos de Lactobacillus spp. en yeyuno; aunque, sin consecuencias significativas sobre los parámetros productivos. El perfil de AG de la grasa abdominal reflejó el perfil de AG de las grasas, sin observarse importantes modificaciones.
Como conclusiones podemos decir que L es una fuente de energía alternativa adecuada para pollos de carne en crecimiento y acabado, pudiendo sustituir S hasta un 2% sin alterar el rendimiento productivo, la utilización de energía y los AG. Además, la combinación L y A es una alternativa interesante para pollos adultos gracias a la existencia de interacciones positivas sobre la utilización de la energía y los AG.Fat addition is a common practice in feed manufacturing in order to increase the energetic density of diets and provide essential nutrients to livestock animals. The availability of conventional energetic ingredients for broiler chicken diets may be compromised by a constant growing world-wide population and the current tendency to use vegetable oils for biodiesel production. In this context, soybean lecithin (L), as a co-product obtained during soybean oil (S) refining process, may represent an economical and alternative energy source due to its high content in phospholipids, triacylglycerols, free fatty acids (FFA), phosphorus, choline and antioxidant compounds. Therefore, the global aim of the present thesis was to investigate the potential use of L, as energy source for broiler chicken diets. Several trials were performed with the aim to evaluate the inclusion of L as energy source in broiler feeding and study its influence on performance, energy utilization, fatty acid (FA) digestibility and the FA profile of the abdominal fat pad. A basal diet was supplemented at 3% with either S or acid oil (A) and increasing amounts of L (crude and high in FFA for Chapter Three and Four, respectively) were included in replacement (1%, 2% and 3%). In relation to S replacement, despite no effects were observed on performance parameters, results from the digestibility balances indicated that S replacement by L, in starter broiler chickens, lowered FA digestibility and the apparent metabolizable energy content of the diets. However, in grower-finisher broiler chickens, partial replacements up to a 2%, did not modify performance, and the utilization of energy and total FA. Regarding the replacement of A by L, in starter and grower-finisher broiler chicken diets, it was observed that blending both co-products have resulted in improvements on energy and nutrient utilizations. Finally, the FA profile of the adipose tissue was a clear reflect of the FA composition of the added fats, and S replacement by L produced slight changes on the FA profile of the abdominal fat pad. The last experiment (Chapter Five) consisted in a field trial under experimental conditions with the main objective to study, in grower and finisher broiler chicken diets, different levels of L inclusion in replacement of S and its effects on growth performance. In addition, ileal absorption of FA, FA profile of the abdominal fat pad and gut health markers were assessed. Soybean oil total replacement by L (2% of inclusion), in diets that also contained palm and A (3.25% and 4.5% of total added fats for grower and finisher diets, respectively), did not modify performance parameters, total FA ileal digestibility and jejunal morphology. On the other hand, a reduction on the digestibility of the polyunsaturated FA and an increase on Lactobacillus spp. counts at the jejunum were linked to total replacement; however, with no significant consequences on growth efficiency. Slight modifications were observed on the saturation degree of the abdominal fat pad, associated to the FA profile of the different added fats. Taking all the results into account, it was evidenced that L is a suitable energetic ingredient for grower and finisher broiler chicken diets due to it was observed that S partial replacements up to a 2% by L do not alter growth performance and the utilization of energy and FA. Besides, the blending of L and A results an interesting option, for adult broiler diets, due the existence of positive interactions on energy and FA utilization.
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Mackie, Andrew C. "Lecithin-stabilised silica dispersions in non-aqueous media." Thesis, University of Nottingham, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.236022.
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Alsaab, Hashem O. "Evaluation of the Percutaneous Absorption of Chlorpromazine Hydrochloride from PLO Gels Across Porcine Ear and Human Abdominal Skin." University of Toledo Health Science Campus / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=mco1435670713.
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Low, J. K. "Protein and cell therapy for lecithin-cholesterol acyltransferase (LCAT) deficiency." Thesis, University College London (University of London), 2009. http://discovery.ucl.ac.uk/14474/.
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Lecithin-cholesterol acyltransferase (LCAT) is an enzyme principally secreted by the liver into the circulation where it esterifies cholesterol and plays a key role in high- density lipoprotein (HDL) metabolism. In familial and acquired (liver disease) LCAT deficiency, the failure to esterify cholesterol causes many cellular and metabolic disturbances. Here, I describe the purification of recombinant LCAT and assess two approaches to treat LCAT deficiency. Human LCAT cDNA was cloned into a selectable expression vector and used to generate a stably–transfected Chinese hamster ovary (CHO) cells secreting human LCAT tagged with 6 histidine residues. Productive clones were selected, monitoring LCAT activity by a modification of a radioactive enzymic assay for plasma, and the enzyme purified from culture medium by immobilised cobalt affinity chromatography. The pure LCAT, as judged by SDS- PAGE, was used to raise monoclonal antibodies in LCAT knockout mice for future development of a sensitive immunoassay. For therapy, I evaluated injection of pure LCAT into the peritoneal cavity of LCAT knockout mice using single and repeat dose regimes. LCAT activity was measurable in plasma post-injection and the percentage of esterified cholesterol increased, while agarose gel electrophoresis confirmed a rise in HDL levels. In a second approach, I encapsulated the recombinant CHO cells in biocompatible and semipermeable alginate-polylysine microcapsules using a syringe pump extrusion method. A study in vitro showed that, after an initial lag phase, LCAT was secreted for over 90 days with the capsules remaining intact. These microencapsulated cells were implanted into peritoneal cavities of LCAT-deficient mice. LCAT activity was detected in mice plasma one week post-implantation; the relative amount of esterified cholesterol was increased and lipoprotein profile was improved. I conclude that injection of recombinant enzyme or of encapsulated LCAT-secreting cells are feasible therapies for familial and acquired LCAT deficiency.
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Lucht, Julie. "Viscosity Characterization of 20% Pluronic Lecithin Organogel at varying pHs." The University of Arizona, 2009. http://hdl.handle.net/10150/623980.
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Class of 2009 AbstractOBJECTIVES: The primary objective of this experiment was to characterize the pH stability range of 20% Pluronic lecithin organogel (PLO). We intended to determine the viscosity at varying pHs. We prepared six samples of 20% PLO. METHODS: An initial rheological reading of each sample was recorded by a dynamic stress rheometer. Each sample was titrated drop-wise with citric acid or KOH in 0.5 pH increments. When the desired pH was obtained, a 0.5 mL sample was analyzed with a dynamic stress rheometer, RS-200, using Rheos software. RESULTS: Since PLO is a non-Newtonian substance, viscosity changed relative to shear stress and we were not able to examine a correlation of pH with viscosity. Instead we inputted the data into Microsoft Excel® and plotted a shear stress versus viscosity curve for each sample to identify trends. CONCLUSIONS: We were unable to achieve our primary objective of determining the viscosity characterization of 20% PLO at varying pHs due to the non-Newtonian nature of the material. Subjectively, we determined the viscosity of 20% PLO is not substantially affected by pH. Other factors such as temperature, excess liquid, and surfactant ability may influence viscosity and need to be examined in the future.
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Taylor, Lynn Elizabeth. "Acid-base regulation during sprint exercise in horses fed lecithin." Diss., This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-06062008-163251/.
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Dalmazzo, Andressa. "Utilização da lecitina de soja para a refrigeração e criopreservação do sêmen de cães." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/10/10131/tde-02102012-105414/.
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Sabe-se que a criopreservação do sêmen provoca uma perda significativa na qualidade espermática. Apesar de diversos estudos visando à melhora na qualidade do sêmen pós-descongelamento, é de consenso geral que a gema de ovo apresenta uma significante capacidade em evitar as crio-injúrias. No entanto, a grande variação na sua composição, assim como o risco potencial para a contaminação do diluidor, caso certos contaminantes estejam no produto in natura, são empecilhos para sua utilização para a exportação do sêmen, assim como sua utilização em humanos. Deste modo, estudos visando substituir a gema de ovo por produtos quimicamente definidos e de origem não-animal, são de extrema importância. Neste contexto, a lecitina da soja, por possuir uma fração de lipoproteína de baixa densidade semelhante à encontrada na gema de ovo, pode ser uma alternativa interessante. O presente estudo visa comparar diluidores a base de lecitina de soja e aqueles contendo gema de ovo utilizados rotineiramente para a refrigeração e criopreservação do sêmen canino. Para isto, foi utilizado o sêmen de 12 cães adultos, que foi refrigerado e criopreservado em diluidores a base de gema de ovo (OVO) e a base de lecitina de soja (LEC) em diferentes concentrações (0,01; 0,05 e 0,1%) e apresentações (FP40, 8160 e Solec F). O sêmen foi avaliado após refrigeração (2, 24, 48, 72, 96 e 120 horas; Experimento 1) e após criopreservação (pós refrigeração, pós glicerolização e pós descongelação; Experimento 2) através da análise convencional do sêmen (i.e., motilidade - CASA) e funcionais (i.e., integridade de membrana - eosina/nigrosina; integridade de acrossomo - Fast Green / Rosa Bengala; atividade mitocondrial - 3´3 Diaminobenzidina; fragmentação do DNA - SCSA; susceptibilidade ao estresse oxidativo - substâncias reativas ao ácido tiobarbitúrico). Os resultados do Experimento 1 indicaram que, semelhante ao ovo, todas as lecitinas na concentração 0,01% foram capazes de manter a motilidade em torno de 50% por até 72 horas. Após 96 horas, o diluidor Solec F apresentou melhor resultado em relação ao ovo na atividade mitocondrial, e após 120 horas a concentração 0,01%, apresentou maior motilidade do que o ovo (30,00 ± 10,69; 8,33 ± 1,84, respectivamente). No sêmen criopreservado (Experimento 2), as menores concentrações de lecitina apresentaram resultados semelhantes ao ovo tanto na motilidade quanto na atividade mitocondrial. Os resultados indicam que a lecitina pode ser uma boa alternativa à gema de ovo para a refrigeração e criopreservação do sêmen canino.Semen cryopreservation, an essential step on biotechnologies applied to reproduction, is known to induce significant loss on sperm quality. Despite several studies aiming to improve post-thaw quality, it is generally agreed that egg yolk is the most effective in protecting sperm against cryo-injuries. However, the considerable variation on egg yolk composition as well as the potential risk of disseminating diseases when used in natura, are obstacles to semen exportation as well as the use in human. Therefore, studies aiming to substitute the egg yolk for chemically defined components or animal free products are extremely important. In this context, soy lecithin, which contains a fraction of low density lipoprotein, appears to be an interesting alternative. Thus, the present study aims to compare semen extenders containing soy lecithin or egg yolk on dog semen cryopreservation and refrigeration. Towards this aim, semen of 12 adult dogs were be refrigerated and cryopreserved in Tris-Fructose-Citric acid extenders with egg yolk (OVO) or soy lecithin (LEC; in different concentrations - 0,01; 0,05; 0,1% and presentations - FP40; 8160; Solec F). Semen was evaluated after chilling (2, 24, 48, 72, 96 and 120 hours; Experiment 1) and after cryopreservation (post refrigeration, post-glycerolization, and post-thaw; Experiment 2) for routine semen analysis (e.g., motility, CASA) and functional tests (e.g., membrane integrity - eosin/nigrosin; acrosome integrity - fast green/Bengal rose; mitochondrial activity - 3´3 diaminobenzidine; DNA fragmentation - SCSA; susceptibility to oxidative stress - thiobarbituric acid reactive substances). Results were statistically analyzed using the SAS System for Windows. Results of experiment 1 indicate that, similar to the egg yolk, all types of lecithin used in the 0.01% concentration, were able to maintain sperm motility around 50% for 72 h. After 96 h, the extender containing the lecithin Solec F showed better results regarding mitochondrial activity when compared to the egg yolk. Furthermore, after 120 h, the same extender with the 0.01% concentration, showed higher motility when compared to the egg yolk (30.00 ± 10.69 and 8.33 ± 1.84%, respectively). On the other hand, for the cryopreserved samples (Experiment 2), lower concentrations of lecithin showed similar results for mitochondrial activity and motility when compared to the egg yolk. Results found in the present study indicate that soy lecithin may be a good alternative to substitute the egg yolk for both refrigeration and cryopreservation of dog semen.
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Mello, Érica Santos [UNESP]. "Variação dos níveis de energia na dieta com goma de soja para poedeiras comerciais, desempenho e digestibilidade." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/150426.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
O experimento foi conduzido na Universidade Estadual Paulista – UNESP, Faculdade de Engenharia de Ilha Solteira no Setor de Avicultura, com a finalidade de avaliar o efeito da valorização energética da goma de soja na dieta de poedeiras comerciais e verificar a viabilidade econômica de sua utilização como um produto comercial derivado da soja. Foram utilizadas 240 poedeiras da linhagem Lohmann LSL, com 49 semanas, durante um período de 112 dias (quatro ciclo de 28 dias) distribuídas em um delineamento inteiramente casualizado em um esquema fatorial (4x2) sendo esses: quatro níveis de energia metabolizável (2.610, 2.690, 2.770 e 2850 kcal/kg de ração) x dois níveis de inclusão de goma na dieta (0 e 2%), com cinco repetições de seis poedeiras cada. A goma de soja aumentou o consumo de ração, auxiliou no aumento do peso do ovo, da massa do ovo e do tamanho da gema do ovo, melhorou a digestibilidade do Extrato etéreo e da energia da ração. O índice Economic Feed Efficiency apontou melhor retorno econômico com o tratamento de menor nível de energia (2610 kcal/kg) independente da inclusão da goma.
The experiment was carried out in the Universidade Estadual Paulista - UNESP, Faculty of Engineering of Ilha Solteira in the Poultry Sector, with the purpose of evaluating or energetic valorization of soybean gum in the diet of commercial laying hens and verify the economic viability of its use as a Commercial product derived from soybeans. A total of 240 laying hens of the Lohmann LSL line were used during a period of 112 days (four cycles of 28 days) distributed in a completely randomized design (DIC) in a factorial scheme (4X2). Gum in the diet (0 and 2%) X four levels of metabolizable energy (2,610, 2,690, 2,770 and 2850 kcal / kg of feed), with five replicates of six layers each. Soybean gum increased feed intake, increased weight of weight, egg yolk size, improved digestibility of stress and energy, EMA and AMEn. The EFE index indicated as the best economic return no treatment of lower energy level (2610 kcal / kg) regardless of the inclusion of the gum.
FAPESP: 2016/03607-1
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Mello, Érica Santos. "Variação dos níveis de energia na dieta com goma de soja para poedeiras comerciais, desempenho e digestibilidade /." Ilha Solteira, 2017. http://hdl.handle.net/11449/150426.
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Orientador: Antonio Carlos de LaurentizResumo: O experimento foi conduzido na Universidade Estadual Paulista – UNESP, Faculdade de Engenharia de Ilha Solteira no Setor de Avicultura, com a finalidade de avaliar o efeito da valorização energética da goma de soja na dieta de poedeiras comerciais e verificar a viabilidade econômica de sua utilização como um produto comercial derivado da soja. Foram utilizadas 240 poedeiras da linhagem Lohmann LSL, com 49 semanas, durante um período de 112 dias (quatro ciclo de 28 dias) distribuídas em um delineamento inteiramente casualizado em um esquema fatorial (4x2) sendo esses: quatro níveis de energia metabolizável (2.610, 2.690, 2.770 e 2850 kcal/kg de ração) x dois níveis de inclusão de goma na dieta (0 e 2%), com cinco repetições de seis poedeiras cada. A goma de soja aumentou o consumo de ração, auxiliou no aumento do peso do ovo, da massa do ovo e do tamanho da gema do ovo, melhorou a digestibilidade do Extrato etéreo e da energia da ração. O índice Economic Feed Efficiency apontou melhor retorno econômico com o tratamento de menor nível de energia (2610 kcal/kg) independente da inclusão da goma.
Mestre
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Cavaco, Carolina Cavaco M. Carolina. "Structural and dynamic properties of giant polymer-like lecithin reverse micelles /." [S.l.] : [s.n.], 1994. http://e-collection.ethbib.ethz.ch/show?type=diss&nr=10897.
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Svensson, Dag. "Creating High Fat Emulsions with Mango, Rapeseed Oil and Soy Lecithin." Thesis, Linnéuniversitetet, Institutionen för naturvetenskap, NV, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-24084.
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Food inevitably plays a vital role in our lives and is of great importance to our health and wellbeing. With increasing age, it is equally important to achieve adequate nutrition to prevent and alleviate age-related diseases. One problem is that far too many older adults find it difficult to eat enough nutritious food which in the long term may lead to malnutrition. With an increasing life expectancy the older population is growing and the problem with malnutrition is of great concern. Malnutrition can be caused by many different factors which make it difficult to find a single unique solution to the problem. Oral nutritional supplementation is one approach which has proved to be useful for improving the nutritional intake. This paper examines the possibility of creating high fat fruit emulsion with mango puré, rapeseed oil and lecithin, using simple blending equipment. The puré-like products were evaluated for emulsion stability by a storage test, oil droplet size by a light microscope and light scattering device, viscosity by a viscometer, sensory properties by Flavoring profiling. Furthermore the nutritional values were calculated. Successful emulsions were created using up to 50 g/100g rapeseed oil with adequate emulsion stability without lecithin. The energy content of the highest fat emulsion was 475kcal/100g. The quantities of lecithin used in these products reduced the oil droplet size but lowered the emulsion stability perhaps by depleting the stabilizing effect of mango originated particles. The lecithin made the product more viscous, also the oily and creamy/Rich mouth-feel were perceived higher with increasing lecithin. In these products and with the quantities used the lecithin was redundant. Further development of similar products but with addition of protein and perhaps sugar, to enhance flavor, should be of high interest.
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Kotzian, Roland. "Removal of metal ions from aqueous solutions using lecithin enhanced ultrafiltration." Thesis, Loughborough University, 1998. https://dspace.lboro.ac.uk/2134/15378.
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This work is concerned with an alternative method for metal ion removal from aqueous solutions - surfactant enhanced ultrafiltration. Surfactant monomers aggregate above a certain concentration, specific to the surfactant, to form micelles. Anionic surfactant micelles will attract and bind metal cations. Free metal ions and surfactant monomers pass freely through an ultrafiltration membrane, but if the micelle-metal ion complex is sufficiently large it is rejected. Research reported in this thesis has been carried out on well defined aqueous solutions containing only one type of metal ion together with the natural surfactant lecithin. Lecithin is a food grade by-product of the soybean processing industry and it was chosen because it is non-toxic, biodegradable, abundant and inexpensive. It has a high molecular weight of about 750 Daltons and forms large size micelles. The main aim was to identify the basic mechanisms which influence the permeate flux and rejection levels of the process. The project was carried out in three stages. Stage one was the characterisation of the feed solution which included the determination of the critical micelle concentration using surface tension measurements, measurement of micelle size and zeta potential using a Malvern zeta sizer and visualisation of the micelle shape using scanning electron microscopy of freeze fractured lecithin solution droplet. In the second stage filtration experiments were carried out at a wide range of lecithin concentrations, metal ion concentrations and operating conditions. The experiments were run for 5 hours, by which stage a steady state condition was reached in all cases. Permeate samples were taken after I, 3 and 5 hours. Permeate flux was monitored throughout the experiment. The following properties were monitored for the feed solution at the beginning and the end of each experiment and for all permeate samples: lecithin concentration, copper concentration, pH, conductivity. In the 3 stage Electron Dispersive Analysis by X-ray (EDAX), Scanning Electron Microscopy (SEM) and a X-ray Photoelectron Spectrum Technique (XPS) were employed to investigate any membrane feed solution interactions. The results of the 3 stages were used to identify the basic mechanisms which control the permeate flux levels and the extent of component rejection in lecithin enhanced ultrafiltration.
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Yip, Shiu Hang. "Supercritical Fluid Extraction and Chromatography of Various Lipids from Soybean Lecithin." Thesis, Virginia Tech, 2007. http://hdl.handle.net/10919/35349.
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Phospholipids are commonly found in biological membranes. They have a polar head group and two ester linked fatty acids tails. Different methods such as thin layer chromatography and high performance liquid chromatography coupled with ultraviolet, refractive index, flame ionization detector, and mass spectrometry (MS) detection have long been used in the study of phospholipids. These methods were time-consuming and lacked quantitative accuracy. In this work, phosphatidylcholine, phosphatidyl-ethanolamine, phosphatidylinositol and phosphatidylserine have been studied by supercritical fluid chromatography (SFC) coupled with evaporative light scattering detection (ELSD) and mass spectrometry (MS). Four different silica-based stationary phases were studied: 2-ethylpyridine, 4-ethylpyridine, diol and conventional cyanopropyl. The influence of different mobile phase additives on the elution of phospholipids has been studied. The results have shown that isopropylamine is a better additive compared with ammonium acetate, tetrabutyl-ammonium acetate, and trifluoroacetic acid for the elution of phospholipids. All phospholipids have been eluted with baseline separation in less than 15 minutes although there is some partial overlap on the pyridine columns. The second goal for this work was fractionation of phospholipids from lecithin (a by-product from soybean) by using supercritical fluid extraction (SFE) with methanol-modified CO2. Neutral lipids were first removed from the crude sample using pure CO2. Partrial fractionation of PE and nearly pure fractionated PC were obtained by varying the modifier concentration in the extraction fluid at 460 atm and 40oC with silica gel inside the extraction vessel. A total of six components were isolated from crude soybean lecithin.Master of Science
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Corswant, Christian von. "Lecithin-based microemulsions for pharmaceutical use phase behavior and solution structure /." Lund : Lund University, 1998. http://catalog.hathitrust.org/api/volumes/oclc/68945035.html.
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Sperber, Galia. "Attempts to generate atheroprotective lecithin-cholesterol acyltransferase (LCAT) phenotypes by chimeraplasty." Thesis, University College London (University of London), 2006. http://discovery.ucl.ac.uk/1446120/.
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Lecithin-cholesterol acyltransferase (LCAT) is a high-density lipoprotein (HDL)-associated enzyme, which is secreted mainly by the liver. By esterifying cholesterol in the surface of immature HDL, LCAT drives reverse cholesterol transport, an important process in preventing atherosclerosis. Specific point mutations in the LCAT gene, producing serine to alanine amino acid substitutions at positions 208 or 216, are reported to increase enzymatic activity up to 14 times. Here, I attempt to create these mutations using a new technology, termed chimeraplasty targeted gene repair in situ using synthetic RNA-DNA oligonucleotides (chimeraplasts). First, I demonstrated that the Ser208Ala and Ser216Ala mutations do increase LCAT specific activity by comparing recombinant Ghinese hamster ovary (CHO) cells secreting wild-type LCAT (CHO-LCAT), LCATser2i6Aia, or LCATser208Aia+ser2i6Aia. I then targeted CHO-LCAT cells, and a human hepatoma cell line (HepG2), in vitro with chimeraplasts directed at the Ser208 and Ser216 sites. However, I was unable to create the required mymidine to guanine nucleotide substitution required using standard procedures, even by varying transfection conditions, repeat targeting, or altering chimeraplast design. I studied, therefore, chimeraplast uptake into the nucleus with various polyethylemmine (PEI)-based transfection reagents by using fluorescently-labelled oligonucleotides and a validated chimeraplast, able to mutate the apolipoprotein E (APOE) gene. I found that melittin-PEI, transferrin-PEI and galactose4-PEI were superior to linear PEI, but targeting the LCAT gene with these optimal reagents failed to produce either Ser208Ala or Ser216Ala mutations. Moreover, co-targeting cells simultaneously with LCAT and apoE chimeraplasts mutated the APOE gene, but not the LCAT gene. Finally, to investigate possible gene position or sequence effects I produced recombinant CHO cells expressing both LCAT and apoE targeting regions adjacent to each other. When these cells were co-targeted the Ser216Ala mutation was successful. I conclude that chimeraplast-directed gene mutation/ repair is a promising technique but further investigation is required to explain inconsistent results when targeting different cell lines.
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Ayres, Benjamin Robert. "Use of Soybean Lecithin in Shape Controlled Synthesis of Gold Nanoparticles." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/628.
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The work presented in this dissertation is a composite of experiments in the growth of gold nanoparticles with specific optical properties of interest. The goal is to synthesize these gold nanoparticles using soybean extract for not only shape control, but for propensity as a biocompatible delivery system. The optical properties of these nanoparticles has found great application in coloring glass during the Roman empire and, over the centuries, has grown into its own research field in applications of nanoparticulate materials. Many of the current functions include use in biological systems as biosensors and therapeutic applications, thus making biocompatibility a necessity. Current use of cetyltrimethylammonium bromide leads to rod-shaped gold nanoparticles, however, the stability of these gold nanoparticles does not endure for extended periods of time in aqueous media. In my research, two important components were found to be necessary for stable, anisotropic growth of gold nanoparticles. In the first experiments, it was found that bromide played a key role in shape control. Bromide exchange on the gold atoms led to specific packing of the growing crystals, allowing for two-dimensional growth of gold nanoparticles. It was also discerned that soybean lecithin contained ligands that blocked specific gold facets leading to prismatic gold nanoparticle growth. These gold nanoprisms give a near infrared plasmon absorption similar to that of rod-shaped gold nanoparticles. These gold nanoprisms are discovered to be extremely stable in aqueous media and remain soluble for extended periods of time, far longer than that of gold nanoparticles grown using cetyltrimethylammonium bromide. Since soy lecithin has a plethora of compounds present, it became necessary to discover which compound was responsible for the shape control of the gold nanoprisms in order to optimize the synthesis and allow for a maximum yield of the gold nanoprisms. Many of these components were identified by high performance liquid chromatography and liquid chromatography-mass spectrometry. However, re-spike of these components into growth solutions did not enhance the growth of gold nanoprisms. Upon separating the shapes of the gold nanoparticles using gel electrophoresis, addition of KCN to the separated gold nanoparticles allowed us to extract the culpable ligands for shape control. Analysis of these ligands by mass spectrometry elucidated the identity of PA and upon re-spike of the PA into a growth solution of PC95, the growth of a near-infrared plasmon absorption was seen. The stability of these gold nanoparticles was tested with and without the addition of decane thiol and it was concluded that addition of the thiol allowed for improved stability of the gold nanoparticles towards cyanide. It was determined that at a concentration of 2 μM decanethiol, spherical gold nanoparticles remained stable to cyanide at the expense of the prismatic gold nanoparticles. However, at 5 μM decanethiol, both spherical and prismatic gold nanoparticles retained stability to cyanide in aqueous conditions.
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Ivana, Lončarević. "Uticaj lecitina različitog porekla na kristalizaciona svojstva masne faze i kvalitet mazivog krem proizvoda sa dodatkom funkcionalnih biljnih ulja." Phd thesis, Univerzitet u Novom Sadu, Tehnološki fakultet Novi Sad, 2013. https://www.cris.uns.ac.rs/record.jsf?recordId=85309&source=NDLTD&language=en.
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Konditorska industrija Srbije za proizvodnju mazivog krem proizvoda isključivo koristi sojin lecitin. Veliki obim proizvodnje ulja iz semena suncokreta i uljane repice u Srbiji uticao je na proizvodnju suncokretovog i repičinog lecitina, kao nusproizvoda postupka degumiranja u fazi rafinacije ovih ulja.Masna faza mazivog krem proizvoda sadrži biljne masti dobijene metodama hidrogenacije, koje kao nusprodukte imaju visok udeo nepoželjnih trans-masnih kiselina. U cilju poboljšanja mazivosti ovog proizvoda dodaje se i rafinisano suncokretovo ulje, koje sadrži veliki udeo linolne esencijalne masne kiseline, kao i α-tokoferol (E vitamin), ima prosečan sadržaj sterola, nizak sadržaj skvalena i karotenoida, ali gotovo da ne sadrži esencijalnu α-linolensku masnu kiselinu i antioksidante δ- i γ-tokoferol.U prvoj fazi doktorske teze ispitana je mogudnost zamene sojinog lecitina u proizvodnji mazivog kakao-krem proizvoda sa suncokretovim i repičinim lecitinom u smislu optimizacije koncentracije dodatog lecitina i vremena mlevenja u laboratorijskom kugličnom mlinu. U drugoj fazi ispitana je mogudnost poboljšanja nutritivne vrednosti mazivog kakao-krem proizvoda zamenom dela i celokupne količine suncokretovog ulja funkcionalnim uljima iz semena soje, uljane repice i susama.Gasnom hromatografijom ispitan je sastav masnih kiselina u masti, biljnim uljima i lecitinima različitog porekla, gde je u lecitinima određen i sastav fosfolipida primenom kvantitativne fosforne nuklearno-magnetno-rezonantne tehnike. Kristalizacione osobine masne faze mazivog kakao-krem proizvoda ispitane su pulsnom nuklearno-magnetnom-rezonantnom spektroskopijom, dok je kinetika kristalizacije definisana primenom Gompertz-ovog matematičkog modela.Reološke karakteristike mazivog kakao-krem proizvoda ispitane su rotacionom viskozimetrijom, određene su teksturalne karakteristike proizvoda na teksturometru i toplotne osobine primenom diferencijalne skenirajude kalorimetrije. Boja proizvoda definisana je tristimulusnom kolorimetrijom, a senzorna analiza određena je metodom skale u vremenskom intervalu od šest meseci čuvanja uzorka na tamnom mestu i sobnoj temperaturi. Ispitivanje održivosti mazivog kakao-krem proizvoda obuhvatilo je određivanje nastalih aldehida, kao proizvoda oksidacije lipida, gasnom hromatografijom.Soy lecithin is widely used emulsifier in confectionery industry of Serbia. On the other hand, there is a large production of sunflower and rapeseed oil, which contributed the production of sunflower and rapeseed lecithin as a by-product of degumming of crude oil during refining process. Another issue is a high level of undesirable trans-fatty acids in hydrogenated vegetable fats that are being used in the production of cream spread. Beside hidrogenated fats, cream product contains sunflower oil with essential fatty acids (oleic and linoleic) and α-tocopherol (E vitamin), has an average content of sterols, squalene and a low content of carotenoids, but almost does not contain the essential α-linolenic acid and antioxidants, δ-and γ-tocopherol.The first phase of this work investigatesthe possibility of soy lecithin replacement in cocoa spread cream production with sunflower and rapeseed lecithin, in terms of optimizing the amount of lecithin and milling time in laboratory ball mill.The second phase investigates nutrition value improvement of cocoa spread cream, with partly or completely replacing sunflower oil with functional soybean, rapeseed and sesame oil.Gas chromatography was used in order to examine the fatty acid composition in edible non trans-fat and vegetable oils, as well as in lecithin from different sources. Phospholipid composition in soy, sunflower and rapeseed lecithin was determined using quantitative phosphorus nuclear magnetic resonance technique. Crystallization properties of fat phase of cocoa spread cream were examined by pulsed nuclear magnetic resonance spectroscopy, while crystallization kinetics was defined using the Gompertz's mathematical model.Rheological properties of cocoa spread cream were analyzed by rotational viscosity, certain textural characteristics were determined using texture analyser and also thermal properties using differential scanning calorimetry. The color on the surface of cocoa spread cream was defined using tristimulus colorimetric method, and sensory analysis was determined by the scale over a period of six months of storage in the dark and room temperature. Shelf-life of cocoa spread cream was determined applying gas chromatographic analyses of the formed aldehydes as secondary products of lipid oxidation.
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Vargová, Alžběta. "Pokročilé membránové systémy." Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2017. http://www.nusl.cz/ntk/nusl-316229.
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The diploma thesis deals with cellular membrane model preparation on microfluidic devices. It summarizes means of microfluidic device fabrication, phospholipid bilayer formation mechanisms, optimization techniques and characterization methods of those systems. It focuses on free-standing planar lipid bilayers which are easily accessible by a number of different characterization methods and at the same time exhibit good stability and variability. The aim of this work is to design and prepare a microfluidic chip on which a planar lipid bilayer can be prepared. It therefore presents microfluidic device prepared by soft lithography of PDMS adapted for model membrane formation by self-assembly of phospholipids at the interface of aqueous and organic phases created by the architecture of the microfluidic device. Formation of the model membrane was visualized by optical microscopy and fluorescence-lifetime imaging microscopy.
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Yao, Zemin. "Isolation of rat liver CTP: phosphocholine cytidylyltransferase and regulation of hepatic phosphatidylcholine biosynthesis." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25073.
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Two kinds of affinity chromatography, CDP-choline- and CTP-Sepharose 4B, were investigated for purification of the cytosolic CTP:phosphocholine cytidylyltransferase from rat liver. The enzyme did not show strong affinity for the CDP-choline Sepharose resin, but bound to the CTP-Sepharose column in the presence of 14 mM magnesium acetate. The combination of CTP affinity chromatography
with ion-exchange techniques provided about 70-fold purification of the cytosolic enzyme with a specific activity of about 90 units per milligram protein.
The influence of diphenylsulfone compounds on the synthesis
of phosphatidylcholine by the CDP-choline pathway was examined in
isolated rat hepatocytes and HeLa cells. The administration of
the sulfones (100 ug/ml), except dapsone, to HeLa cells inhibited
the total [methyl-³H]choline incorporation into the cells, but did not change the rate of conversion of choline to phosphatidylcholine.
The addition of the sulfones (100 ug/ml) to rat hepatocytes
did not inhibit the biosynthesis of phosphatidylcholine and choline metabolism.
The effect of vasopressin on the distribution of cytidylyl-transferase between cytosol and microsomes in rat hepatocytes was also investigated. The digitonin-mediated release of cytosolic cytidylyltransferase was reduced from the cells treated with vasopressin (5-20 nM) , while the enhanced rate of incorporation of [methyl-³H]choline into phosphatidylcholine was not observed.Medicine, Faculty of
Biochemistry and Molecular Biology, Department of
Graduate
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Basso, Rodrigo Corrêa 1978. "Estudo do processo de limpeza de membrana ceramica e obtenção de lecitina de soja por ultrafiltração seguida de diafiltração." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/254791.
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Orientador: Luiz Antonio ViottoDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Tendo como objetivo avaliar o processo de limpeza de uma membrana cerâmica de diâmetro de poro de 0,01mm, foram realizadas oito corridas de ultrafiltração com uma miscela de óleo bruto de soja e hexano de composição constante, sempre nas mesmas condições operacionais: temperatura de 40°C, pressão transmembrana de 1,0bar e velocidade tangencial de escoamento de 3,4m/s. Após cada uma das ultrafiltrações, foi avaliada a influência dos parâmetros pressão transmembrana, velocidade tangencial de escoamento e abertura da válvula de permeado no processo de limpeza, feito apenas pela recirculação de hexano. Foi testada a associação de quatro diferentes condições de limpeza: baixa pressão transmembrana (0,5bar) e elevada velocidade tangencial de escoamento (5,0m/s); elevada pressão transmembrana (2,0bar) e baixa velocidade tangencial de escoamento (1,0m/s); pressão transmembrana e velocidade tangecial de escoamento intermediárias, 1,0bar e 3,4m/s, respectivamente; baixa pressão transmembrana (0,5bar) e elevada velocidade tangencial de escoamento (5,0m/s), mantendo sempre a válvula de permeado aberta. A melhor condição de limpeza obtida foi a associação de baixa pressão transmembrana e elevada velocidade tangencial de escoamento que conseguiu recuperar o fluxo da membrana em aproximadamente 85 minutos. Foram calculadas as resistências intrínseca da mebrana, da camada gel polarizada e do ¿fouling¿, e foi constatado que na limpeza a própria membrana exerce a maior resistência ao fluxo de permeado, seguida pela do ¿fouling¿ e pela da camada gel polarizada. Foram ainda explorados os processos de concentração e diafiltração, realizados em membrana cerâmica de 0,01mm, na obtenção e purificação da lecitina de soja a partir dos retentados resultantes dos processos de ultrafiltração da miscela de óleo bruto de soja e hexano. O retentado foi concentrado até um fator de concentração de 9,6 e diafiltrado, utilizando dois e quatro ciclos. A lecitina obtida teve um teor de insolúveis em acetona, respectivamente para dois e quatro ciclos de diafiltração, de 69,7 e 90,7%
Abstract: One of the objectives of this work was to study the cleaning process of a 0.01mm pore size ceramic membrane. The operational conditions used at eigth ultrafiltration process realized were 40°C of temperature and 1.0bar and 3.4m/s of transmembrane pressure and cross flow velocity. After each ultrafiltration it have been studied the influence of transmembrane pressure, tangential flow velocity and permeate valve position on the membrane cleaning process realized by pure hexane recirculation. Four different cleaning associated conditions were tested: low transmembrane pressure (0.5bar) and high cross flow velocity (5.0m/s); high transmembrane pressure (2.0bar) and low cross flow velocity (1.0m/s); intermediate transmembrane pressure and cross flow velocity, 1.0bar 3.4m/s; low transmembrane pressure (0.5bar) and high tangential flow velocity (5.0m/s) keeping permeate valve opened. The best condition evaluated to membrane cleaning process was the application of high cross flow velocity and low transmembrane pressure that have been recovered the original flux, took with pure hexane, in 85 minutes. The intrinsic membrane resistance, fouling resistance and polarized gel layer resistance were calculated and was concluded that the major resistance to permeate flux was the intrinsic membrane resistance followed by fouling resistance and polarized gel layer resistance. Concentration and diafiltration process in 0.01mm pore size ceramic membrane have been studied in extraction and purification of soybean lecithin from ultrafiltrations retentate. The retentate had concentrated until a concentration factor of 3 and diafiltrated using two and four cicles. The soybean lecithin purified using two and four diafiltrations cicles result in an acetone insoluble matter of 69.7 and 90.7% respectively
Mestrado
Mestre em Engenharia de Alimentos
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Santos, KÃssia Moreira. "Sebo bovino e emulsificante na dieta de suÃnos em crescimento e terminaÃÃo." Universidade Federal do CearÃ, 2014. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13245.
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CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel SuperiorForam realizados dois ensaios para determinar a composiÃÃo quÃmica e a energia metabolizÃvel do sebo bovino e para avaliar este ingrediente como fonte lipÃdica alternativa em raÃÃes para suÃnos nas fases de crescimento e terminaÃÃo com ou sem a adiÃÃo de emulsificante, sobre o desempenho, digestibilidade dos nutrientes das raÃÃes, triacilglicerÃis sÃricos, caracterÃsticas de carcaÃa e avaliaÃÃo econÃmica. Para o ensaio de metabolismo foram utilizados 15 suÃnos machos castrados de peso inicial de 22,03Â0,62 kg que foram distribuÃdos em delineamento inteiramente ao acaso, pelo mÃtodo de coleta total de fezes e urina. Os tratamentos foram: RR â raÃÃo referÃncia, formulada a base de milho e farelo de soja; RT1 â raÃÃo teste composta por 95% da raÃÃo referÃncia e 5% de sebo bovino e RT2 â raÃÃo teste composta de 90% de raÃÃo referÃncia e 10% de sebo bovino. O sebo bovino apresentou 99,94% de matÃria seca e 7130,97 kcal de energia metabolizÃvel (EM)/kg. Para o ensaio de desempenho foram utilizados 30 suÃnos machos castrados com peso inicial de 24,85Â1,18 kg, distribuÃdos no delineamento em blocos ao acaso, com cinco tratamentos e seis repetiÃÃes de um animal. Os tratamentos diferiram quanto à fonte lipÃdica incluÃda, nÃvel de EM e adiÃÃo do emulsificante, sendo: T1 â dieta com inclusÃo de Ãleo de soja e 3230 kcal de EM/kg; T2 â dieta com inclusÃo de sebo bovino e 3230 kcal de EM/kg; T3 â dieta com inclusÃo de sebo bovino e 3080 kcal de EM/kg; T4 â dieta com inclusÃo de sebo bovino, 3080 kcal de EM/kg e adiÃÃo de 0,1% emulsificante; T5 â dieta com inclusÃo de sebo bovino, 2930 kcal de EM/kg e adiÃÃo de 0,1% de emulsificante. NÃo houve efeito dos tratamentos sobre as variÃveis de consumo de raÃÃo e ganho diÃrio de peso em todas as fases avaliadas. Entretanto, observou-se que houve diferenÃa significativa para a conversÃo alimentar no crescimento II e na terminaÃÃo, onde os animais alimentados com a raÃÃo contendo sebo bovino e reduÃÃo na energia para 3080 kcal/kg (T3) e para 2930 kcal/kg com adiÃÃo de emulsificante (T5) apresentaram pior conversÃo alimentar. NÃo houve diferenÃa significativa (P>0,05) para os nÃveis de triacilglicerÃis no sangue e para as caracterÃsticas de carcaÃas (peso, rendimento e comprimento de carcaÃa, quantidade e percentual de carne magra, espessura de toicinho, profundidades de lombo e de gordura, Ãreas do olho de lombo e da gordura e relaÃÃo gordura carne). Dependendo do valor energÃtico, o sebo bovino pode substituir o Ãleo de soja como fonte lipÃdica em raÃÃes para suÃnos nas fases de crescimento e terminaÃÃo. A reduÃÃo em 150 kcal de EM/kg da raÃÃo com uso de sebo bovino pode ser compensada com a adiÃÃo de emulsificante.
This study aimed to determine the chemical and metabolizable energy of beef tallow and evaluate this feedstuff as an alternative lipid source in diets for growing and finishing pigs with or without emulsifier addition, on performance, digestibility of the nutrients, serum triacylglycerols, carcass characteristics and economic evaluation. For the metabolism assay a total of 15 barrows were used with an initial weight of 22.03 Â 0.62 kg and distributed in a completely randomized design, using the total of feces and urine method. The treatments were: RR - basal diet, formulated based on corn and soybean meal; RT1 - ration test comprised 95% of basal diet and 5% beef tallow and RT2 - test diet composed of 90% of basal diet and 10% beef tallow. The beef tallow showed 99.94% of dry matter and 7130.97 kcal of metabolizable energy (ME)/kg. To test the performance, a total of 30 barrows with an initial weight of 24.85 Â 1.18 kg were distributed in a randomized block design with five treatments and six repetitions of an animal. The treatments differed in fat source included, level of ME and addition of emulsifier, as much: T1 - diet with soybean oil and 3230 kcal ME/kg; T2 - diet with beef tallow and 3230 kcal ME/kg; T3 - diet with beef tallow and 3080 kcal ME/kg; T4 - diet with beef tallow, 3080 kcal ME/kg and addition of 0.1% of emulsifier; T5 - diet with beef tallow, 2930 kcal ME/kg and addition of 0.1% of emulsifier. It was not observed effects on variables of feed intake and average daily gain in all phases. However, it was observed that there was a significant difference in feed conversion in growing II and finishing phase; animals fed the diet containing beef tallow and reduction in energy to 3080 kcal ME/kg (T3) and 2930 kcal ME/kg with emulsifier (T5) presented worse feed conversion. There was no significant difference (P>0.05) among levels of triglycerides in the blood and carcass characteristics (weight, yield and carcass length, amount and percentage of lean meat, backfat thickness, loin depth and fat depth, loin eye area and fat area and meat/fat ratio). Depending on the energy level, beef tallow can replace soybean oil as a lipid source in diets for pigs during the growing and finishing phases. The reduction of metabolizable energy at 150 kcal/kg with the use of beef tallow can to be compensated with the addition of emulsifier.
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Hammes, Martim Victor. "Estudo da influência da adição de lecitina de soja na molhabilidade do leite de búfala em pó obtido por spray-drying." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/96508.
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Existe atualmente uma crescente produção de leite de búfala no Brasil e no mundo, sendo que 13% do leite mundial é produzido por esta espécie, perdendo somente para a produção do leite bovino. Esse crescimento deve-se às características peculiares do leite desta espécie em comparação ao bovino, incluindo teores mais elevados de vitamina C, minerais (como cálcio e fósforo), gordura e proteína. Uma alternativa para dar maior rentabilidade econômica ao leite consiste na transformação do produto para a forma de pó de fácil reconstituição (instantâneo) através de um processo de secagem. Como a reconstituição de um alimento em pó depende significativamente das suas características de molhabilidade, é comum a utilização de processos como aglomeração e lecitinação para melhorar a molhabilidade do leite em pó. Neste contexto, o objetivo deste estudo consiste em investigar a influência da adição de lecitina, antes da secagem por atomização, na molhabilidade do leite de búfala em pó. Com esta finalidade, o leite de búfala in natura foi semidesnatado, pasteurizado, concentrado a 40% (percentual mássico) de sólidos totais e seco por pulverização. Nos produtos preparados com lecitina, este aditivo foi utilizado em proporções de 0,3, 0,5 e 1,0 g de lecitina/100 g de sólidos totais no leite concentrado, previamente ao processo de secagem por atomização. Nestas condições, o efeito da concentração de lecitina na molhabilidade do leite em pó produzido foi avaliado através da técnica de Washburn e do teste de molhamento estático. Ainda, o material seco foi avaliado quanto ao teor de umidade, distribuição de tamanho de partículas e, para amostras específicas, quanto à área superficial, atividade de água, cor e morfologia das partículas (via microscopia eletrônica de varredura). Foi observado que a adição de lecitina diminuiu o tempo de molhamento (valores compreendidos entre 63,9 e 188,4 s) quando comparado ao leite in natura (300,9 s). O ângulo de contato das amostras de leite em pó obtidas em níveis superiores a 0,3% de lecitina adicionada diminuiu significativamente, para valores compreendidos entre 82,73 ± 2,76° e 81,21 ± 2,23°, com relação ao valor obtido sem adição do aditivo (89,01 ± 0,48°). Entretanto, a presença de lecitina não apresentou considerável influência na umidade, atividade de água, cor, morfologia, área superficial e na distribuição de tamanho das partículas obtidas.There is nowadays a growing production of buffalo milk in Brazil and in the world. It already represents 13% of total world milk production, being second only to the production of bovine milk. This growth is due to the peculiar characteristics of this kind of milk compared to cow milk, such as higher content of vitamin C, minerals (such as calcium and phosphorous), fat and protein. An alternative to provide greater economic return from milk consists in converting the product to powder for easy reconstitution (i.e. instant food) through a drying process. As the reconstitution of a powdered food depends strongly on its characteristics of wettability, the utilization of alternatives such as agglomeration and addition of lecithin are commonly used to improve the wettability of the final product. In this context, the aim of this study is to investigate the influence of the addition of lecithin, previously to the spray drying on the wettability of buffalo milk powder. For such purpose, the fresh buffalo milk was partially-skimmed, pasteurized, concentrated to 40% (mass percent) of total solids and spray-dried. Four milk powders were produced, one without addition of lecithin and three with different contents of lecithin (0.3, 0.5 and 1.0 g of lecithin/100 g of total solids). The effect of the concentration of lecithin on the wettability of the powder produced was measured by the Washburn technique and static wetting test. Further, the dried material was analyzed for moisture content, particle size distribution, and for specific samples, for surface area, water activity, color and particle morphology (scanning electron microscopy). It was observed that the addition of lecithin decreased the wetting time (values comprised between 63.9 and 188.4 s) when compared to lecithin-free milk (300.9 s). The contact angle of the milk powder samples obtained with levels greater than 0.3% of added lecithin significantly decreased to values between 82.73 ± 2.76° and 81.21 ± 2.23°, with respect to the value obtained without addition of the additive (89.1°). However, the presence of lecithin showed no significant influence on the moisture content, water activity, color, morphology, surface area and particle size distribution of the produced powders.
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Rostichelli, Luiz Gustavo Nascimento. "Valorização e associação das matrizes nutricionais da enzima fitase e emulsificante para frangos de corte /." Ilha Solteira, 2018. http://hdl.handle.net/11449/183135.
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Orientador: Antonio Carlos de LaurentizResumo: Um experimento foi realizado na UNESP – Faculdade de Engenharia – Campus de Ilha Solteira Setor de Avicultura, tendo como objetivo avaliar a matriz nutricional, preconizada pela literatura, da enzima fitase e da goma de soja, isoladas e associadas em dietas para frangos de corte nas fases inicial, crescimento e final, avaliando características de desempenho zootécnico ( consumo de ração, ganho de peso e conversão alimentar) nas fases de 7 a 21, 22 a 35, 36 a 42 e na fase total de 7 a 42 dias de idade, sendo estes dados utilizados para a análise econômica. Foram utilizadas 700 aves da linhagem Coob® (lote sexado – machos), as aves foram distribuídas em um delineamento inteiramente casualizado, contendo 7 tratamentos e 5 repetições de 20 aves. Os dados foram submetidos à análise de variância e quando apresentaram diferenças significativas as médias foram comparadas pelo teste SNK 5% de probabilidade, utilizando o programa estatístico SISVAR 5.1 (2001). A valorização individual da matriz nutricional da enzima fitase e da goma de soja, na formulação de ração para frango de corte é uma alternativa para reduzir custos de produção sem afetar o desempenho zootécnico, entretanto ao associar essas matrizes o efeito acumulativo não ocorre.
Abstract: An experiment was carried out at UNESP - Faculty of Engineering - Campus de Ilha Solteira Poultry Sector, with the objective of evaluating the nutritional matrix, recommended by the literature, of phytase enzyme and soybean gum, isolated and associated in diets for broiler chickens. (feed intake, weight gain and feed conversion) in stages 7 to 21, 22 to 35, 36 to 42 and in the total phase of 7 to 42 days of age , and these data are used for economic analysis. A total of 700 birds of the Coob lineage were used (batch sexed - males), the birds were distributed in a completely randomized design, containing 7 treatments and 5 replicates of 20 birds. The data were submitted to analysis of variance and when significant differences were found the mean values were compared by the SNK 5% probability test, using the statistical program SISVAR 5.1 (2001). The individual valorization of the nutritional matrix of the enzyme phytase and soybean gum in the formulation of ration for broiler chickens is an alternative to reduce production costs without affecting the zootechnical performance, however when associating these matrices the cumulative effect does not occur.
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Holland, Janice Lee. "Lecithin containing diets for the horse: acceptance, digestibility, and effects on behavior." Thesis, Virginia Tech, 1994. http://hdl.handle.net/10919/30978.
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Lecithins may improve the digestibility of high fat diets and the tractability of horses. Experiments were conducted to determine the acceptability, digestibility and effects on behavior of lecithin-containing diets. Seven young horses of light breeds were used for the studies.
The four concentrates consisted of corn, oats, beet pulp, trace mineralized salt, dried sugar cane molasses plus 10% added fat: corn oil (CO);soy lecithin-corn oil (SL\CO); soy lecithin-soybean oil (SL\SO); or soy lecithin-corn oil-soybean oil (SL\CO\SO). Half the ration was provided by chopped hay. The CO concentrate was the most palatable (P=.OOOl). The remaining three concentrates were palatable in the following order: SL\CO, SL\CO\SO, and SL\SO, with SL\CO diet preferred (P=.OOl) to SL\SO.
In the digestibility experiment, a complete mixed diet was fed containing chromic oxide as a marker. The control diet had no added fat: the others contained CO, SL\CO, or SL\SO at 10% by weight. Apparent digestibility was higher in the control diet than in the others for dry matter (P=.OOOl). Apparent digestibilities of crude protein (P=.0002) and acid detergent fiber (P=.08) decreased with any of the three fats. In contrast, apparent digestibility of ether extract was increased (P=.OOOl) in the fat containing diets.
In the activity experiments, horses on the SL\CO diet were less spontaneously active (P=.0125) than horses on the control diet. Horses on the CO and SL \SO diet also had slightly lower activity levels (P=.125). Horses fed the SL\SO diet reacted less (P=.0625) than control horses to the opening umbrella. Horses fed CO and SL\CO diets showed trends towards less reactivity (P=.125 and P=.25, respectively), compared to the control horses.
These studies support the practical feasibility of using lecithins in diets for horses. Especially interesting would be studies of interactivity with trainers and riders.Master of Science
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Cooke, Allison L. B. A. "The Molecular Interaction of Apolipoprotein A-I and Lecithin: Cholesterol Acyl Transferase." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1543580636448357.
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Wilson, Judith A. "Sarcoplasmic reticulum responses to repeated sprints, conditioning and dietary lecithin in the horse." Diss., This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-06062008-163309/.
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Souza, Rosemary Pereira de Pedro [UNESP]. "Goma de soja: uma alternativa de emulsificante para dietas de poedeiras comerciais." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/150207.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O experimento foi conduzido no Setor de Avicultura da Universidade Estadual Paulista – UNESP, Faculdade de Engenharia de Ilha Solteira, com a finalidade de avaliar o efeito da inclusão de níveis crescentes de goma de soja (0, 1, 2, 3, 4 e 5%) na alimentação de poedeiras comercias, e verificar a viabilidade econômica de sua utilização como mais um produto comercial derivado da soja. Foram utilizadas 180 poedeiras comerciais leves da linhagem Lohmann, com 40 semanas de idade, durante o período de 112 dias (quatro ciclos de 28 dias), distribuídas em um delineamento inteiramente casualizado, totalizando 6 tratamentos com 5 repetições (6 aves por parcela). No experimento foram avaliados dados de parâmetros zootécnicos: porcentagem de postura (ave/dia), consumo de ração (g/ave/dia), peso dos ovos (g), conversão alimentar (kg/kg), qualidade interna e externa dos ovos e estabilidade oxidativa dos ovos. No que se refere aos parâmetros de desempenho a inclusão de 5% de goma na dieta aumentou o consumo de ração e a maior produção de ovos foi observada nos tratamentos com a inclusão de 3 e 5% de goma. Quanto ao peso médio dos ovos e massa de ovos a inclusão de goma a partir de 3% favoreceu o aumento dos mesmos. Para os parâmetros de qualidade dos ovos os tratamentos com 4 e 5% de goma foram os que apresentaram os menores valores de unidade Haugh, o aumento da coloração da gema ocorreu a partir da inclusão de 3% de goma. A estabilidade oxidativa dos ovos apresentou diferença (P<0,05) apenas para os ovos provenientes do tratamento com 4% de goma armazenados sob refrigeração por 21 dias. A análise econômica mostrou maior retorno econômico com a inclusão de apenas 1% de goma de soja na dieta.
The experiment was carried in the Poultry Sector of the Universidade Estadual Paulista - UNESP, Ilha Solteira Campus, in order to evaluate the effect of inclusion of increasing levels of soy gum (0, 1, 2, 3, 4 and 5 %) In the feeding of commercial laying hens, and verify the economic viability of this use as another commercial product derived from soybean. The study used 180 Lohmann commercial laying hens with 40 week old Lohmann commercial laying hens during the period of 112 days (four cycles of 28 days), distributed in a completely randomized design, totaling 6 treatments with 5 replicates (6 birds per plot). The evaluated parameters were feed intake (g/bird/day), egg weight (g), feed conversion (kg/kg), internal and external egg quality and oxidative stability of eggs. Regarding the performance parameters, the inclusion of 5% gum in the diet increased the feed intake and, the higher egg production was observed in the treatments with the inclusion of 3 and 5% of soy gum. Regarding the average egg weight and egg mass, the inclusion of soy gum from 3% favored their increase. For egg quality parameters treatments with 4 and 5% of soy gum were the ones with the lowest values of Haugh unit, the increase of the color of the yolk occurred from the inclusion of 3% of gum. The oxidative stability of the eggs presented a difference (P<0.05) only for the eggs from the treatment with 4% of gum stored under refrigeration for 21 days. The economic analysis showed a higher economic return with the inclusion of 1% of soy gum in the diet.
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Souza, Rosemary Pereira de Pedro. "Goma de soja : uma alternativa de emulsificante para dietas de poedeiras comerciais /." Ilha Solteira, 2017. http://hdl.handle.net/11449/150207.
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Orientador: Antonio Carlos de LaurentizResumo: O experimento foi conduzido no Setor de Avicultura da Universidade Estadual Paulista – UNESP, Faculdade de Engenharia de Ilha Solteira, com a finalidade de avaliar o efeito da inclusão de níveis crescentes de goma de soja (0, 1, 2, 3, 4 e 5%) na alimentação de poedeiras comercias, e verificar a viabilidade econômica de sua utilização como mais um produto comercial derivado da soja. Foram utilizadas 180 poedeiras comerciais leves da linhagem Lohmann, com 40 semanas de idade, durante o período de 112 dias (quatro ciclos de 28 dias), distribuídas em um delineamento inteiramente casualizado, totalizando 6 tratamentos com 5 repetições (6 aves por parcela). No experimento foram avaliados dados de parâmetros zootécnicos: porcentagem de postura (ave/dia), consumo de ração (g/ave/dia), peso dos ovos (g), conversão alimentar (kg/kg), qualidade interna e externa dos ovos e estabilidade oxidativa dos ovos. No que se refere aos parâmetros de desempenho a inclusão de 5% de goma na dieta aumentou o consumo de ração e a maior produção de ovos foi observada nos tratamentos com a inclusão de 3 e 5% de goma. Quanto ao peso médio dos ovos e massa de ovos a inclusão de goma a partir de 3% favoreceu o aumento dos mesmos. Para os parâmetros de qualidade dos ovos os tratamentos com 4 e 5% de goma foram os que apresentaram os menores valores de unidade Haugh, o aumento da coloração da gema ocorreu a partir da inclusão de 3% de goma. A estabilidade oxidativa dos ovos apresentou diferença (P<0,05) apen... (Resumo completo, clicar acesso eletrônico abaixo)
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Henley, Cheryl Lynn. "Ã-naphthylisothiocyanate induced cholestasis with secondary lecithin, cholesterol acyltransferase deficiency in C57BL/6 mice." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ36465.pdf.
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Hodgson, Isaac Owusu Afriyie. "Removal of lead, copper and cadmium ions from aqueous streams using lecithin enhanced microfiltration." Thesis, Loughborough University, 2003. https://dspace.lboro.ac.uk/2134/12130.
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The removal of lead, copper and cadmium ions from aqueous streams using lecithin enhanced micro filtration with 0.2μm pore size tubular ceramic membranes has been investigated. Measurements of the surface tension at varying lecithin concentrations were carried out to determine the critical micelle concentration (CMC) of lecithin and the effects of lead ions, mixtures of lead and copper ions, and mixtures of lead, copper and cadmium ions in solutions on the CMC of lecithin. The zeta potential and the effects of the single and multiple metal ions on the zeta potential of lecithin were also investigated. The influence of lecithin concentrations, cross flow velocity and transmembrane pressure on the rejections and steady state permeate flux behaviours were examined. The CMC of lecithin was found to be 9 grl. An increase in metal ion concentration caused a decrease in the CMC and an increase in the zeta potential of lecithin solutions, suggesting the binding of the metal ions onto the lecithin. An increase in lecithin concentration was found to improve metal ions removal. Lecithin showed preference for the metal ions in the order Pb2+ > Cd 2+ > Cu 2+. Metal ion removal was influenced more by lecithin concentration and less by transmembrane pressure and cross flow velocity. The steady state permeate flux and rejection behaviours have been explained by microscopic phenomena and a mathematical model has been developed to predict the steady state permeate flux. The lecithin concentration that remains in the permeate was less than 9% of the feed solution. The study has shown that lecithin enhanced micro filtration is a technically suitable technique for removal of lead, copper and cadmium ions in aqueous solution.
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Bonam, Sindhu Prabha. "Preparation and Evaluation of Pluronic Lecithin Organogel Containing Ricinoleic acid for Transdermal Drug Delivery." University of Toledo Health Science Campus / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=mco1384437353.
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Arnold, Gunther. "Wirkungsbeziehungen von Lecithinen und Phospholipiden in ölbasierten Systemen." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-154174.
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Lecithin wird unter anderem zur Steuerung der rheologischen Eigenschaften von Lebensmittelsuspensionen wie zum Beispiel Schokolade eingesetzt. In erster Linie findet dabei Sojalecithin Verwendung, wogegen die Wirkungen von Lecithinen aus Sonnenblumen oder Raps unzureichend dokumentiert sind. Anhand von Untersuchungen an Modellsuspensionen werden Wirkungsbeziehungen von Lecithin auf mikrostruktureller Ebene beleuchtet, um Ursachen für dessen Funktionalität in ölbasierten Suspensionen abzuleiten. Darüber hinaus erfolgt ein Vergleich der Wirkung von Soja-, Raps- und Sonnenblumenlecithin auf rheologische, sensorische und morphologische Eigenschaften von Schokolade. Rheologische Untersuchungen an Zucker/Öl- und Glaskugel/Öl-Suspensionen verdeutlichen den Einfluss der Suspensionsbestandteile auf die Wirkung von Lecithin in ölbasierten Suspensionen. Sedimentationsanalysen an Zucker/Öl-Suspensionen zeigen, dass die Reduktion der rheologischen Parameter mit der Senkung des Sedimentvolumens und einer verstärkt polydispersen Sedimentation einhergeht. Glaskugel/Öl-Suspensionen bilden im Vergleich zu Zucker/Öl-Suspensionen ein deutlich kompakteres Sediment, was auf geringer ausgeprägte Interaktionen zwischen den Glaspartikeln hindeutet und durch Untersuchungen mittels Rasterkraftmikroskop bestätigt wird. Die Anreicherung des Dispersionsmediums mit Lecithin führt zur Adsorption von grenzflächenaktiven Molekülen an der fest/flüssig-Grenzfläche und reduziert die adhäsiven Kräfte zwischen Zuckeroberflächen. In Zucker/Sojaöl-Suspensionen zeigen die Phospholipide Phosphatidsäure, Phosphatidylcholin und Phosphatidylethanolamin im Vergleich zu Sojalecithin eine geringer ausgeprägte Funktionalität bei kleinen Phospholipidkonzentrationen. Soja-, Raps- und Sonnenblumenlecithine besitzen in dunkler und in milchhaltiger Schokoladenmasse lediglich hinsichtlich ihrer Wirkung auf die Fließgrenze leichte Unterschiede. Die Präparate zeigen keine verallgemeinerbaren Wirkunterschiede auf die Fettkristallmorphologie und die Textur von gelagerter dunkler und milchhaltiger Schokolade. Des Weiteren lassen sensorische Untersuchungen keine signifikant ausgeprägte Präferenz für dunkle oder milchhaltige Schokolade erkennen, wenn die Probe mit Soja-, Raps- oder Sonnenblumenlecithin versetzt wird. Die Ergebnisse zeigen, dass die Reduktion der adhäsiven Kräfte zwischen Zuckerpartikeln eine Ursache für die Senkung der rheologischen Parameter und des Sedimentvolumens von Zucker/Öl-Suspensionen darstellt. Außerdem ist zu erkennen, dass bei geringen Phospholipidkonzentrationen synergetische Effekte zwischen unterschiedlichen grenzflächenaktiven Substanzen zu einem Anstieg der Funktionalität des eingesetzten Präparates führen können. Darüber hinaus ist festzustellen, dass Soja-, Raps- und Sonnenblumenlecithin die rheologischen, sensorischen und morphologischen Eigenschaften von Schokolade in gleichem Maß beeinflussenLecithin is used in the food industry, for example to control the rheological properties of oil-based suspensions, such as chocolate. First and foremost, soybean lecithin is used, whereas the effects of possible alternatives, such as lecithin from sunflower or canola, are still insufficient documented. On the basis of model suspensions the effect of lecithin on the microstructural level will be investigated to derive causes of the functionality of the surfactant in oil-based suspensions. Additionally, a comparison is made regarding the effects of soybean lecithin, canola lecithin and sunflower lecithin on the rheological and morphological properties as well as on sensory characteristics of chocolate. Rheological studies illustrate the influence of the suspension components to the action of lecithin in oil-based suspensions. While, in sugar/oil-suspensions, lecithin reduces apparent viscosity and yield stress, the effect of the surfactant in glass sphere/oil-suspensions depends on the dispersion medium. Sedimentation analyses of sugar/oil-suspensions show that the reduction of the rheological parameters coincides with the reduction of the sediment volume and an increased polydisperse sedimentation. The sediment of glass sphere/oil-suspensions is more compact in comparison to sugar/oil-suspensions, indicating less pronounced interactions between glass spheres. Investigations using atomic force microscopy show the less pronounced interactions between glass spheres. While interactions (adhesive forces) are detectable between sugar surfaces dispersed in oil, no interactions can be determined between glass surfaces. The enrichment of the dispersion medium with lecithin results in the adsorption of the surfactants at the sugar surface and reduces the adhesive forces. In sugar/soybean oil suspensions and at low phospholipid concentrations the results indicate a less pronounced functionality of the individual phospholipids, phosphatidylcholine, phosphatidylethanolamine and phosphatidic acid in comparison to soybean lecithin. In dark chocolate and milk chocolate soybean lecithin, canola lecithin and sunflower lecithin reduces apparent viscosity at low to medium shear rate in the same way. In contrast, small differences in terms of their effect on the yield stress are observed. The lecithins do not show differences regarding their impact on fat crystal morphology and texture of stored dark chocolate and milk chocolate. Furthermore, in sensory studies, no significant preference differences were detectable in case of dark chocolate or milk chocolate containing soybean lecithin, canola lecithin or sunflower lecithin. The results show that the reduction of the adhesive forces between sugar particles causes the reduction of rheological parameters and the sediment volume of sugar/oil-suspensions. Furthermore, at low phospholipid concentrations possible synergistic effects between different surfactants can lead to an increase of the functionality of suractants. Additionally it can be concluded that soybean lecithin, canola lecithin and sunflower lecithin affect the rheological and morphological properties as well as the sensory characteristics of chocolate in equal measure
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Weddle, Carolyn A. "Optimization of HPLC techniques for separation of oxidized phosphatidylcholines." Virtual Press, 2005. http://liblink.bsu.edu/uhtbin/catkey/1319835.
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In cellular studies of patients with lipid related disorders such as mammary cancers, leukemia, and artheroscierosis, separation of molecular species of oxidized phosphatidylcholine (PC) can be an important assistance in research or diagnosis. Goals of this project were to optimize separation of oxidized and unoxidized PC molecular species in a single HPLC chromatogram followed by in line identification of hydroperoxides. Oxidized egg PC's were produced using UV light exposure in air. Separations were performed on an Ultrasphere ODS column and an Asahipak ODPVA column using a Waters 2695 system with photodiode array. The ODPVA column routinely gave 10 times larger plate numbers. Various mobile phase mixtures (methanol, acetonitrile, water) and gradients were tested. The optimum gradient on our system is (1) 5 minutes, 47 % methanol/40 % acetonitrile/13 water in a linear gradient to (2) 17 minutes, 49 % methanol/40 % acetonitrile/11 % water to (3) 18 minutes, 29 % methanol/60 % acetonitrile/11 % water linearly to (4) 50 minutes, 31 % methanol/60 % acetonitrile/9 % water continued isocratically to 110 minutes. Oxidized hydroperoxides were detected by fluorescence using a post column reaction with diphenyl-1 pyrenylphosphine (DPPP). Both iron (III) and pyridine were tested as catalysts for this reaction.Department of Chemistry
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Mantovani, Raphaela de Araujo 1986. "Estabilidade e digestibilidade de emulsões contendo lecitina e proteínas do soro." [s.n.], 2012. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255576.
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Orientadores: Rosiane Lopes da Cunha, Ângelo Luiz Fazani CavallieriDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: As proteínas do soro do leite (WPI) e lecitina de soja são amplamente utilizadas em alimentos devido às suas excelentes propriedades emulsificantes. Este trabalho visou avaliar as propriedades emulsificantes da mistura de WPI e lecitina em diferentes condições de pH e concentração dos ingredientes. A primeira etapa consistiu no estudo das interações entre os emulsificantes em meio aquoso em diferentes razões WPI:lecitina e condições de pH. Os resultados mostraram que na razão 1:1 e em pH abaixo do pI da proteína, no qual os emulsificantes encontravam-se opostamente carregados, foi favorecida a formação de complexos eletrostáticos. Na segunda etapa, emulsões O/A contendo proteínas do soro e/ou lecitina foram avaliadas através da estabilidade à cremeação, microestrutura, distribuição do tamanho de gota, densidade de carga superficial, reologia, eletroforese em gel de poliacrilamida e digestão in vitro, verificando-se a influência do pH e da pressão de homogeneização. As emulsões estabilizadas somente por proteínas apresentaram separação de fases e comportamento não-Newtoniano somente em pH próximo ao pI. As emulsões contendo somente lecitina não separaram de fases e apresentaram comportamento Newtoniano. Os sistemas em pH abaixo do pI, contendo a mistura de emulsificantes apresentaram elevada instabilidade cinética devido à forte interação eletrostática entre os componentes. No entanto, em pH próximo ao pI da prote, a interação foi favorável e levou ao aumento da estabilidade das emulsões e a menores tamanhos de gota, resultando em fluidos pouco viscosos. O aumento da pressão de homogeneização, em emulsões com pH próximo e acima do pI favoreceu a formação de agregados de alta massa molecular, o que não foi observado em pH mais ácido. Também não foi notada a formação de agregados na presença de lecitina em nenhuma das condições de pH. Os ensaios de eletroforese deram indícios de que a interação entre os emulsificantes levou a modificações na estrutura das proteínas e revelaram maior afinidade da lecitina com a ?-lactoalbumina (?-la). Finalmente, na etapa de simulação do processo de digestão as proteínas mostraram-se mais resistentes, uma vez que a presença de lecitina promoveu a liberação do óleo da emulsão logo no início da etapa gástrica. De maneira geral, a utilização das proteínas do soro juntamente com a lecitina como emulsificante levou a resultados satisfatórios pois permitiu o desenvolvimento de sistemas estáveis à cremeação em diferentes valores de pH, inclusive em pH próximo ao pI, e consideravelmente resistentes às condições adversas do trato gastrointestinal
Abstract: Whey proteins (WPI) and soybean lecithin are widely used in food due to its excellent emulsifying properties. This study aimed to evaluate the emulsifying properties of the mixture of whey protein and lecithin at different conditions of pH and concentration of ingredients. Firstly, the interactions between emulsifiers in an aqueous medium at different ratios (WPI:lecithin) and pH conditions were studied. The results showed that at mixing ratio of 1:1 and at pH below the isoelectric point of the protein (pI) in which the emulsifiers were oppositely charged, was favored the formation of electrostatic complexes. Afterwards, O/W emulsions containing WPI and/or lecithin were prepared and the influence of pH and pressure homogenization were studied. Stability, microstructure, droplet size distribution, surface charge density, rheology, electrophoresis in polyacrylamide gel (SDS-PAGE) and digestion in vitro were evaluated. The emulsions stabilized by proteins showed phase separation and non-Newtonian behavior only in pH close to the pI. The emulsions containing only lecithin were stable and showed Newtonian behavior. Systems containing the mixture of emulsifiers at pH below the pI showed high kinetic instability due to the strong electrostatic interactions between the components. However, at pH close to the pI the interaction was favorable and led to an increase of the emulsion stability and to smaller droplet sizes, resulting in lower viscosities. When the pressure homogenization was increased, emulsions at a pH close to and above the pI favored the formation of high molecular weight protein aggregates which was not observed in emulsions at lower pH. In the presence of lecithin, protein aggregates were not formed in any of the pH conditions. The SDS-PAGE analysis showed that the interaction between emulsifiers led to modifications in the structure of proteins and indicated a higher affinity of lecithin to ?-lactalbumin (?-la). Finally, proteins were more resistant to digestion, since the presence of lecithin promoted release of oil emulsion at the beginning of gastric step. In general, the use of whey protein with lecithin as emulsifier led to satisfactory results because it allowed the development of stable emulsions to creaming at different pH values, even at pH close to the pI, and substantially resistant to the adverse conditions of the gastrointestinal tract
Mestrado
Engenharia de Alimentos
Mestre em Engenharia de Alimentos
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Santos, Kássia Moreira. "Sebo bovino e emulsificante na dieta de suínos em crescimento e terminação." reponame:Repositório Institucional da UFC, 2014. http://www.repositorio.ufc.br/handle/riufc/18786.
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SANTOS, Kássia Moreira. Sebo bovino e emulsificante na dieta de suínos em crescimento e terminação. 2014. 43 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Zootecnia, Fortaleza-CE, 2014Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-08-02T13:12:13Z No. of bitstreams: 1 2014_dis_kmsantos.pdf: 490581 bytes, checksum: 564e4ee99c250be2753b821f893f9b95 (MD5)
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This study aimed to determine the chemical and metabolizable energy of beef tallow and evaluate this feedstuff as an alternative lipid source in diets for growing and finishing pigs with or without emulsifier addition, on performance, digestibility of the nutrients, serum triacylglycerols, carcass characteristics and economic evaluation. For the metabolism assay a total of 15 barrows were used with an initial weight of 22.03 ± 0.62 kg and distributed in a completely randomized design, using the total of feces and urine method. The treatments were: RR - basal diet, formulated based on corn and soybean meal; RT1 - ration test comprised 95% of basal diet and 5% beef tallow and RT2 - test diet composed of 90% of basal diet and 10% beef tallow. The beef tallow showed 99.94% of dry matter and 7130.97 kcal of metabolizable energy (ME)/kg. To test the performance, a total of 30 barrows with an initial weight of 24.85 ± 1.18 kg were distributed in a randomized block design with five treatments and six repetitions of an animal. The treatments differed in fat source included, level of ME and addition of emulsifier, as much: T1 - diet with soybean oil and 3230 kcal ME/kg; T2 - diet with beef tallow and 3230 kcal ME/kg; T3 - diet with beef tallow and 3080 kcal ME/kg; T4 - diet with beef tallow, 3080 kcal ME/kg and addition of 0.1% of emulsifier; T5 - diet with beef tallow, 2930 kcal ME/kg and addition of 0.1% of emulsifier. It was not observed effects on variables of feed intake and average daily gain in all phases. However, it was observed that there was a significant difference in feed conversion in growing II and finishing phase; animals fed the diet containing beef tallow and reduction in energy to 3080 kcal ME/kg (T3) and 2930 kcal ME/kg with emulsifier (T5) presented worse feed conversion. There was no significant difference (P>0.05) among levels of triglycerides in the blood and carcass characteristics (weight, yield and carcass length, amount and percentage of lean meat, backfat thickness, loin depth and fat depth, loin eye area and fat area and meat/fat ratio). Depending on the energy level, beef tallow can replace soybean oil as a lipid source in diets for pigs during the growing and finishing phases. The reduction of metabolizable energy at 150 kcal/kg with the use of beef tallow can to be compensated with the addition of emulsifier.
Foram realizados dois ensaios para determinar a composição química e a energia metabolizável do sebo bovino e para avaliar este ingrediente como fonte lipídica alternativa em rações para suínos nas fases de crescimento e terminação com ou sem a adição de emulsificante, sobre o desempenho, digestibilidade dos nutrientes das rações, triacilgliceróis séricos, características de carcaça e avaliação econômica. Para o ensaio de metabolismo foram utilizados 15 suínos machos castrados de peso inicial de 22,03±0,62 kg que foram distribuídos em delineamento inteiramente ao acaso, pelo método de coleta total de fezes e urina. Os tratamentos foram: RR – ração referência, formulada a base de milho e farelo de soja; RT1 – ração teste composta por 95% da ração referência e 5% de sebo bovino e RT2 – ração teste composta de 90% de ração referência e 10% de sebo bovino. O sebo bovino apresentou 99,94% de matéria seca e 7130,97 kcal de energia metabolizável (EM)/kg. Para o ensaio de desempenho foram utilizados 30 suínos machos castrados com peso inicial de 24,85±1,18 kg, distribuídos no delineamento em blocos ao acaso, com cinco tratamentos e seis repetições de um animal. Os tratamentos diferiram quanto à fonte lipídica incluída, nível de EM e adição do emulsificante, sendo: T1 – dieta com inclusão de óleo de soja e 3230 kcal de EM/kg; T2 – dieta com inclusão de sebo bovino e 3230 kcal de EM/kg; T3 – dieta com inclusão de sebo bovino e 3080 kcal de EM/kg; T4 – dieta com inclusão de sebo bovino, 3080 kcal de EM/kg e adição de 0,1% emulsificante; T5 – dieta com inclusão de sebo bovino, 2930 kcal de EM/kg e adição de 0,1% de emulsificante. Não houve efeito dos tratamentos sobre as variáveis de consumo de ração e ganho diário de peso em todas as fases avaliadas. Entretanto, observou-se que houve diferença significativa para a conversão alimentar no crescimento II e na terminação, onde os animais alimentados com a ração contendo sebo bovino e redução na energia para 3080 kcal/kg (T3) e para 2930 kcal/kg com adição de emulsificante (T5) apresentaram pior conversão alimentar. Não houve diferença significativa (P>0,05) para os níveis de triacilgliceróis no sangue e para as características de carcaças (peso, rendimento e comprimento de carcaça, quantidade e percentual de carne magra, espessura de toicinho, profundidades de lombo e de gordura, áreas do olho de lombo e da gordura e relação gordura carne). Dependendo do valor energético, o sebo bovino pode substituir o óleo de soja como fonte lipídica em rações para suínos nas fases de crescimento e terminação. A redução em 150 kcal de EM/kg da ração com uso de sebo bovino pode ser compensada com a adição de emulsificante.
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Parekh, Khushboo K. "Preparation, Characterization, and In Vitro Protein Release Studies in Pharmaceutically relevant Lecithin Microemulsions." University of Toledo Health Science Campus / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=mco1300753350.
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St, Clair Caryn M. "Neonatal Respiratory Distress Syndrome as a Function of Gestational Age and the Lecithin/Sphingomyelin Ratio." [New Haven, Conn. : s.n.], 2007. http://ymtdl.med.yale.edu/theses/available/etd-08272007-123115/.
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Borsatti, Liliane. "Utilização de subprodutos da indústria do óleo de soja e biodiesel e suas misturas em diferentes proporções na alimentação de frangos de corte." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/156638.
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A presente tese foi desenvolvida com objetivo de avaliar a utilização dos subprodutos do processamento do óleo de soja (OS) (óleo ácido de soja -OAS, lecitina - LEC) e do biodiesel (glicerol - GLI) na alimentação de frangos de corte. Dois estudos foram conduzidos para determinar EMA destes subprodutos e suas combinações. Foram usados 390 frangos de corte machos com 21 d para cada experimento distribuídos em um delineamento experimental inteiramente casualizado com arranjo fatorial com 4 fontes de gordura e 3 níveis de inclusão mais uma dieta basal sem suplementação de gordura. Cada experimento foi composto por 13 tratamentos dietéticos com 6 repetições de 5 aves por repetição. No primeiro ensaio foi usado: OAS, GLI e LEC, bem como uma mistura contendo 85% OAS, 10% GLI e 5% LEC (MIS). As proporções das fontes de energia na mistura foram semelhantes à encontrada no óleo de soja bruto. No segundo ensaio foi usado quatro diferentes misturas destas fontes de energia sendo elas: 85% OAS e 10% GLI; 80% OAS e 15% GLI; 75% OAS e 20% GLI e 70% OAS e 25% GLI, em todas as misturas estabeleceu-se 5% LEC. Os tratamentos dietéticos foram formados pela adição de cada fonte energética suplementar aos níveis de 0% (100% da dieta basal (DB), 2% (98% DB + 2% fonte de energia), 4% (96% DB + 4% fonte de energia) ou 6% (94% DB + 6% fonte de energia) Nos dois ensaios foi realizado coleta total de excretas por 72h. Aos 28 dias de idade no final do período experimental um frango por repetição foi abatido para coleta do fígado e coleta de sangue para análise de glicerol e triglicérides plasmático e enzima hepática glicerol quinase. Para os dois experimentos houve diferença estatística entre as fontes energéticas (P<0,05). No primeiro ensaio a mistura das três fontes (85:10:5) mostrou melhor valor de EMA, no entanto no segundo experimento a mistura de 80% OAS 15% GLI e 5% LEC apresentou melhor valor quando comparado as demais misturas. Para a concentração de glicerol e triglicerídeos plasmático, assim como para a atividade da enzima glicerol quinase, houve interação entre as fontes e o nível de inclusão (P<0,05). A medida que aumentou o nível de inclusão aumentou-se a concentração de glicerol no plasma e diminuiu a atividade da enzima, no entanto, isto não foi suficiente para saturar a enzima. Em conclusão, os tratamentos mostraram que a mistura de subprodutos do óleo de soja e do biodiesel podem ser usadas como fontes energéticas em dietas de frangos de corte sem acarretar problemas no metabolismo normal do glicerol.This thesis was carried out to evaluate the utilization of soybean oil (SO) (acidulated soap stock - ASS, lecithin - LEC) and biodiesel (glycerol - GLY) in broiler feeds. Two studies were conducted to determine AME these byproducts and their combinations. At total of 390 21-d-old male broilers were utilized for each experiment distributed in a completely randomized design with factorial arrangement of 4 fat sources and 3 levels of inclusion plus the basal diet without any fat source. Each study contained 13 dietary treatments with 6 replicates of 5 chickens per replicate. In the first experiment, the fat sources used were OAS, GLY and, LEC as well as a mixture (MIX) containing 85%, 10% and 5% respectively. The proportions of energy sources in the mix were similar to that found in crude soybean oil. In the second experiment, it was used four different mixtures of these energy sources, which are, 85% ASS: 10% GLY; 80% ASS: 15% GLY; 75% ASS: 20% GLY and 70% ASS: 25% GLY in all mixtures was fixed 5% LEC. The experimental treatments consisted of addition of each supplemental fat source at the levels of 0% (100% of basal diet (BD)), 2% (98% BD + 2% fat source), 4% (96% BD + 4% fat source) or 6% (94% BD + 6% fat source). The total excreta collection was conducted for 72h. At 28 days of age, the end of the study period one chicken by repetition was slaughtered to collect the liver and blood collection for analysis of plasmatic glycerol and triglycerides and the liver was used for analysis of glycerol kinase enzyme For both experiments was observed statistical difference between energy sources (P <0.05) in the first experiment the mixture of the three sources (85:10: 5) showed best value of AME, however, in the second experiment the mixture of 80% OAS GLI 15% and 5% LEC showed better value when compared to the other mixtures. For the concentration of plasma glycerol and triglycerides, as well as the activity of the enzyme glycerol kinase, there was an interaction between the sources and the inclusion level (P <0.05). As we increased the level of inclusion increased the concentration of glycerol in plasma and decreased enzyme activity, however, this was not enough to saturate the enzyme. In conclusion, the treatment showed that the mixture of soybean oil and biodiesel by-products could be used as energy sources in broiler diets without causing problems in the normal metabolism of the glycerol.
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Madenci, Dilek. "Study of the aggregation behaviour of egg yolk lecithin/bile salt mixtures by increasing the ionic strength." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/4918.
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This thesis describes a study of the aggregational behaviour of egg yolk lecithin (EYL), a natural lecithin, and bile salt mixtures especially with respect to an increase of the ionic strength of the solvent. Mixtures of two amphiphiles with very different spontaneous curvature as EYL lecithin and bile salt form mixed micelles and vesicles in aqueous solution. Their properties have been well-studied under physiological conditions, i.e. 150 mM electrolyte concentration and pH 7- 8, while other conditions are still hardly explored. Upon increasing ionic strength the formed structures and the transitional pathways (micelles, coexistence of micelles and vesicles, and vesicles) change the generated structures completely from those observed under physiological conditions. We quantitatively determined these structures formed in a broad range of electrolyte concentrations with various scattering techniques, x-ray, light and neutron scattering and calorimetry. With calorimetry, phase diagrams in the EYL and bile salt concentration phase plane were determined at various ionic strength ranging from physiological salt concentration to up to 1000 mM. Additionally a new electrochemical approach using functionalised electrodes, i.e. sensitive and selective to bile salt, and thus to control the bile salt concentration in solution (concentrations below the critical micellar concentration (cmc)) was attempted, since bile salt removal or injection drives the micelle-to-vesicle or the vesicle-to-micelle transition, respectively, of the mixed aggregational system of EYL/bile salt. Although this control was not achieved within the framework of this thesis, promising results show directions for future experiments.
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Ayyobi, Amir Fardad. "Analysis of lecithin : cholesterol acyltransferase (LCAT) protein structure and its influence on binding to plasma lipoproteins." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0014/NQ56499.pdf.
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Wang, Guang. "Functionality of egg yolk lecithin and protein and functionality enhancement of protein by controlled enzymatic hydrolysis." [Ames, Iowa : Iowa State University], 2007.
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Kline, Kristen Alissa. "Metabolic effects of incremental exercise on Arabian horses fed diets containing corn oil and soy lecithin." Thesis, Virginia Tech, 1997. http://hdl.handle.net/10919/37030.
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Feeding a fat-containing diet to the exercising horse is a facile way to increase energy density without risking the complications associated with hydrolyzable carbohydrates. Fat adaptation may also result in increases in the utilization of free fatty acids for fuel during exercise and sparing of muscle glycogen. Phosphatidylcholine, the main component of lecithins, can influence muscle contraction and improve endurance capacity during exercise. When it is combined with corn oil in a total mixed ration, soy lecithin is both highly digestible and palatable to horses. Our objectives in this study were to compare the effects of incremental exercise and isocaloric control (CON), corn oil (CO), and a soy lecithin/corn oil (LE) diets on plasma free fatty acids (FFA), cholesterol, glycerol, triglyceride (TG), lactate, and glucose. Also three different statistical models were compared for goodness of fit to the lactate curve.
Plasma lactate and glucose both increased slowly early in the incremental exercise test (IET), then increased rapidly as the work intensity increased. Both decreased during recovery. No effects of IET or diet were found for either of these variables.
Plasma TG was unchanged during exercise, but increased rapidly during recovery. Plasma FFA decreased from resting early in the IET then remained steady throughout the remainder of exercise. During recovery a rapid increase was exhibited. Plasma glycerol was constant during exercise, but increased during recovery. Plasma cholesterol did not change during exercise or recovery.
Diet affected plasma FFA. Plasma FFA were lower for the CO and LE diets than the CON diet during the IET. Plasma glycerol was lower for the CO diet than the CON diet during the IET, with the LE diet intermediate between the two. Plasma cholesterol was higher for the CO and LE diets than the CON diet during the IET.
A segmented model and an exponential model were found to have a good fit to the lactate curve. A point of inflection for a rapid increase in plasma lactate during incremental exercise was discovered. When this model was applied to diet, no differences in lactate threshold were found between the diets.
Some criteria for fat adaptation were met, namely diet affected plasma FFA, glycerol, and cholesterol. However diet did not affect plasma TG, lactate, or glucose. This indicates that the rate of fatty acid oxidation was increased following fat adaptation, but it did not affect the rate of glucose oxidation and glycolysis during exercise. A lactate threshold for the equine can be obtained using a broken line model. Further studies using this approach are needed to establish its correlation with performance.Master of Science
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Andrade, Valléria Matos. "Obtenção de gel PLO contendo rutina para aplicação transdérmica : caracterização, estabilidade e atividade antioxidante." Pós-Graduação em Ciências Farmacêuticas, 2017. http://ri.ufs.br/jspui/handle/riufs/7785.
Full textAbstract:
Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPqCoordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
Rutin is a flavonoid widely reported in the literature for its antioxidant properties, anti-inflammatory, vasoprotective, antithrombogen, among others. However, its low solubility in aqueous media reduces its bioavailability orally and, therefore, transdermal administration proves to be promising. Thus, the present work aimed to obtain, characterize and evaluate an activity and antioxidant activity of a gel. PLO (Pluronic Lecithin Organogel) containing rutin for transdermal administration.The analytical methodology for rutin quantification was developed and validated by high performance liquid chromatography (HPLC). Initially it was evaluated as an influence of the concentration of Polaxamer 407, obtained by the extrusion method with the aid of syringes, in front of the centrifugation test. The formulation that remained stable after the test was characterized by partical size determination, in vitro release study, in vitro skin penetration study, in vitro skin adhesion study. Also assessed for stability for 60 days at varying temperatures and at predetermined times, physico-chemical characteristics such as pH, density, viscosity and spreadability, as well as organoleptic characteristics, were evaluated. The antioxidant activity of the formulation was evaluated by the TRAP and TAR methods, comparing it with a positive control, Trolox. The results demonstrate that a formulation with higher concentration of Polaxamer is more stable and that is why it was characterized. The partical size were perfect for dermal administration. The formulation demonstrated controlled release of the drug after 24 hours, being able to permeate as deeper layers of the skin and to be absorbed into the systemic circulation, in addition to good adhesion to the skin surface. During the accelerated stability study, as formulations stored at low temperature, they underwent small variations in density, viscosity and spreadability relative to those stored at room temperature, while the pH remained stable throughout and favorable for application in skin. However, as observed variations were not sufficient to cause visual signs of instability. As for the antioxidant activity, a formulation showed greater activity in relation to the Trolox control and the free rutin, but it was not able to sustain an activity for a longer time, presenting a lower TAR value than Trolox. Thus, a chosen formulation has been shown capable of promoting a permeation of the rutin by transdermal route in a controlled manner, as well as being stable at an ambient temperature and having more significant antioxidant activity than the free rutin, and is therefore promising to administration of rutin by this route.
A rutina é um flavonoide bastante estudado devido principalmente as suas propriedades antioxidantes, anti-inflamatória, vasoprotetora e antitrombogência. No entanto, sua baixa solubilidade em meio aquoso reduz sua biodisponibilidade por via oral e, portanto, a administração por via transdérmica pode ser uma alternativa promissora. Dessa forma, o presente trabalho teve por objetivo obter, caracterizar e avaliar a estabilidade e a atividade antioxidante de um gel contendo Pluronic Lecithin Organogel (PLO) contendo rutina, para administração pela via transdérmica. A metodologia analítica para quantificação de rutina foi desenvolvida e validada por cromatografia líquida de alta eficiência (CLAE). Inicialmente foi avaliado qual a influência da concentração do Polaxamer 407, obtidos pelo método de extrusão com auxílio de seringas, frente ao teste de centrifugação. A formulação que permaneceu estável após o teste foi caracterizada através da determinação do tamanho de partícula, estudo de liberação, penetração cutânea e adesão à pele, todos in vitro. Foi também avaliada a estabilidade do produto durante 60 dias em variadas temperaturas em tempos pré-determinados, além das análises físico-químicas, como pH, densidade, viscosidade e espalhabilidade, bem como características organolépticas. A atividade antioxidante da formulação foi determinada pelos métodos TRAP e TAR, em comparação com um controle positivo, o Trolox. Os resultados demonstraram que a formulação contendo maior concentração de Polaxamer é mais estável e por isso esta foi caracterizada. O tamanho de partícula encontrado foi 4,33 μm e o sistema se mostrou homogêneo, ideal para administração cutânea. A formulação demonstrou liberação controlada do fármaco após 24 horas, sendo capaz de permear as camadas mais profundas da pele e ser absorvida para circulação sistêmica, além de boa adesão à superfície da pele. Durante o estudo de estabilidade acelerada, as formulações armazenadas em baixa e alta temperatura, sofreram pequenas variações na densidade, na viscosidade e na espalhabilidade, em relação àquelas armazenadas a temperatura ambiente, enquanto que o pH se manteve estável durante todo o tempo e favorável à sua aplicação na pele. Além disso, as variações observadas não foram suficientes para provocar alterações visuais de instabilidade. Quanto à atividade antioxidante, a formulação demonstrou maior atividade em relação ao controle Trolox e à rutina livre, porém de forma não duradoura, apresentando valor de TAR menor que o Trolox. Sendo assim, a formulação escolhida, demonstrou-se capaz de promover a permeação da rutina por via transdérmica de forma controlada, bem como estabilidade a temperatura ambiente e com atividade antioxidante significativa, sendo considerada então promissora a administração da rutina por esta via.
São Cristóvão, SE