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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Suplementação de ração de codornas com vitaminas A, D e E sobre o desempenho e qualidade dos ovos

Marques, Rafael Henrique [UNESP] 23 February 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:28:23Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-23Bitstream added on 2014-06-13T19:57:43Z : No. of bitstreams: 1 marques_rh_me_jabo.pdf: 872111 bytes, checksum: f6895ead9075f94d304b4015bc226911 (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Objetivou-se verificar o desempenho, concentração das vitaminas na gema e qualidade dos ovos armazenados em diferentes períodos e condições, quando codornas japonesas foram submetidas a suplementações acima das exigências de vitaminas A, D e E na dieta. Foram utilizadas 192 codornas, com 6 repetições e 8 aves por parcela, distribuídas em delineamento inteiramente casualizado. Foram avaliadas características de desempenho, concentração das vitaminas, qualidade interna e externa dos ovos frescos e armazenados. O método utilizado para quantificar as vitaminas na gema foi a Cromatografia Líquida de Alta Eficiência. A suplementação das vitaminas não proporcionou melhora no desempenho produtivo e na qualidade interna e externa dos ovos, com exceção da suplementação de vitamina D que proporcionou aumento no consumo. Quanto ao armazenamento dos ovos, pode-se concluir que a suplementação de ambas as vitaminas não influenciou estatisticamente as características estudadas. Em relação ao período de armazenamento, os resultados mostraram que a qualidade dos ovos não se alterou até os 30 primeiros dias de armazenamento. A condição de armazenamento influenciou todos os parâmetros estudados, mostrando que em temperatura refrigerada os ovos apresentaram melhor estado de conservação. Quanto à incorporação das vitaminas na gema dos ovos, verificou-se aumento de 536,27% de vitamina A para o nível de 30000 UI/kg, 13,43% de vitamina D para o nível de 1500 UI/kg e 479,05% de vitamina E para o nível de 600 UI/kg, sugerindo que o valor nutricional dos ovos, relacionado à vitamina, pode ser aumentado pela suplementação na dieta das codornas / The objective of this study was to evaluate the performance, concentration of vitamins and yolk quality of eggs stored at different times and conditions when Japanese quail were subjected to A, D and E vitamins supplementation above the diets requirements. One hundred and ninety two laying quails were used, with 6 replicates of 8 birds per unit distributed in a completely randomized design. We evaluated the performance characteristics, concentration of vitamins in the yolk, internal quality (Haugh unit, yolk index, percentage of yolk and albumen), external quality (specific weight, shell thickness, shell percent) of fresh and stored eggs. Supplementation of vitamins did not improve the performance and the internal and external quality of eggs, except for supplementation of vitamin D that provided an increase in consumption. Supplementation of both vitamins did not influence statistically the characteristics studied for stored eggs. The results showed that egg quality has not changed over the first 30 days of storage. The storage temperature influenced all traits studied and the under refrigeration than those stored in environment temperature had better quality. The incorporation of vitamins into the egg yolk could be verified. There was an increase of 536.27% of vitamin A to the level of 30000 IU / kg, 13.43% of vitamin D to the level of 1500 IU / kg and 479.05% of vitamin E to the level of 600 IU / kg, suggesting that the nutritional value of eggs, related to the vitamins may be increased by supplementation in the diet of quails
22

Estudo da degradação da vitamina E (a-tocoferol) durante as etapas do refino do óleo de babaçu (Orbignya phalerata, Mart.): validação de um método / Study of degradation of vitamin E (a-tocopherol) during the stages of refining oil from babassu (Orbignya pharlerata Mart.): validation of a method

Luz, Djavania Azevêdo da 09 August 2011 (has links)
Made available in DSpace on 2015-05-14T13:21:09Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2168020 bytes, checksum: 4c76c2dedc4c3011463de068ef339d86 (MD5) Previous issue date: 2011-08-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Due to its territorial location and the sort of oily plant adapted to its clamate, Maranhão has a vast agricultural potential for producing vegetable oil and their bioderivates. Among them is the babassu palm (Orbignya pharlerata, Mart.), a vegetal rich in oil that is composed by 95% of triglycerides and traces of tocopherols. Such tocopherols act as antioxidative agents that prevent the degradation of unsaturated fatty acids of vegetal oils. Therefore, several methods have being proposed for quantifying these natural antioxidants in both oil and bioderivate products; however, they often require long time of analysis and a pretreatment of the sample. Thus, this paper aims to propose an alternative method for quantifing a-tocopherol in babassu oil, as well as, evaluating its degradation during the oil refining (industrial and laboratorial scales) by mean of high performance liquid chromatography (HPLC) and Fourier transform infrared spectroscopy (FTIR). Hence, no previous sample treatments were performed, being the sample only diluted in 2-propanol (HPLC) or chloroform (FTIR) solvents. The use of the spectroscopy technique was rather limited, once it was incapable of distinguish between the tocopherols and/or tocotrienols (β, γ and δ) presented in the media. Conversely, the developed chromatographic method provided an efficient separation of such compounds, yielding in a significant sensibility and good linearity, precision and accuracy of the results. / O Maranhão apresenta um grande potencial agrícola para produção de óleos vegetais já que várias espécies oleaginosas são adaptadas ao seu clima e geografia. Dentre estas se encontra a palmeira de babaçu (Orbignya pharlerata, Mart.), de onde é extraído um óleo rico em triglicerídeos (95%) e tocoferois. Em óleos vegetais, os tocoferóis atuam como agentes antioxidantes, inibindo a oxidação dos ácidos graxos insaturados. Neste sentido, diversas metodologias para quantificação deste antioxidante têm sido propostas, entretanto, tais procedimentos geralmente demandam elevados tempos de análises e pré-tratamento da amostra. Neste contexto, o presente trabalho propõe um método alternativo para quantificação de a-tocoferol em amostras de óleo de babaçu. Também foi avaliado o grau de degradação desta espécie durante o processo de refino do óleo de babaçu, em escalas (industrial e laboratorial) por cromatografia líquida de alta eficiência (CLAE) e espectroscopia de infravermelho com transformada de Fourier (FTIR). Para tanto, as amostras não foram submetidas a qualquer tratamento prévio, sendo apenas diluídas em 2-propanol (CLAE) e clorofórmio (FTIR). Os dados espectroscópicos indicaram uma baixa resolução do método uma vez que não foi possível distinguir entre os vários tipos de tocoferois e/ou tocotrienois (β, γ e δ) existentes nas amostras. Por outro lado, o método cromatográfico desenvolvido apresentou uma excelente separação e resolução do composto em estudo, além de uma boa linearidade, precisão e exatidão, sendo este validado.
23

Determinação da exigência de vitamina E para o dourado Salminus brasiliensis (Cuvier, 1816) e a avaliação do seu efeito imunomodulador / Determination of vitamin E requirement for dourado Salminus brasiliensis (Cuvier, 1816) and evaluation of its immunomodulatory effect

Fernando Yugo Yamamoto 23 March 2015 (has links)
Agentes estressores em piscicultura intensiva afetam a condição fisiológica e o sistema imune dos peixes aumentando a susceptibilidade a infecções e causando prejuízos econômicos. Para contornar este problema, o uso de nutrientes moduladores do sistema imunológico na dieta, como o tocoferol, se tornam estratégia profilática para as pisciculturas assegurarem uma maior sobrevivência e consequente produtividade. O presente estudo visou avaliar a exigência nutricional do dourado, Salminus brasiliensis, por meio de um ensaio dose-resposta e aferir seu efeito imunomodulador. O delineamento utilizado foi o inteiramente casualizado, com sete tratamentos/dietas semi purificadas elaboradas com doses crescentes de vitamina E (0; 50; 100; 150; 200, 250 e 3500 mg kg-1α-tocoferol acetato) (n=4). Quinze juvenis de dourado foram alojados em caixas de polipropileno, em sistema de recirculação fechado com filtragem mecânica e biológica, trocador de calor com termostato e aeração forçada através de sopradores e pedras difusoras. Após serem alimentados por 30 dias com a dieta basal para depleção de vitamina E nas reservas corporais de vitamina, os animais foram pesados (20,04 ± 0,09 g), redistribuídos em 28 tanques (500 L; 15 peixes por tanque) e alimentados durante 78 dias até saciedade aparente (duas refeições diárias: 08h00m e 17h00m). Os peixes apresentaram diferença no ganho de peso, porém não de maneira dependente do tratamento de vitamina E. Após o período de alimentação os peixes foram desafiados com a bactéria Aeromonas hydrophila. Os parâmetros imunológicos foram aferidos antes e após o desafio e não houveram diferenças significativas para: atividade respiratória dos leucócitos, atividade da lisozima sérica, proteína e albumina total no soro e sobrevivência. Houve aumento da concentração das globulinas totais no soro após infecção em função do nível de vitamina E na dieta, e a dose ótima foi definida por meio da regressão segmentada: 151,07 mg kg-1 de vitamina E na ração. A exigência de vitamina E para o dourado foi determinada em 58,90 mg kg-1 pelas substâncias reativas ao ácido tiobarbiturico da fração mitocondrial do fígado por análise de regressão segmentada. / Stressors in intensive fish farming affect fish physiological conditions and immune system, promoting susceptibility to infections and causing economic losses. To overcome this issue, using immunomodulatory nutrients such as tocopherol on fish feeds may become a prophylactic strategy to fish farms to ensure a higher survival and productivity. The present study aimed at determining vitamin E requirement of dourado, Salminus brasiliensis, through a dose dependent trial and how the immune system responded to vitamin E crescent doses. The experiment design was randomly distributed in seven treatments (n=4) of semi purified diets (0; 50; 100; 150; 200; 250 and 3,500 mg kg-1). After exposing the fish during 30 days for tocopherol depletion, fifteen dourado juveniles (20.04 ± 0.09 g) were stocked in 500 L tanks in a closed loop system and fed twice a day until apparent satiation. Differences in weight gain were observed however not in a vitamin E dose dependent way. After feeding for 78 days fish were challenged with intraperitoneal bacterial infection (Aeromonas hydrophila). Immunological parameters were measured before and after infection and no significant differences were observed in: blood leukocyte burst respiratory activity, serum lysozyme activity, serum protein and albumin, and survival. However a higher total serum globulin was detected after infection and the best response determined through a broken-line regression was 151.07 mg kg-1 of vitamin E on fish feed. Dietary requirement of vitamin E was determined by broken-line regression from thiobarbituric reactive substances of liver mithocondrial fraction to be 58.90 mg/kg of α-tocopherol acetate.
24

Implantação das metodologias de caracterização e estudo da remoção de acidos graxos livres dos destilados desodorizados de oleos vegetais por meio da destilação molecular

Martins, Patricia Fazzio 18 February 2005 (has links)
Orientadores: Maria Regina Wolf Maciel, Cesar Benedito Batistella / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-04T03:08:23Z (GMT). No. of bitstreams: 1 Martins_PatriciaFazzio_M.pdf: 4266626 bytes, checksum: a048f065c12ba7c99e232ca5dd0eb892 (MD5) Previous issue date: 2005 / Resumo: Os destiladores desodorizados de óleos vegetais (DDOV) são constituídos por diversas substâncias, entre elas, os ácidos graxos livres, fitoesteróis, tocoferóis, ésteres de fitoesteróis, hidrocarbonetos, glicerídeos e produtos da decomposição destas moléculas. O teor de ácidos graxos livres (AGL) nos DDOV varia entre 24 e 85%. Devido ao seu alto teor, a separação dos AGL dos destilados desodorizados dos óleos vegetais é uma etapa importante para proceder à concentração de tocoferóis e fitoesteróis em alta pureza. Os tocoferóis são substâncias naturais valiosas usadas em alimentos, cosméticos e fármacos devido às suas propriedades vitamínicas e antioxidantes. Os fitoesteróis têm recebido grande atenção ultimamente, devido à sua atividade anticolerolêmica e potencialidade de aplicação em nutracêuticos. Neste trabalho, foram realizados ensaios para estudar a remoção dos AGL presentes nos destilados desodorizados de óleos vegetais provenientes do refino de óleo de girassol (DDOG) e de canola (DDOC), utilizando o processo de destilação molecular. Para isso, diversas condições operacionais de temperatura do evaporador e da vazão de alimentação foram utilizadas. O objetivo é avaliar o comportamento do sistema e determinar as melhores condições operacionais para realizar a eliminação de ácidos graxos, minimizando as perdas de tocoferóis durante o processo... Observação: O resumo, na íntegra, poderá ser visualizado no texto completo da tese digital / Abstract: Distilates of the vegetable oil deodorization (DVOD) are composed by free fatty acids, phytosterols, tocopherols, phytosterol esters, hydrocarbons, acylglycerols and products of decomposition of these molecules. The content of free fatty acids (FFA) in the deodorizer distillates varies between 24% and 85%. Due to its high content, free fatty acid separation from deodorizer distillate is an important step to concentrate tocopherols and phytosterols in high purity. Tocopherols are valuable natural substances used in food, cosmetic and pharmaceutical industries due to its vitaminic and antioxidant properties. Phytosterols have received grat attention because its hipocholesterolemic properties and potential to be used in nutraceutics. In this work, separation of free fatty acids from sunflower (SuODD) and canola oil (CODD) deodorizer distillates was investigated through molecular distillation. For this, different operating conditions of evaporator temperature and feed flow rate were used. The intention is to evaluate the behavior of the system and to determine the best operating conditions to eliminate FFA, minimizing tocopherol losses during the process. Furthermore, in this work, it was necessary to establish analytical techniques to determine the contents of tocopherols, phytosterols, triacylglycerols, diacylglycerols, monoacylglycerols and free fatty acids in DVOD. Besides, of DDOC and DDOG, the soybean oil deodorizer distillate (SODD) was also characterized... Note: The complete abstract is available with the full electronic digital thesis or dissertations / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química
25

Tocopherol regeneration by phospholipids in soybean oil-in-water emulsions: effect of tocopherol homologue and emulsifier type

Samdani, Gautam 21 March 2018 (has links)
Phospholipids can regenerate oxidized tocopherols and help delay lipid oxidation. The impact of emulsifier type, tocopherol homologue and phospholipid head group on tocopherol-phospholipid interaction was investigated in this study. Three µmol tocopherol/kg emulsion and 15.0µmol/kg emulsion of PE or PS were dissolved in oil and emulsions were prepared. Tween 20 or bovine serum albumin(BSA) was used as emulsifier and the continuous phase contained 10mM imidazole/acetate buffer at pH 7. Lipid hydroperoxides and hexanal were measured as lipid oxidation products and the lag phase was determined. With Tween 20 as the emulsifier, α and δ-tocopherol had a hexanal lag phase of 2 and 4 days respectively. PE and PS both extended the lag phase to 7 and 10 days respectively in presence of δ-tocopherol. Whereas, PS extended the lag phase to 6 days and PE could not exhibit any synergism with α-tocopherol. With BSA as the emulsifier, α and δ-tocopherol had a lag phase of 4 days. PE and PS extended the lag phase to 11 days and 10 days respectively in presence of δ-tocopherol and to 7 and 8 days respectively in presence of α-tocopherol. PE and PS both exhibited synergism with mixed tocopherol and the extent of synergism was in less than δ-tocopherol but more than α-tocopherol. Phospholipids could potentially be used with tocopherols to improve the oxidative stability of emulsions. PE was more effective with BSA whereas PS was equally effective with both emulsifiers.
26

Antioxidant Combination of High Phosphatidylserine (PS) Lecithin with Mixed Tocopherol in Soybean Oil-in-Water Emulsion: Effect of pH and Salt

Agnihotri, Princy 20 October 2021 (has links)
Lipid oxidation is one of the major challenges faced by the food industry as it contributes to the loss of nutritional quality and loss of flavor in food products. Studies have shown that naturally occurring phospholipids like phosphatidylserine (PS) and phosphatidylethanolamine (PE) can regenerate oxidized tocopherols and help delay the lipid oxidation in bulk oils and oil-in-water emulsions. Since consumers desire simpler and cleaner labels, without chemically synthesized antioxidants, this research is of great interest. The combination of PS and PE with tocopherols has already been studied. However, PS was a better antioxidant in combination with tocopherols in the oil-in-water emulsion system whereas PE was a better antioxidant in combination with tocopherols in bulk oils. But obtaining pure phospholipids is an expensive deal, therefore, this study uses the more economical alternative, high phosphatidylserine (PS) lecithin in combination with mixed tocopherols in soybean oil-in-water system. PS (30 µmol/kg emulsion) along with mixed tocopherols (3 µmol/kg emulsion) were dissolved in oil and emulsions stabilized by Tween20 were prepared. To determine the most effective concentration of mixed tocopherols, 0.5, 1.0, and 3 µmole of tocopherols/kg emulsion were used at pH of 3 and 7. Tocopherol with a concentration of 3 µmole/kg emulsion was found to be the most effective at pH 3. Tocopherols showed an extended lag phase at lower pH. The synergistic activities of authentic PS and high PS lecithin were compared in combination with tocopherol under similar conditions. They both had an almost similar lag phase. This combination was then tested for different pH of 3 and 7 and different salt concentrations of (0.5, 1, and 1.5 wt% of the emulsion) at pH 7 to determine the effects of external factors on the synergistic antioxidant combination. It was observed that the combination had extended antioxidant ability at lower pH of 3 whereas salt had no effect on the combination. The results showed that high PS lecithin forms a synergistic combination with mixed tocopherols to increase the lag phase in oil-in-water emulsions and can be used as a clean label antioxidant for oil-in-water emulsions.
27

The Effects of Dietary α-Tocopherol and Polyunsaturated Fat on Modulating Ischemia-Reperfusion Injury

Huang, Annong, Kao, Race L., Ma, Yanshan, Stone, William L. 28 September 1999 (has links)
We investigated the effects of dietary α-tocopherol and polyunsaturated fatty acids (PUFA) on ischemia-reperfusion injury and cardiac lipid composition. Rats were fed corn oil (CO) diets either deficient (CO - E) or supplemented (CO + E) with RRR-α-tocopherol (100 IU kg-1 diet), or butter oil (BO) diets either deficient (BO - E) or supplemented (BO + E) with RRR-α-tocopherol (100 IU kg-1 diet). Intact rat hearts were subjected to ischemia before reperfusion. Dietary RRR-α-tocopherol supplementation contributed to recovery of aortic output, cardiac output and diastolic pressure after ischemia-reperfusion. In contrast, the type of dietary fat did not influence most measures of cardiac recovery. RRR-α-tocopherol levels in cardiac tissues and plasma were significantly higher for rats fed the BO + E diet than for rats fed the CO + E diet. In contrast to plasma, PUFA in cardiac tissues were maintained at a high level even when rats were fed BO containing diets. Our results suggest that dietary RRR-α-tocopherol, but not dietary PUFA levels, modulate oxidative damage to intact rat hearts during ischemia-reperfusion.
28

Gamma Tocotrienol and Prostate Cancer: The Regulation of Two Independent Pathways to Potentiate Cell Growth Inhibition and Apoptosis

Campbell, S., Whaley, S. G., Phillips, R., Aggarwal, B. B., Stimmel, J. B., Leesnitzer, L., Blanchard, S. G., Stone, W. L., Christian, Muenyi, Krishnan, K. 01 October 2008 (has links)
Dietary vitamin E, highly expressed in palm oil, exists as either tocopherols or tocotrienols. Evidence indicates that vitamin Es maybe potent cancer preventive agents. In this study, the y- and O- isoforms of vitamin E were found to he the most effective at cancer cell growth inhibition, with the tocotrienols being more effective than the tocopherols in androgen-independent PC-3 prostate cancer cells. To assure that these compounds were selective toward cancer cells, the growth arrest of PrEC normal prostate cells was compared to PC-3 cells. At concentrations of -30 iM dietary, y-vitamin Es showed no signficant growth arrest on PrEC cell growth, hut selectively inhibited growth in the PC-3 cancer cells. Moreover y-Tocotrienol demonstrated a greater potential to inhibit growth in cancer cells at these lower concentrations than did y-Tocopherol. Two independent pathways important in carcinogenesis were tested: PPAR y and NFicB. The PPAR y was up regulated by both dietary y-vitamin Es by the modulation of the endogenous ligand 15-S-HETE, while NFicB was only regulated by y-Tocotrienol. The modulation of NFicB was confirmed by the down regulation of the pro-Apoptotic proteins clAP, xIAP, and BcL-2 which potentiate apoptosis and are down stream effectors of NFicB.
29

Studies on IgA Induction in Intestine and Mammary Glands of Mammals / 哺乳動物の小腸と乳腺におけるIgA産生に関する研究

Wang, Mengdong 23 March 2015 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第19021号 / 農博第2099号 / 新制||農||1030(附属図書館) / 学位論文||H27||N4903(農学部図書室) / 31972 / 京都大学大学院農学研究科応用生物科学専攻 / (主査)教授 久米 新一, 教授 祝前 博明, 教授 廣岡 博之 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
30

The effect of α-tocopherol on the membrane dipole potential

Le Nen Davey, Sterenn January 2011 (has links)
α-Tocopherol has a well known antioxidant action but is also considered likely to exert significant non-antioxidant effects in cell membranes. Due to its lipophilic nature α-tocopherol inserts into biological membranes where it influences the organisation of the component lipids and may therefore influence biophysical parameters including the membrane dipole potential. The dipole potential has been demonstrated to modulate the function of several membrane associated proteins and perturbation of this physical parameter by α-tocopherol may prove to be a significant non-antioxidant mechanism underlying several of its cellular effects. This study investigates the influence of α-tocopherol, and the non-antioxidant structural analogue α-tocopherol succinate, on the membrane dipole potential employing fluorescence spectroscopy techniques with the dipole potential sensitive probe Di-8-ANEPPS. Similar techniques are utilised with the surface potential sensitive probe FPE to investigate the interaction of the charged α-tocopherol succinate molecule with membranes. α-Tocopherol and α-tocopherol succinate are shown to decrease the dipole potential of egg-phosphatidylcholine vesicles and Jurkat T-lymphocyte cell membranes. This effect is placed in the context of the significant influence of membrane cholesterol oxidation on the dipole potential. 7-ketocholesterol, an oxidised form of cholesterol, significantly influences several cellular processes and is thought to mediate these effects, in part, through its physical effects on the cell membrane. These include altering the composition, and therefore biophysical properties, of rafts; structures which are considered to support the function of a host of membrane proteins. This study attempts to correlate the effect of 7-ketocholesterol on the dipole potential of microdomains with the influence of the oxysterol on the function of two microdomains associated receptors: P-glycoprotein and the insulin receptor, assessed by determining the extent of ligand binding using flow fluorocytometry. α-Tocopherol has been suggested to inhibit the raft-mediated effects of 7-ketocholesterol and the influence of this molecule on the effect of 7-ketocholesterol on the dipole potential are investigated as a potential mechanism for this inhibition. It is hypothesized that α-tocopherols may protect against the deleterious effects of cholesterol oxidation in cell membranes by excluding 7-ketocholesterol from specific microdomains, of which rafts are a subset, acting to preserve their dipole potential and maintain the function of the proteins they support. However, where significant cholesterol oxidation has previously occured the concurrent changes in the microdomain landscape of the membrane is suggested to prevent α-tocopherol succinate from eliciting this protective effect.

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