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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.
51

Aspectos tecnológicos da síntese de carbonato de glicerila e a avaliação de algumas de suas propriedades físico-químicas / Technological aspects of the synthesis of glyceryl carbonate and evaluation of some of its physicochemical properties

Rossana Giudice Ribeiro de Araujo 21 September 2011 (has links)
Tendo em vista a busca por matérias-primas de fontes renováveis e menos poluentes, e o crescente aproveitamento de subprodutos gerados por estas fontes, surgiu o interesse em estudar a síntese do carbonato de glicerina a partir da glicerina obtida como subproduto principal na fabricação de biodiesel. Sintetizou-se este composto no Laboratório de Química Orgânica Aplicada. Este tensoativo não é disponível no Brasil e possui propriedades cosméticas interessantes, que, no entanto, ainda devem ser mais exploradas na atualidade. No estudo, adicionou-se o carbonato a sabões líquidos obtidos a partir dos ácidos graxos provenientes dos óleos de soja e de mamona. Os sabões produzidos apresentaram baixa alcalinidade, reduzindo, assim, as adições de agentes químicos que podem ser agressivos à pele, como mostraram os resultados parciais. A partir do planejamento experimental, verifica-se a influência da temperatura e o tempo de reação da síntese do carbonato, assim como o tipo de catalisador utilizado. Análises de espectroscopia vibracional Raman e infravermelho, juntamente com ensaios de viscosidade, mostraram que a temperatura ideal para a carboxilação é de 140 °C, sendo que o tempo reacional deve ser de 6 a 7 h, utilizando-se como catalisador o sulfato de magnésio. Demonstrou-se também, a sensibilidade das duas técnicas na identificação dos picos das reações de síntese de carbonato de glicerila. Comparativamente, foram realizados testes de espuma dos sabões adicionados de carbonato de glicerila e de lauril sulfato de sódio. De um modo geral, a adição de carbonato de glicerila aos sabões propiciou a formação de uma espuma mais densa e persistente. A utilização de água dura reduziu o volume de espuma formado para todas as amostras. Comparando os dois óleos vegetais, soja e mamona, percebeu-se que os sabões produzidos a partir de óleo de mamona apresentaram menor formação de espuma. A adição de dietanolamina reduziu significativamente a estabilidade das espumas em todas as amostras. Estudos reológicos demonstraram que o tensoativo carbonato de glicerila é um fluido newtoniano, comportamento semelhante ao da glicerina pura. / In order to search for raw materials from cleaner and renewable sources, and the growing use of byproducts generated by these sources, has appeared the interest in studying the synthesis of glycerol carbonate from glycerol obtained as a main byproduct in the manufacture of biodiesel. This compound was synthesized at the Laboratory of Applied Organic Chemistry. This surfactant is not available in Brazil and has interesting cosmetic properties, which, however, should be more exploited at present. In the study, carbonate was added to liquid soaps from the fatty acids from soybean oil and castor oil. Soaps produced had low alkalinity, thereby reducing the additions of chemicals that can be aggressive to the skin, as partial results showed. From the experimental design, the influence of temperature and reaction time of the synthesis of carbonate is investigated, as well as the type of catalyst used. Analysis of partial Raman vibrational spectroscopy, together with viscosity experiments showed that the optimal temperature for carboxylation is 140 °C, and the reaction time should be from 6 to 7 h, using magnesium sulphate as the catalyst. It also demonstrated the sensitivity of both techniques in identifying the peaks of the reactions of synthesis of glycerol carbonate. In comparison,foam tests were made of soaps added glycerol carbonate and sodium laurylsulfate. Overall, the addition of glycerol carbonate to soap provided the formation of denser and persistent foam. The use of hard water reduced the volume of foam formed for all samples. Comparing the two vegetable oils, soy and castor bean, it was noticed that soaps produced from castor oil had lower foaming. The addition of diethanolamine significantly reduced the stability of foams in all samples. Rheological studies demonstrated that the surfactant glycerol carbonate is neuwtonian fluid, behavior similar to that of pure glycerin.
52

Dietas para frangos de corte contendo diferentes fontes lipídicas suplementadas ou não com lisofosfolipídios e ácidos orgânicos / Diets for broiler chickens containing different lipid sources supplemented with or without lysophospholipids and organic acids

Gustavo do Valle Polycarpo 27 March 2015 (has links)
Os óleos e as gorduras, assim denominados em função de sua origem, são ingredientes internacionalmente indispensáveis na formulação de rações para que haja sucesso na produção de frangos de corte. Os lipídios advindos da dieta são grandes fornecedores de energia e de ácidos graxos essenciais ao metabolismo. O aproveitamento nutricional depende da digestibilidade, que, por sua vez, é influenciada pela composição química das moléculas lipídicas. Características ligadas ao comprimento da cadeia carbônica, presença ou não de duplas ligações, configuração das ligações (cis ou trans), presença de ácidos graxos na forma de triglicerídio ou livre e posição do ácido graxo na molécula de glicerol são fatores que alteram não só a digestibilidade dos lipídios, mas também de compostos lipossolúveis. No entanto, em ensaios biológicos é preciso abordar uma ótica multifacetada, considerando, dentro dos limites técnicos da experimentação animal, as diversas interações que se apresentam. Os fatores fisiológicos da ave, principalmente aqueles ligados à digestão, são de extrema importância na condução de estudos de nutrição. Existe uma infinidade de interações físico-químicas durante o processo digestivo, no qual a microbiota intestinal exerce importantes funções. A modulação dos microrganismos presentes no trato gastrintestinal do frango tem influência direta e indireta no aproveitamento da dieta, com mérito em destaque dobrado, especialmente diante dos desafios enfrentados após a União Europeia vetar o uso de antibióticos em rações para animais. Ao longo dos anos, foram realizadas pesquisas que demonstraram o efeito negativo da proliferação indesejada de microrganismos sobre a digestão dos lipídios, afetando principalmente fontes lipídicas com grandes quantidades de ácidos graxos saturados, que são mais susceptíveis às condições inadequadas da digestão. Esse efeito ocorre pela ação da coliltaurina hidrolase bacteriana, que causa desconjugação dos sais biliares endógenos das aves, prejudicando a emulsificação dos lipídios e a consequente formação de micelas. Portanto, este trabalho tem o objetivo de avaliar dietas contendo óleo de soja ou sebo bovino suplementadas com lisofosfolipídios e ácidos orgânicos, explorando as possíveis interações e benefícios que podem haver na associação desses dois aditivos / Oils and fats, so named because of their origin, are internationally indispensable ingredients in feed formulation for success in broilers production. The lipids coming from the diet are major suppliers of energy and essential fatty acids for metabolism. The nutrient utilization is dependent on digestibility, which, in turn, is influenced by the chemical composition of the lipid molecules. Characteristics related to the length of the carbon chain, presence or not of double bonds, links configuration (cis or trans), presence of fatty acids in the form of triglycerides or free fatty acids and the position of fatty acids in the glycerol molecule are factors that alter not only the digestibility of lipids, but also fat-soluble compounds. However, in biological assays, a multifaceted vision approach is required, considering, within the technical limits of animal experimentation, the various existing interactions. The physiological factors of the bird, especially those related to digestion, are extremely important in the conduction of nutrition studies. There is an infinity of physical and chemical interactions during the digestive process, in which the intestinal microbiota plays important roles. Modulation of microorganisms in the gastrointestinal tract of the chicken has direct and indirect influence on the diet utilization, with merit in featured folded, especially considering the challenges faced after the European Union prohibit the use of antibiotics in animal feeds. Over the years, researches have shown the negative effect of undesired proliferation of microorganisms on the lipid digestion, mainly affecting lipid sources with large amounts of saturated fatty acids, which are more susceptible to poor digestion conditions. Such effect occurs by the bacterial cholyltaurine hydrolase activity, causing deconjugation of endogenous bile salts of birds, damaging the emulsification of lipids and the consequent micelles formation. Therefore, this study aims to evaluate diets containing soybean oil or beef tallow supplemented with lysophospholipids and organic acids, exploring the possible interactions and benefits that can occur in the combination of these two additives
53

Otimização das variáveis de processo da transesterificação do óleo de soja e milho = produção de biodiesel em uma coluna de pratos perfurados / Optimization of the process variables of the transesterification of soybean oil and corn oil : biodiesel production in a sieve tray column

Dantas, Tarcisio Soares Siqueira, 1980- 19 August 2018 (has links)
Orientador: Maria Regina Wolf Maciel / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Química / Made available in DSpace on 2018-08-19T03:53:54Z (GMT). No. of bitstreams: 1 Dantas_TarcisioSoaresSiqueira_M.pdf: 911186 bytes, checksum: 5dd1da3ddee6346c9e4cbb05214e5f7d (MD5) Previous issue date: 2011 / Resumo: A transesterificação com etanol é um tópico de pesquisa bastante atual devido à possibilidade de produzir um combustível utilizando apenas fontes renováveis. Este trabalho apresenta a produção de biodiesel em uma coluna de destilação reativa de pratos perfurados e a otimização de suas variáveis de processo foi realizada utilizando ferramentas estatísticas. A destilação reativa é a implementação simultânea de reação e separação em uma mesma unidade de processo e, através dela, é possível atingir conversões altas rapidamente e com menores gastos energéticos. O óleo de soja e o óleo de milho refinados foram utilizados como matérias-primas na reação de transesterificação com o etanol e o catalisador (hidróxido de sódio). Os resultados finais de conversão em éster foram comparados com resultados obtidos por outros pesquisadores em uma coluna de destilação reativa empacotada. A conversão ótima de éster foi de 99,84% em peso com 6 minutos de reação e um modelo, com significância estatística, da conversão em éster em função da razão molar álcool:óleo e da concentração de catalisador foi obtido / Abstract: Transesterification with ethanol is very up-to-date due to the possibility of producing a fuel solely from renewable sources. This work presents the biodiesel production with a reactive distillation sieve tray column and the optimization of the process variables using statistical tools was carried out. Reactive distillation is the simultaneous implementation of reaction and separation within a single process unit and it is able to achieve very fast conversions and high yields with relatively low energy requirements. Refined soybean oil and corn oil where used as feedstocks in the transesterification with the ethanol and the sodium hydroxide catalyst. The results on the final ester conversion where compared to results obtained with a packed reactive distillation column by other researchers. The optimum ester (biodiesel) conversion was 99.84 wt. % after 6 minutes of reaction and a model, with statistical significance, of the ester conversion as a function of molar ratio and catalyst concentration was obtained / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química
54

Desacidificação de óleo de soja por resina de troca iônica / Deacidification of soybean oil by ion exchange resin

Deboni, Taiana Maria, 1986- 19 August 2018 (has links)
Orientador: Antonio José de Almeida Meirelles / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T16:22:26Z (GMT). No. of bitstreams: 1 Deboni_TaianaMaria_M.pdf: 3340128 bytes, checksum: 2c048258852d2e09abea9ae1b84c123e (MD5) Previous issue date: 2012 / Resumo: Um método alternativo para a remoção de ácidos graxos livres presentes em óleos vegetais brutos se baseia no uso de resinas de troca iônica. Este método mostra-se adequado e vantajoso, devido às condições brandas de processamento, provável minimização das perdas de óleo neutro e a não geração de sabões. Deste modo, o objetivo deste trabalho foi estudar o processo de desacidificação de óleo de soja utilizando resina de troca iônica em meio orgânico. Para isto, realizou-se um prétratamento da resina em coluna de leito fixo utilizando isopropanol. Avaliou-se a influência deste pré-tratamento sobre a capacidade de troca iônica e sobre o teor de água no interior da resina. Curvas de ruptura foram obtidas de acordo com um delineamento composto central rotacional 22, sendo que os parâmetros avaliados foram vazão e acidez da alimentação. As respostas obtidas foram a eficiência de recuperação de soluto e eficiência de utilização de leito, ambas calculadas a partir das curvas de ruptura. No estudo, foi utilizado leito fixo com 150 mL de resina aniônica forte (Amberlyst A26 OH), sendo que a miscela de alimentação do leito foi composta por uma mistura de óleo de soja degomado com acidez original igual 2,16 % e ácido linoléico, utilizando como solvente isopropanol na proporção de 50 %. A temperatura empregada durante o processo foi de 50 °C. Também foi analisado o comportamento do teor de óleo, água e altura de leito durante a operação. Condições de temperatura e pressão foram investigadas para a evaporação do solvente. O óleo obtido foi caracterizado quanto às suas propriedades físico-químicas e então comparado ao óleo de soja degomado antes da etapa de desacidificação e ao óleo industrial desacidificado com hidróxido de sódio. Nos resultados observou-se que utilizando o pré-tratamento em coluna de leito fixo com isopropanol consegue-se diminuir o teor de água na resina, mantendo a capacidade de troca iônica que a mesma teria em meio aquoso. A eficiência de recuperação de soluto apresentou valores altos para todas as condições estudadas de vazão e acidez na alimentação. A eficiência de utilização do leito diminuiu com o aumento da vazão utilizada, mas não mostrou ser afetada pela acidez da corrente de alimentação. Também foi observado que o óleo é eliminado totalmente na corrente de saída, ocorrendo somente uma pequena adsorção no início da operação. O teor de água na corrente de saída do processo foi próximo ao teor de água gerada pela troca iônica, com a diferença de valores ocorrendo em função da quantidade de água acumulada inicialmente na estrutura da resina. Para evaporação do solvente, condições como 120 °C e 170 mmHg foram suficiente para removê-lo até a quantidade residual de (1 %) no óleo. O processo de desacidificação por troca iônica mostrou-se viável no caso do óleo de soja, diminuindo consideravelmente a acidez e ainda removendo compostos indesejáveis como fosfolipídios e peróxidos. Contudo, uma diminuição de componentes desejáveis, como os tocoferóis, também foi observada / Abstract: An alternative method for the removal of free fatty acids present in crude vegetable oils is based on the use of ion exchange resins. This method has shown to be adequate and advantageous due to its mild processing conditions, minimal loss of neutral oil and nongeneration of soaps. Thus, the objective of this work was to study the process of soybean oil deacidification using ion exchange resin in organic media. Pre-treatment of the resin was first performed in a fixed-bed column using isopropanol. The influence of pretreatment on ion exchange capacity and water content in the resin was evaluated. Breakthrough curves were obtained according to a central composite rotational design 22, where the parameters evaluated were flow and acidity of the feed stream. The responses obtained were the solute recovery efficiency and bed utilization efficiency, both calculated from the breakthrough curves. In this study, a fixed bed with 150 mL of a strong anionic resin was used (Amberlyst A26 OH), where the miscella fed to the bed was composed of a mixture of crude soybean oil with original acidity equal to 2.16% and linoleic acid, using isopropanol as a solvent at the proportion of 50%. The temperature employed during the process was 50 °C. Also analyzed was the behavior of the oil content, water and bed height during operation. Conditions of temperature and pressure were investigated for evaporation of the solvent. The oil obtained was characterized according to its physicochemical properties and then compared to the crude soybean oil before the deacidification step and industrial oil deacidified with sodium hydroxide. Results showed that when using the pre-treatment in a fixed-bed column with isopropanol it is possible to reduce the water content in the resin, maintaing the ion exchange capacity that it would have in aqueous medium. The solute recovery efficiency was high for all studied conditions of flow and acidity of the feed. Bed utilization efficiency decreased with increasing flow rate, but was not affected by the acidity of the supply stream. It was also observed that the oil is completely eliminated in the outlet stream, in which only a small amount is adsorbed at the beginning of the operation. The water content of the outlet stream was similar to the water content generated by ion exchange, with the difference in values resultant of the water initially accumulated in the resin structure. For evaporation of the solvent, conditions of 120 °C and 170 mmHg were sufficient to remove until a residual concentration (1%) in the oil. The deacidification process by ion exchange showed to be a feasible option in the case of soy oil, significantly reducing acidity and even removing undesirable compounds such as phospholipids and peroxides. However, a decrease in desirable components, such as tocopherols, was also observed feasible option in the case of soy oil, significantly reducing acidity and even removing undesirable compounds such as phospholipids and peroxides. However, a decrease in desirable components, such as tocopherols, was also observed / Mestrado / Engenharia de Alimentos / Mestre em Engenharia de Alimentos
55

Impact of vitamin A nutrified soybean oil on the vitamin A status of a selected community in Southern Brazil

Fradera, Ursula G. January 1990 (has links)
Previous studies have revealed that marginal vitamin A deficiency poses a common public health problem among poor population groups in Southern Brazil. Nutrification programs in Guatemala (sugar) and in the Philippines (MSG) have resulted in improved vitamin A status, accompanied by positive changes in the anthropometric and general health status. Accordingly, the main purpose of the present pilot study was to evaluate the potential impact of vitamin A nutrified soybean oil on the vitamin A status of a selected community in Southern Brazil. Additional objectives were to assess the vitamin A and general nutritional status of the participants. The study was conducted in Vila Piratininga, a shanty town located on the periphery of Ribeirao Preto, a typical agricultural town in the sugarcane and coffee region of the state of Sao Paulo. Fifty-seven families were randomly assigned to experimental and control groups and were provided for four months with soybean oil that was either fortified with vitamin A (92,000 IU of retinyl palmitate per one litre can) or unfortified. To evaluate the impact of nutrification, biochemical and dietary indicators of vitamin A status were assessed before and after the supplementation. Dietary intake data were obtained from the female head of each household using the 24 hour recall method. Additional information on the usual consumption pattern of vitamin A containing foods was collected at the start of the study, using a food frequency questionnaire. Plasma retinol and (β-carotene levels of all subjects were analysed. Anthropometric measurements served as additional indicator of general nutritional status. Furthermore, throughout the intervention mothers, were questioned about the incidence of diarrhea and respiratory diseases among their children. Results from the serum vitamin A analysis at baseline confirmed that vitamin A deficiency was a public health problem among this low income population. Forty percent (control group) and 59% (experimental group) of preschool children, the most vulnerable age group, had low or deficient serum retinol concentrations. Plasma (β -carotene and dietary data showed that the intake of vitamin A and carotenoids from the rice and bean based diet was very low. The consumption of nutrified soybean oil increased the estimated daily vitamin A intake of the experimental group by 500% (p<0.001). However, this improved intake was not reflected in plasma retinol levels. Plasma vitamin A values of supplemented individuals dropped significantly (p<0.001) during the intervention, indicating that vitamin A nutrified soybean oil was not effective in improving their vitamin A status. The lack of response to supplementation in this study does not necessarily suggest that soybean oil is not a feasible vehicle for vitamin A nutrification. The fortified oil was well accepted by the participants and used daily for the preparation of meals; eventual losses of vitamin A during cooking and/or storage can be regarded as minimal. Therefore, this negative impact is more likely due to other factors. In populations with marginal vitamin A deficiency, as in Vila. Piratininga, the limitations of serum retinol levels as an accurate indicator of vitamin A body reserves should be appreciated. In addition, morbidity data revealed that infections were common among participating children. Infections may have impaired vitamin A absorption and utilization, increased requirements and consequently interfered with a successful nutrification. This was the first study to use vegetable oil as the carrier for vitamin A. Although this trial did not result in the expected impact on vitamin A status of the present study population, the feasibility of this vehicle should be further studied. In future investigations, the relative dose response test (RDR), which is a more sensitive index of vitamin A body reserves, should be performed on a subsample of the whole study population. Furthermore, concurrent reduction in the magnitude and severity of precipitating or contributary risk factors such as parasitic infestation, diarrheal and respiratory infections could improve the outcome of a nutrification intervention. / Land and Food Systems, Faculty of / Graduate
56

Avaliação da atividade antioxidante de extrato hidroalcoólico de murtilla (Ugni molinae Turcz.) / Evaluation of antioxidant activity of hydroalcoholic murtilla (Ugni molinae Turcz.)

Thalita Riquelme Augusto 02 October 2013 (has links)
A oxidação lipídica é uma das causas mais importantes que levam à perda das qualidades nutricionais e sensoriais dos alimentos que possuem lipídios em sua composição, diminuindo assim sua vida de útil e provocando rejeição por parte dos consumidores. Considerando estes aspectos, a indústria de alimentos faz o uso de compostos antioxidantes, capazes de retardar a oxidação. A maioria dos antioxidantes utilizados atualmente é de origem sintética, que apresentam restrições quanto ao seu uso em alimentos que variam de país para país. Tais restrições fundamentam-se em aspectos relacionados ao impacto dos antioxidantes sintéticos sobre a saúde do consumidor. Em consequência, na última década ocorreu um aumento considerável no número de pesquisas que abordam uso de antioxidantes obtidos de fontes naturais em alimentos, a fim de identificar fontes promissoras desses compostos. Com esse objetivo, o presente trabalho avaliou a atividade antioxidante de extratos hidroalcoólicos de duas amostras de frutos de murtilla (Ugni molinae Turcz.), silvestre e a cultivar melhorada 14-4, por meio da aplicação de testes in vitro e em sistema modelo a base de óleo de soja. A aplicação da Metodologia de Superfície de Resposta permitiu a seleção da melhor condição operacional para a produção de extratos hidroalcoólicos a partir dos frutos desidratados. A condição que apresentou maior eficiência para recuperação dos compostos fenólicos foi o emprego de etanol 49,5% (v/v) a temperatura de 30ºC, sendo que para a murtilla silvestre o teor foi de 18,39 mg GAE/ g matéria seca e 26,14 mg GAE/ g matéria seca para a cultivar 14-4. As análises de ABTS e DDPH foram realizadas nos extratos produzidos nas condições otimizadas e os resultados obtidos foram 471?mol TEAC/g matéria seca de murtilla silvestre e 881,84 ?mol TEAC/g matéria seca de murtilla 14-4 para o ABTS e 229,59 ?mol TEAC/g matéria seca de murtilla silvestre e 403 ?mol TEAC/g matéria seca de murtilla 14-4 para o DPPH. Análise cromatográfica em fase gasosa acoplada a detector de massas foi realizada visando a identificação dos compostos presentes nos extratos, após derivatização das amostras. Foram identificados componentes como quercetina, epicatequina, ácido gálico, ácido benzoico e ácido hidrocafeico, que possuem atividade antioxidante comprovada. Os extratos potencialmente antioxidantes foram aplicados em sistema modelo (50, 100, 150 e 200 mg kg-1) com óleo insaturado (óleo refinado de soja, sem adição de antioxidantes sintéticos) em condições aceleradas: Teste de estufa (Schaal Oven Test) e Rancimat. No teste de Estufa e no Rancimat as concentrações que apresentaram melhor poder antioxidante foram a de 150 e 200 mg kg-1 para as duas amostras de extratos de frutos de murtilla analisadas. Os resultados de análise sensorial com provadores treinados demonstraram que não houve diferenças estatisticamente significativas entre as concentrações dos extratos adicionados ao óleo de soja submetido à oxidação em estufa, sendo que o TBHQ demonstrou a melhor aceitação. Contudo, considerando as observações feitas pelos provadores é possível afirmar que após as 96 horas de estufa, o odor de ranço foi mascarado pelo odor agradável do extrato dos frutos. / Lipid oxidation is one of the most important causes that promote the loss of nutritional and sensory qualities of foods containing lipids in their composition, thus decreasing their shelf life and causing rejection by consumers. Considering theses aspects, the food industry uses antioxidant compounds that are able to inhibit or retard oxidation. However most of antioxidants currently used are synthetic, with restrictions as to its use in lipid-based foods that vary from country to country. Such restrictions are based on aspects related to the impact of synthetic antioxidants on consumer\'s health. Due to this, in the last decade there was an increase in the number of researches that focuses on using natural sources of antioxidants, such as vegetables, fruits, among others, in food, in order to identify potential sources of antioxidants. With this objective, the present study evaluated the antioxidant activity of hydroalcoholic extracts of two varieties of murtilla\'s fruits (Ugni molinae Turcz.), wild and 14-4, through the application of in vitro assays and in a model system based on soybean oil. The application of response surfaces methodology allowed the selection of the optimal operating condition for the production of hydroethanolic extracts from dried fruit. The total phenolic compounds were determined for evaluation of extracts\' antioxidant activity and adjustment of mathematical models. The condition with the highest phenolic content was extracted using ethanol 49,5% (v/v) and temperature at 30°C, the content for the wild murtilla was 18,39 mg GAE/g dry matter and 26,14 mg GAE/g dry sample for 14-4. The ABTS and DDPH analyses were proceeded with selected optimization extracts and the results were 471?mol TEAC/g dry sample of wild murtilla and 881,84 ?mol TEAC/g dry sample of 14-4 murtilla for ABTS and 229,59 ?mol TEAC/g dry sample of wild murtilla and 403 ?mol TEAC/g dry sample of 14-4 murtilla for DDPH. The analysis by gas chromatography-mass detector was performed for the identification of compounds presents in the extracts after derivatization of the samples. Were identified compounds as quercetin, epicatechin, gallic acid, benzoic acid and hidrocafeico that have proven antioxidant activity. The extracts potentially antioxidants were applied to the model system in increasing doses (50, 100, 150 and 200 mg kg-1) with unsaturated oil (refined soybean oil without addition of synthetic antioxidants) under accelerated conditions: Oven Test (Schaal Oven Test) and Rancimat. Concentrations that better presented antioxidant power were 150 and 200 mg kg-1for both of murtilla samples. Sensory results showed that there was no statistically significant difference among the concentrations of the extracts, and TBHQ showed a better acceptance by the trained panel. However, considering the comments made by the tasters is possible to affirm that after 96 hours of oven, the rancid odor is masked by the pleasant odor of the fruit.
57

Estudo da biossíntese de poli-3-hidroxibutirato-co-hidroxialcanoatos de cadeia média (P3HB-co-3HAmcl) a apartir de ácidos graxos livres e óleo vegetal. / Biosynthesis study of poly-3hydroxybutirate-co-hydroxyalkanoates of medium chain length (P3HB-co-3HAmcl) from fatty acids and plant oil.

Cézar Vanzin 19 May 2008 (has links)
Os polihidroxialcanoatos constituem um grupo de poliésteres acumulados por inúmeras bactérias na forma de grânulos intracelulares, que podem representar até 80% da massa seca celular. No presente trabalho, foi avaliado o comportamento de diferentes linhagens quanto a capacidade de metabolizarem ácidos graxos livres e óleo de soja para a produção de biopolímeros e, posteriormente, em biorreator, algumas linhagens selvagens e recombinantes foram testadas na presença ou não de um inibidor da b-oxidação. Experimentos em frascos agitados, mostraram valores de teor de PHA em até cerca de 70% na biomassa total com cerca de 5% de monômeros de cadeia média permitindo selecionar as linhagens Cupriavidus necator e Burkholderia cepacia para os ensaios seguintes. Experimentos em biorreator mostraram que, as variáveis manipuláveis quanto ao fluxo de óleo de soja, de co-substratos e o inibidor de b-oxidação não influenciaram, significativamente, no rendimento de P3HB/3HAmcl formado quando utilizado Burkholderia cepacia IPT-048, entretanto, contribuíram na síntese de 3HV. Durante os ensaios, o aumento do número de cópias do gene phaB em Cupriavidus necator, aparentemente, não contribuíram para o aumento do rendimento de 3HHx, porém, outras variáveis manipuláveis deverão ser propostas para a confirmação. / The poly-3-hydroxyalkanoates (PHA) are a group of polyesters accumulated for several bacteria in the intracellular granule form, that can represent up to 80% of the dry mass cellular. The main advantage of the biopolymers on the synthetic materials is its degradation in the environment. Recycable raw materials can be used as carbon sources for the production biodegradable polymer. Some polymers have appeared in literature having mechanical characteristic considered appropriate in such a way for use in packings (flexible and covering films), how base for controlled release of asset to be applied in the pharmacological-medical and foods area. The P3HB-co-3HAmcl are 3-hydroxybutyrate copolymers and 3-hydroxyacyl of 6 or more carbon atoms which has aroused interest for to present intermediate properties between HB and HAmcl, having taken care of the requirements for diverse applications. Some strains are distinguished, however, assays in bottles agitated with the Cupriavidus sp. and Burkholderia sp. strains, using as substratum greasy free acid and soy oil, had led the promising results. In the present work, first, was evaluated the behavior of different strains (Cupriavidus necator DSM545 IPT-026, C. necator H16 IPT-027, Pseudomonas sp. IPT-066, Burkholderia cepacia IPT-048 and B. sacchari IPT-189) how much to metabolizer capacity of free fatty acids and soybean oil for the production of biopolymers and, later, in tank bioreactor some wild strains and recombinant had been tested together or not of an inhibitor of the boxidation (acid acrylic). Experiments in bottles with agitation, had shown values of PHA in about 70% of the total biomass with about 5% monomers chain average allowing to select the Burkholderia cepacia IPT-048 and Cupriavidus necator DSM545 strains for the following assays. Experiments in tank bioreactor had shown that, the interactions between the substratum, co-substratum and the inhibitor of boxidation had influenced in the amount of formed P3HB/3HAmcl when used the Burkholderia cepacia IPT-048 strains, contributing for the synthesis of 3HV and 3HHx. When used only the soybean oil (5g/L) was gotten an amount of HHx with about 6 mol% with Burkholderia cepacia strains. In this same condition was verified that after some determined period also proved monomer HV in an amount of 0.20 mol%. Adding the acid acrylic (0.18 g/L) were gotten 1.50 mol% of HHx, however, differently of the previous condition the amount of HV varied of 0.91 - 2.77 mol%. A conclusion for the condition soybean oil and acrylic acid is that, the strains is using the acrylic fatty acid as carbon source, or either, the formation of acrylil-CoA with consequent formation of chains with 5 carbons. Similar results had been gotten when analyzed extracted polymer, or either, after the stage of extraction with chloroform was verified that the amount varied of 1.60 - 2.14 mol%. When added to a cosubstratum in the phase of accumulation (caproic fatty acid) and absence of the acrylic acid, it did not have the increase of HHx in relation to the previous variable, as much that, the amount of monomer reached about 0.50 mol%. In this condition, the presence of the acrylic fatty acid also did not contribute for the HV synthesis, not having been observed monomers during the assays. In the following phase, in which we work with Cupriavidus necator and a recombinant (Cupriavidus necator::phaB) strains, was verified that the gotten amount of HHx had been similar, about 0.30 mol%. Our hypothesis, we believe that the increase of the number of copies of the gene phaB could contribute for the increase of the carbon flow in the direction to raise the amount of 3HB how much of other monomers. As in the assays in bottles with agitation substrat caproic and caprylic fatty acids they had been distinguished also when availabled 2g/L and the soybean oil of in a concentration of 5g/L, we analyze the strains recombinant with soybean oil and caprylic fatty acid with 5 g/L. The insistence in the use of the caprylic fatty acid was based on the fact of the possibility of strains to oxidate part of fatty acids for the production of cells and energy and, at the moment that had the nitrogen limitation, to begin the accumulation phase dividing two carbons for the production of acetyl-CoA and the remain of the chain was stored in the form of 3HHx. The caprylic fatty acid disponibility it did not have the monomer attainment, therefore, Cupriavidus necator and Cupriavidus necator::phaB had its replyed inhibited capacity by the substratum. In the added soybean oil bottles with and without the acrylic fatty acid the behavior it was the opposite to the observed with caprylic fatty acid. During the incubation period, for both the strains, the amount of PHA, and consequently, the percentage of 3HB in the dry mass cellular was of 22.95% (100 mol%) and 25.90% (100 mol%) in 28ª and 24ª hours, respectively. In this condition, in the recombinant strains, also was observed the presence of HHx between 32ª and 49ª hour with a maxim amount of 1.10 mol%. From the results it can be concluded that the Burkholderia cepacia is considered a promising strains for the attainment of HHx and HV allowing that soybean oil with and without the acrylic fatty acid, respectively. The increase in the number of copies of the gene phaB in Cupriavidus necator apparently did not contribute with the increase of 3HHx efficiency however, other handling variables will be proposed for confirmation.
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Estudo do comportamento do óleo de soja como fluido de têmpera na presença de aditivos anticorrosivos / Study behavior of soybean oil as a quenching fluid in the presence of anticorrosion additives

Daniel Komatsu 30 March 2009 (has links)
Estuda o desempenho de diferentes anticorrosivos, adicionados ao óleo de soja aditivado com o Irganox L 109, um antioxidante. O objetivo é verificar qual deles oferece melhor proteção ao latão e ao aço, simultaneamente. Ensaios de perda de massa e análise potenciodinâmica foram feitos com essa finalidade. Essas formulações foram caracterizadas com ensaios de viscosidade, curvas de resfriamento, espectroscopia de infravermelho e ângulo de contato. O estudo se estendeu, também, para o óleo de soja puro (sem adição de aditivos). Essas formulações de óleo de soja com diferentes concentrações de anticorrosivos e com uma concentração fixa de antioxidante foram submetidas a um processo de envelhecimento acelerado e após isso, foram novamente realizados os ensaios citados anteriormente. Com isso, pode-se comparar qual das formulações sofreu a menor variação na sua propriedade. Com isso, pode-se verificar que a formulação 0,1% 2-mercaptobenzotiazol foi a que apresentou o melhor comportamento para a finalidade requerida. / This work presents studies the performance of different anticorrosion additives, that were added in a composition of soybean oil and antioxidant Irganox L 109. The objective was determine which one offers good protection to the brass and steel, simultaneously. Tests of loss mass and potentiodynamic analysis were performed for this purpose. These formulations were characterized with tests of viscosity, cooling curves, infrared spectroscopy and contact angle measures. Similar studies were also extended to the pure soybean oil (without additives). The soybean oil formulations (different anticorrosion concentrations and fixed antioxidant concentration) were subjected to process of accelerated aging (oxidation) and new characterization tests were performed again. Comparative analyses between before and after oxidation tests were performed in order to verify which formulation had less variation on the properties. Results shown formulation 0.1% 2-Mercaptobenzothiazole has the best behavior for the purpose required.
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Studies on colloidal and emulsifying properties of naturally-derived molecular assemblies / 天然由来の分子集合体コロイド特性および乳化特性に関する研究

Ishii, Toya 25 March 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第21811号 / 農博第2324号 / 新制||農||1066(附属図書館) / 学位論文||H31||N5183(農学部図書室) / 京都大学大学院農学研究科農学専攻 / (主査)教授 松村 康生, 教授 白岩 立彦, 教授 丸山 伸之 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM
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Identifying possible misspecification in South African soybean oil future contracts

Nordier, Jean-Pierre January 2021 (has links)
Soybean crushing plants operate on a crush margin, which is the monetary difference between the combined sales value of mainly soybean meal and soybean oil and the cost of raw soybeans. However, given the high volatility in the prices of these three products, crushing plants normally secure these prices simultaneously. If not, they are vulnerable to the relative price variation between these three products. Futures markets, such as the Johannesburg Stock Exchange (JSE) Commodities Derivatives Market (CDM) (previously known, and hereafter referred to, as the South African Futures Exchange (SAFEX)), provide futures contracts that can be used as a mechanism for securing these prices. Soybean crushing plants would usually buy soybean futures contracts whilst simultaneously selling soybean meal and soybean oil futures contracts (in a ratio aligned with production), thereby securing the processing plant’s gross margin or better known in the industry as the ‘crush margin’. But this is only viable given adequate liquidity within these futures contracts (which is not the case for SAFEX soybean oil futures contracts). Furthermore, if South Africa is a net importer of the underlying commodity, as is the case with soybean oil, the CBOT contract, as traded on SAFEX futures’ price normally represents the majority of the import cost also known as the import parity cost. Therefore, with most soybean oil usually being imported from Argentina, one would expect SAFEX soybean oil futures contracts to reflect the cost of imported soybean oil from Argentina (which are significantly different at times through the season). However, currently (2020), the SAFEX soybean oil futures contract is a CBOT contract, that is dual listed and cash-settled . The research study seeks to determine whether this is a misspecification and whether or not SAFEX soybean oil futures contracts should rather be based on the Argentina fob soybean oil prices which is a much better representation of South Africa’s import parity and local industry prices. If correct, it may also explain why market participants are reluctant to utilize SAFEX listed CBOT soybean oil futures contracts, explaining the low trading volumes and inadequate liquidity. Hence, the study used the Engle-Granger (1987) cointegration approach, alongside a range of diagnostic tests to evaluate the existence of adequate long and short-run cointegration relationships amongst a linear combination of data variables underlying the current specifications of SAFEX soybean oil futures contracts versus that of an alternative linear combination of data variables that are cash settled of Argentina fob prices (settlement values). Essentially evaluating its efficiency under Eugene Fama’s semi-strong-form of market efficiency, in an attempt to identify possible misspecification by referencing CBOT settlement values as opposed to Argentina settlement values that could ultimately lead to greater participation and improved liquidity. The study however failed to produce overwhelming statistical evidence for using Argentina settlement values as opposed to CBOT settlement values. Diagnostic tests revealed possible misspecification amongst the long-run equilibrium relationships for both CBOT and Argentinian soybean oil future prices, while concluding for no-misspecification amongst CBOT soybean oil future prices in the short-run. These results suggest that SAFEX soybean oil futures contracts does not incorporate all the information used by market participants in forming a prediction of subsequent spot market prices in the long-run. But does however incorporate sufficient information for such practices in the short-run, attracting speculators who hope to profit from short-term price variations in the absence of hedgers (typically soybean crushers) who in turn seek to employ effective long-term hedging strategies. Therefore, the study rather pointed towards using CBOT settlement values until South Africa becomes self-sustainable, meeting local demand with local production. In such case, a local physically settled soybean oil futures contract should be listed that accurately reflects local supply and demand conditions, given the collective participation amongst the majority of market participants within the South African soybean industry. / Dissertation (MScAgric (Agricultural Economics))--University of Pretoria, 2021. / African Economic Research Consortium / Agricultural Economics, Extension and Rural Development / MScAgric (Agricultural Economics) / Unrestricted

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