Submitted by ÉRICA SANTOS MELLO null (ericamello29@gmail.com) on 2017-04-24T00:57:16Z No. of bitstreams: 1 Versão final - Dissertação Érica Santos Mello 20-04.pdf: 1103199 bytes, checksum: 16064b2a0adb96fb4ac459ad1c9124df (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-04-25T20:06:17Z (GMT) No. of bitstreams: 1 mello_es_me_ilha.pdf: 1103199 bytes, checksum: 16064b2a0adb96fb4ac459ad1c9124df (MD5) / Made available in DSpace on 2017-04-25T20:06:17Z (GMT). No. of bitstreams: 1 mello_es_me_ilha.pdf: 1103199 bytes, checksum: 16064b2a0adb96fb4ac459ad1c9124df (MD5) Previous issue date: 2017-03-03 / 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

Orientador: Antonio Celso Pezzato / Resumo: Esta pesquisa avaliou a ação de um emulsificante comercial Avilac E em rações com óleo de soja, óleo de vísceras e mistura de ambas em partes iguais na alimentação de frangos de corte. Foram feitos dois experimentos, no experimento 1 foram alojados 720 pintos machos em 24 boxes com 30 aves/box, distribuídos em um delineamento em blocos casualisados com esquema fatorial 3x2, com três fontes de óleo: óleo de soja, óleo de vísceras e mistura de 50% de óleo de soja e 50% de óleo de vísceras; e com e sem adição do emulsificante, totalizando seis tratamentos. Foram avaliados desempenho para os períodos acumulados de 1 a 7, 1 a 14 e 1 a 42 dias de idade para peso corporal, ganho de peso, ganho de peso diário, consumo de ração, conversão alimentar, mortalidade e no último período, fator de produção.Foram avaliados rendimentos de carcaça, partes e gordura abdominal ao abate com 42 dias de idade. Também foram avaliados nesta idade níveis séricos de colesterol, triacilglicerol, HDL colesterol e através de analise do pâncreas a atividade da lipase pancreática. No experimento 2 foram alojados, em uma câmara com controle de temperatura, 72 pintos machos em baterias com 24 gaiolas, com delineamento em blocos casualisados com esquema fatorial 3x2, com três fontes de óleo: com óleo de soja, com óleo de vísceras e com 50% de óleo de soja e 50% de óleo de vísceras; e com e sem adição do emulsificante, totalizando seis tratamentos, com 4 repetições (gaiolas) de 3 aves cada, onde se avaliou a partir do 21º dia, por 3 dias consecutivos, o coeficiente de digestibilidade dos excretas para matéria seca (MS), extrato etéreo (EE), proteína bruta (PB) e fibra bruta (FB). As análises estatísticas dos experimentos 1 e 2 foram feitas pelo método de análise de variância com auxílio do procedimento GLM do programa...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This research evaluated the action of a commercial emulsifier in diets with soy oil, poultry fat and the blend of both sources in equal fraction as fat sources in feeding of broilers. Two experiments were conducted, in experiment 1, 720 male chicks in were housed 24 boxes with 30 chicks/box, in a randomized blocks design with a factorial arrangement 3x2, with three sources of oil: soy oil, poultry fat and the blend of 50% of soy oil and 50% of poultry fat, with emulsifier or not, resulting in six treatments. The performance was estimated for the accumulating periods of 1 to 7, 1 to 14 and 1 to 42 days old for body weight, weight gain, daily weight gain, feed intake, feed conversion ratio and mortality. The carcass yield, parts and abdominal fat were estimated on 42nd day old Blood levels of cholesterol, triacilglicerol, HDL cholesterol and pancreatic analysis of the lipases activity were also estimated on the 42nd day old. In experiment 2; 72 male chicks were housed, in a climatic chamber, in a battery of 24 cages, in a randomized blocks design with a factorial arrangement 3x2, with three sources of oil: soy oil, poultry fat and the blend of 50% of soy oil and 50% of poultry fat; with emulsifier or not, resulting in six treatments, with 4 repetition (cages) with 3 chicks each, the rate of digestibility of excrements for dry matter (MS), ether extract (EE), crude protein (PB) e crude fiber (FB), were estimated on the 21st day old, for 3 consecutives days. The statistical analyses of experiments 1 and 2 were submitted to analysis of variance using the GLM procedure of SAS (1996), and the different means were compared using the Tukey's Test. The performance of the broilers with the use of emulsifier was better for weight...(Complete abstract click electronic access below) / Mestre

Orientador: Gabriela Alves Macedo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-12T23:26:09Z (GMT). No. of bitstreams: 1 Lopes_DanielleBranta_M.pdf: 1927712 bytes, checksum: 4c84529dc29400d6dfb671ad68c0abc8 (MD5) Previous issue date: 2009 / Resumo: O aumento da demanda por esteres obtidos naturalmente ou por processos biotecnologicos, para aplicacoes como aditivos em alimentos, cosmeticos, industrias farmaceuticas e de lubrificantes, faz necessario o desenvolvimento de catalisadores altamente especificos. Por esta razao, o uso de enzimas como catalisadores para a sintese de esteres de alto valor agregado vem sofrendo um rapido desenvolvimento, por proporcionar a possibilidade de obtencao de um produto atraves de um processo biologico. Embora destinada pela natureza para realizar a hidrolise de lipideos, lipases (E.C. 3.1.1.3) podem, sob condicoes apropriadas de reacao, promover a formacao de esteres atraves de reacoes de acidos e álcoois (esterificacao). Comparadas com processos quimicos ja realizados em uma escala industrial, reacoes enzimaticas ocorrem sob condicoes brandas (e ecologicamente mais favoraveis) apesar de poderem ser mais lentas. A grande vantagem e a especificidade apresentada pelas enzimas, que permite a formacao de derivados lipidicos, os quais nao sao facilmente preparados por processos laboratoriais convencionais. Neste trabalho, foi avaliado o desempenho de lipases microbianas e vegetais, nao-comerciais, e comparadas a uma lipase comercial, na síntese de esteres com possiveis propriedades emulsificantes, bem como a influencia das condicoes de reacao (concentracao de enzima, quantidade de agua, relacao molar dos substratos, tipos de meios reacionais, e cinetica) no processo de esterificacao. A etapa seguinte do estudo foi constituida de um planejamento experimental fatorial completo com o proposito de otimizar a producao do ester oleato de oleila, em meio livre de solvente organico, com a lipase de Rhizopus sp. selecionada por apresentar melhor desempenho catalitico. O mesmo estudo foi realizado tambem com a lipase comercial Lipozyme TL IMR, com finalidade comparativa. Os parametros reacionais estudados foram: razao molar entre os substratos (acido:alcool) e concentracao de enzima (% m/m em relacao a massa de reagentes). Destes ensaios, verificou-se melhor habilidade catalitica da lipase de Rhizopus sp. utilizando maior proporcao de alcool (2:1) e maior quantidade de enzima (9,8%). O mesmo foi observado com a enzima comercial Lipozyme TL IMR, a qual tambem apresentou maior producao de ester quando se fez uso de uma maior proporcao de alcool (3:1) e maior quantidade de enzima (7,0%). A porcentagem de esterificacao obtida pela lipase de Rhizopus sp. (93,1%) foi muito proxima a porcentagem obtida pela lipase comercial Lipozyme TL IMR (94,2%), evidenciando o grande potencial desta enzima nao-comercial na sintese do oleato de oleila. Por fim, foi realizada a caracterizacao parcial do ester quanto as atividades emulsificante e antimicrobiana. Resultados indicaram que o ester produzido neste trabalho demonstrou atividade emulsificante, porem esta nao foi tao alta quando comparada aos emulsificantes comerciais: Dodecil Sulfato de Sodio (SDS) e Tween 80. Observou-se tambem que o oleato de oleila nao foi capaz de inibir o crescimento microbiano de Bacillus subtilis, sendo assim, ate o presente momento, nao foi detectada atividade antimicrobiana para este ester / Abstract: The increasing demand for esters obtained either through natural or biotechnological processes for use as food additives, cosmetics, pharmaceuticals and lubricants requires the development of highly specific catalysts for ester production. For this reason, the use of enzymes as catalysts for the synthesis of esters with high added value is undergoing rapid development. Although the main function of lipases in nature is to catalyze the hydrolysis of lipids, it can also be made to promote ester formation through the reaction of acids and alcohols (esterification) under specific reaction conditions. Although on an industrial scale enzymatic reactions may be longer when under milder and ¿greener¿ conditions compared to chemical processes. The great advantage of working with enzymes is their great specificity, which often allows for the preparation of lipid derivatives not easily obtained using conventional laboratory procedures. This work first evaluated a few variables affecting the synthesis of esters and the esterification process, namely the influence of: the use of commercial and non-commercial lipases of vegetable and fungi origin, reaction conditions, enzyme concentration, amount of water, molar ratio of substrates, types of organic solvents and reaction kinetics. In a second step, a complete factorial design was considered in order to optimize ester production in solvent-free systems using Rhizopus sp. lipase and Lipozyme TL IMR which were chosen because of their good performance. The reaction parameters chosen were molar ratio of substrates (acid:alcohol) and enzyme concentration. Lipase from Rhizopus sp. displayed the best catalytic activity at a molar ratio of 1:2 (acid:alcohol) and an enzyme concentration of 9.8%, whereas Lipozyme TL IMR had the best catalytic activity at a molar ratio of 1:3 and enzyme concentration of 7.0%. The rate of the sterification reaction yielded 93.1% using lipase from Rhizopus sp., very close to what it is obtained using commercial Lipozyme TL IMR that is 94.2%. This result shows a high potential for this non-commercial enzyme to be used as a catalyst for the oleyl oleate synthesis. The characterization of the ester included evaluation of emulsifier and antimicrobial activities. Oleyl oleate synthesized in this study proved to have lower emulsifier activity compared to commercial emulsifiers like sodium dodecyl sulfate (SDS) and Tween 80. Also, oleyl oleate did not inhibit the growth of Bacillus subtilis, thus no antimicrobial activity was observed for this substance / Mestrado / Mestre em Ciência de Alimentos

Arthrospira platensis ou Spirulina é uma microalga com alto valor nutricional. Foram preparados extratos de Spirulina, caracterizados e aplicados como estabilizadores de emulsão de óleo de girassol comercial em água (O/A) (10% v/v) na ausência e na presença de quatro tipos de hidroxipropil metilcelulose (HPMC). Os extratos brutos de Spirulina foram preparados em tampões a pH 6 (EB6) e pH 8 (EB8) por sonicação para promover a lise celular e a libertação de proteínas e fosfolípides; Parte dos extratos foi centrifugada (EC6 ou EC8). Independentemente das condições de extração, todos os extratos apresentados apresentaram valores de potencial-&#950 médio variando de - (16 ± 2) mV a - (20 ± 2) mV, tamanho médio variando de (108 ± 52) nm a (306 ± 68) nm e atividade interfacial. As emulsões O/A preparadas com extratos de Spirulina (10 g / L) exibiram partículas com potencial- médio variando de - (16 ± 2) mV a - (27 ± 4) mV, tamanho médio variando de ~ 70 nm (EB6 ou EB8) a ~ 700 nm (EC6 ou EC8). No entanto, o EB6 levou a emulsões ligeiramente mais estáveis do que as outras. A combinação de EB6 (10 g / L) e HPMC (1,0 % m/m) levou a um aumento substancial na estabilidade da emulsão, embora os valores de potencial- diminuíram uma ordem de grandeza. Em particular, a HPMC com a maior massa molar e o maior grau de substituição de grupos metila conduziu a i) camada interfacial mais robusta resultante da formação de complexos entre cadeias HPMC e proteínas EB6 e (ii) meio contínuo mais viscoso. / Arthrospira platensis or Spirulina is a microalga with a high nutritional value. Extracts of Spirulina were prepared, characterized and applied as oil in water (O/W) (10 % v/v) emulsion stabilizers in the absence and presence of four types of hydroxypropyl methylcellulose (HPMC). The emulsions were prepared with edible sunflower oil. Crude extracts of Spirulina were prepared in buffers at pH 6 (CE6-Crude extract pH6) and pH 8 (CE8-Crude extract pH8) by sonication to promote cell lysis and protein and phospholipids release; part of the extracts was centrifuged (CCE6 or CCE8). Regardless of the extraction conditions, all extracts presented mean -potential ranging from (16 ± 2) mV to (20 ± 2) mV, mean diameter ranging from (108 ± 52) nm to (306 ± 68) nm and interfacial activity. The emulsions prepared with Spirulina extracts (10 g/L) displayed particles with mean -potential ranging from (16 ± 2) mV to (27 ± 4) mV, mean diameter ranging from ~ 70 nm (CCE6 or CCE8) to ~ 700 nm (CE6 or CE8). However, CE6 led to emulsions slightly more stable than the others did. The combination of CE6 (10 g/L) HPMC (1.0 wt %) led to substantial increase in the emulsion stability, although the -potential values decreased one order of magnitude. Particularly, the HPMC with the highest molecular weight and highest methyl substitution degree led to the most (i) robust interfacial layer resulting from the complex formation between HPMC chains and CE6 proteins and (ii) viscous continuous medium.

Colloidal dispersions such as oil-in-water or water-in-oil emulsions have found widespread use in the food industry. Oil-in-water emulsions consist of three principal components i.e. oil dispersed in the form of droplets, water surrounding the droplets as the continuous phase, and emulsifiers comprising the interface. Because of the complicated interaction among components, it is often difficult to predict the physicochemical properties and final functionalities of emulsions. Nevertheless, the structural and functional features of emulsions allow scientists to create many unique emulsions that may serve as suitable carriers for lipophilic functional compounds. These functional compounds may include antioxidants, flavors, colors and antimicrobials, the latter which is the principal topic of this thesis. Incorporation of food antimicrobials in emulsions could create value-added emulsions that may improve the safety and quality of a variety of foods, but to date, few systematic studies on their formulation have been reported. The objective of this thesis was therefore to formulate food emulsions that are physicochemically stable and able to deliver antimicrobial compounds to microbial target sites. Two antimicrobial agents, N-α-lauroyl-L-arginine ethyl ester monohydrochloride, (LAE) and eugenol were used as model compound to be incorporated into the colloidal food dispersion. The two antimicrobials were selected because they are either amphiphilic (LAE) or predominantly lipophilic (eugenol). When emulsions were formulated with eugenol, an essential oil component, it was found that O/W emulsions were only stable when emulsions were formulated with other lipids (hexadecane, dodecane, tetradecane, and corn oil). Above a critical loading of the carrier lipid with eugenol, Ostwald’s ripening led to rapid destabilization while above this critical loading concentration, the ripening rate was greatly reduced and depended on type of carrier lipid and concentration of eugenol. Alternatively, when emulsions were formulated with LAE as emulsifier, results indicated that emulsions were not stable to aggregation and coalescence. Consequently, LAE had to be combined with a nonionic surfactant (Tween 20) to improve the emulsion stability. Higher Tween20 composition led to more stable emulsions droplets. Both systems (emulsions with either eugenol or LAE) had high antimicrobial efficacies and were able to completely inhibit microbial growth at concentrations that depended on the type of microorganisms and formulation of the emulsions. Generally, eugenol were able to more effectively inhibit the growth of E.coli O157:H7 while LAE containing emulsions were more effective against L.monocytogenes. Finally, a food emulsion was formulated that contained both antimicrobial agents; eugenol in the lipid phase and LAE in the droplet interface. Interestingly, stability of these emulsions depended both on the LAE and eugenol loading. The antimicrobial activity in this double antimicrobial emulsion was high but was principally influenced by the interfacial formulation that is the ratio of LAE to Tween 20. The combined emulsion similar to the LAE stabilized emulsion more effectively inhibited growth of L.monocytogenes.

Selected emulsifiers, enzymes, and a fat substitute were incorporated into a standard muffin recipe, and their effects were compared to a full fat counterpart. Physical and sensory data were reported at the 0.01 significance level. Physical tests indicated no significant differences (p>0.01) among crust “L” and “b” values, specific gravity, water activity, and staling rate after 48 hours storage. The control muffin had a significantly (p<0.01) more yellow crumb, was significantly (p<0.01) less firm, and contained less moisture (p<0.01). The versions containing SSL and DATEM were less firm (p<0.01) and retained slightly more moisture (p<0.01) than the other reduced fat muffins. The control muffins and the versions containing SSL and DATEM were significantly (p<0.01) greater in volume than the other reduced fat muffins. Fat and DATEM were found to prolong retrogradation at a significantly (p<0.01) slower rate than in the other versions after 24 hours storage. Sensory results indicated no significant differences (p>0.01) in perceived adhesiveness. The muffins containing only the fat substitute and enzymes were rated with a significantly (p<0.01) darker crust color and (p<0.01) aftertaste than the other versions. The control muffin was significantly (p<0.01) moister, and contained a larger crumb (p<0.01) than the other versions. The control muffin was significantly (p<0.01) less cohesive. The results obtained from the data indicated that there were similarities and differences between the reduced fat versions and the control. / Master of Science

Emulsion explosives have become the preferred choice as blasting agents for numerous industries including mining, agriculture, and construction. One of the most important components in such an emulsion is an emulsifier, which controls the emulsification properties of the explosive. The present study involves the production of one such emulsifier, which is produced by reacting two immiscible liquids, PIBSA (polyisobutylene succinic anhydride) and MEA (monoethanolamine). The study examines the effect of design variable such as the impeller speed, impeller type and the dispersed phase volume fraction on interfacial area. Experiments were carried out in a 0.15 m diameter fully baffled stirred tank using a 6-bladed Rushton turbine impeller and a marine propeller. Drop size was determined using a microscope with a video camera and image processing system. The transient concentration of PIBSA was determined using FTIR analysis and used to estimate the volume fraction of the dispersed phase (ƒÖ). The effective interfacial area was calculated using the Sauter mean drop diameter, d32 and ƒÖ. Impeller speeds ranging from 150 to 600 rpm and dispersed phase volume fractions, ƒÖ ranging from 0.01 to 0.028 were examined in the experimental study. It was found that that the evolution of Sauter mean drop diameter, d32 has four different trends depending on ƒÖ and impeller speed. At high impeller speeds and high ƒÖ, d32 values decrease initially and reach constant values after a long period of time. This trend is consistent with the findings in previous investigations. Under certain operating conditions, d32 values increase initially with stirring time to reach a maximum value and then decrease to reach a steady state value. The presence of these trends has been attributed to the effect of changing physical properties of the system as a result of chemical reaction. Results indicate that, in general, Sauter mean drop diameter d32 decreases with an increase in agitation intensity. However a decrease in the dispersed phase volume fraction is found to increase d32. These trends are found to be the same for both impeller types studied. Comparing the drop size results produced by the two impellers, it appears that low-power number propeller produces s ignificantly smaller drops than the Rushton turbine. It was found that the concentrations of reactants decrease with time for all impeller speeds thereby leading to a decrease in interfacial area with the progress of the reaction. Interfacial area values obtained at higher impeller speeds are found to be lower in spite of lower d32 values at these speeds. Also, these values decrease with time and become zero in a shorter duration indicating the rapid depletion of MEA. The interfacial area values obtained with the propeller at a given impeller speed are lower as compared to those for Rushton turbine. They also decrease and become zero in a shorter duration as compared to those for Rushton turbine suggesting propeller¡¦s performance is better in enhancing the reaction rate.

Polymere sind zweifelsohne der Werkstoff in unserer Zeit. Ein bedeutender Anteil der heute industriell produzierten Polymere wird durch Emulsionspolymerisation hergestellt. Obwohl die Emulsionspolymerisation breite Anwendung findet, sind die involvierten Mechanismen von Teilchenbildung und -wachstum noch heute Gegenstand heftiger Kontroversen.<br> Ein Spezialfall der Emulsionspolymerisation ist die emulgatorfreie Emulsionspolymerisation. Hierbei handelt es sich um ein scheinbar einfacheres System der Emulsionspolymerisation, weil diese Methode ohne Zusatz von Emulgatoren auskommt.<br><br> Die Teilchenbildung ist ein fundamentaler Vorgang im Verlauf der Emulsionspolymerisation, da sie zur Ausbildung der polymeren Latexphase führt. Detaillierte Kenntnisse zum Mechanismus der Nukleierung ermöglichen eine bessere Kontrolle des Reaktionsverlaufes und damit der Eigenschaften des Endproduktes der Emulsionspolymerisation, dem Polymer-Latex.<br> Wie bereits vorangegangene Arbeiten auf dem Gebiet der emulgatorfreien Emulsionspolymerisation von Styrol sowie Methylmethacrylat und Vinylacetat zeigen konnten, verläuft die Teilchenbildung in diesen Systemen über den Mechanismus der aggregativen Nukleierung. Im Zusammenhang mit den Ergebnissen der genannten Arbeiten tauchte dabei immer wieder ein interessanter Effekt im Bereich der Partikelnukleierung auf. Dieses als JUMBO-Effekt bezeichnete Phänomen zeigte sich reproduzierbar in einem Anstieg der Transmission im Bereich der Teilchenbildung von emulgatorfreien Emulsionspolymerisationen von Styrol, MMA und VAc. Nach der Initiierung der Polymerisation in einer wässrigen Monomerlösung durch Kaliumperoxodisulfat steigt die Durchlässigkeit bei 546 nm auf über 100 % an. Für diese „Abnahme der optischen Dichte“ wurden verschiedene Erklärungsmöglichkeiten vorgeschlagen, jedoch blieb ein Nachweis der Ursache für den JUMBO-Effekt bisher aus. Dieser Mangel an Aufklärung eines offenbar grundlegenden Phänomens in der emulgatorfreien Emulsionspolymerisation bildet den „Nukleus“ für die vorlie¬gende Arbeit.<br><br> Durch die vorliegende Dissertation konnte das Verständnis für Phänomene der Teilchenbildung in der emulgatorfreien Emulsionspolymerisation von Styrol mit KPS erweitert werden. In diesem Rahmen wurde das Online-Monitoring des Polymerisationsvorganges verbessert und um verschiedene Methoden erweitert:<br> Zur simultanen Erfassung von Trübungsdaten bei verschiedenen Wellenlängen konnte ein modernes Spektrometer in Kombination mit einer Lichtleitersonde in die Reaktionsapparatur integriert werden.<br><br> Es wurde ein verbesserter Algorithmus zur Datenbearbeitung für die Partikelgrößenbestimmung mittels faseroptischer dynamischer Lichtstreuung entwickelt.<br> Es wurden Online-Partikelgrößenanalysen mittels statischer Vielwinkellichtstreuung bei Polymerisationen direkt in entsprechenden Lichtstreuküvetten durchgeführt.<br><br> Diese zur Beschreibung des untersuchten Systems eingeführten Methoden sowie ein zeitlich vollständiges Monitoring des gesamten Polymerisationsverlaufes, beginnend mit der Zugabe von Monomer zu Wasser, führten zu neuen Erkenntnissen zur emulgatorfreien Emulsionspolymerisation.<br> Es wurden große Monomeraggregate, die sog. Nanotröpfchen, in wässriger Lösung (emulgatorfrei) nachgewiesen. Diese Aggregate bilden sich spontan und treten verstärkt in entgastem Wasser auf.<br><br> Die Existenz von Nanotröpfchen in Verbindung mit Trübungs- und gaschromatografischen Messungen lässt auf eine molekular gelöste „Wirkkonzentration“ von Styrol in Wasser schließen, die bedeutend geringer ist als die absolute Sättigungskonzentration.<br> Es konnten Hinweise auf eine Reaktion höherer Ordnung im System Wasser/Styrol/KPS gefunden werden.<br><br> Es konnte gezeigt werden, dass eine präzise Einstellung der Nukleierungsdauer über die Zeit der Equilibrierung von Wasser mit Styrol möglich ist.<br> Der JUMBO-Effekt, dem in dieser Arbeit ein besonderes Interesse galt, konnte in gewisser Weise entmystifiziert werden. Es konnte gezeigt werden, dass die Durchlässigkeit der Reaktionsmischung bereits beim Lösen von Styrol in Wasser durch Bildung von Styrolaggregaten abnimmt. Der darauf folgende kurzzeitige Transmissionsanstieg im Zusammenhang mit der Nukleierung erreicht dabei nicht mehr 100 % des Referenzwertes von reinem Wasser. Alle experimentellen Daten sprechen für die Nanotröpfchen als Ursache des JUMBO-Effekts.<br> Wie die Ergebnisse dieser Arbeit zeigen, ist selbst das relativ „einfache“ System der emulgatorfreien Emulsionspolymerisation komplizierter als angenommen. Die Existenz von großen Styrolaggregaten in wässriger Lösung erfordert eine neue Betrachtungsweise des Reaktionssystems, in die auch der Lösungszustand des Monomers mit einbezogen werden muss. / Polymers are doubtless the material of today. Large amounts of industrially produced polymers are made via emulsion polymerization. Although emulsion polymerization is widely used commercially, the mechanisms of particle formation and -growth involved are still intensely controversial.<br><br> A special case of the emulsion polymerization is the emulsifier-free emulsion polymerization. This apparently easier procedure is performed without addition of emulsifier.<br> Particle formation is a fundamental event in the progression of emulsion polymerization because it leads to the formation of a polymeric latex phase. Explicit knowledge concerning the mechanism of nucleation facilitates better control of the reaction process and therefore of the properties of the final polymeric latex product.<br><br> Other contributions in emulsifier-free emulsion polymerization of styrene could already proof that particle formation in the present system proceeds via aggregative nucleation. In the context of the results of these contributions, an interesting effect was always detected in the time range of particle nucleation. This so-called “JUMBO-effect” appeared highly reproducible as an increase of transmittance during nucleation period in the emulsifier-free emulsion polymerization of styrene. After initiation of the polymerization in an aqueous monomer solution with potassiumperoxodisulfate the transmittance at 546 nm increases to more than 100 %. For this “decrease in optical density” various possible explanations have been suggested, but a proof for any of them is still to be found. This lack of insight into an apparently fundamental phenomenon in emulsifier-free emulsion polymerization arises as the “nucleus” of the present thesis.<br><br> Within this work the understanding of the phenomena of particle formation in emulsifier-free emulsion polymerization of styrene with potassiumperoxodisulfate could be enhanced. In this frame the online monitoring of the polymerization process could be improved and expanded to several methods:<br><br> For the simultaneous recording of UV-spectra respectively turbidity data at various wavelengths a modern spectrometer in combination with a fibre optical probe could be integrated into the reaction vessel.<br> An improved algorithm for data treatment of particle size determination via fibre optical dynamic light scattering was developed.<br> We implemented online particle size determinations via multi angle laser light scattering directly in light scattering cuvettes.<br><br> These newly introduced methods, in combination with temporally complete monitoring of the whole polymerization progression, starting with the addition of monomer to water, lead to novel insight into emulsifier-free emulsion polymerization of styrene:<br> Big monomer aggregates, so called “nano droplets”, could be detected in an aqueous solution of styrene. These aggregates form spontaneously and appear especially in degassed water. Polymerisation as the origin of the nano droplets can be excluded.<br> In context with turbidity and gas chromatographic measurements, the existence of nano droplets leads us to conclude that there is a molecularly dissolved “effective” concentration of styrene in water which is much lower than the absolute concentration reported in the literature.<br> We could find some hints for a higher reaction order in the system water/styrene/potassiumpersulfate. The induced decomposition of the peroxodisulfate ion in the presence of styrene and ethylbenzene shows an additional reaction of the initiator with aromatic compounds besides the thermolytical cleavage.<br> Furthermore it could be shown that it is possible to precisely adjust the duration of nucleation with the solubilisation time of styrene in water. This kind of control can be useful for other applications.<br> The JUMBO-effect, which was a major topic of this thesis, could be partly de-mystified. It could be shown that the turbidity of the reaction mixture already increases during the dissolution process of styrene due to the formation of aggregates. The turbidity decrease which is depicted by the JUMBO-effect in the time range of nucleation never reaches 100 % of the reference water. An interference of the used measuring wavelength with the domain size of density fluctuations according to the theory of spinodal decomposition could not be verified. The experimental data suggest rather the nano droplets as origin of the JUMBO-effect.<br> The results of the present thesis show clearly that the relatively “simple” system of the emulsifier-free emulsion polymerisation (water/styrene/potassiumpersulfate) is more complex than expected. The existence of big styrene aggregates in aqueous solution requires a new approach of the reaction system, which also includes the solution state of the monomer.

Submitted by Caio César dos Ouros null (caio_ouros@hotmail.com) on 2016-02-12T09:50:10Z No. of bitstreams: 1 Caio Cesar dos Ouros - Dissertação.pdf: 1048583 bytes, checksum: 02b725b1fbb61bc95af346ded3ffd3ad (MD5) / Approved for entry into archive by Sandra Manzano de Almeida (smanzano@marilia.unesp.br) on 2016-02-12T13:03:42Z (GMT) No. of bitstreams: 1 ouros_cc_me_ilha.pdf: 1048583 bytes, checksum: 02b725b1fbb61bc95af346ded3ffd3ad (MD5) / Made available in DSpace on 2016-02-12T13:03:42Z (GMT). No. of bitstreams: 1 ouros_cc_me_ilha.pdf: 1048583 bytes, checksum: 02b725b1fbb61bc95af346ded3ffd3ad (MD5) Previous issue date: 2016-02-05 / O objetivo deste trabalho foi avaliar a viabilidade da utilização do resíduo do óleo de soja (goma de soja) como um emulsificante na dieta de frangos de corte em fase inicial (1 a 21 dias). Foram realizados dois experimentos, uma para fonte lipídica de origem vegetal (óleo de soja) e outro para fonte lipídica de origem animal (gordura suína), sendo utilizados 600 pintos de corte macho da linhagem Cobb® 500, distribuídos em um esquema fatorial (3x4) sendo três níveis de goma (0%; 1,25%; 2,5%) e quatro níveis de fonte lipídica (0%; 1,3%; 2,6%; 3,9%), totalizando em 12 tratamentos com 5 repetições para cada um dos experimentos. Foram analisados parâmetros de desempenho, coeficientes de digestibilidade e atividades de enzimas pancreáticas. No experimento onde se utilizou óleo de soja como fonte lipídica foi possível verificar melhorias de desempenho a partir dos 14 dias, e também melhora do coeficiente de digestibilidade do extrato etéreo e aumento nos níveis de energia metabolizável aparente. Quando utilizada a gordura suína como fonte lipídica não foram obtidas diferenças de desempenho relacionadas a inclusão da goma, mas foi possível observar efeitos diretos da interação da utilização da goma com a gordura nos níveis de energia metabolizável aparente. / The objective of this study was to evaluate the feasibility of using soybean oil residue (soy gum) as an emulsifier in broiler diet at an early stage (1-21 days). Two experiments were conducted, one for lipid source of vegetable (soybean oil) and one for fat source of animal origin (pork fat) and used 600 male broiler chicks of the lineage Cobb® 500, distributed in a factorial scheme (3x4) with three levels of gum (0%, 1.25%, 2.5%) and four lipid source levels (0%, 1.3%, 2.6%, 3.9%), totalizing 12 treatments with 5 replicates for each of the experiments. Performance parameters, digestibility coefficients and activities of pancreatic enzymes were analyzed. In the experiment which we used soy oil as a lipid source was possible to see performance improvements from 14 days, and also improves the digestibility coefficient of ether extract and increase the apparent metabolizable energy levels. When used in pork fat as lipid source, performance differences were not obtained related to the inclusion of soy gum, but we observed direct effects of the use of gum interaction with the fat in the apparent metabolizable energy levels

Orientador: Lúcia Regina Durrant / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-22T11:02:32Z (GMT). No. of bitstreams: 1 Pescumo_FernandaFranzoni_M.pdf: 1387373 bytes, checksum: baa6cd7b83f29182ab90172ebb03c248 (MD5) Previous issue date: 2013 / Resumo: Biossurfactantes e bioemulsificantes são compostos ativos de superfícies (CAS) produzidos por micro-organismos. Desempenham várias funções biológicas, e sua característica anfifílica, juntamente com baixa toxicidade, biodegradabilidade e resistência a extremos de pH, temperatura e salinidade, tem despertado o interesse para a aplicação dessas moléculas em processos biotecnológicos. Porém, o alto custo aliado à baixa produção ainda são impedimentos para a utilização em larga escala. Os desafios para se implementar a produção são: desenvolvimento de estratégias para tornar a produção economicamente viável e o isolamento de moléculas e microorganismos mais eficientes. Neste trabalho, foi estudada a produção, isolamento, extração e caracterização de um CAS por Gordonia amicalis. O micro-organismo foi cultivado em meio GYP (glucose, extracto de levedura, peptona) por 7 dias, e a extração foi feita por precipitação com sulfato de amônio, que resultou em uma concentração de 0,5 g/L do extrato bruto em meio líquido. O CAS não reduziu significativamente a tensão superficial do meio GYP, e apresentou um balanço hidrofílico-lipofílico (HBL) de caráter lipofílico, apresentando mais emulsões do tipo água em óleo (A/O) do que óleo em água (O/A). A molécula apresentou estabilidade a temperaturas de 25ºC a 100ºC, pH de 2 a 10 e salinidades de 5% a 15% quando cultivado por 7 dias, e foi capaz de modificar a interface água/superfície na análise de ângulo de contato. O extrato de 14 dias apresentou Atividade Emulsificante em 24 horas (AE24) reduzida em temperaturas acima de 50ºC, e ausente em pH ácido e salinidades de 5% e 10%. Análises de Cromatografia de Camada Delgada (CCD) revelaram presença de aminoácidos e açúcares na molécula e a análise do potencial zeta revelou que o CAS é um surfactante aniônico. Nas análises de Espectrometria no Infravermelho com Transformadas de Fourier (IR-TF) foram observados estiramentos indicativos de agrupamentos O-H e C-O, que podem indicar presença de grupos éter ou ésteres. O CAS produzido por Gordonia amicalis em meio sintético GYP mostrou-se um eficiente agente emulsificante, com potencial para aplicações biotecnológicas futuras / Abstract: Biosurfactants and bioemulssifiers are surface active compounds (SACs) produced by microorganisms. They have a wide variety of biological functions. Its amphiphilic characteristic, with low toxicity, biodegradability and resistance to extremes of pH, temperature and salinity, has increased the interest of these molecules for application biotechnological process. However, high costs and low production rates are restrictions to their widespread use. The challenges for implementing production are: developing strategies to turn the production economically feasible and isolating more efficient molecules and microorganisms. In this work, we studied the production, isolation, extraction and characterization of a SAC by a Gordonia amicalis. The microrganism was grown in GYP (Glucose, Yeast extract, Peptone) medium for 7 days, and the isolation was carried out by precipitation with ammonium sulfate, which resulted in 0.5 g / L of crude extract. The SAC did not significantly reduce the surface tension of GYP medium, and showed an hydrophilic-lipophilic balance (HLB) with lipophilic character, showing more water in oil (W/O) emulsions than oil in water (O/W) emulsions. The molecule extracted at 7 days was stable at temperatures ranging from 25 to 100 ° C, pH of 2-10 and salinities of 5-15%, and can modify the water/surface contact by the angle of contact analysis. The 14-day isolated extract showed EA24 reduced at temperatures above 50 ºC, and had no Emulsification Activity in 24 hours (EA24) in acid pH and salinity of 5% and 10%. Thin Layer Chromatography (TLC) analysis revealed the presence of sugars and amino acids in the molecule and the zeta potential analysis revealed the compound is an anionic surfactant. In the Fourier Transformed Infrared Spectrometry (FTIV) it were observed stretches indicatives of O-H and C-O groups, that might indicate ether or ester groups. The SAC produced by Gordonia amicalis in GYP medium proved to be an efficient emulsifier, with potential for biotechnological applications / Mestrado / Ciência de Alimentos / Mestra em Ciência de Alimentos