Tesi sul tema "Spray oils"

virgen en spray para cocinar y para consumo directo. Utilizará una novedosa tecnología que evita el contacto entre el gas y el aceite y se orienta a un segmento de la sociedad que busque un producto saludable y de propiedades organolépticas agradables. Con relación al mercado para este producto el consumo interno va en aumento gracias a una tendencia creciente a consumir productos de estas características, proyectando al 2021 una demanda potencial de 807 toneladas de este producto. Sin embargo, considerando la competencia en el sector al que se dirige este producto y su intención e intensidad de compra, estimamos que la demanda del proyecto para el 2017 será de 21.46 toneladas del producto y para el 2021, 53 toneladas. Respecto a la localización de la planta, la provincia más adecuada luego de realizar un ranking de factores es Arequipa. Esto se debe a que, junto con Tacna, su producción de aceitunas es la más alta del Perú y la cercanía a la materia prima es vital. Su mayor proximidad a Lima a comparación a Tacna es lo que la define como el lugar más adecuado. La planta se localizará en el distrito Arequipa.
Trabajo de investigación

The results of the 3-year project successfully indicated that petroleum-derived spray oils can be used for effective control of a range of citrus pests including citrus leafminer, Asiatic citrus psyllid, chaff scale, red scale, citrus red mite. The results suggested that it should be possible, through use of horticultural and agricultural mineral oils and enhanced natural enemy activity, to reduce the number of pesticide sprays applied annually in China from 14-16 sprays to significantly fewer sprays in most regions. The results are also valuable as references for the implementation of citrus integrated pest management programs in Australia and other citrus-growing countries. However, despite extensive use of PDSOs in citrus and other crops since the late 1800s, few studies have been undertaken to determine their disruptive effects on orchard ecosystems or to compare their effects with those of synthetic pesticides, and these studies are limited in their sc
Doctor of Philosophy (PhD)

The results of the 3-year project successfully indicated that petroleum-derived spray oils can be used for effective control of a range of citrus pests including citrus leafminer, Asiatic citrus psyllid, chaff scale, red scale, citrus red mite. The results suggested that it should be possible, through use of horticultural and agricultural mineral oils and enhanced natural enemy activity, to reduce the number of pesticide sprays applied annually in China from 14-16 sprays to significantly fewer sprays in most regions. The results are also valuable as references for the implementation of citrus integrated pest management programs in Australia and other citrus-growing countries. However, despite extensive use of PDSOs in citrus and other crops since the late 1800s, few studies have been undertaken to determine their disruptive effects on orchard ecosystems or to compare their effects with those of synthetic pesticides, and these studies are limited in their sc

Orientadores: Miriam Dupas Hubinger, Vanessa Martins da Silva
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: O óleo de café verde merece destaque na área cosmética por sua capacidade de bloquear a radiação solar UVB (290-320 nm) e por suas propriedades emolientes. Nesse contexto, para melhor aproveitar as propriedades desse óleo e aumentar a sua estabilidade oxidativa, pretendeu-se com este trabalho produzir micropartículas de óleo de café verde, pelo processo físico de spray drying. Como agentes encapsulantes foram utilizados lecitina, um fosfolipídeo de caráter aniônico quando em pH 3,0, quitosana, um polissacarídeo de caráter catiônico também em pH 3,0 e solúvel somente em sistemas ácidos diluídos, além de sólidos de xarope de milho ou amidos modificados derivados do milho, HiCap 100 e Snow-Flake. O preparo das emulsões foi feito através da técnica de estabilização por atração eletrostática de cargas opostas entre a lecitina e a quitosana. Com o propósito de se obter emulsões com dupla camada estáveis à separação de fase, foi utilizado um rotor-estator e um homogeneizador a alta pressão. As emulsões foram analisadas quanto à estabilidade, distribuição de tamanho e diâmetro médio das gotas, microscopia ótica, potencial zeta e comportamento reológico. As emulsões preparadas com Snow-Flake e xarope de milho/Snow-Flake (50/50) apresentaram comportamento pseudoplástico, além de apresentarem os maiores diâmetros de gota variando de 3,70 a 5,19 µm. Contudo, as emulsões com xarope de milho, HiCap 100 e xarope de milho/HiCap 100 (50/50) apresentaram comportamento de fluidos Newtonianos e diâmetros menores de gota, entre 1,15 e 1,51 µm. Para o processo de secagem foi utilizado um secador laboratorial do tipo mini spray dryer, com temperatura do ar de secagem de 170 °C. As micropartículas obtidas foram caracterizadas em relação ao conteúdo de umidade, atividade de água, distribuição de tamanho e diâmetro médio de partículas e microestrutura. Além disso, foram também determinados: a eficiência de encapsulação, o fator de proteção solar in vitro das micropartículas e estabilidade oxidativa pelo método Rancimat. As micropartículas apresentaram diâmetro entre 14,51 e 29,19 µm e excelentes valores de eficiência de encapsulação, superiores a 84%. As partículas produzidas com os amidos modificados apresentaram formato esférico sem rachaduras ou poros, já as micropartículas produzidas com somente xarope de milho apresentaram alguns poros e rachaduras, que causaram a menor estabilidade oxidativa dessas micropartículas. As micropartículas produzidas com HiCap 100 e xarope de milho/HiCap 100 (50/50) estabilizadas por lecitina-quitosana apresentaram maior estabilidade oxidativa. O fator de proteção das partículas variou entre 1,37 e 2,45, sendo de 2,12 para o óleo de café verde puro
Abstract: The green coffee oil stands out for its ability to block the UVB radiation (290-320 nm) and its emollient property. In this context, to improve the properties of this oil and increase its stability, the aim of this work was to produce microparticles of green coffee oil by spray drying. Encapsulating agents used were lecithin, a phospholipid with anionic character at pH 3.0, chitosan, a polysaccharide with cationic character also in pH 3.0 and soluble only in diluted acid solutions and corn syrup solids or corn modified starches as HiCap 100 and Snow-Flake. Emulsions preparation involved the technique of stabilization by electrostatic attraction between lecithin and chitosan. A rotor-stator homogenizer and a high pressure homogenizer were used in order to obtain stable emulsions by electrostatic layer-by-layer deposition. The emulsions were analyzed in relation to stability, size distribution and droplet diameter, optical microscopy, zeta potential and rheological behavior. The emulsions prepared with Snow-Flake and corn syrup/Snow-Flake (50/50) showed pseudoplastic behavior, besides having the biggest droplet diameters ranging from 3.70 to 5.19 µm. However emulsions prepared with corn syrup, HiCap 100 and corn syrup/HiCap 100 (50/50) showed Newtonian behavior and smaller droplet diameters ranging from 1.15 to 1.51 µm. For the drying process, a laboratory spray dryer and air temperature of 170 °C were used. Microparticles were characterized with respect to moisture content, water activity, particle size distribution and microstructure. Furthermore, encapsulation efficiency, sun protection factor in vitro and oxidative stability by the Rancimat method were determined. The microparticles had a diameter ranging from 14.51 and 29.19 µm and high values of encapsulation efficiency, above 84%. The particles produced with modified starches showed spherical shape without cracks or pores and those produced with only corn syrup showed some holes and cracks, that caused lower oxidative stability of these microparticles. The microparticles produced with HiCap 100 and corn syrup/HiCap 100 (50/50) stabilized by lecithin-chitosan showed the highest oxidative stability. The sun protection factor of particles ranged from 1.37 and 2.45 and 2.12 for the pure green coffee oil
Mestrado
Engenharia de Alimentos
Mestra em Engenharia de Alimentos

A Lippia sidoides é planta largamente difundida nas práticas da medicina popular no Brasil, sendo utilizada como anti-séptico de uso tópico, fato justificável pela presença de timol. Como estratégia para a obtenção de novos produtos com atividade antimicrobiana, a partir de fonte vegetal, o presente estudo visou o desenvolvimento tecnológico de extratos secos padronizados e a encapsulação do óleo essencial dessa planta, através da técnica de secagem por atomização (spray drying). Para obtenção dos extratos secos padronizados, utilizou-se metodologia capaz de avaliar a qualidade da matéria-prima vegetal, das ações de transformação, dos produtos intermediários e do produto final. A solução extrativa foi obtida a partir das folhas secas e moídas dessa planta, empregando-se o método de extração por maceração dinâmica, avaliando-se alguns fatores que influenciavam sua eficiência. A solução extrativa selecionada foi submetida à secagem por atomização, investigando-se a combinação de adjuvantes tecnológicos sobre o desempenho do equipamento e sobre características físico-químicas do produto obtido. Além disso, avaliou-se a atividade antifúngica in vitro dos extratos secos, confirmando-se o efeito antimicrobiano dos mesmos. Para a encapsulação do óleo essencial de Lippia sidoides, utilizou-se a técnica de spray drying (método físico) e a inclusão molecular com -ciclodextrina (método químico) com subseqüente secagem por spray drying. Na microencapsulação por spray drying foi utilizado um conteúdo de óleo de 20 e 25% em relação ao material de parede. Como material de parede foram empregadas diferentes proporções de maltodextrina DE 10 e goma-arábica, sendo as emulsões de alimentação atomizadas até à concentração de 60% de sólidos totais. A eficiência da encapsulação foi avaliada através da quantidade específica de óleo essencial encapsulado nas micropartículas, sendo obtido valor máximo de 65%, dependente das condições experimentais empregadas. Observou-se existir teor de sólidos ótimo (50%) e relação entre o aumento da retenção de óleo total e as maiores concentrações de goma-arábica nas emulsões de alimentação, sendo que todas as micropartículas demonstraram atividade antifúngica. A inclusão molecular do óleo essencial, através de sua complexação com moléculas de -ciclodextrina exibiu eficiência de encapsulação de até 70%. As diferentes proporções de óleo essencial e -ciclodextrina testadas influenciaram esses resultados, sendo que menores retenções foram observadas quando maiores quantidades de óleo foram adicionadas às suspensões de alimentação. Pelas análises térmicas foi possível demonstrar a mais alta estabilidade térmica dos produtos encapsulados (micropartícula/complexo de inclusão) comparados ao óleo essencial original. Os dados adquiridos durante os estudos de desenvolvimento de produtos secos, a partir de Lippia sidoides, indicaram o potencial desses como agentes antimicrobianos naturais para fins medicinais, representando assim, alternativa para o aproveitamento da espécie vegetal pelo setor farmacêutico.
Lippia sidoides is an aromatic shrub widely used in a folk medicine in Brazil as local antiseptic, justified by thymol presence as the major constituent of its essential oil. As strategy for production of new antifungal herbal products, the present study aimed the technological development of Lippia sidoides standardized spray dried extracts as well as the encapsulation of its essential oil by spray drying/ molecular inclusion. In order to obtain the standardized dried extract, process control parameters of manufacturing operations were established and they were continuously tracked to provide reproducibility from batch-to-batch and to assure productsquality. Extraction (maceration) from Lippia sidoides leaves was used to produce thymol-containing liquid extracts. Optimal extraction conditions were determined and the selected extractive solution was spray dried. Effect of different carrier ratios on physicochemical and antifungal properties of dried extracts was evaluated. Lippia sidoides dried extract showed an important antifungal effect against the tested strains. Lippia sidoides essential encapsulation was carried out by spray drying technique (physical method) and molecular inclusion within -cyclodextrin (chemical method) followed by spray drying of the slurries in order to produce inclusion complex in a powder form. For microencapsulation by spray drying, maltodextrin DE 10 and gum arabic in different were used as carrier. Content of essential oil related to carrier was 20 and 25% in weight and the emulsions were atomized from 30% up to 60% of total solid concentration. Encapsulation efficiency was estimated through determination of the content of essential oil in the microcapsules and a maximum value obtained was 65%, depending on experimental parameters adopted. An optimal solid content of the encapsulating composition (50%) was observed. The increase of gum arabic amount in the infeed emulsion was related to the increase in the total oil retention in the microparticles. Antifungal activities of microparticles were evaluated, evidencing their potential as important antifungal agent. For inclusion complex formation between essential oil and -cyclodextrin, the encapsulation efficiency was up to 70%. The entrapment ability was influenced by the different essential oil: -cyclodextrin ratios tested. A decreasing tendency in the total oil content was observed, when the initial amount of added oil was increased. The greater thermal stability of the encapsulated products (microparticles/ inclusion complexes) in comparison to the original oil was confirmed by thermal analysis. The finding acquired during the development of Lippia sidoides dried products indicated their potential as natural antimicrobial agent for medicinal propose and provided evidences which support the use of such plant specimen by pharmaceutical industry.

Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia
FucoPol is an exopolysaccharide produced by the Enterobacter A47, using glycerol byproduct from the biodiesel industry as carbon source. In this work, the potential of this biopolymer to produce microparticles and to encapsulate bioactive compounds by spray drying was studied. The particles were characterized in terms of morphology (Scanning Electron Microscopy), crystallinity (X-Ray Diffraction), chemical characteristics (Fourier Transform Infrared), and thermal properties (Thermogravimetric Analysis and Differential Scanning Calorimetry). FucoPol was able to form spherical microcapsules (size from 0.5 to 26.7 μm) with a thin wall (thickness from 222 to 1094 nm) and a smooth surface. A population of small particles with dented surfaces was obtained. The microcapsules presented an amorphous structure. Gallic acid (GA) and oregano essential oil (OEO) were encapsulated using FucoPol as wall material. The bioactive loading was 12.2 wt.% and 3.1 wt.% for OEO and GA, respectively. Additionally, the encapsulation efficiency was 20% for OEO and 5.3% for GA. The release profile in simulated gastric (SGF) and intestinal (SIF) fluids revealed a total release, except for the GA in SGF, where 68% retention was observed. The compounds antioxidant capacity was not affected by the encapsulation process. From the results obtained, FucoPol reveals a good potential as microcapsules forming and encapsulating material

Orientador: Lireny Aparecida Guaraldo Gonçalves
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: O uso de gorduras vegetais em alimentos é amplo e muitas matérias primas, tecnologias e ingredientes são continuamente pesquisados em busca de funcionalidade e aspectos nutricionais mais adequados, ampliando o uso destas gorduras e melhorando a qualidade dos produtos finais. Uma das técnicas utilizadas para adequar a lenta cristalização do óleo de palma é o uso do processo de semeadura com óleos totalmente hidrogenados (OTH). O presente trabalho se refere à obtenção de cristais de OTH de soja ou de palma microencapsulados em material de parede amido de milho ¿OSA (AMM) ou maltodextrina (MD), em diversas proporções por spray drying. Estas micropartículas apresentaram tamanho de partícula (7,8-9,7µm), eficiência de encapsulação (61,8-89,6%) e morfologia características de produtos por spray dryer, além de manterem o polimorfismo original do material de recheio. Os OTH microencapsulados com quantidade de material de recheio superior (60%) apresentaram maior dificuldade de produção. Na aplicação em óleo de palma puro foram observadas a indução de cristalização e a formação de uma rede homogênea, densa e com poucos aglomerados. Os OTH de soja (45%) microencapsulados em MD e AMM inibiram a formação de polimorfos ? na mistura de óleo de palma. Os OTH microencapsulados com menor quantidade de recheio (30%), apresentaram comportamento de não liberação total do material de recheio nas aplicações, porém, atuaram como sementes de cristalização e influenciaram na transição polimórfica para forma ?. O OTH de soja (30%) microencapsulado em AMM, em sistemas de óleo de palma e açúcar auxiliou na textura e na redução de exsudação de óleo. Os OTH de soja (45%) microencapsulados em AMM e MD aplicados em emulsão A/O desempenharam papel de estruturantes e estabilizantes. Em geral, as micropartículas produzidas com AMM e OTH de soja apresentaram melhores desempenhos. A forma de dispersão ao meio dos cristais de OTH presentes nas micropartículas permitiu a formação de uma rede cristalina mais homogênea, acelerando o processo de cristalização, aumentando a consistência do óleo de palma no meio aplicado. E aos meios específicos, favoreceu a estabilidade em relação à separação de fase de emulsões, como margarinas e cremes, e reduziu a exsudação de óleo em sistemas anidros hidrofóbicos, a exemplo de recheios de biscoitos e de bombons, problemas de processo e qualidade de produto muito indesejável. Além disto, o uso destas micropartículas promove valores de consistência adequados e resistentes a oscilações térmicas, com ausência de ácidos graxos trans. Estas micropartículas podem servir como carreadoras de compostos lipofílicos com caráter nutracêutico se estes forem microencapsulados conjuntamente com o OTH, desempenhando função tecnológica e nutricional com facilidade de manuseio, estocagem e aplicação por estarem na forma de pó
Abstract: The technique of seeding is a option for the oils and fats industry to adapt to the physical characteristics of oils adding nutritional improvements and desirable consistency, expanding its application. This research refers to production of fully hydrogenated oils (FHO) by spray drying with maltodextrina (MD) and modified corn starch¿OSA (MCS) as wall materials to obtain possible seeds of crystallization. FHO of palm and soybean were used in different proportions. These particles were evaluated by mean diameter (7.8-9.7?m), efficiency of encapsulation (61.8-89.6%), polymorphism (maintained the original polymorphism corresponding material filling) and morphological characteristics (spherical form with some surface depression). In palm oil application, these particles induced crystallization and formed an homogeneous and dense crystal network with few agglomerates. FHO of soybean microencapsulated (45%) in MD and MCS inhibited the formation of the ? polymorph in palm oil. The FHO microencapsulated with smaller amount of filled material (30%) acted as seeding and polymorphic transition to influence the ? form, although it partially released the filled material in applications. FHO of soybean microencapsulated (30%) in MCS was applied in palm oil with sugar systems, enhancing the texture and the reduction of oil exudation. FHO of soybean microencapsulated (45%) with MCS and with MD were applied in W/O emulsion, in which these particles were structural network and stabilizers. In general, the particles produced using MCS as wall material and FHO of soybean as filling material showed better performance. The arrangement of the dispersion throughout the FHO crystals present in the particles allowed the formation of a more homogeneous crystal lattice, accelerating the crystallization process, increasing palm oil consistency in the applied mean. In specific means, it favored stability in relation to the separation of emulsions phase, such as margarines and creams, reducing exudation oil in hydrophobic anhydrous systems, such as fillings of cookies and candies, which is a very undesirable product quality problem. Furthermore, the use of these particles promotes consistency and temperature variation stability containing no trans fatty acids. These particles can serve as a carrier for nutraceutical lipophilic compounds if they were microencapsulated together with the FHO. Therefore these particles, which are in the powder form, can perform technological and nutritional functions allowing ease handling, storage and application
Doutorado
Tecnologia de Alimentos
Doutora em Tecnologia de Alimentos

Os carreadores micro e nanoparticulados como os lipossomos, nanoparticulas polimericas e microparticulas e nanoparticulas lipidicas solidas sao investigadas por suas vantagens em relacao as formulacoes tradicionais, tais como: liberacao sustentada dos ativos, minimizar efeitos colaterais, aumentar estabilidade fisico-quimica das moleculas labeis, diminuir a toxicidade entre outras. As microparticulas lipidicas solidas produzidas neste trabalho sao compostas de cera de abelha e oleo de cafe verde, este oleo e um produto rico em acidos graxos, esterois, di e triterpenos e tocoferois. Para a producao destas microparticulas foi escolhida a tecnica de spray congealing, que e considerada rapida e ambientalmente correta, uma vez que nao utiliza nenhum tipo de solvente. As misturas fundidas contendo concentracoes determinadas de oleo de cafe verde e cera de abelha foram atomizadas numa camara de resfriamento onde houve a solidificacao e formacao das microparticulas. Foi utilizado um planejamento experimental do tipo Box-Behnken, que auxiliou na avaliacao dos resultados obtidos, verificando a influencia das diversas variaveis do processo. As microparticulas foram caracterizadas por analise termica, microscopia de varredura eletronica, tamanho, atividade fotocatalitica, eficiencia de encapsulacao e estabilidade. A avaliacao das microparticulas mostrou que a concentracao do oleo de cafe verde foi a variavel que mais influenciou no processo. Em concentracoes maiores, este oleo aumenta a viscosidade da mistura fundida atomizada, aumentando o tamanho da particula formada e provocando maiores imperfeicoes em sua superficie, o que foi confirmado por um estudo reologico das misturas de cera de abelhas e oleo de cafe verde. Os tamanhos das microparticulas obtidas em diferentes condicoes de spray congealing variaram de 50 a 140 ?Êm, e estao adequadas para que nao ocorra a sua penetracao cutanea. O estudo de atividade fotocatalitica demonstrou que o oleo de cafe verde microencapsulado apresenta propriedades de protecao antioxidante ao oleo de ricino muito maiores do que o oleo puro. A composicao do oleo de cafe verde em relacao ao acido linoleico, palmitico, oleico e estearico, determinada por cromatografia a gas com espectrometria de massa esta de acordo com o encontrado na literatura. As microparticulas formadas a partir de misturas contendo 40% de oleo de cafe verde apresentaram melhor estabilidade e melhor acao na protecao de outras substancias contra a oxidacao. No teste de estabilidade acelerada, usando o acido linoleico como marcador quimico, as perdas corresponderam a 27, 6 e 3% para as microparticulas encapsuladas com 20, 30 e 40% de oleo de cafe verde, respectivamente. No mesmo teste, a perda de acido linoleico foi de 45% para o oleo nao encapsulado. Os resultados demonstram que a microencapsulacao do oleo de cafe verde pode ser uma excelente alternativa para a protecao deste contra a oxidacao e que o processo de spray congealing, bem como a cera de abelhas foram escolhas adequadas para a sua preparacao.
The micro and nanoparticulate carriers such as liposomes, polymeric nanoparticles and solid lipid nanoparticles and microparticles are investigated for their advantages over traditional formulations such as sustained release of the drugs, minimize side effects, increase physical and chemical stability of labile molecules, decrease toxicity among others. The solid lipid microparticles produced in this work are composed of beeswax and green coffee oil, this oil is a product rich in fatty acids, sterols, tocopherols and di and triterpenes. For the generation of microparticles was chosen spray congealing technique, which is considered fast and environmentally friendly, since it does not use any type of solvent. The molten mixtures containing certain concentrations of green coffee oil and beeswax were atomized in a cooling chamber where there was solidification and formation of microparticles. We used an experimental design like Box-Behnken, who assisted in the evaluation of the results, checking the influence of various process variables. The microparticles were characterized by thermal analysis, scanning electron microscopy, size, photocatalytic activity, encapsulation efficiency and stability. The evaluation of the microparticles showed that the green coffee oil concentration was the variable that most influenced the process. At higher concentrations, this oil increases the viscosity of the molten mixture atomized, increasing the size of the particle formed and causing major imperfections on its surface, which was confirmed by a study of the rheological mixture of beeswax and green coffee oil. The sizes of the microparticles obtained at different spray congealing conditions ranged from 50 to 140 ?Ým, and are not suitable for your skin penetration occurs. The study showed that the photocatalytic activity of green coffee oil microencapsulated has properties antioxidant protection to castor oil much higher than the pure oil. The composition of green coffee oil relative to linoleic, palmitic, oleic and stearic acids, determined by gas chromatography with mass spectrometry is consistent with findings in the literature. The microparticles formed from mixtures containing 40% of green coffee oil showed better stability and better action in protecting other substances from oxidation. In accelerated stability test, using linoleic acid as a chemical marker, the losses amounted to 27, 6 and 3% for the microparticles containing 20, 30 and 40% green coffee oil, respectively. In the same test, the loss of linoleic acid was 45% for the unencapsulated oil. The results show that the microencapsulation of green coffee oil can be an excellent alternative for protection against this oxidation and that the spray congealing process, as well as beeswax were appropriate choices for their preparation.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior
Com o objetivo de preservar as propriedades e otimizar o encapsulamento do Ãleo essencial de Lippia sidoides (OELS), foi preparado nanopartÃculas de quitosana e goma carregadas com OELS via spray-drying, usando gomas nativas da regiÃo do Nordeste brasileiro. As gomas foram extraÃdas dos exsudatos das Ãrvores da Anacardium Occidentale (goma do cajueiro), Sterculia striata (goma do chichÃ) e Anadenanthera macrocarpa (goma do angico). As nanopartÃculas foram caracterizadas por espectroscopia na regiÃo do infravermelho (FTIR) e na regiÃo do UV/VIS, tamanho de partÃculas e potencial zeta, anÃlise tÃrmica (TGA/DSC), e cromatografia gasosa (GC-MS). O espectro do FTIR mostrou as principais bandas da quitosana e das gomas, em 1550 e em 1647 cm-1. Observou-se diferentes propriedades nas nanopartÃculas em funÃÃo do tipo de matriz utilizada. As partÃculas produzidas apresentaram tamanho de 17 a 800 nm, onde a matriz de goma do cajueiro produziu as partÃculas maiores, e a matriz de goma do chichà as partÃculas menores. O potencial zeta variou de -40 mV a +30 mV, onde houve maior variaÃÃo quando utilizou-se a matriz com goma do chichÃ. A anÃlise tÃrmica evidenciou os eventos de perda de massa para as amostras, onde atà 200 ÂC as amostras perdem no mÃximo 20% da sua massa inicial. O encapsulamento do OELS variou entre 6 e 16 %, onde as matrizes com goma do cajueiro e do chichà apresentaram os maiores valores. As amostras com goma do cajueiro apresentaram boa estabilidade de encapsulamento apÃs 12 meses, onde o teor de Ãleo encapsulado nÃo se alterou. A anÃlise por cromatografia gasosa mostrou que o Ãleo encapsulado nÃo apresentou em sua composiÃÃo diferenÃa significativa à do Ãleo inicial, encapsulando os principais componentes. A liberaÃÃo do OELS pelas matrizes foi relativamente lenta, onde entre 60 e 100% do Ãleo foi liberado em 48 horas. O estudo cinÃtico da liberaÃÃo do OELS indicou que a liberaÃÃo segue o modelo de Higuchi, com a liberaÃÃo pelas amostras variando entre fenÃmenos fickianos e nÃo-fickianos.
Aiming to preserve the properties and optimize the encapsulation of the Lippia sidoides essential oil (LSEO), this work reports on the preparation of chitosan-gum nanoparticles loaded with LSEO by spray-drying, using gums extracted from native trees of northeast of Brazil. The gums used were extracted from exudates of Anacardium Occidentale tree (Cashew gum), Sterculia striata trees (Chichà gum) and Anadenanthera macrocarpa trees (Angico gum). Samples were characterized by FTIR and UV/VIS spectroscopy, particle size and zeta potential, thermal analysis (TGA/DSC) and gas chromatography (GC-MS). The FTIR spectrum showed the main bands of chitosan and gums, in 1550 and 1647 cm-1. Particle sizes ranged from 17 nm to 800 nm, where the angico gum matrix presented the smallest sizes and cashew gum matrix the larger sizes. The zeta potential varied from -40 mV +30 mV, where chichà gum matrix presented the biggest variation. Thermal analysis showed the events of mass loss for the samples, where up to 200 C there are a maximum of 20% mass lost compared to the initial mass. The encapsulation of LSEO ranged between 6 and 16%, where the cashew gum and chichà gum matrixes presented the highest values. Cashew gum samples showed good encapsulation stability after 12 months, where the encapsulated oil content has not changed. The encapsulated oil did not present significant difference in its composition to the initial oil, encapsulating the key components. The release of LSEO from the matrixes was relatively slow, where between 60 and 100% of the oil was released in 48 hours. The kinetic study of LSEO release indicated that the release followed the Higuchi model, with the release by the samples varying between fickians and non-fickians phenomena.

The consumption of omega-3 fatty acids and phytosterol promotes the reduction of cholesterol and triacylglycerol levels. However, such compounds are susceptible to oxidation, which hampers their application. First, the aim of this work was to encapsulate echium oil (Echium plantagineum L.), source of omega-3 fatty acids, with hydrophilic phenolic compounds (sinapic acid and rutin) by double emulsion followed by complex coacervation in order to evaluate the best hydrophilic phenolic compound. In this case, sinapic acid showed better performance as antioxidant. Then, the second objective of this work was to study the microencapsulation of echium oil by complex coacervation using gelatin-arabic gum and gelatin-cashew gum as wall materials and sinapic acid and transglutaminase as crosslinkers. In this step, it was possible to observe that sinapic acid, besides to be an antioxidant, could also act as crosslinker. So, the third objective was to study the effect of sinapic acid in echium microparticles obtained by emulsion followed by spray or freeze drying using arabic gum as carrier agent in order to compare different encapsulation techniques. In addition to these methods, the fourth objective was to compare these techniques already mentioned to the combination of microfluidic devices and ionic gelation in order to encapsulate echium oil. In this case, sinapic acid and quercetin were also incoporated in the microcapsules. All the microcapsules/ microparticles obtained in the mentioned different techniques presented characteristics feasible for application and also promoted the protection of the oil. However, the encapsulation by complex coacervation and the addition of sinapic acid as crosslinkers was the method choosen for the coencapsulation of echium oil and phytosterols since presented the better results. Moreover, the treatment GA075 (microcapsule with gelatin-arabic gum as wall materials and 0.075g sinapic acid/ g gelatin) promoted the better protection to the encapsulated compounds. In this way, this treatment was applied into yogurt and compared to the one with the compounds nonencapsulated and the yogurt control. The yogurt containing microcapsules, presented a pH range from 3.89-4.17 and titratable acidity range from 0.798-0.826%, with good sensorial acceptance. It was possible to apply the microcapsules in yogurt, without compromising the rheological properties and physicochemical stability of the product, obtaining a functional product rich in omega-3 fatty acids, phytosterols and phenolic compound.
O consumo de ácidos graxos ômega-3 e fitosterol promove a redução dos níveis de colesterol e triacilglicerol. No entanto, esses compostos são susceptíveis à oxidação, o que dificulta sua aplicação. Primeiramente, o objetivo deste trabalho foi encapsular o óleo de echium (Echium plantagineum L.), fonte de ácidos graxos ômega-3, com compostos fenólicos hidrofílicos (ácido sinápico e rutina) por emulsão dupla seguida de coacervação complexa com intuito de avaliar o melhor composto fenólico hidrofílico. Neste caso, o ácido sinápico apresentou melhor desempenho como antioxidante. Em seguida, o segundo objetivo deste trabalho foi estudar a microencapsulação do óleo de echium por coacervação complexa utilizando as combinações gelatina-goma arábica e gelatina-goma de caju como materiais de parede e ácido sinápico e transglutaminase como agentes de reticulação. Nesta etapa, foi possível observar que o ácido sinápico, além de ser um antioxidante, também pode atuar como agente de reticulação. Assim, o terceiro objetivo foi estudar o efeito do ácido sinápico em micropartículas de óleo de echium obtidas por emulsão seguida de atomização ou liofilização utilizando goma arábica como agente carreador, com a finalidade de comparar diferentes técnicas de encapsulação. Além desses métodos, o quarto objetivo foi comparar essas técnicas já mencionadas com a combinação de dispositivos microfluídicos e gelificação iônica utilizando o óleo de echium como composto bioativo. Neste caso, o ácido sinápico e a quercetina também foram incorporados nas microcápsulas. Todas as microcápsulas/ micropartículas obtidas pelas diferentes técnicas mencionadas apresentaram características viáveis para aplicação e também promoveram a proteção do óleo. No entanto, a encapsulação por coacervação complexa e a adição de ácido sinápico como reticulante foi o método escolhido para a coencapsulação de óleo de echium e fitosteróis, uma vez que apresentou melhor resultado. Além disso, o tratamento GA075 (microcápsula com gelatina-goma arábica como materiais de parede e 0,075g de ácido sinápico/ g gelatina) promoveu a melhor proteção aos compostos encapsulados. Desta forma, este tratamento foi aplicado em iogurte e comparado com o mesmo adicionado dos compostos não encapsulados e o iogurte controle. O iogurte contendo microcápsulas apresentou faixa de pH de 3,89-4,17 e acidez titulável de 0,798-0,826 %, com boa aceitação sensorial. Foi possível a aplicação das microcápsulas no iogurte, sem comprometer as propriedades reológicas e a estabilidade físico-química do produto, obtendo um produto funcional rico em ácidos graxos ômega-3, fitosteróis e compostos fenólicos.

Dissertation presented to Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa for obtaining the master degree in Membrane Engineering
Food emulsions play an important role in product development and formulation, as well as to encapsulation of food additives. Conventional methods for emulsion production may present some drawbacks, such as the use of high shear stress, high energy demanding and polydisperse droplet size distribution. In this sense, membrane emulsification emerges as an alternative method to overcome all this issues and to produce fine and stable emulsions. Linseed oil has been widely studied in the last years, due to its nutritional composition, being the richest ω-3 vegetable source and for that reason it was used as the raw material for emulsion production. Premix and direct (cross flow) membrane emulsification were carried out using three different membrane materials: polissulphone, cellulose ester and α-alumina membrane. For premix membrane emulsification (PME) the variables transmembrane pressure, membrane material, surfactant type and membrane mean pore size were evaluated. The membrane mean pore size was the crucial factor to achieve emulsions by PME, once it was not possible to achieve stable emulsion with mean pore sizes lower than 0.8 μm. For direct membrane emulsification, transmembrane pressure, surfactant concentration and cross flow velocity were evaluated by means of a experimental design. The evaluated responses were stability, droplet size and distribution and dispersed phase flux. For all the variables studied, only dispersed phase flux showed to have significant influence of pressure. Comparing both methods of membrane emulsification, premix showed to be more suitable in terms of emulsion production throughput and droplet size correlation with membrane pore size, however, in terms of stability, direct membrane emulsification showed much better results. Encapsulation of linseed oil by spray drying was promoted using the optimum point of the performed experimental design and the droplets size distribution has considerably changed with the addition of the wall material to the emulsion.
The EM3E Master is an Education Programme supported by the European Commission, the European Membrane Society (EMS), the European Membrane House (EMH), and a large international network of industrial companies, research centres and universities

Orientadores: Miriam Dupas Hubinger, Renata Valeriano Tonon
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: O óleo de linhaça é um óleo rico em ácidos graxos poliinsaturados bastante susceptível à oxidação lipídica, que pode ocorrer durante o processamento, manipulação e estocagem, provocando o aparecimento de aromas desagradáveis e a redução de sua vida de prateleira. Nesse contexto, a microencapsulação por spray drying representa uma alternativa no sentido de proteger o óleo contra a oxidação, diminuir as reações do mesmo com o ambiente externo e facilitar seu manuseio. A maltodextrina é um amido hidrolisado muito utilizado como material de parede e possui vantagens como baixo custo, boa disponibilidade e eficiência na proteção contra oxidação; porém é deficiente em relação à capacidade emulsificante. Este trabalho teve como objetivo avaliar o efeito da combinação de maltodextrina com diferentes materiais de parede (goma arábica, concentrado protéico de soro e dois tipos de amidos modificados), em diferentes concentrações, na microencapsulação do óleo de linhaça por spray drying, visando-se maximizar a eficiência de encapsulação e minimizar a oxidação lipídica. As propriedades da emulsão a partir da qual as partículas foram produzidas influenciaram o processo de microencapsulação por spray drying. O aumento da concentração de maltodextrina levou a uma diminuição da viscosidade das emulsões. Em relação às propriedades das partículas, todos os pós apresentaram baixo conteúdo de umidade e atividade de água e uma distribuição de tamanho com comportamento bimodal. As combinações de HiCap/maltodextrina e goma arábica/maltodextrina apresentaram maiores eficiências de encapsulação na proporção de 75/25, sendo que a primeira apresentou a maior eficiência entre todas as combinações estudadas. Dessa forma, a proporção 75/25 (material de parede/maltodextrina) foi selecionada e as partículas produzidas nessas condições, assim como o óleo não encapsulado foram submetidos a um estudo de estabilidade sendo que a combinação de concentrado protéico de soro/maltodextrina foi considerada a melhor na proteção do óleo de linhaça contra oxidação
Abstract: Flaxseed oil is rich in polyunsaturated fatty acids highly susceptible to lipid oxidation, which can occur during processing, handling and storage, causing the appearance of unpleasant aromas and reducing its shelf life. In this context, the microencapsulation by spray drying is an alternative way to protect the oil against oxidation, reducing the reactions of this product with the external environment and to facilitate its handling. Maltodextrin is a hydrolyzed starch that has been used as wall material. It has advantages such as low cost, good availability and good efficiency in protection against oxidation, but it lacks in relation to emulsifying capacity. This study aimed to evaluate the effect of combinations of maltodextrin with different wall materials (gum arabic, whey protein concentrate and two types of modified starch) at different concentrations, in the microencapsulation of flaxseed oil by spray drying, in order to maximize the encapsulation efficiency and minimize lipid oxidation. Emulsion properties from which the particles were produced influenced the microencapsulation process by spray drying. The increase in maltodextrin concentration led to a decrease in emulsion viscosity. About particles properties, all powders showed low moisture content and low water activity. Particles size distribution had a bimodal behavior. The HiCap/maltodextrin and gum arabic/maltodextrin combinations had higher encapsulation efficiencies in the 75/25 proportion and the first one was the most efficient of all. Thus, this proportion was selected and the particles produced under these conditions, as well as the oil not encapsulated, were subjected to a stability study where the whey protein concentrate/maltodextrin combination was considered the best in protection of the active material against oxidation
Mestrado
Engenharia de Alimentos
Mestre em Engenharia de Alimentos

The current project represents the first attempt to test the environmental performance of the direct utilisation of purified used cooking oil as a fuel in a heavy goods vehicle under real world driving conditions. The properties of the used cooking oil were different from those of petroleum diesel (PD) standards however, its heat value, carbon footprint reduction potential and low cost were the key incentives driving it’s use as a fuel. The current research was a collaborative project between Convert to Green (C2G), the fuel provider, the United Biscuits Midlands Distribution Centre, the heavy goods vehicle provider and the University of Leeds as the scientific consultant and research executor. The brand of used cooking oil was Convert to Green Ultra-biofuel (C2G UBF) tested on a Mercedes-Benz EURO 5 emissions standard compliant 44 tonne articulate heavy goods vehicle (HGV). The HGV was modified for on-board UBF heating and mixing with PD. UBF was heated by heat recovery from the engine cooling system. The results showed that the UBF/PD blending ratio was 0.845 as a journey average for the entire test series. However, the HGV was recorded to run on 100% UBF at steady high speed on the M1 motorway in the Midlands region of the UK. There were no discernible deficiencies in the HGV’s performance or its traction effort. Nevertheless a slight increase in specific fuel consumption (SFC) was detected for the blended fuel. Engine durability, combustion chamber deposits and maintenance frequency were not affected by the UBF content in the fuel. Although the engine technology was designed to suppress particulate matter (PM) within the combustion process, the use of blended UBF further reduced the tailpipe PM emissions compared to the use of PD. Carbon monoxide emissions decreased when using the blended fuel, while nitrogen oxides, total hydrocarbons and carbon dioxide increased compared to PD emissions. The benefits of UBF utilisation as a fuel lie in the huge carbon savings and reduced PM emissions when compared to the use of PD as well as its use in providing a cost effective fuel supply and waste management technique.

Management of earwax problems is inconsistent and under-researched with a paucity of evidence currently available to inform ear care strategy. This study aimed to determine if daily lubrication of the external ear canal with olive oil enhances the normal expulsion of earwax. The study comprised four components: • A pilot questionnaire survey of 55 ear care exhibition attendees • A cross-sectional ear survey of 483 people in Essex and South Yorkshire. • An experimental study of 50 people over 50 years old, presenting with bilateral occlusive earwax. Subjects instilled nightly measure of olive oil into one ear over 24 weeks, the untreated ear acting as control. • Pre- and post-experiment interviews with experimental subjects. A Visual measure of earwax accumulation throughout the experimental period demonstrated a greater increase in treated ears. This was confirmed by the mean weight of earwax removed from treated ears being 72.6% greater than control ears. All earwax was successfully removed before and after the experimental study without adverse effects, by a novel procedure using olive oil application immediately before earwax removal. The mass of earwax accumulated was much greater in males than females. A slower rate of earwax accumulation with increasing age was demonstrated. A history of prior earwax problems correlated with increased earwax accumulation. Interview data illuminated changes in personal ear care post 11 study and linked some earwax problems to the availability of General Practice care and treatment provided. It is concluded that normal expulsion of earwax from the ear canal is not enhanced by regular lubrication with olive oil: on the contrary the accumulating mass of earwax is increased. Olive oil is, however, beneficial in alleviating itchiness and dry ear skin and to aid earwax removal when applied immediately before this procedure. This study contributes new knowledge, which should encourage future studies and guide development of ear care practice. 12

Orientador: Carlos Raimundo Ferreira Grosso
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Neste trabalho a oleoresina de páprica oriunda de frutos maduros de pimentões (Capsicum annuum L.), foi encapsulada por processo de atomização, utilizando-se os agentes encapsulantes aglomerados porosos de grânulos de amido de arroz / gelatina e goma arábica. A extração da oleoresina encapsulada foi realizada em ultra-som durante cinco minutos em álcool etílico hidratado apresentando rendimentos de extração de 48,8 e 77,5% para os encapsulados em goma arábica, e aglomerados de amido/gelatina respectivamente. Os rendimentos em relação à retenção durante o processo de encapsulação, corrigidos pela deficiência do método de extração, foram de 100% para cápsulas de goma arábica e em torno de 89% para encapsulados de aglomerados porosos de grânulos de amido de arroz / gelatina, expressos em base úmida. A estabilidade da oleoresina livre e microencapsulada foi avaliada frente às diferentes condições de temperatura (- 18 °C; 25 ± 3°C; 50 °C) e ao efeito da luz, com parte das cápsulas sendo mantidas em ambiente sem iluminação. Em ambos ensaios cápsulas fabricadas com goma arábica apresentaram maior proteção a oleoresina de páprica quanto à perda da cor original. A morfologia da parede mostrou que a parede dos encapsulados de aglomerados porosos de grânulos de amido de arroz / gelatina apresentou porosidade e interstícios foram evidenciados na matriz individualmente e nos aglomerados; em relação as microcápsulas de goma arábica, observou-se parede contínua, sem rachaduras ou poros aparentes, mas apresentando concavidades na superfície provocadas pelo processo de secagem. A distribuição de tamanho das partículas foi unimodal, com tamanho médio de 16,0 mm para as cápsulas de goma arábica e 20,3 mm para os aglomerados porosos de grânulos de amido de arroz / gelatina. A funcionalidade das microcápsulas quanto à liberação do recheio, foi avaliada por adição a dois sistemas alimentícios, um contendo somente gel de gelatina incolor sem sabor e em outro, contendo proteína, gordura, carboidratos (bolo). A distribuição da cor foi homogênea em ambos os sistemas, ou seja, não foi verificado à formação de pontos de concentração de cor nos produtos. A avaliação sensorial foi realizada através do teste afetivo de aceitação em escala hedônica de nove pontos, em relação às formulações dos padrões de gel de gelatina e, de bolo isentas de microcápsulas e do teste de comparação da coloração pela escala estruturada mista. As notas obtidas foram altas para os dois produtos antes da ingestão, média na faixa de seis e sete para a gelatina contendo encapsulados dos aglomerados porosos de grânulos de amido de arroz/gelatina e de goma respectivamente, e média de sete e nove para os bolos
Abstract: In this study the resinous paprika oil obtained from ripe peppers (Capsicum annuum L.), was encapsulated by a spray drying process, in porous agglomerates of rice starch/gelatin and gum Arabic capsules. The process of extracting the encapsulated resinous oil was carried out by breaking the capsules by ultrasonication in a solvent (hydrated ethyl alcohol) for five minutes, showing yields of 48,8 and 77,5% when Arabic gum and starch/gelatin were used respectively. The yields during the encapsulation process with respect to the retention of resinous oil as compared to the amount added, corrected by extractions methods, was 100% for gum Arabic capsules and about 89% when starch granules were formed (wet base). The stabilities of the free and micro encapsulated resinous oils were evaluated under different temperature and light conditions (freezer - 18 °C; room temperature 25 ± 3°C; and 50°C). Exposing part of the capsules in a controlled illumination chamber and maintaining the other part in a chamber with no light tested the effect of light. In both trials (temperature and light), capsules produced with gum Arabic provided greater protection to the paprika resinous oil, with respect to loss of the original color. By morphological observations the porosity of the rice starch was apparent when this material was used as wall material, interstices being observed in the matrix both individually and when agglomerated. When gum Arabic was used as wall material, the walls of the capsules were continuous, with no apparent cracks or pores, although showing some indentations on the surface provoked by the drying process. The average size of the capsules was determined by measuring particle size, both presenting a unimodal distribution, with an average particle size of 16,0 mm for the gum Arabic capsules and 20,3 mm for the rice starch/gelatin. In order to determine the functionality of the microcapsules with respect to the liberation of the core material, the capsules were added to two food systems, a simple system containing non-colored gelatin with no added flavor, and a more complex system containing protein, fat and carbohydrate (cake mix). The color distribution was homogenous in both systems, no localized concentrations of color being noted in any of the products. A preference test with a nine point hedonic scale was used for the sensory evaluation of the gelatin formulations and the cakes, as compared to those containing no microcapsules. The scores for both products were high before tasting, in the range from 6 to 7 for the gelatin containing starch/gelatin and gum capsules respectively, and 7 and 9 for the cakes
Doutorado
Doutor em Alimentos e Nutrição

Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia
The food industry by-products such as olive oil processing solid waste are an important source of natural bioactive compounds. The aim of the present work was to extract bioactive compounds from olive pomace using supercritical carbon dioxide extraction and to investigate the viability of their encapsulation in a food-stuff carrier as a way of protection from antioxidant properties losses. Several supercritical extractions were performed at a 250 bar and a 40 ºC with and without pre-treatments and levels of moisture content were also tested. Yields between 8 and 12% (w/w) were achieved and fatty acid content, sterols and total poliphenolic compounds were evaluated in all supercritical extracts. Since there are a strong correlation between antioxidant activity and poliphenolic compounds, the two most representative phenols, hydroxytyrosol and tyrosol, were identified and quantified. Antioxidant activity was also investigated using ORAC and HORAC methods. Extraction of bioactive compounds from olive pomace in soxhlet apparatus were also carried out for control and yields of 13% (w/w) were achieved. Encapsulation of the most bioactive extract achieved was performed by spray-drying using inulin as the wall material and antioxidant activity was evaluated.

Glavni cilj istraživanja ove doktorske disertacije je bio valorizacija sporednog proizvoda žalfije (Salvia officinalis L.) iz fabrike čaja za dobijanje visoko-vrednih ekstrakata željenih osobina koji bi imali primenu u gotovim proizvodima prehrambene, kozmetičke i farmaceutske industrije.U cilju ekstrakcije polifenolnih jedinjenja su primenjene konvencionalne (maceracija) i savremene (ultrazvučna ekstrakcija, mikrotalasna ekstrakcija i ekstrakcija subkritičnom vodom) ekstrakcione tehnike. U postupaku maceracije je optimizovana koncentracija etanola u ekstragensu, dok je za optimizaciju savremenih ekstrakcionih tehnika primenjen eksperimentalni dizajn i metoda odzivne površine. Prinos polifenola (ukupnih fenola i ukupnih flavonoida) i antioksidativna aktivnost određena različitim in vitro testovima su bili ispitivani odzivi. Za svaki od navedenih ekstrakcionih postupaka je ispitivan uticaj glavnih ekstrakcionih parametara: ultrazvučna ekstrakcija (temperatura, vreme ekstrakcije i snaga ultrazvuka), mikrotalasna ekstrakcija (koncentracija etanola, vreme ekstrakcije i odnos rastvarač-droga) i ekstrakcija subkritičnom vodom (temperatura, vreme ekstrakcije i koncentracija HCl u ekstragensu). Tečni ekstrakti dobijeni ultrazvučnom, mikrotalasnom i subkritičnom ekstrakcijom su pokazali izuzetno visoku antioksidativnu aktivnost određenu „hvatanjem“ DPPH i O2∙- radikala i kapacitetom redukcije Fe3+ jona i imali su znatno veći sadržaj polifenola u odnosu na ekstrakte dobijene maceracijom.U cilju ekstrakcije terpenoidnih jedinjenja su primenjeni postupci Soxhlet ekstrakcije, destilacije vodenom parom i ekstrakcije superkritičnim CO2. Postupak superkritične ekstrakcije je optimizovan metodom odzivne površine i optimalni uslovi ekstrakcije su bili pritisak 290 bar, temperatura 55˚C i protok CO2 od 0,4 kg/h, dok su predviđene i eksperimentalne vrednosti prinosa ekstrakcije bile 8,90 i 8,84%. Hemijskom analizom lipofilnih ekstrakata i etarskog ulja je utvrđeno da su oksidovani monoterpeni (α-tujon i kamfor), oksidovani seskviterpeni (viridiflorol) i polifenolni diterpeni (epirosmanol) dominantna jedinjenja prisutna u ovim uzorcima.Tečni ekstrakti žalfije dobijeni konvencionalnim i savremenim ekstrakcionim tehnikama su spray drying tehnikom osušeni u cilju prevođenja u stabilniju formu suvog ekstrakta. Suvim ekstraktima su određene fizičko-hemijske osobine (hemijski sastav, sadržaj vlage, higroskopnost, moć rehidratacije, WAI i WSI) i biološka aktivnost (antimikrobna i antioksidativna aktivnost) i procenjena je njihova mogućnost primene u prehrambenoj i farmaceutskoj industriji.
The main aim of this dissertation was valorization of sage (Salvia officinalis L.) by-product from filter-tea factory for recovery of high-value extracts with desirable properties for application in food, cosmetics and pharmaceutical products.Conventional (maceration) and novel (ultrasound-assisted, microwave-assisted and subcritical water extraction) extraction techniques were applied for polyphenols recovery. Ethanol concentration was optimized in maceration process, while experimental design and response surface methodology were applied for optimization of novel extraction techniques. Polyphenols yield (total phenols and total flavonoids) and antioxidant activity, determined by various in vitro assays, were investigated responses. Influence of main process parameters was determined for each technique: ultrasound-assisted extraction (temperature, extraction time and ultrasonic power), microwave-assisted extraction (ethanol concentration, extraction time and sample-solvent ratio) and subcritical water extraction (temperature, extraction time and HCl concentration in solvent). Liquid extracts obtained by novel extraction technique exhibited higher antioxidant activity determined by scavenging of DPPH and O2∙- radicals and reduction of Fe3+ and also provided higher polyphenols yield comparing to extracts obtained by maceration. Soxhlet extraction, hydrodistillation and supercritical fluid extraction were applied for terpenoids recovery. Supercritical fluid extraction process was optimized by response surface methodology and optimal conditions were pressure of 290 bar, temperature of 55˚C and CO2 flow rate of 0.4 kg/h, while predicted and experimentally obtained values of total extraction yield at these conditions were 8.90 i 8.84%, respectively. According to chemical analysis, the most abundant compounds in lipid extracts and essential oil were oxygenated monoterpenes (α-thujone and camphor), oxygenated sesquiterpenes (viridiflorol) and diterpene polyphenols (epirosmanol).Sage liquid extracts obtained by conventional and novel extraction techniques were spray dried in order to obtain dry extract form. Physico-chemical properties (chemical profile, moisture content, hygroscopicity, rehydratation time, WAI and WSI) and biological activity (antimicrobial and antioxidant activity) were determined in dry extracts and their potential application in food and pharmaceutical formulations was discussed.

La thèse porte sur le développement et la caractérisation d’un additive pour l’alimentation du bétail contenant de l’huile essentielle. Dans cette formulation, un mélange d’huiles essentielles avec des effets anti-inflammatoires et antioxydants est encapsulaté dans une matrice d’huile de tournesol hydrogéné par spray cooling. Ces premières particules sont enrobées par une couche d’huiles essentielles dans un lit fluidisé. Du spray cooling conduit à la formation d’une poudre fluide avec une fluidité des microparticules qui décroit avec la concentration en huiles essentielles. A haute concentration en huiles essentielles, les particules maintiennent leur fluidité durant le stockage alors que sans ou avec de faibles concentrations en huiles essentielles, elles ont tendance à s’agglomérer.Cet effet dépend des conditions de stockage. Les études de la structure de la surface des microparticules révèlent qu’un effet d’efflorescence des matières grasses à la surface des particules est la cause de l’agglomération. L’analyse thermique différentielle et la spectrométrie aux rayons X démontrent une accélération de la transformation polymorphique des triglycérides de la matrice grasse en présence d’huile essentielle. L'utilisation d’un 'agent de fluidisation dans l'huile essentielle a permis l’application d’un enrobage contenant une huile essentielle et accroissant la palatabilité des particules
The thesis aimed at the development and the characterization of an essential oil containing feed additive formulation. In this formulation one essential oil mixture with anti-inflammatory and antioxidative properties shall be imbedded into a hydrogenated sunflower oil-based matrix via spray cooling and the resulting microparticles shall be furnished with a coating comprising a second essential oil in a fluidized bed process. Spray cooling resulted in the formation of freeflowing powders with the flowability of the microparticles decreasing with increasing essential oil concentration. High-concentrated microparticles maintained their flowability during storage whilst those without and with less essential oil tended to agglomerate. This effect also depended on the storage conditions. Surface structure investigations revealed that fatblooming on the microparticles surface causes agglomeration. Differential scanning calorimetry and X-ray scattering powder diffraction proved the accelerating effect of essential oil on the polymorphic transformation of the triacylglycerides of the fat matrix. The use of an essential oil loaded flow agent allowed the successful application of a coating containing a second palatability increasing essential oil mixture

Omega-3 polyunsaturated fatty acids (Ï 3 PUFAs) provide important health benefits, but dietary consumption is low. Supplementing foods with Ï 3 PUFAs is of interest, but intervention strategies are necessary to preserve the integrity of these unstable compounds. Microencapsulation of Ï 3 PUFA sources is one means of improving their stability. In this work, Ï 3 PUFA microcapsules were prepared by spray drying with chitosan and blends of chitosan, high-amylose starch, and pullulan as wall materials. The primary objectives of this research were (1) to evaluate the effect of chitosan type and oil:wall ratio on Ï 3 PUFA microcapsule properties, (2) to evaluate the effect of blending chitosan with high-amylose starch and pullulan on Ï 3 PUFA microcapsule properties, and (3) to evaluate the oxidative stability of Ï 3 PUFA microcapsules by monitoring primary and secondary oxidation products during storage. Microcapsule encapsulation efficiencies (EE) ranged from 63% to 79% with the highest EEs observed for microcapsules prepared from chitosan with higher degree of deacetylation (DD) and lower molecular weight (MW). Median microcapsule size ranged from 3μm to 11μm. Moisture contents were all below 7% and water activities (aw) were below 0.27. Microcapsules prepared from blends of chitosan with starch and/or pullulan had lower aw values than those prepared from chitosan alone. Oxidative stability was evaluated by measuring oxidation induction time (OIT) using pressure differential scanning calorimetry. OIT values ranged from 14 to 20 minutes. Microcapsules prepared from chitosan with lower DD and higher MW had longer OITs than those prepared from chitosan with higher DD and lower MW. Microcapsules prepared from blends of chitosan, starch, and pullulan had longer OITs than those prepared from chitosan alone. Oxidative stability of microcapsules during long term storage was evaluated on one microcapsule formulation by monitoring peroxide value (PV) and secondary oxidation products by HS-SPMEGC/ MS. Volatiles including propanal, 1-penten-3-ol, pentanal, hexanal, and 2,4-heptadienal were detected in the headspace of the microcapsules; however, PVs did not indicate substantial oxidation of the Ï 3-PUFA source during 5 weeks of storage. Chitosan, high-amylose starch, and pullulan are effective materials for microencapsulation of Ï 3 PUFA sources.
Ph. D.

Thesis (M.S. in Mechanical Engineering)--Naval Postgraduate School, June 2006.
Thesis Advisor(s): Raymond Shreeve. "June 2006." Includes bibliographical references (p. 131). Also available in print.

O emprego de óleos vegetais como combustível em motores ciclo diesel tem se demonstrado viável após diversos estudos de desempenho já desenvolvidos em diversos motores e configurações, porém apresentando algumas restrições quanto ao seu uso contínuo, dentre as quais se destacam a ocorrência de quebras do motor devido ao excesso de carbonização no cabeçote. No Brasil, a abundância de óleos de origem vegetal constitui um incentivo para a realização de estudos visando ao aproveitamento desses combustíveis alternativos, neste contexto, este trabalho apresenta um estudo das características macroestruturais da formação de sprays de óleo vegetal de soja in natura em um atomizador utilizado em motores diesel em condições de pressão semelhantes às de um motor. Para isso foi montada uma bancada que é constituída de uma câmara pressurizada projetada e fabricada para simular as mesmas condições de massa específica do ar obtidas dentro da câmara de combustão do motor ciclo diesel no instante do início da injeção do combustível. Também é dotada de um sistema de injeção de combustível projetado para que as pressões de funcionamento do conjunto porta injetor mecânico utilizado fosse atingido. O registro da formação do spray é realizado por meio de uma câmara de alta velocidade e alta taxa de aquisição de imagens, como o qual é possível avaliar o comportamento dos jatos de óleo de soja e óleo diesel quanto a distância de quebra, penetração da ponta, velocidade e ângulo de abertura de spray. Das propriedades físico-químicas do óleo vegetal de soja, a que mais se destaca com relação às propriedades do óleo diesel é a viscosidade, que para os líquidos utilizados nesse trabalho foi verificado que é aproximadamente 15 vezes maior que a viscosidade do óleo diesel. Essa grande diferença nas mesmas condições de temperatura produziram resultados de atomização bem distinta entre os líquidos e verifica-se a necessidade de modificação de mais parâmetros do que somente a densidade do gás para que a atomização seja mais próxima do óleo diesel e o óleo vegetal in natura possa ser utilizado nos motores, pois os regimes de atomização observados condizem com o previsto considerando as propriedades dos dois óleos nas condições testadas.
The use of vegetable oils as fuel in diesel engines has proven to be viable after several performance studies already developed in several engines and settings, but presenting some restrictions on its continued use, among which stand out the occurrence of engine failures due to over-charred on the head. In Brazil, plenty of vegetable oils is an incentive to carry out studies for the use of these alternative fuels, in this context, this work presents a study of macro-structural characteristics of the formation of vegetable oil sprays soy in kind in an atomizer used in diesel engines into pressure conditions similar to those of an engine. To this it was mounted on a stand which consists of a pressure chamber designed and manufactured to simulate the same conditions of air density obtained within the combustion chamber of the diesel engine cycle at the time of start of fuel injection. It is also equipped with a fuel injection system designed for operating pressures of the whole mechanical door gun used was reached. The record of the formation of the spray is carried out by means of a camera high speed and high rate of image acquisition, as which it is possible to evaluate the behavior of soybean oil jets and diesel oil as the distance break, tip penetration , speed and spray opening angle. From the physico-chemical properties of vegetable soybean oil, which excels in respect of diesel fuel properties is viscosity, as for liquids used in this work was found that it is approximately 15 times greater than the viscosity of diesel oil. This great difference in the same conditions of temperature produced very different atomization results between the liquid and there is a need for more parameters change than just the density of the gas for atomization is closer to diesel oil and vegetable oil in nature can be used in engines, because atomization schemes observed consistent with the expected considering the properties of both oils under the conditions tested.

Le phénomène de dérive constitue un enjeu environnemental et sanitaire majeur lors de la pulvérisation de solutions phytosanitaires sur les surfaces agricoles. Sous l'action du vent, des gouttelettes peuvent dériver loin des champs ciblés et être source de pollution. Une stratégie pour limiter la dérive est de contrôler la distribution de taille des gouttes de spray, en réduisant la proportion de petites gouttes. Dans ce but, des additifs anti-dérives, tels que des émulsions diluées d'huile dans l'eau, ont été développés. Bien que largement étudiés, les effets de ces émulsions ne sont pas encore bien compris. L'objectif de cette thèse est d'élucider les mécanismes à l'origine de l'augmentation de la taille des gouttes de spray à base d'émulsions.La pulvérisation implique la fragmentation d'un flux de liquide par une buse hydraulique. A la sortie de la buse, une nappe libre de liquide est formée, puis déstabilisée en gouttes. Afin d'élucider les mécanismes à l'origine des effets anti-dérives des émulsions, nous étudions l'influence de ces émulsions sur les mécanismes de déstabilisation des nappes liquides. Une expérience modèle basée sur la collision d'une goutte de solution sur une cible solide est utilisée pour produire et visualiser des nappes liquides. Lors de l'impact, la goutte s'aplatit en une nappe qui s'étend radialement dans l'air, bordée par un bourrelet plus épais. Différents mécanismes de déstabilisation sont observés en fonction des propriétés des fluides. Une nappe d'eau pure s'étale radialement puis se rétracte par effet de la tension de surface ; simultanément, le bourrelet est déstabilisé en gouttes. Pour une émulsion diluée d'huile dans l'eau, le mécanisme de déstabilisation dominant est considérablement modifié: les nappes sont déstabilisées par la nucléation de trous qui perforent le film liquide lors de son expansion; les trous grandissent jusqu'à la formation d'un réseau de ligaments, qui est ensuite déstabilisé en gouttes.Une étude systématique de l'influence des paramètres physico-chimiques de l'émulsion, tels que la concentration en huile et la distribution de taille de gouttelettes d'huile, sur le mécanisme de perforation est conduite. Nous établissons une corrélation entre le nombre d'évènements de perforations observés dans les nappes modèles et la distribution de taille de gouttes de sprays formés avec des buses de pulvérisation agricoles. Ce résultat démontre la pertinence expérimentale de notre expérience modèle pour comprendre les mécanismes d'actions des formulations anti-dérives. Nous montrons ainsi que le mécanisme à l'origine de l'augmentation de la taille des gouttes de spray à base d'émulsion est un mécanisme de perforation.Pour comprendre les mécanismes à l'origine de la perforation, nous développons une technique optique permettant de mesurer le champ d'épaisseur de nappes liquides. Nous constatons que la formation d'un trou dans la nappe est systématiquement précédée par un amincissement local du film liquide. Nous montrons que cet amincissement est le résultat de l'entrée puis de l'étalement par effet Marangoni de gouttelettes d'huile à l'interface air/eau. L'amincissement du film liquide conduit in fine à sa rupture.Nous proposons un mécanisme de perforation en deux étapes: les gouttelettes d'huile (i) entrent à l'interface air/eau, et (ii) s'étalent à l'interface. La formulation de l'émulsion est un paramètre critique pour contrôler le processus de perforation. L'addition de sels ou de copolymères amphiphiles à des émulsions stabilisées par des tensio-actifs ioniques peut soit déclencher, soit inhiber le mécanisme de perforation. Nous montrons que l'entrée de gouttes d'huile à l'interface air/eau est l'étape limitante de ce mécanisme. Les interactions répulsives de nature stérique et/ou électrostatique entre les gouttelettes d'huile et l'interface stabilisent le film liquide, empêchant les gouttelettes d'entrer à l'interface, et ainsi inhibent le processus de perforation
One of the major environmental issues related to spraying of pesticides on cultivated crops is the drift phenomenon. Because of the wind, small droplets may drift away from the targeted crop and cause contamination. One way to reduce the drift is to control the spray drop size distribution and reduce the proportion of small drops. In this context, anti-drift additives have been developed, including dilute oil-in-water emulsions. Although being documented, the effects of oil-in-water emulsions on spray drop size distribution are not yet understood. The objective of this thesis is to determine the mechanisms at the origin of the changes of the spray drop size distribution for emulsion-based sprays.Agricultural spraying involves atomizing a liquid stream through a hydraulic nozzle. At the exit of the nozzle, a free liquid sheet is formed, which is subsequently destabilized into droplets. In order to elucidate the mechanisms causing the changes of the spray drop size distribution, we investigate the influence of emulsions on the destabilization mechanisms of liquid sheets. Model single-tear experiments based on the collision of one tear of liquid on a small solid target are used to produce and visualize liquid sheets with a fast camera. Upon impact, the tear flattens into a sheet radially expanding in the air bounded by a thicker rim. Different destabilization mechanisms of the sheet are observed depending on the fluid properties. A pure water sheet spreads out radially and then retracts due to the effect of surface tension. Simultaneously, the rim corrugates forming radial ligaments, which are subsequently destabilized into droplets. The destabilization mechanism is drastically modified when a dilute oil-in-water emulsion is used. Emulsion-based liquid sheets are destabilized through the nucleation of holes within the sheet that perforate the sheet during its expansion. The holes grow until they merge together and form a web of ligaments, which are then destabilized into drops.The physical-chemical parameters of the emulsion, such as emulsion concentration and emulsion droplet size distribution, are modified to rationalize their influence on the perforation mechanism. We correlate the size distribution of drops issued from conventional agricultural spray with the amount of perforation events in single-tear experiments, demonstrating that the single-tear experiment is an appropriate model experiment to investigate the physical mechanisms governing the spray drop size distribution of anti-drift formulations. We show that the relevant mechanism causing the increase of drops size in the emulsion-based spray is a perforation mechanism.To gain an understanding of the physical mechanisms at the origin of the perforation events, we develop an optical technique that allows the determination of the time and space-resolved thickness of the sheet. We find that the formation of a hole in the sheet is systematically preceded by a localized thinning of the liquid film. We show that the thinning results from the entering and Marangoni-driven spreading of emulsion oil droplet at the air/water interface. The localized thinning of the liquid film ultimately leads to the rupture of the film. We propose the perforation mechanism as a sequence of two necessary steps: the emulsion oil droplets (i) enter the air/water interface, and (ii) spread at the interface. We show that the formulation of the emulsion is a critical parameter to control the perforation. The addition of salt or amphiphilic copolymers can trigger or completely inhibit the perforation mechanism. We show that the entering of oil droplets at the air/water interface is the limiting step of the mechanism. Thin-film forces such as electrostatic or steric repulsion forces stabilize the thin film formed between the interface and the approaching oil droplets preventing the entering of oil droplets at the interface and so inhibit the perforation process

[ES] El proceso de emulsificación de aceites ricos en compuestos bioactivos permite su mejor aplicación y conservación durante el tiempo de almacenamiento. Entre los diversos mecanismos de emulsificación, se destaca el método de Pickering ya que utiliza nanopartículas sólidas naturales en sustitución de los tensioactivos artificiales. Debido a sus propiedades antioxidantes, no toxicidad y disponibilidad, en este trabajo se estudiaron distintas modificaciones del quitosano para su potencial aplicación como partícula de Pickering. Las modificaciones estudiadas fueron la autoagregación, también denominada desprotonación, y el entrecruzamiento con tripolifosfato de sodio. Se evaluó el comportamiento de estas partículas emulsionando aceite de café tostado, un subproducto de la industria de café con un alto contenido de compuestos bioactivos y compuestos volátiles de interés. Posteriormente, se analizaron las propiedades físico-químicas y la estabilidad de las microcápsulas producidas tras el secado de las emulsiones mediante técnicas de secado por atomización y liofilización. Todas las emulsiones se caracterizaron por tener un comportamiento reológico pseudoplástico, sufriendo desintegración a lo largo del proceso de digestión. Las emulsiones formuladas con nanopartículas de quitosano desprotonadas y menor concentración de aceite mostraron una mejor estabilización y, en consecuencia, una mayor bioaccesibilidad de los compuestos fenólicos totales. Las diferentes nanopartículas de quitosano se caracterizaron estudiando su carga superficial, distribución del tamaño de partícula, microestructura y afinidad agua/aceite. A medida que se aumentó la concentración de estas partículas, se afectó positivamente la viscosidad de las emulsiones debido a la formación de una red tridimensional en la fase continua. Las nanopartículas obtenidas al entrecruzar quitosano con tripolifosfato de sodio fueron más pequeñas, dando como resultado emulsiones con gotas más pequeñas. Las emulsiones de Pickering que contenían un 10% de aceite de café tostado se secaron por atomización y se liofilizaron utilizando las diferentes nanopartículas de quitosano estudiadas y maltodextrina como agentes portadores. Las microcápsulas obtenidas tuvieron la humedad, actividad del agua y solubilidad adecuada para su manipulación y almacenamiento. La presencia de nanopartículas de quitosano permitió una mayor retención de aceite en las microcápsulas y mayor eficiencia de encapsulación. Los compuestos bioactivos y las propiedades antioxidantes se conservaron mejor durante la liofilización. Por otro lado, las microcápsulas obtenidas por atomización presentaron mayor protección de estos compuestos durante la digestión. Las microcápsulas formuladas con nanopartículas desprotonadas fueron sometidas a almacenamiento durante 30 días a 25 ºC. Durante el almacenamiento, se evaluó la protección contra la oxidación de lípidos y la liberación de volátiles. Las isotermas de sorción de agua de estas muestras se determinaron también previamente en las condiciones de almacenamiento. Ambas muestras presentaron isotermas del tipo II, lo que permitió un buen ajuste del modelo de GAB a los datos experimentales. La determinación del índice de peróxido y del contenido de dienos conjugados dio lugar a valores adecuados durante el almacenamiento, aunque las muestras liofilizadas presentaron una ligera tendencia a la oxidación debido a la mayor cantidad de aceite superficial. Aunque hubo ligeras diferencias entre las muestras secas, todas mostraron menos pérdida de aromas totales (~28%) en comparación con el aceite no encapsulado (~51%) al final del almacenamiento. Así, se concluyó que las nanopartículas de quitosano estudiadas fueron eficientes para encapsular el aceite de café tostado y preservar sus características frente a la acción de agentes externos.
[CA] El procés d'emulsificació d'olis rics en compostos bioactius permet la seua millor aplicació i conservació durant el temps d'emmagatzematge. Entre els diversos mecanismes d'emulsificació, destaca el mètode de Pickering, ja que utilitza nanopartícules sòlides naturals en substitució als tensioactius artificials. A causa de la seua propietat antioxidant, de la no toxicitat i de la disponibilitat, aquest treball va buscar analitzar el quitosà i les seues modificacions com potencials partícules de Pickering. Les modificacions estudiades van ser la autoagregació, també anomenada desprotonació, i l'entrecreuament amb tripolifosfat de sodi. Es va avaluar el comportament d'aquestes partícules emulsionant oli de cafè torrat, un subproducte de la indústria del cafè amb un alt contingut de compostos bioactius i volàtils d'interès. Posteriorment, es van analitzar les propietats fisicoquímiques i l'estabilitat de les microcàpsules produïdes després de l'assecat de les emulsions mitjançant tècniques d'assecatge per atomització i liofilització. Totes les emulsions tenien un comportament reològic pseudoplàstic, sofrint desintegració al llarg del procés de digestió. Les emulsions formulades amb nanopartícules de quitosà desprotonades i menor concentració d'oli van mostrar una millor estabilització i, en conseqüència, una major bioaccesibilitat als compostos fenòlics totals. Les diferents nanopartícules de quitosà es van caracteritzar estudiant la seua càrrega superficial, distribució del tamany de partícula, microestructura i afinitat aigua/oli. A mesura que es va augmentar la concentració d'aquestes partícules, es va afectar positivament la viscositat de les emulsions a causa de la formació d'una xarxa tridimensional en la fase contínua. Les nanopartícules obtingudes a l'entrecreuar quitosà amb tripolifosfat de sodi van ser més menudes, donant com a resultat emulsions amb gotes més menudes també. Les emulsions de Pickering que contenien un 10% d'oli de cafè torrat es van assecar per atomització i es liofilitzaren utilitzant les diferents nanopartícules de quitosà estudiades i maltodextrina com a agents portadors. Les microcàpsules obtingudes van obtenir una humitat, activitat de l'aigua i solubilitat adequada per a la seua manipulació i emmagatzematge. La presència de nanopartícules de quitosà va permetre major retenció d'oli en les microcàpsules i major eficiència d'encapsulació. Els compostos bioactius i les propietats antioxidants es van conservar millor durant la liofilització. D'altra banda, les microcàpsules obtingudes per atomització presentaren major protecció d'aquests compostos durant la digestió. Les microcàpsules formulades amb nanopartícules desprotonades també van ser sotmeses a la prova d'emmagatzematge durant 30 dies a 25°C. Durant l'emmagatzematge, es va avaluar la seua protecció contra l'oxidació de lípids i l'alliberament de volàtils. Per això, les isotermes de sorció d'aigua d'aquestes mostres es van determinar prèviament en les condicions d'emmagatzematge. Les dues mostres van presentar isotermes de tipus II, el que va permetre un bon ajust del model de GAB a les dades experimentals. L'índex de peròxids i el contingut de diens conjugats van resultar en valors adequats durant l'emmagatzematge, encara que les mostres liofilitzades van presentar una lleugera tendència a l'oxidació a causa de la major quantitat d'oli superficial. Encara que va haver lleugeres diferències entre les mostres seques, totes van mostrar menys pèrdua d'aromes totals (~28%) en comparació amb l'oli no encapsulat (~51%) a la fi de l'emmagatzematge. Així, es va concloure que les nanopartícules de quitosà estudiades van ser eficients per encapsular l'oli de cafè torrat i preservar les seues característiques enfront de l'acció d'agents externs.
[EN] The emulsification process of bioactive-rich oils makes possible their better application and preservation over the storage time. Among the many emulsification mechanisms, the Pickering method has been highlighted as it uses natural solid nanoparticles in replacement of artificial surfactants. Due to the antioxidant properties, non-toxicity and availability, this work aimed at studying chitosan modifications to produce potential Pickering particles. The studied modifications comprised self-aggregation, also called deprotonation, and crosslinking with sodium tripolyphosphate. The performance of these particles was evaluated in the emulsification of roasted coffee oil, a by-product of the coffee industry with a high content of bioactive and volatile compounds of interest. Subsequently, the physicochemical properties and stability of the microcapsules produced after drying the emulsions using spray-drying and lyophilization techniques were analyzed. All emulsions were characterized as shear-thinning, being them destabilized over the digestion process. Emulsions formulated with deprotonated chitosan nanoparticles and lower oil concentrations showed better stabilization and, consequently, greater bioaccessibility of total phenolic compounds. The different chitosan nanoparticles were characterized regarding surface charge, particle size distribution, microstructure and oil/water affinity. Deprotonated chitosan nanoparticles had a larger particle size, which resulted in emulsions with larger oil droplets. As the concentration of these particles increased, the viscosity of the emulsions was positively affected by the formation of a three-dimensional network in the continuous phase. The nanoparticles obtained by crosslinking with sodium tripolyphosphate were smaller, resulting in emulsions with smaller droplets. The viscosity of these emulsions was lower and little affected by the concentration of particles. Pickering emulsions containing 10% roasted coffee oil were spray-dried and freeze-dried, using the different studied chitosan nanoparticles and maltodextrin as carrier agents. The resulting microcapsules showed adequate moisture content, water activity and solubility for subsequent handling and storage. The presence of chitosan nanoparticles resulted in greater oil retention in the microcapsules and higher encapsulation efficiency. Microcapsules obtained by spray-drying had a more regular spherical shape, while the microparticles obtained by freeze-drying were larger with irregular morphology. Bioactive compounds and antioxidant properties were more preserved during freeze-drying. On the other hand, spray drying allowed greater protection of these compounds during the in vitro digestion. The spray- and freeze-dried microcapsules formulated with deprotonated nanoparticles were subjected to the storage test for 30 days at 25 ºC. During storage, their protection against lipid oxidation and volatile release were evaluated. The water sorption isotherms of these samples were previously determined under the storage conditions. Both samples presented type II isotherms, which resulted in a good fitting accuracy of the GAB model to the experimental data. The peroxide index and the conjugated dienes content resulted in adequate values during storage, although the freeze-dried samples showed a slightly higher tendency to oxidation due to the higher amount of surface oil. Although slight differences were observed between the dried samples, both of them showed less loss of total volatile compounds (~28%) when compared to the non-encapsulated oil (~51%) at the end of storage. Thus, it was concluded that the studied chitosan nanoparticles were efficient to encapsulate roasted coffee oil and to preserve its characteristics against the action of external agents.
The authors would like to thank the project RTI-2018-099738-B-C22 from the ‘Ministerio de Ciencia, Innovación y Universidades’, the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brazil (CAPES) - (Finance Code 001; Grant number 88887.468140/2019-00) and the São Paulo Research Foundation (FAPESP – Grant number 2016/22727-8) for the financial support.
Franco Ribeiro, E. (2021). Microencapsulation of roasted coffee oil from chitosan nanoparticles-stabilized Pickering emulsions [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/163234
TESIS

In food and pharma industry, fish oils are highly demanded due to the many associated health benefits of omega-3 fatty acids. However, the delivery of fish oil through food is a major challenge as this oil is susceptible to oxidation and to produce off-flavors. To prevent these undesired effects, microencapsulation techniques are used. Typically oil encapsulation is carried out by two steps (i) emulsion preparation (ii) drying. The main objective is to study the effect of the emulsification method, emulsion formulation, membrane type and microcapsule formulation on relevant physic-chemical parameters of fish oil microcapsules.The approach of the project is to combine, for the first time, the advantages of using a low energy emulsification technique (membrane emulsification) and spray drying to obtain food-grade fish oil microcapsules. The results show a clear improvement in the oil encapsulation efficiency (OEE) when decreasing the droplet size of the emulsion and increasing the amount of wall material. The combination of a polysaccharide with a protein has been found to improve protection against oxidation during storage of the microcapsules, while the addition of denatured proteins as a part of the microcapsule wall material enhances OEE but does not improve the mechanical strength of the microcapsules.
El aceite de pescado es altamente valorado en la industria alimentaria por su demostrada actividad en la prevención y tratamiento de numerosas patologías, asociada a su contenido en ácidos grasos omega-3. La incorporación de aceite de pescado en alimentos presenta algunas dificultades relacionadas con su rápida oxidación y su característico aroma y sabor. La encapsulación del aceite de pescado retrasa la oxidación y permite enmascarar sus propiedades sensoriales. Tradicionalmente, la encapsulación se lleva a cabo combinando una etapa de emulsificación seguida de secado por atomización. El objetivo principal del trabajo es estudiar el efecto del método de emulsificación y la formulación de la emulsión y las microcápsulas en los parámetros físico-químicos más relevantes de las microcápsulas. En este proyecto se combina por primera vez la emulsificación por membranas con el secado por atomización para obtener microcápsulas de aceite de pescado aplicables a la industria alimentaria. Los resultados muestran una clara mejora en la eficiencia de encapsulación del aceite cuando se reduce el tamaño de gota de la emulsión y se incrementa la cantidad de material de pared de las microcápsulas. La combinación de un polisacárido con una proteína para la formación de la pared mejora la estabilidad oxidativa de las microcápsulas durante el almacenamiento. Por otra parte la adición de proteínas desnaturalizadas para reforzar las paredes de las microcápsulas ha resultado en una mejora de la eficiencia de encapsulación de aceite pero no ha mejora su resistencia mecánica

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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
The main objective this bstudy was microencapsulate pequi oil in whey protein concentrate (WPC) and maltodextrin by spray drying, studying the variables of microencapsulation process and subsequently to evaluate the stability of the microcapsules pequi oil by sorption isotherms, glass transition temperature and thermal stability. The study of the production process of microcapsules in pequi oil maltodextrin DE4-7 and WPC by atomization were conducted using a design central composite rotational complete. The independent variables were atomization pressure (2.6 - 5.5 bar) and inlet temperature (136-165 ° C) and the responses were mean diameter, yield and encapsulation efficiency. Microcapsules intended for the stability study were produced following process conditions: inlet temperature 170 °C, 4 bar atomizing pressure, compressed air flow, air drying and feeding, 2.4 m3.h-1 270 m3. h-1 and 120.0 mL.h-1, respectively. The sorption isotherms were determined by generating isotherms at temperatures of 20 °C, 30 °C and 40 °C, the glass transition temperature was measured by DSC and thermal stability by TG. Pequi oil used had monounsaturated fatty acid profile, with over 50% oleic acid, and thermal stability at temperatures of maximum 225 °C. Increasing the inlet temperature led to increased encapsulation efficiency and reduction in process yield. The microcapsules have spherical shape and their surfaces showed no pores and tooth, has similar capacity to absorb water at temperatures evaluated, being different between 0.4 O objetivo deste trabalho foi microencapsular o óleo de pequi em concentrado protéico de soro de leite e maltodextrina utilizando a técnica de atomização ou “spray drying”, estudando as variáveis de processo de microencapsulação envolvidas na técnica e, posteriormente, avaliar a estabilidade das microcápsulas de óleo de pequi produzidas na condição otimizada determinada no estudo de processo de microencapsulação pelas isotermas de sorção, transição vítrea e estabilidade térmica. O estudo do processo de produção de microcápsulas de óleo de pequi em maltodextrina dextrose equivalente 4-7 e concentrado protéico de soro de leite por atomização foi realizado utilizando o delineamento composto central rotacional completo. As variáveis independentes foram a pressão de atomização (2,6 – 5,5 bar) e a temperatura de entrada (136 – 165 °C) e as respostas o diâmetro médio, o rendimento e a eficiência de encapsulação. As isotermas de sorção foram determinadas por gerador de isotermas nas temperaturas de 20°C, 30 °C e 40 °C; a temperatura transição vítrea foi medida por Calorimetria Diferencial Exploratória e a estabilidade térmica por Termogravimetria. O óleo de pequi utilizado apresentou perfil de ácidos graxo monoinsaturados, sendo que apresentava mais de 50% de ácido oléico e estabilidade térmica a temperaturas máximas de 220 °C. O estresse fotoxidativo aplicada na avaliação da estabilidade do óleo de pequi produziu processos oxidativos de modo que houve degradação de β-caroteno e produção de peróxidos e aldeídos, produtos do processo oxidativo lipídica. O óleo de pequi exposto diretamente ao estresse apresentou redução da entalpia de cristalização em comparação ao branco, sugerindo que a calorimetria diferencial exploratória pode ser uma análise útil para verificação do estagio oxidativos de produtos lipídicos. O aumento da temperatura de entrada conduziu ao aumento da eficiência de encapsulação e redução no rendimento de processo. As microcápsulas apresentaram formatos e superfícies, respectivamente, esféricos e com enrugamentos e ausência de poros; exibiram semelhantes capacidades de adsorverem água nas temperaturas avaliadas, sendo diferentes entre o intervalo 0,4 < Aw <0,6 onde essa capacidade foi maior com o aumento da temperatura. O modelo GAB foi o que melhor ajustou-se para as isotermas obtidas nas temperaturas de 20 °C e 30 °C, enquanto, em 40 °C melhor ajustou-se o modelo de Oswin. As temperaturas de transição vítrea das microcápsulas Ton =-22,5 °C e Toff=-2,5 °C. A microcápsula de óleo de pequi possui estabilidade térmica até 180°C.

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CAPES
Neste trabalho, foram desenvolvidos métodos para determinação de cádmio e chumbo em amostras ambientais e antimônio e arsênio em amostras de alimentos, utilizando técnicas de espectrometria atômica. A determinação do cádmio e do chumbo foi realizada através de um sistema de injeção em fluxo acoplado a técnica TS FF AAS. Os íons de cádmio (II) e chumbo (II) foram retidos em uma mini-coluna de Amberlite de XAD – 7 impregnada com ditizona. O planejamento Box- Behnken foi empregado para determinação das condições ótimas da etapa de concentração do chumbo e do cádmio. Os limites de detecção foram de 0,012 e 0,34 μg L-1 para cádmio e chumbo, respectivamente. O método foi aplicado em amostras de resíduos de refinaria de petróleo. A exatidão foi confirmada por análise da CRM NIST 1643d. Foi também desenvolvido um método para determinação de espécies tóxicas de arsênio e antimônio em amostras de alho e cogumelos, respectivamente por HG AFS. A determinação das espécies (III) e (V) de arsênio e antimônio foram baseadas na eficiência de geração de hidreto empregando NaBH4, com e sem uma prévia redução com KI, usando equações proporcionais correspondentes para as duas condições de medida. Os analitos foram extraídas com ácido sulfúrico nas condições de 1,0 e 0,5 mol L-1 para arsênio e antimônio, respectivamente. Com o método desenvolvido obteve-se limites de detecção de 0,6, 1,1, 0,84 e 1,4 ng g-1 para Sb(III), Sb(V), As(III) e As(V), respectivamente. A exatidão do método foi confirmada através de testes de adição e recuperação das espécies bem como, um material de referência certificado NIST 1573a. Um método para determinação de arsênio total em vinho também foi desenvolvido. O arsênio foi determinado por FI-HG AAS com um sistema de atomização eletrotérmica. O planejamento Box-Behnken foi utilizado na determinação das condições ótimas para geração de hidreto. Com método proposto obteve um limite de detecção de 0,06 μg L-1 e foi aplicado em 20 amostras de vinhos comercializadas do Brasil.
Salvador

Naturally occurring food antimicrobials such as plant essential oils are receiving tremendous interest as intervention systems to enhance microbiological safety and quality. Poor water solubility of essential oils makes it difficult to incorporate them in foods, impacting visual appearance, antimicrobial effectiveness, and possibly organoleptic properties. Engineered nanoscale delivery systems can principally solve these challenges, but those based on low-cost food ingredients and inexpensive and scalable processes are currently scarce. This dissertation presents a simple and scalable two-step technology to prepare nano-delivery systems. The first encapsulation step, based on emulsion-evaporation, involves preparing emulsions composed of an oil phase with thymol or eugenol, major compounds in extracts from thyme and clove respectively, in hexane and an aqueous phase with conjugates of whey protein isolate and maltodextrin, followed by evaporation of hexane by spray drying. The second step is to hydrate spray dried capsules to enable the formation of nanoscale particles. The encapsulation performance and dispersion characteristics were affected by amounts and types of conjugates (ratio of protein: maltodextrin and maltodextrin chain length), volume fraction and composition of the oil phase. The optimal conditions corresponded to 55.8 % encapsulation efficiency and 12.6 % loading for thymol and 47.9 % encapsulation efficiency and 7.9 % loading for eugenol. Dispersions prepared from the identified capsules contained particles smaller than 100 nm and were transparent at pH 3.0-7.0 and 0-50 mM before and after heating at 80°C for 15 min. Nano-dispersions and free oil were tested for antimicrobial activity against Escherichia coli O157:H7, Listeria monocytogenes, Staphylococcus aureus, and Salmonella typhimurium. Nano-dispersed and free antimicrobials had similar effectiveness at various pH and temperatures in tryptic soy broth and apple cider, while in 2 % reduced fat milk, nano-dispersed antimicrobials were consistently more effective than unencapsulated ones. Therefore, the commercially viable nanoscale technology presented in this study enables the delivery of lipophilic antimicrobials for enhanced microbial safety and quality, without compromising visual appearance of foods, especially clear beverages.

Atomization characteristics of liquid fuel sprays control combustion efficiency and emissions in engines. The present work is motivated by the need to study the atomization and spray structure of vegetable oil biofuels for which no data in the literature exists. In this work, various laser-based diagnostic techniques such as laser shadowgraphy, Particle/Droplet Image Analysis (PDIA) and Laser Sheet Dropsizing (LSD) are applied for studying atomization characteristics, tip penetration, droplet size and liquid volume fraction of Pongamia vegetable oil (SVO) and its blends with diesel. A constant volume high pressure spray visualization chamber is designed and fabricated to study SVO sprays at high gas pressure and temperature conditions. This optical chamber can be used for gas pressures up to 60 bar and temperatures up to 600 K. Optical access inside the chamber is provided through four quartz windows to perform various optical spray diagnostic studies. A high pressure spray injection facility based on components of common rail diesel injection system is designed. This facility can provide an injection pressure of up to 1700 bar with independent control over injection duration and timing. A marked difference is observed between diesel and SVO spray structures under atmospheric gas pressure condition. A very interesting observation related to the behavior of 100% SVO fuel when sprayed into atmospheric pressure is the presence of an intact liquid core even at injection pressure as high as 1600 bar. The presence of liquid core at high injection pressures is attributed to the high viscosity of SVOs and the non-Newtonian behavior of these oils under high pressure and shear. The spray characterization of the oil and its blends at high gas pressure shows that although the atomization is dramatically different from that at atmospheric gas pressure, it is still incomplete even at very high injection pressures. For a gas pressure of 30 bar, it is observed that the Sauter Mean Diameter (SMD) for Pongamia oil is more than twice that of diesel. A new method of simultaneously obtaining two-dimensional droplet size and quantitative liquid volume fraction data in sprays has been developed. Measurements with this method reveal a higher liquid volume fraction at the central axis of spray for Pongamia oil compared to that of diesel indicating potentially poor air-fuel mixing. The experimental data obtained and the spray tip penetration correlations developed for the vegetable oils and blends serve as useful inputs for fuel injection and engine system designers.

Research Doctorate - Doctor of Philosophy (PhD)
Gac fruit (Momordica cochinchinensis Spreng) aril contains extraordinarily high levels of β-carotene and lycopene and unsaturated fatty acids, especially oleic and linoleic acids. These bioactive compounds have been proven to be beneficial to human health and are linked with a reduced risk of cardiovascular disease and cancers. Importantly, it has been found that a significant improvement in the absorption of the carotenoids into the human body occurs when they are digested with fat. The current study hypothesised that optimisation of conditions for several processing steps, including oil extraction, emulsion preparation conditions and spray drying process using response surface methodology (RSM), is expected to maximise the oil yield and increase the retention of bioactive compounds. The aim of this study was therefore to develop optimal conditions for the extraction of Gac oil enriched in β-carotene and lycopene, and the preparation of the Gac oil rich in β-carotene and lycopene encapsulated powder, for use as nutrient supplement or natural food additive and natural food colourant. The objectives of this study were to investigate the effect of (1) pre-treatments prior to supercritical carbon dioxide extraction, (2) ultrasound-assisted aqueous extraction, (3) microwave-drying followed by pressing on the Gac oil extraction efficiency, and β-carotene and lycopene contents. Moreover, this study was also to optimise the conditions for spray-drying encapsulation of Gac oil using RSM: (1) wall material concentration and ratio of Gac oil to wall material, and (2) spray-drying conditions including air inlet and outlet temperatures. The shelf life and stability of the encapsulated Gac oil powder were also evaluated. The results showed that high extraction efficiencies in terms of Gac oil, β-carotene and lycopene were obtained using the three different extraction methods. Supercritical carbon dioxide extraction gave the highest oil extraction efficiency (95%), followed by ultrasound-assisted extraction (90%) and microwave-drying followed by pressing (86%). The Gac oil extracts from the different extraction methods contained high concentration of β-carotene and lycopene and had low peroxide value. For encapsulation, the results indicated that the response surface model was sufficient to describe and predict the response variables with high R²value. Under optimal conditions for wall material (whey protein and gum Arabic, 7/3) concentration (29.5%) and the ratio of Gac oil to wall material (0.2, g/g), the encapsulation efficiencies in terms of Gac oil, β-carotene and lycopene, peroxide value, moisture content and total colour difference were predicted and validated. For spray-drying, using optimal conditions (inlet and outlet temperatures of 154 and 80 oC, respectively), the encapsulation efficiencies in terms of Gac oil, β-carotene and lycopene, encapsulation yield, moisture content, water solubility and peroxide value were predicted and confirmed. Furthermore, physicochemical (Aw, pH, bulk density, fatty acid composition, and particle morphology), reconstitution and colour properties of the optimally encapsulated Gac oil powder were also evaluated. The results indicated that the encapsulated Gac oil powder could be stored for a long time due to low Aw and good protective structure of particles against light, oxidation, and unwanted release of the oil droplets and carotenoids. A storage study was conducted to determine preservation of quality in the encapsulated Gac oil powder. Findings from the storage study confirmed that preservation of colour, β-carotene and lycopene in the encapsulated Gac oil powder with a lower peroxide value was more effective when vacuum-packed into laminated aluminum bag and stored at ambient temperature or lower for up to 12 months. The results also showed that during storage, the incorporated Gac oil in yoghurt, pasteurised milk and cake mix were found to be satisfactory in terms of preserving an attractive colour and β-carotene and lycopene contents, and having a low peroxide value. In summary, the hypothesis was supported and the aims were achieved in this study. The high extraction efficiency for Gac oil containing high level of β-carotene, lycopene and unsaturated fatty acids was obtained using different extraction methods. The Gac oil rich in those bioactive compounds was effectively encapsulated by spray drying. The encapsulated Gac oil powder was highly stable at ambient temperature or lower. Furthermore, the encapsulated Gac oil powder was found to be easily incorporated into a range of food products. Finally, the Gac oil encapsulated powder is considered suitable for use as natural food colourant, a nutraceutical or an additive in the food industry.

Commercial liquid petroleum fuels are complex mixtures of various hydrocarbons. In multicomponent fuel modelling, these liquid fuels are represented typically with two components or up to ten discrete components. Even with ten components, there are limitations on the representation of real commercial fuels such as heavy fuel oil (HFO), which contains large numbers of hydrocarbons with a wide range of molecular weights and dissimilar structures. Continuous thermodynamics and pyrolysis chemical kinetics are used to model the behaviour of HFO in diesel spray combustion. The evaporation model is developed using the principle of continuous thermodynamics rather than discrete component modelling, to accurately cover the entire range of composition. Continuous thermodynamics reduces the computational simulation load compared to conventional discrete thermodynamics, without degrading the quality of prediction of the complex behaviours of such multicomponent fuels. In continuous thermodynamics modelling, liquid mixture compositions are simply represented by probability density functions (PDF). In the present study, HFO is represented by four fuel fractions: n-paraffins, aromatics, naphthenes and heavy residue. Each of these fractions is assigned a separate distribution function. In the evaporation model, both low-pressure and high-pressure formulations for the calculation of vapour-liquid equilibrium (VLE) at the droplet surface are provided. The formulations for high-pressure VLE are developed for a semicontinuous mixture and a generic approach to the equation of state (EOS) is used. Therefore, depending on the mixture compositions (continuous or semicontinuous) these formulations can be applied with any EOS. It is identified that in the high-pressure model, interaction coefficients between the liquid-liquid components and between the liquid component and air plays an important role during evaporation. Interaction coefficients help to improve the evaporation rate of heavy molecules. HFO is primarily composed of high molecular weight hydrocarbons which cannot evaporate but are pyrolised at high temperatures. Pyrolysis produces volatile gases and polymers through thermal cracking and polymerisation respectively. Baert’s pyrolysis model based on chemical kinetics for thermal cracking and polymerisation rate is developed. Results of this pyrolysis model show that polymer formation within a droplet is dependent on droplet heating rate and composition. Moreover, it is observed in Baert’s pyrolysis model results that the process of polymerisation starts prior to the thermal cracking. This order of thermal cracking and polymerisation is contradictory to the experimental evidence. Subsequently, Baert’s pyrolysis model parameters are modified. Results of the modified pyrolysis model did not show any significant dependency of polymer formation on droplet heating rate and in addition it showed thermal cracking beginning earlier than the polymerisation. The low and high-pressure evaporation models along with the modified pyrolysis model are applied to a single HFO droplet in a high pressure environment, showing good agreement with experimental results obtained by other researchers. A comparison of the low-pressure model with the high-pressure model for 100 micron and 30 micron droplets at high pressure and temperature show that evaporation of the volatile hydrocarbons (nparaffins, aromatics, naphthenes) from HFO occurs at a faster rate for the high-pressure model. However, this faster evaporation does not significantly affect the droplet lifetime because modelled HFO contains only 30% volatile hydrocarbons (cutter stock) by mass. Therefore, droplet lifetime is found to be similar for both models. Thus in sprays where droplets are generally small, the VLE calculation can be obtained with sufficient accuracy by the low-pressure model avoiding the use of the complex high-pressure EOS model. The low-pressure evaporation and modified pyrolysis models along with a heterogeneous liquid phase soot burnout model are implemented via subroutines in a diesel spray simulation in the CFD package StarCD. This simulation is applied to two different constant volume spray combustion chambers which are used to examine the combustion characteristics of HFO. The models are tested for two representative fuel samples; one with the good combustion quality and the other poor. Good qualitative agreement is shown between the computer simulations and the published experimental data. A sample of HFO is characterised in the laboratory using chemical characterisation procedures such as; sequential elution solvent chromatography (SESC), gaschromatography (GC), mass spectrometry (MS) and elemental analysis, to obtain the composition and mean molecular weights of HFO fractions required for continuous thermodynamics modelling. A CFD simulation of the characterised HFO is performed using the developed low-pressure evaporation and modified pyrolysis models.

碩士
國立臺灣大學
機械工程學研究所
88
When we explore the sorts of lubrication oil, we find out they are differentiated by not only their different brands and purposes but their individual situation of being used. According to this, we choose the waste lubrication oil that is produced by automobiles and scooters to be the waste lubrication oil of this experiment. In this experiment, we use this kind of lubrication oil that is produce the atomizing droplet clouds with the atomizer, and then burn the atomizing droplet clouds in the combustion chamber at high temperature. By this experiment, we would like to discuss the dissolving characteristics of the mixture mixed by waste lubrication oil and diesel oil 、the burning efficiency 、the second pollution which the mixture may produce after being burned in 1 atm 、at the same temperature, but at different weight percentage of waste lubrication oil.

碩士
國立臺北科技大學
能源與冷凍空調工程系碩士班
98
This study investigates the evaporation heat transfer performance of R-245fa and R-245fa with lubricant RL -150S mixture (1%, 2% and 5% lubricant mass fraction) in pool boiling and falling film. Two kinds of tubes, a smooth tube and a fin tube of 0.4mm fin height, 60FPI(Fins Per Inch) were tested. Experiments were performed at saturation temperatures of 5, 10 and 20oC. The liquid flowed through a liquid feeder with a row of circular holes at a rate of 0.012 ~ 0.04kg/ms, and heat fluxes varied from 6 to 50kW/m2. For pure refrigerant, the results show that falling film heat transfer coefficient is better than pool boiling with fin tube. The heat transfer coefficient of R-245fa is similar to R-123. Hence, R-245fa is a good refrigerant to replace R-123. For pool boiling in R-245fa-oil mixtures, different results are shown in smooth and fin tube. The heat transfer coefficient of smooth tube decreases with increasing oil concentration. The smooth tube has a greater heat transfer coefficient at low heat flux than in falling film, but the performance slightly decreases at high heat flux. The fin tube has the same tend in pool boiling and falling film, the heat transfer coefficient increases with increasing oil concentration. The performance of refrigerant-oil mixtures depends on the tube surface structure. For falling film evaporation, the falling fluid flow pattern depends on tube location. Hence, the tube location is an additional factor on performance. A heat transfer correlation of falling film evaporation on smooth tube, which predicts the data in this study within

碩士
吳鳳科技大學
消防研究所
102
The principle of transformer is used by electromagnetic induction, altered to voltage and electric current, the immobile electric device to delivery the power of electric energy. So many of classification, the one of the transformer of oil immersion is commonly used in our country of electric power system.The study for the reason of breakdown in the transformer of oil immersion and fire risk, according to NFPA version to give a right way to keep in fire preventive facilities of water spray fire system to protect oil-filled transformer. This research on domestic and foreign laws and regulations related to research and analysis, and the actual to the substation site inspection, to understand the current situation and fire protection design to items substation fire safety, the proposed fire safety design a suitable oil-immersed transformers guidelines. Besides serving as reference for fire regulating authorities when they stipulate related regulations and laws and for designers during fire safety design, this study can also be referred to by Taipower when it tries to improve old and outdated fire safety equipment so as to enhance its ability to ensure fire safety and reduce potential crises as a result of power failure caused by fires, accordingly improving the business image of the company.

碩士
東海大學
食品科學系
106
Sesame oil is a commonly used condiment oil, and it blend with soybean oil to produce blended sesame oil regularly. However, sesame oil has constrained development and application due to the different characteristic with other condiment oil. This research try to improve extensibility and applicability by using spray dried sesame oil powder which use MD and HPMC as wall material. Although there already has some product of sesame oil powder in the market, but most of them has insufficient flavor when it dissolved in water. To find the most suitable usage in modern food industry, this experiment controls the amount of oil added in 7.5, 10, 12.5 % and sesame oil blending ratio in 20, 40, 60, 80, 100 %. The results showed that the drying yield is in 55.07 to 68.79 % range, the production decreased as amount of oil increased, and it had no significant difference by using different emulsifier. The moisture content also decreased by the amount of oil added. However by adding 10 % of oil, the moisture content is increased (4.28 to 5.87 %) and the sesame oil blending ratio increased, the water activity is in 0.541 to 0.661 range, it decreased by amount of oil added, and sesame oil blending ratio increased. The result indicated that if the oil contents sets in between 7.5 and 12.5 %, it had no significant difference. In 7.5 %of oil added, the oil content is increased from 39.11 to 44.11 %, and sesame oil blending ratio increased by the amount of oil added. The surface oil content increased by the amount of oil added, and only in 7.5 % of oil added, it decrease significantly between 30.50 to 24.79 % but sesame oil blending ratio increase; the encapsulation efficiency is increased from 23.59 to 43.78 % when sesame oil blending ratio increase. Furthermore, in 80 and 100 % of sesame oil blending ratio, it decreased significantly by the amount of oil added. Aerated and tapped bulk density are increased significantly by amount of oil added, but decreased significantly by sesame oil blending ratio decreased. The hausner ratio is in between 1.4 to 1.45. Compared with temperature in 25℃ and 90℃, and the solubility is increased significantly only in 7.5 % of oil added with 40, 60, 100 % of sesame oil blending ratio. The hygroscopicity is increased by the amount of oil added, but it has no significant difference with sesame oil blending ratio. In the appearance, this research observes that the color of powder became deeper by the amount of oil added and sesame oil blending ratio increase, also, all of them were caking. After spray drying process finished, except in 20 % of blending oil ratio, the POV is increased significantly by the amount of oil added. After storage 7 days with in 25℃and 60℃, except in 40 % of blending oil ratio with 25℃, the POV is increased significantly by the amount of oil added. As result, compare with control sample in the same environment, the powder has poor preservation. The Concentration result showed that high sesame oil blending ratio can earn better favor and recognized with strong sesame flavor. However in the 12.5 % of oil added and 20 % of sesame oil blending ratio, the result shown poor concentration because of rancid flavor oil. Based on the result above, the powder has better quality with the research setting of lower water content, water activity and hygroscopicity. Besides, it has good solubility in both heat and cold water this indicated the high extensibility and applicability as well.

Biomass fast pyrolysis liquid (bio-oil) is a cellulose based alternative fuel with the potential to displace fossil fuels in stationary heat and power applications. To better understand the combustion behavior and emissions of bio-oil, a 10 kW spray burner was designed and constructed. The effect of swirl, atomization quality, ignition source (pilot) energy, air/fuel preheat and equivalence ratio on the stability and emissions of bio-oil spray flames was investigated. A blend of 80% pyrolysis liquid and 20% ethanol by volume was used during the tests and the results were compared to burner operation with diesel. It is important to have good atomization, thorough mixing and high swirl in order to stabilize ignition, promote the burnout of bio-oil and decrease CO, hydrocarbon and particulate matter emissions. The total amount of primary air and atomizing air that can be used to improve turbulence, mixing, droplet burnout and overall combustion quality is limited by the distillable fraction and narrow lean blow-out limit associated with pyrolysis liquid. Air and fuel preheat are important for reducing hydrocarbon and CO emissions, although subsequent fuel boiling should be avoided in order to maintain flame stability. The NOx produced in bio-oil flames is dominated by the conversion of fuel bound nitrogen. The particulate matter collected during bio-oil combustion is composed of both carbonaceous cenosphere residues and ash. Under good burning conditions, the majority consists of ash. Pilot flame energy and air/fuel preheat have a weak effect on the total particulate matter in the exhaust. Generally, these results suggest that available burner parameters can be adjusted in order to achieve low hydrocarbon, CO and carbonaceous particulate matter emissions when using pyrolysis liquid. Total particulates can be further mitigated by reducing the inherent ash content in bio-oil. Comparative burner tests with diesel reveal much lower emissions for this fuel at most of the operating points considered. This is due to the fully distillable nature, better atomization and improved spray ignition characteristics associated with diesel. Because of its superior volatility, diesel can also operate over a much wider range of primary air and atomizing air flow rates compared to bio-oil.

碩士
雲林科技大學
機械工程系碩士班
96
This study carries out the research assessment of the effects on the characteristics of oil spray by the flow structure inside the engine inlet manifold of a motorcycle. Stator ring with different blade design were installed upstream of the manifold in order to change the flow structure. Commercial software FloWork was used to simulate the flow field before and after airflow entering the cylinder. The characteristics of the oil spray were then evaluated using laser particle sizer, together with balance for oil wetting measurement. Major experiment parameters in this research include different throttle openings, stator ring designs and the actions of the inlet valve of the cylinder. The experimental result reveals that no matter how the flow structure changes, the more the throttle opening, the smaller the SMD value. The motion (open-close) of the inlet valve will increase the oil particle size due to the existence of unexpected huge oil droplets. Although the installation of stator rings in general increase the SMD value, however, the oil wetting at the wall was dropped clearly. This outcome may be attributed to the change of the flow structure, which imposes rotating motion to the flow field and provides better chance for the oil droplets to collide and combine, and brings the oil back to the flow field from the oil film on the wall and prevents liquid oil flows into the cylinder too. Based on the comprehensive simulation and experimental result, it is clear that the change of flow structure inside the inlet manifold can indeed influence the characteristics of the oil spray and the oil wetting at the wall.

Mestrado de dupla diplomação com a UTFPR - Universidade Tecnológica Federal do Paraná
The generation of waste is one of the greatest and most damaging environmental risks. In the passion fruit juice industry, where only pulp is used, seed residues represent 12% of the fruit. They contain a high oil content (28 to 30%) rich in unsaturated fatty acids, tocopherols, carotenoids, and phenolic compounds, being also reported as presenting antioxidant activity and health benefits. Liposomes are spherical vesicles formed by phospholipids that, due to their amphoteric nature, when placed in aqueous solution self-aggregate, exposing the hydrophilic part and hiding the hydrophobic part, thus being able to encapsulate substances. In this context, the application of the oil extracted from the passion fruit seed (obtained from UTFPR), its characterization and encapsulation in liposomes for cosmetic applications was studied. The oil was characterized in terms of fatty acid profile, antioxidant activity, and oxidative stability. The fatty acid profile showed a predominance of unsaturated fatty acids, especially linoleic and oleic acids. The antioxidant activity was measured through the reducing activity related to the presence of phenolic compounds and through the capture of DPPH free radicals, being verified an intermediate antioxidant activity. The study of the oxidative stability proved the low stability of the oil, justifying its encapsulation before application, to preserve properties. To prepare the liposomes, the phosphatidylcholine was used as the lipid and the ethanol injection method (scalable) selected as the productive process. The method consists of preparing an aqueous phase and an organic phase containing the active ingredient to be encapsulated. Then, the organic phase is pumped into the aqueous phase under controlled flow, temperature, and stirring. After the production of the vesicles, the final step corresponds to the evaporation of the solvent in a rotary evaporator. The influence of parameters such as stirring and solvent evaporation times, on the vesicle final sizes was studied, being verified that the increase in stirring and evaporation time favor the agglomeration of liposomes. Liposomes were characterized in terms of size, morphology, stability and encapsulation efficiency. Through optical microscopy (OM) it was verified the spherical morphology of the liposomes and the influence of the solvent in their behaviour. Encapsulation efficiency tests for different oil concentrations were done indicating that the one comprising 20% w/w of oil was the higher one. The zeta potential was measured (-28.23 mV), showing the low stability of the vesicles that were further subjected to coating with chitosan. Two methodologies for particle’s drying were studied: lyophilization, with the use of a cryo-protector (maltodextrin), and spray-drying after chitosan coating. Dry liposomes were characterized in what concerns size, morphology and stability. Optical and scanning electron microscopy proved the sphericity of the vesicles. The laser diffraction technique allowed measuring the size of the particles, showing that the size increased after drying due, which was associated to particle agglomeration. Visual analyses allowed to check stability, being verified that lyophilized liposomes released part of the encapsulated oil after 2 months of storage, being spray-drying after chitosan coating the most suitable methodology to produce liposomes in the dry form.
A geração de resíduos constitui um dos maiores e mais danosos riscos ambientais. Na indústria de sumo de maracujá, por exemplo, apenas a polpa é utilizada. Entre estes resíduos, as sementes, que representam 12% do fruto, contêm um elevado teor de óleo (28 a 30%) rico em gorduras insaturadas, tocoferóis, carotenóides e compostos fenólicos, apresentando atividade antioxidante e benefícios para a saúde. Os lipossomas são vesículas esféricas formadas por fosfolipídios que devido à sua natureza anfotérica, quando colocados em solução aquosa, auto agregam-se expondo a parte hidrofílica e ocultando a parte hidrofóbica, podendo assim, encapsular substâncias. Neste contexto, a aplicação do óleo da semente de maracujá (obtido na UTFPR), sua caracterização e encapsulação em lipossomas visando aplicações cosméticas será estudado. A caracterização do óleo foi feita em termos do perfil de ácidos gordos, atividade antioxidante e estabilidade oxidativa. O perfil de ácidos gordos revelou a predominância de ácidos gordos insaturados, com destaque para os ácidos linoleico e oleico. A atividade antioxidante medida através da atividade redutora na presença de compostos fenólicos e através da captura de radicais livres DPPH, revelou uma atividade antioxidante intermédia. O estudo da estabilidade oxidativa comprovou a baixa estabilidade do óleo, justificando a sua encapsulação. Para a preparação dos lipossomas, utilizou-se a fosfotidilcolina como lípido e a metodolodia de injeção de etanol (factível de escalonamento) como o processo produtivo. O método consiste na preparação de uma fase aquosa e uma fase orgânica contendo o princípio ativo. Posteriormente, a fase orgânica é bombeada para a fase aquosa a caudal, temperatura e agitação controladas. Após produção das vesículas, procedeu-se à evaporação do solvente em evaporador rotativo. Estudou-se a influencia de parâmetros como tempo de agitação e de evaporação do solvente no tamanho das vesículas, verificando-se que o aumento destes favorecem a aglomeração dos lipossomas. Os lipossomas foram caracterizados quanto ao tamanho, morfologia, estabilidade e eficiência de encapsulação. Através de microscopia óptica (OM) comprovou-se a morfologia esférica dos lipossomas e a influência da presença de solvente no comportamento das mesmas. Os testes de eficiência de encapsulação para diferentes concentrações de óleo mostraram que a formulação contendo 20% m/m de óleo resultou no valor de eficiência mais elevado. O potencial zeta foi medido (-28,23 mV), evidenciando a baixa estabilidade das vesículas, tendo-se procedido ao revestimento com quitosano. Quanto à secagem estudou-se a liofilização, com o uso de um crioprotetor (maltrodextrina), e spray-drying após revestimento com quitosano. Os lipossomas secos foram caracterizadas quanto ao tamanho, morfologia e estabilidade. A microscopia óptica e eletrônica de varrimento comprovaram a esfericidade das vesículas. A técnica de difração a laser permitiu medir o tamanho de partícula, mostrando o aumento deste após o processo de secagem, em parte devido à aglomeração das partículas. A análise visual permitiu avaliar a estabilidade, sendo que os lipossomas liofilizados libertaram parte do óleo encapsulado após 2 meses de armazenamento, sendo a técnica de spray-drying após revestimento com quitosano a melhor técnica para obter lipossomas na forma seca.
This work was financially supported by CIMO (UIDB/00690/2020) through Foundation for Science and Technology (FCT, Portugal) under national funds FCT/MCTES.

Fish and fish waste can be used to produce various value added by products such as proteins, oil, omega-3 fatty acids, biodiesel, amino acids, peptides, collagen, gelatin and silage, each of which has various applications in the food industry, renewable energy and medicinal purposes. Fish protein contains amino acids and many bioactive peptides . Fish proteins are found in the flesh, head, frames, fin, tail, skin and guts in varying quantities. After removing the flesh, all other parts are considered waste which is not properly utilized. The aim of this study was to evaluate the enzymatic extraction of amino acids from fish protein for use as substrates in the microbial production of jadomycin, an antimicrobial agent and potential anti-cancer drug. In this study, enzymatic extraction of proteins was carried out using Alcalase enzyme at three enzyme concentrations (0.5, 1 or 2%) and four time intervals (1, 2, 3 and 4 h). The fish protein hydrolysate was dried using spray dryer to obtain protein powder. The highest protein yield (76.30% from whole fish and 74.53% from the frame) was obtained using 2.0% enzyme concentration after 4 h of hydrolysis. The enzymatic extraction of amino acids were carried out using the enzymes Alcalase and Neutrase (individually and in combination) and the effect of reaction time (24 and 48 h) on the hydrolysis of proteins was studied. The profiling of amino acids was carried out using gas chromatography. Fourteen amino acids were extracted from fish proteins of which twelve amino acids have been used by researchers for the production of jadomycins. These are: alanine (7.59%), glycine (5.82%), histidine (3.59%), isoleucine (5.30%), leucine (9%), lysine (7.34%) methionine (2.2%), phenylalanine (4.2%), serine (4.3%), threonine (5.40%), tyrosine (3.17%) and valine (7.2%). Tryptophan which is suitable of producing jadomycin was not present in the fish protein. No reports were found in the literature for jadomycin production from glutamic acid. Therefore, glutamic acid (9.85%), and proline (0.98%) which are present in the fish protein should be investigated for possible production of jadomycins.

Mestrado em Engenharia Alimentar - Instituto Superior de Agronomia
The essential oils (EO) in general and of oregano (Origanum virens L.) in particular are usually very unstable. Thus, the present study intends to study the potential of encapsulation of EO on matrices obtain from gelatin/sucrose systems, by spray-drying and freeze-drying. Several analytical techniques (scanning electron microscopy, confocal fluorescence microscopy, FTIR and diffusion) were used for morphological evaluation of the encapsulated and the presence of EO in the matrices. In the case of encapsulation by spray-drying, size average particles were also considered, witch, with more frequency, presented sizes between 0.9 and 10 micrometers. The spray-drying encapsulated were smooth and spherical capsules, while those obtained by freeze-drying had no shape or defined structure. The EO presence in the encapsulated was confirmed by FTIR and confocal fluorescence microscopy analysis. It was found that the encapsulated obtained by the spray-drying process had a low value of diffusion coefficient (≈ 10-15 m2/s) and that during the first two hours, the release of EO was greater (0.2 to 0.4 mg) of those encapsulated by freeze drying (0.025 to 0.2 mg). The encapsulation of oregano EO on gelatin/sucrose systems through spray-drying or freeze-drying can be a viable process.-------------------------------------Os óleos essenciais (OE) em geral e o de orégão (Origanum virens L.) em particular são geralmente muito instáveis. Assim, pretendeu-se com o presente trabalho estudar a potencialidade do encapsulamento de OE de orégão em matrizes obtidas a partir de sistemas de gelatina/sacarose, por atomização e liofilização. Foram utilizadas várias técnicas analíticas (SEM, microscopia confocal de fluorescência, FTIR e Difusão) para a avaliação morfológica dos encapsulados e detecção da presença do OE nas matrizes. No caso dos encapsulados por atomização, foi ainda analisado o tamanho médio das partículas que com maior frequência apresentaram tamanhos entre 0,9 e 10 μm. Os encapsulados por atomização apresentavam-se na forma de cápsulas lisas e esféricas, enquanto os obtidos por liofilização não apresentavam forma ou estrutura definida. A presença de OE nos encapsulados foi corroborada por análise FTIR e microscopia Confocal de fluorescência. Verificou-se que os encapsulados obtidos por atomização apresentaram um baixo valor de coeficiente de difusão (≈10-15m2/s) e que, durante as primeiras duas horas, libertavam maior quantidade de OE (0,2 a 0,4 mg) do que os encapsulados por liofilização (0,025 a 0,2 mg). O encapsulamento de OE de orégão em sistemas gelatina/sacarose através da atomização ou da liofilização pode constituir um processo viável.

Mestrado em Engenharia Alimentar - Qualidade e Segurança Alimentar - Instituto Superior de Agronomia
Inulin and fructo-oligosaccharides are prebiotic compounds and, for that reason, the growing interest in these natural constituents has been increasing in the last decade, raising the attention of food industry. On the other hand, their properties, namely the ability of capsule formation, allow their use as encapsulation material. This thesis was to study inulin as an encapsulating matrix of bioactive compounds, for what there were used drying processes by spray-drying and freeze-drying. The tests done have shown that the atomization process is the most efficient in the formation of inulin capsules. The size of the particles formed, ranged between 3 and 5 μm, and it was observed that their size decreases as the polymerization degree increases. So, to optimize the particles’ size and other characteristics, there were tested different drying conditions, and so it was done an inulin matrix. The concentration of soluble solids and the drying temperature were the studied variables. Trough the response surface methodology, it was verified that both variables have influence on the particles’ size, although the solids concentration showed a bigger influence. The encapsulation of oregano oil has showed that inulin is an effective encapsulating agent.-------------------------------------A inulina e os FOS são compostos prebióticos, e deste modo o crescente interesse nestes constituintes naturais tem aumentado na última década, e suscitado a atenção por parte da indústria alimentar. Por outro lado, as suas propriedades, nomeadamente a capacidade de formação de cápsulas, permite a sua utilização como agente encapsulante. A presente dissertação pretendeu estudar a inulina, como matriz encapsulante de compostos bioactivos, para o que se recorreu a processos de secagem por liofilização e atomização. Os ensaios efectuados mostraram que o processo de atomização é o mais eficaz na formação de cápsulas de inulina. O diâmetro médio das partículas formadas variou entre 3 e 5 μm, e observou-se que o diâmetro diminui à medida que o grau de polimerização aumenta. De forma a optimizar o diâmetro e outras características das partículas, foram testadas diferentes condições de secagem, elaborando-se uma matriz de inulina. A concentração de sólidos solúveis e a temperatura de secagem foram as variáveis estudadas. Através da metodologia de superfície de resposta, verificou-se que ambas as variáveis têm influência sob o diâmetro de partícula, mas a concentração de sólidos apresentou uma maior influência. O encapsulamento do óleo de orégão comprovou que a inulina é um eficiente agente encapsulante.