A utilização de bioativos naturais como ingredientes está em constante expansão na indústria alimentícia, devido ao aumento das exigências pelos consumidores por alimentos mais saudáveis. Por isso, há uma busca constante de tecnologias que possibilitem a incorporação de tais substâncias em alimentos. O β-caroteno é uma substância hidrofóbica, cujos benefícios estão relacionados principalmente à sua ação antioxidante. Devido à sua característica hidrofóbica, a utilização deste pigmento implica em desafios tecnológicos para ser incorporado em formulações alimentícias de base aquosa. Por este motivo, a encapsulação em lipossomas pode ser uma ótima alternativa, devido à capacidade de englobar tais substâncias em sua bicamada lipídica. Além da proteção, essas matrizes encapsulantes podem proporcionar a liberação controlada dos ingredientes encapsulados, bem como aumento de sua biodisponibilidade. O objetivo deste trabalho foi produzir e caracterizar dispersões de lipossomas encapsulando β-caroteno estabilizadas com a adição de hidrocolóides(goma xantana ou mistura de goma xantana e goma guar). O diâmetro médio hidrodinâmico, a distribuição de tamanho das partículas e a morfologia foram avaliadas. Os lipossomas produzidos foram vesículas multilamelares (MLV), as distribuições de tamanho dos lipossomas apresentaram-se heterogêneas e as micrografias revelaram a forma esférica dos lipossomas dispersos no meio aquoso, assim como a integridade da sua bicamada lipídica. Foram realizadas análises de quantificação do β-caroteno e colorimetria instrumental, sendo que todas as dispersões mostraram-se eficientes na preservação do β-caroteno ao longo do período de armazenamento. Os hidrocolóides adicionados foram eficazes no aumento da viscosidade da fase contínua, evitando a agregação das vesículas ao longo do tempo, exceto para dispersão estabilizada com a mistura de goma xantana e goma guar, com 0,15% de goma total. Em relação à adição das dispersões de lipossomas em iogurte, as formulações mostraram-se homogêneas, com ausência de grumos ou qualquer tipo de separação de fases, e também foram aprovados por uma parcela de painelistas na análise sensorial. / The use of natural bioactives as ingredients is in constant expansion in the food industry, due to increasing consumer demands for healthier foods. Therefore, there is a constant search for technologies capable of incorporating such substances in food. β-carotene is a hydrophobic substance, whose benefits are mainly related to its antioxidant action. Because of its hydrophobic characteristics, the use of this pigment implies technical challenges to be incorporated into aqueous-based food formulations. For this reason, encapsulation in liposomes may be a good alternative, because of their ability to incorporate such substances in their lipid bilayer. Besides the protection, these encapsulants matrix can provide controlled release of the encapsulated ingredients, as well as increasing its bioavailability. The objective of this study was to produce and characterize dispersions of liposomes encapsulating β-carotene, which were stabilized with the addition of hydrocolloids: xanthan gum or a mixture of xanthan gum and guar gum. The mean hydrodynamic diameter, distribution of particle size and its morphology were studied. The obtained dispersions were multilamellar vesicles (MLV), the liposomes size distributions were heterogeneous and the micrographs revealed the liposomes spherical shape dispersed in aqueous medium, as well as the integrity of their lipid bilayer. The quantification of β-carotene and instrumental colorimetry analyses indicated the liposomes were efficient in the preservation of β-carotene during the storage period. The hydrocolloids added in the dispersions were highly efficient to increase the viscosity of the continuous phase. Therefore, the hydrocolloids were responsible for the prevention of aggregation of the vesicles during the storage period, except for stabilized dispersion with the mixture of xanthan gum and guar gum, with 0.15% gum total. Regarding the dispersions of liposomes added in yoghurt, the formulations were homogeneous, with absence of lumps or any phase separation, and also have been approved by a significant number of the panelists.

Os sistemas de liberação de fármacos são parte integrante da investigação farmacêutica. Grande ênfase tem sido dada à utilização de polímeros hidrofílicos naturais como carreadores devido às vantagens inerentes a seu baixo custo, biocompatibilidade e segurança de uso. Os objetivos principais deste trabalho foram a preparação e avaliação de sistemas microparticulados a base de pectina e caseína e o estudo da liberação in vitro do aciclovir contido nas micropartículas. Esses sistemas visam uma liberação prolongada do fármaco aumentando sua biodisponibilidade oral. O efeito de parâmetros como pH, força iônica, viscosidade, proporção e concentração total de polímeros foi avaliado. A melhor condição para ocorrência da coacervação foi determinada por mobilidade eletroforética, rendimento do coacervado e microscopia ótica. A pectina e a caseína podem interagir formando complexos insolúveis. A formação do complexo coacervado foi espontânea e ocorreu em condições brandas no intervalo de pH em que os polímeros encontram-se carregados com cargas opostas. As dispersões foram secas em Spray dryer, resultando em partículas bastante pequenas (6µm) e homogêneas. Através da microscopia ótica foi possível observar que o fármaco se encontrava no interior das micropartículas. O pH (4,0-5,0) do meio influenciou decididamente a formação dos complexos coacervados, e a melhor relação mássica para o par pectina/caseína foi 1:1. Proporções superiores ou inferiores reduziram significativamente a extensão da coacervação. O aumento no teor de sólidos totais (4-8% p/v) bem como a adição de sal (0-120 mMol) não suprimiu a formação ou a estabilidade do sistema. Foram preparadas matrizes hidrofílicas contendo as micropartículas encapsuladas com aciclovir. O estudo de dissolução in vitro demonstrou que a liberação do aciclovir foi mais lenta nos sistemas matriciais e microparticulados do que a do fármaco livre. Entretanto, as matrizes apresentaram perfis de liberação sustentada mais adequados do que os sistemas microparticulados. / Drug delivery systems became an integral part of pharmaceutical research. The use of natural hydrophilic polymers as drug carriers has received considerable attention in the last few years, especially from the viewpoint of cost, environmental concerns and safety. The main purpose of this study was to report and discuss the preparation of a microparticulate system by mixing the negatively charged pectin and the amphoteric casein and also the in vitro evaluation of polymeric microparticulate systems loaded with acyclovir. Such drug delivery system was conceived to prolong the therapeutic activity of acyclovir and increase its oral biovailability.The influence of pH, total biopolymers concentration, viscosity of dispersions, pectin/casein ratio and ionic strength were reported. Zeta potential measurements and dry coacervate yield were used to determine the optimal conditions for complex coacervation and were supplemented by optical microscopy. Pectin/casein in aqueous mixture may interact and form insoluble complexes. The complex formation was spontaneous and occurs under mild conditions. The phenomenon of complex coacervation mainly occurs at a pH range when both polyelectrolytes carry opposite charges. Microparticulate preparations were spray dried and results showed that the microparticles obtained were always quite small, the diameters of 80% of the particles did not exceed 6m, and physicochemical characterization showed that the drug was homogeneously dispersed inside the microparticles. Pectin/casein ratio and pH range were found to mainly affect the microparticles formation and encapsulation efficiency. The complex coacervation was dependent on pH (4,0-5,0) and the optimum pectin/casein ratio was 1:1. Superior or inferior proportion significantly decreased the coacervate yield. Increasing in total biopolymer concentration (4-8% w/v) and salt addition (0-120 mMol) did not inhibit the formation and stability of pectin/casein systems. Hydrophilic matrices containing acyclovir loaded microparticles were also prepared. The in vitro dissolution profile of acyclovir from the microparticulate systems and matrices were slower than that for the free drug. However, the sustained release characteristic was more prominent in matrices than in microparticles formulations

Orientador: Florencia Cecilia Menegalli / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-24T19:01:31Z (GMT). No. of bitstreams: 1 Sartori_Tanara_M.pdf: 26131816 bytes, checksum: bc2fedf638aad16f64ae8424a5a52acb (MD5) Previous issue date: 2014 / Resumo: A microencapsulação de aditivos alimentícios é uma alternativa para que a sua liberação ocorra de forma controlada, entre outros benefícios, sendo o spray chilling uma técnica de microencapsulação interessante no que diz respeito a materiais de recheio hidrofílicos. A incorporação de aditivos microencapsulados em filmes de polissacarídeo surge como uma nova proposta, a fim de estabilizá-los e liberá-los em condições específicas para o alimento sobre o qual será aplicado. O objetivo do trabalho foi produzir micropartículas lipídicas contendo ácido ascórbico e incorporá-las em filme de amido de banana verde da variedade "Terra". As micropartículas foram produzidas com misturas dos ácidos graxos láurico e oleico em diferentes proporções, como material de parede. A proporção entre o material de parede e o material de recheio também variou. As micropartículas produzidas foram caracterizadas quanto à eficiência de encapsulação total e efetiva, distribuição de tamanho e perfil de liberação. As micropartículas incorporadas nos filmes foram escolhidas a partir da cinética de liberação (maior liberação, menor liberação e liberação intermediária). Os filmes foram produzidos pelo método de casting e caracterizados quanto à umidade, densidade, propriedades mecânicas, cor e opacidade, fração solúvel em água, permeabilidade ao vapor de água e propriedades antioxidantes. O efeito nas propriedades ópticas de maçãs revestidas com cobertura de filmes de amido de banana com micropartículas de ácido ascórbico, também foi avaliado. As características das micropartículas foram mais influenciadas pela proporção entre os ácidos graxos utilizados como material de parede, do que pela proporção entre material de parede e material de recheio. As micropartículas produzidas apresentaram altos valores de eficiência de microencapsulação total, sem diferença significativa entre os experimentos (p>0,05). Os valores de eficiência de encapsulação efetiva e os diâmetros médios das partículas foram diretamente proporcionais à quantidade de ácido oleico presente na mistura. A análise de liberação do recheio em água mostrou que as partículas com quantidade intermediária de ácido oleico no material de parede (20 %) proporcionaram melhor retenção do recheio que os demais ensaios, com liberação de apenas 37 ± 6 % ao final de 2 h. Os filmes aditivados com as micropartículas lipídicas apresentaram menor permeabilidade ao vapor de água, maior resistência à tração e menor alongamento na ruptura, quando comparados ao controle adicionado de ácido ascórbico não encapsulado. As micropartículas atuaram como agentes protetores da atividade antioxidante durante o processo de obtenção dos filmes. As coberturas contendo micropartículas retardaram o escurecimento enzimático das maçãs, mostrando a importância da proteção do ácido ascórbico pela microencapsulação / Abstract: Microencapsulation of food additives is an alternative to their controlled release, among other advantages. Spray chilling can be used when the additives are hydrophilic active ingredients The incorporation of microencapsulated additives in polysaccharide-based film arise as a new proposal in order to stabilize and release them in specific conditions for the food on which will be applied. The objective was to produce lipid microparticles containing ascorbic acid and incorporate them into film starch isolated from plantain bananas of the variety "Terra". The microparticles were produced using mixtures of lauric and oleic fatty acids in different proportions, as lipid carrier. The ratio between the lipid carrier and core material was also varied. The microparticles produced were characterized for total encapsulation efficiency and effective encapsulation efficiency, size distribution and release kinetic in water. The particles were chosen from the release profile for incorporation in the films (higher release, lower release and intermediate release). The films were produced by casting and characterized regarding moisture, density, mechanical properties, color and opacity, water solubility, permeability to water vapor and antioxidant properties. The effect on the optical properties of coated apples with banana starch coating containing microparticles of ascorbic acid was also evaluated. The characteristics of the microparticles were more influenced by the ratio of the fatty acids used as lipid carrier, than by the ratio between the lipid carrier and core material. The microparticles produced higher values of total microencapsulation efficiency without significant difference between experiments (p>0.05). The values of effective encapsulation efficiency and particle average diameters were directly proportional to the amount of oleic acid present in the mixture. The analysis of core release in water showed that the particles with intermediate amount of oleic acid in the lipid carrier (20 %) showed improved retention of the core than the other tests, releasing just 37 ± 6 % after 2 h. Films additivated with lipid microparticles showed lower water vapor permeability, higher tensile strength and lower elongation when compared to control added ascorbic acid unencapsulated. The microparticles acted as protective agents of the antioxidant activity of ascorbic acid during the process of production of films. Coatings containing microparticles retarded the enzymatic browning of apples, showing the importance of the protection of ascorbic acid by microencapsulation / Mestrado / Engenharia de Alimentos / Mestra em Engenharia de Alimentos

In this thesis, we explore the benefits of microencapsulating isoniazid and pyrazinamide within sporopollenin exine capsules derived from Lycopodium clavatum. Sporopollenin is a natural biopolymer, which is extracted from the outer shell of pollen grains. These hollow microcapsules can encapsulate and release drug actives in a controlled manner and possess many other advantages such as homogeneity in morphology and size, resilience to both strong acids and bases, they have antioxidant properties as well as UV protection to protect the material inside the microcapsule. Compared to artificial microcapsules, sporopollenin’s muco-adhesion to intestinal tissues contributes greatly to the extended contact of the sporopollenin with the intestines leading to an increased efficiency of delivery of drugs. The hollow microcapsules can be easily filled with a solution of the active or active in a liquid form by simply mixing both together. The drug actives are released in the human body depending on pH factors. Active release can otherwise have controlled by adding a coating on the shell, or co-encapsulation with the active inside the shell so that high drug concentrations are delivered to the site of infection. Encapsulation of the drug active will possibly improve therapeutic abilities of the drugs; simplify the treatment of TB-HIV coinfections by eliminating troublesome drug-drug interactions and drastically reduce or eliminates side effects. The SECs were loaded using a passive filling method. The drug active (0.1 g) was dissolved in a solvent and mixed with the SECs (0.1 g) for 10 minutes. After mixing for 10 minutes, the solvent was removed by a rotary evaporator and dried to a constant mass. The surface of the sporopollenin exines were analysed on a FTIR to observe if there are any drug deposits on the surface of the SECs. The loading efficiency and drug release percentage was determined by using calibrations curves and analysed on a UV-vis spectrophotometer. Further work has been proposed in which to characterize the SECs further and producing coated tablets from loaded SECs.

Orientadores: Lucia Helena Innocentini Mei, Sergio Persio Ravagnani / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Quimica / Made available in DSpace on 2018-08-04T01:52:20Z (GMT). No. of bitstreams: 1 Cruz_MariaClaraPinto_D.pdf: 5943553 bytes, checksum: b12150e79224fd5dadd1465609f322d1 (MD5) Previous issue date: 2004 / Resumo: Neste trabalho as análises de difusão de oxitetracilina (OTC) como espécie ativa, foram realizadas a 37 +/- 0,5 °C; em soluções tampão pH=7,4 e 1,2, condições estas similar ao trato gastro-intestinal, com microesferas de alginato de cálcio; microcápsulas de alginato de cálcio coacervado com quitosana (baixa, média e alta viscosidade); microcápsulas de alginato de cálcio coacervada com a quitosana baixa viscosidade, e revestidas com o polietileno glicol - PEG (2000, 4600 e 10000); microcápsulas de alginato de cálcio revestidas com o PEG e, finalmente, microcápsulas de alginato de cálcio revestidas com EUDRAGIT®. Na primeira parte do trabalho, priorizou-se o estudo da estrutura, sequência e composição das unidades repetitivas dos biopolímeros alginato e quitosana, as quais certamente exercem profunda influência na liberação controlada do fármaco. Na segunda parte, o coeficiente de difusão (D) de OTC foi calculado através de equações estabelecidas por Crank, para difusão em esferas, que seguem a segunda lei de Fick. Considerou-se a difusão do interior para o exterior das micropartículas, utilizando o método dos mínimos quadrados e método iterativo de Newton Raphson para ajuste dos dados. Foi verificado que o modelo matemático para a difusão de OTC tem uma representatividade muito boa em meio básico, mesmo com o efeito de disparo de OTC em forma de cristais alojados na superfície das micropartículas, conforme observado por Microscopia Eletrônica de Varredura (MEV). No entanto, em meio ácido, o ajuste não foi o esperado, pois fatores como a alta solubilidade do fármaco no meio; além da presença de fissuras nas microesferas, devido aos cristais na superfície, contribuíram para que o perfil desviasse do obtido em outros meios, resultando em um comportamento não-Fickiano. Finalmente, observou-se a possibilidade de modulação da velocidade de liberação nos diversos tipos de microesferas / Abstract: Diffusion studies of oxytetracycline (OTC) entrapped in microbeads of calcium alginate, calcium alginate coacerved with chitosan (high, medium and low viscosity) and calcium alginate coacerved with chitosan low viscosity, covered with Poly (ethylene glycol) - PEG (2 000, 4 600 and 10 000) and alginate covered with EUORAGITI®, were carried out at 37 +/- 0.5 °C, in buffer solutions at pH 7.4 and pH 1.2, similar to the conditions of the gastric-intestinal system. The diffusion coefficient, or diffusivity (D), of OTC was calculated by equations provided by Crank for diffusion, which follows Fick's second law, considering the diffusion from the inner parts to the surface of the microbeads. The least square and the Newton Raphson methods were used to obtain the diffusion coefficients. The microbeads swelling in pH 7.4 and OTC diffusion is classically Fickian, suggesting that the OTC transport, in this case, is controlled by the exchange rates of free water and relaxation of calcium-alginate chains. In case of acid media, it was observed that the phenomenon did not follow Fick's law, due probably to the high solubility of the OTC in this environment and the presence of cracks formed during the drying process of the microbeads. It was possible to model the release rate of OTC in several types of microbeads / Doutorado / Ciencia e Tecnologia de Materiais / Doutor em Engenharia Química

Orientador: Julian Martínez / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-26T22:24:07Z (GMT). No. of bitstreams: 1 Aguiar_AnaCarolina_D.pdf: 3211663 bytes, checksum: 1dba9003e81cefba0f37a83236458c50 (MD5) Previous issue date: 2015 / Resumo: Neste trabalho a caracterização, a extração e o encapsulamento de extratos de pimentas Capsicum com tecnologia supercrítica foram estudados. Inicialmente, 20 variedades de pimentas foram caracterizadas quanto à concentração de capsaicinoides. Foi observada uma grande variação entre a composição dos capsaicinoides, sendo que a capsaicina e a dihidrocapsaicina foram os compostos majoritários. Com base nos resultados obtidos, foram selecionadas duas pimentas para obtenção de extratos com dióxido de carbono (CO2) supercrítico: a pimenta malagueta para extração de capsaicinoides e a pimenta biquinho para a extração de capsinoides. No que diz respeito à extração supercrítica (SFE) de pimenta malagueta, verificou-se que as concentrações mais elevadas de capsaicinoides foram obtidas com as menores pressões, indicando que pode haver competição entre capsaicinoides e outros compostos solúveis no CO2 supercrítico à pressões mais elevadas. O maior rendimento global foi obtido nas maiores pressões devido ao aumento da densidade do solvente. A pimenta biquinho apresentou uma concentração considerável de capsinoides. O processo de SFE com CO2 resultou em baixos rendimentos globais de extração quando comparado com os resultados obtidos empregando métodos a baixa pressão. Por outro lado, o extrato obtido com a menor densidade do CO2 apresentou uma alta concentração de capsinoides, sugerindo que o CO2 supercrítico sem cossolventes pode ser empregado para a obtenção destes compostos. Adicionalmente, foi realizada uma estimativa de custos de manufatura dos extratos supercríticos de pimenta malagueta nas condições otimizadas de extração (15 MPa e 40 °C) e o resultado obtido foi comparado com o valor comercial de um extrato com as mesmas características. Verificou-se que o processo de SFE de oleorresina de pimenta malagueta pode ser economicamente viável. Em uma segunda etapa, uma unidade de precipitação pelos métodos Antissolvente Supercrítico (SAS) e Extração Supercrítica de Emulsões (SFEE) foi desenvolvida e avaliada quanto ao desempenho de precipitação do poli(ácido lático) (PLLA) puro e coprecipitação de PLLA e ?-caroteno por SAS, e formação de partículas em suspensão de Hi-Cap 100® de oleorresina de pimenta malagueta por SFEE. Os ensaios de SAS para precipitação do PLLA puro e coprecipitação do PLLA com ?-caroteno resultaram em partículas com distintas morfologias em função das condições operacionais empregadas. Embora não tenha sido possível avaliar a influência dos parâmetros operacionais nas partículas obtidas por SAS, a realização dos experimentos foi fundamental para atestar o funcionamento da unidade desenvolvida. As emulsões formadas por ultrassom apresentaram alta estabilidade e a partir dos ensaios cinéticos determinou-se que o tempo apropriado de injeção na coluna de precipitação era de 10 min após a emulsificação. Os ensaios de SFEE resultaram em suspensões com baixa porcentagem de retenção de capsaicinoides, possivelmente devido à alta taxa de extração desses compostos durante a SFE e à perda de oleorresina verificada no frasco de coleta. Quanto ao teor de solvente residual, observou-se que quanto menor a perda de oleorresina, maior a concentração de solvente na suspensão. O diâmetro médio das partículas em suspensão apresentou pouca variação em relação ao diâmetro médio das emulsões injetadas, indicando que o tamanho de partícula está mais relacionado com o tamanho e natureza das gotículas de emulsão do que com as condições de transferência de massa do processo / Abstract: The characterization, extraction and encapsulation of extracts from Capsicum peppers with supercritical technology were studied. Initially, 20 varieties of peppers were characterized in terms of concentration of capsaicinoids. A large variation in the composition of capsaicinoids was observed, whereas capsaicin and dihydrocapsaicin were the major ones. Based on these results, two peppers were selected to obtain extracts with supercritical carbon dioxide (CO2): malagueta for capsaicinoids extraction and biquinho to capsinoids extraction. Regarding the supercritical fluid extraction (SFE) of malagueta pepper, higher concentrations of capsaicinoids were obtained at lower pressures, indicating that there may be competition between capsaicinoids and other compounds soluble in supercritical CO2 at higher pressures. The global yield was greater at higher pressures due to the increase of the solvent density. The extracts from biquinho pepper showed a considerable concentration of capsinoids. The SFE process with CO2 resulted in global extractions yields lower than those obtained using low pressure extraction methods. Moreover, the extract obtained at lower CO2 density had a high concentration of capsinoids, which suggests that supercritical CO2 without cosolvents may be employed to obtain these compounds. Additionally, an estimate of the manufacturing cost of supercritical extracts of malagueta peppers at the optimized conditions (15 MPa and 40 °C) was performed and the result was compared with the commercial value of an extract with the same characteristics. It was found that the SFE process of malagueta pepper oleoresin may be economically viable. In a second stage, a unit of precipitation by Supercritical Antisolvent (SAS) and Supercritical Fluid Extraction of Emulsions (SFEE) methods was developed and evaluated in terms of the precipitation performance of pure PLLA and coprecipitation of poly(lactic acid) (PLLA) and ?-carotene by SAS, and particle formation in suspensions of Hi-Cap 100® and malagueta pepper oleoresin by SFEE. The SAS experiments for precipitation of pure PLLA and coprecipitation of PLLA with ?-carotene resulted in particles with different morphologies when comparing the operating conditions. Although it was not possible to evaluate the influence of operating parameters on the particles obtained by SAS, the experiments were important to demonstrate the operation of the assembled precipitation unit. The emulsions formed by ultrasound showed high stability, and from kinetic experiments it was determined that the appropriate injection time in the precipitation column was 10 min after emulsification. The SFEE experiments resulted in suspensions with low retention percentage of capsaicinoids, possibly due to the high rate of extraction of these compounds during the SFE and the loss of oleoresin verified in the collection flask. Regarding the residual solvent content in the suspensions, it was observed that the smaller the loss of oleoresin, the higher the solvent concentration in the suspension. The average mean diameter of the particles in suspension showed little variation from the average mean diameter of the injected emulsion, indicating that the particle size is more related to the size and nature of the emulsion droplets than to the mass transfer conditions of the process / Doutorado / Engenharia de Alimentos / Doutora em Engenharia de Alimentos

No description available.

Yes / Cells encapsulation is a micro-technology widely applied in cell and tissue research, tissue transplantation, and regenerative medicine. In this paper, we proposed a growth of microtissue model for the human keratinocytes (HaCaT) cell line and an oral squamous cell carcinoma (OSCC) cell line (ORL-48) based on a simple aerosol microencapsulation technique. At an extrusion rate of 20 μL/min and air flow rate of 0.3 L/min programmed in the aerosol system, HaCaT and ORL-48 cells in alginate microcapsules were encapsulated in microcapsules with a diameter ranging from 200 to 300 μm. Both cell lines were successfully grown into microtissues in the microcapsules of alginate within 16 days of culture. The microtissues were characterized by using a live/dead cell viability assay, field emission-scanning electron microscopy (FE-SEM), fluorescence staining, and cell re-plating experiments. The microtissues of both cell types were viable after being extracted from the alginate membrane using alginate lyase. However, the microtissues of HaCaT and ORL-48 demonstrated differences in both nucleus size and morphology. The microtissues with re-associated cells in spheroids are potentially useful as a cell model for pharmacological studies. / Malaysia Ministry of Education (Fundamental Research Grant Scheme, FRGS Vot. 1482 and IGSP Vot. 679).

No / Growing three dimensional (3D) cells is an emerging research in tissue engineering. Biophysical properties of the 3D cells regulate the cells growth, drug diffusion dynamics and gene expressions. Scaffold based or scaffoldless techniques for 3D cell cultures are rarely being compared in terms of the physical features of the microtissues produced. The biophysical properties of the microtissues cultured using scaffold based microencapsulation by flicking and scaffoldless liquid crystal (LC) based techniques were characterized. Flicking technique produced high yield and highly reproducible microtissues of keratinocyte cell lines in alginate microcapsules at approximately 350 ± 12 pieces per culture. However, microtissues grown on the LC substrates yielded at lower quantity of 58 ± 21 pieces per culture. The sizes of the microtissues produced using alginate microcapsules and LC substrates were 250 ± 25 μm and 141 ± 70 μm, respectively. In both techniques, cells remodeled into microtissues via different growth phases and showed good integrity of cells in field-emission scanning microscopy (FE-SEM). Microencapsulation packed the cells in alginate scaffolds of polysaccharides with limited spaces for motility. Whereas, LC substrates allowed the cells to migrate and self-stacking into multilayered structures as revealed by the nuclei stainings. The cells cultured using both techniques were found viable based on the live and dead cell stainings. Stained histological sections showed that both techniques produced cell models that closely replicate the intrinsic physiological conditions. Alginate microcapsulation and LC based techniques produced microtissues containing similar bio-macromolecules but they did not alter the main absorption bands of microtissues as revealed by the Fourier transform infrared spectroscopy. Cell growth, structural organization, morphology and surface structures for 3D microtissues cultured using both techniques appeared to be different and might be suitable for different applications. / (Science Fund Vot No.: 0201-01-13-SF0104 or S024) awarded by Malaysia Ministry of Science and Technology (MOSTI) and IGSP Grant Vot No. U679 awarded by Universiti Tun Hussein Onn Malaysia.

Consumer interest in supplementation with healthy omega-3 fatty acids (Ï 3 FA) has led to increased research in fortification of popular foods with these healthy fats. Yogurt, which is already popular, offers a functional food matrix to fortify with Ï 3 FA. Fish oil, a major source of two important long chain Ï 3 FA eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) is an excellent source of Ï 3 FA enrichment into foods but brings problems of oxidation and off-flavors or odors when added to foods. Encapsulation, deodorized fish oil, and flavoring have been investigated to reduce these off-flavors and odors in food products while producing a fish oil-fortified yogurt. Discrimination of butter, fish or oxidized fish oil at 0.5% (wt/wt) levels was investigated in unflavored low-fat (1%) yogurt using untrained panelists (n=31) and sensory triangle tests. Five sensory attributes (lime, sweet, heat, acid, oxidized) were analyzed by experienced sensory panelists (n=12) in chile-lime flavored yogurts with butter, fish or oxidized fish oils added at low (0.43%) and high (1% wt/wt) levels. Analytical analysis for composition, fatty acid profile, and volatile chemistry of the yogurts was conducted. Consumer acceptance of a low-fat (1.5%) chile-lime flavored yogurt enriched with fish oil was investigated using a 9-point hedonic scale (1="dislike extremely", 9="like extremely"). Untrained panelists (n=31) were unable to differentiate 0.5% (wt/wt) levels of fish and butter oils in unflavored yogurts but were able to detect oxidized fish oil compared to butter or fish oil under in the same conditions. Experienced panelists (n=12) found significant differences (p<0.05) in lime and acid attributes in chile-lime flavored yogurts containing 1% (wt/wt) oxidized fish oil compared with 0.43 and 1% (wt/wt) butter and fish oil yogurts and 0.43% (wt/wt) oxidized fish oil yogurts. Oxidized attributes were determined as significantly different (p<0.05) by experienced panelists in chile-lime yogurts with 1% (wt/wt) fish oil, 0.43 and 1% (wt/wt) oxidized fish oil added. The acceptance of a fish oil-enriched chile-lime flavored yogurt was neutral ("neither liked nor disliked") by consumers (n=100) but 44% rated the product "like slightly" (6 of 9) or greater. A successful chile-lime flavored yogurt offering a novel savory flavor was formulated from pre-pasteurization addition of fish oil to deliver more than 145 mg DHA+EPA/170 g serving of yogurt. / Master of Science