Orientador: Vânia Regina Nicoletti Telis / Banca: Caciano Pelayo Zapata Noreña / Banca: Joel Fernando Nicoleti / Banca: José Francisco Lopes Filho / Banca: José Antônio Gomes Vieira / Resumo: Os objetivos deste trabalho foram analisar a influência do tipo e da quantidade de aditivos, além de diferentes métodos de secagem da polpa de maracujá em pó, nas isotermas, propriedades termodinâmicas de sorção e nos atributos de qualidade do produto obtido. No capítulo 1 descreve-se o efeito de diferentes aditivos - maltodextrina DE 10 e goma arábica - sobre as isotermas de sorção nas temperaturas de 20, 30, 40 e 50 ºC de polpa de maracujá em pó obtida por secagem a vácuo. O modelo de GAB se ajustou aos dados de sorção. As isotermas apresentaram comportamento da curva do tipo II, na classificação de Brunauer. Observou-se que a adição de maltodextrina DE 10 e de goma arábica à polpa de maracujá desidratada reduziu a umidade de equilíbrio em relação à umidade da polpa pura e não houve diferença considerável entre as umidades de equilíbrio das amostras da polpa com 18% de goma arábica e polpa com 18% ou 55% de maltodextrina. O aumento da concentração da maltodextrina não teve influência sobre os valores de umidade de equilíbrio. O calor isostérico de sorção da polpa em pó aumentou com o decréscimo da umidade, ao mesmo tempo em que apresentou menores valores para a polpa em pó com aditivos do que os observados para a polpa pura. Através da teoria da compensação isocinética, pode-se concluir que o processo de sorção de água pela polpa de maracujá em pó é um processo espontâneo e controlado pela entalpia para todas as amostras testadas. No capítulo 2 foi analisada a influência de três métodos de secagem: em estufa a vácuo (60 ºC), spray drying (140 ºC) e liofilização sobre as isotermas da polpa de maracujá em pó com 55% de maltodextrina DE 10. O pó produzido em spray dryer apresentou maior capacidade de sorção em relação aos pós desidratados em estufa a vácuo e em liofilizador. No capítulo 3 foi avaliada a influência... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objectives of this work were to analyze the influence of type and quantity of additives, in addition to different drying methods, on the production of powdered passion fruit pulp, on its water sorption isotherms and on its themodynamical properties, as well as evaluating the quality attributes of the obtained product. Chapter 1 describes the effect of different additives - maltodextrin DE 10 and Arabic gum - on the sorption isotherms at temperatures of 20, 30, 40 e 50 ºC of passion fruit pulp powder obtained by vacuum drying. The sorption data were well adjusted by GAB model. The isotherms presented behavior of type II curves according to the Brunauer classification. The addition of maltodextrin DE 10 and Arabic gum to the passion fruit pulp powder decreased the equilibrium water content when compared to the pure powdered pulp and no considerable differences between the equilibrium moisture content of samples with 18% of arabic gum and with 18% or 55% of maltodextrin were observed. The increase in maltodextrin concentration did not affect the equilibrium water contents. The isosteric heat of sorption of the powdered pulp increased with decreasing water content, at the same time that lower values were obtained to powdered pulp with additives than to pure powdered pulp. Through the isokinetic compensation theory it could be concluded that the water sorption process by the powdered passion fruit pulp is an enthalpy controlled, spontaneous process for all tested samples. In chapter II, the influence of three drying methods: vacuum drying (60 ºC), spray drying (140 ºC) and freeze drying over the powdered passion fruit pulp isotherms with 55% of maltodextrin DE 10, was analyzed. The passion fruit pulp powder produced by spray drying presented higher sorption ability than vacuum dried and freeze dried pulp. In chapter 3, the influence of different concentrations and different dextrose... (Complete abstract click electronic access below) / Doutor

Idebenone is an antioxidant, a synthetic derivative of coenzyme Q10, with several applications, such as neuroprotection. However, this drug has low solubility in water, besides is irritant substance and has chemical instability. Hence, idebenone-loaded nano-organized systems have been developed, such as polymeric nanocapsules (NC). Vegetable oils containing antioxidants such as coconut oil and palm oil can be interesting for the composition of these particles. In this way, the aim of this work was to develop NC suspensions containing different oils as core (palm, coconut or medium chain triglycerides) for delivery of neuroprotective agent idebenone in order to compare the behavior of these systems concerning physico-chemical stability, photostability, controlled release, and conversion to redispersible solid dosage forms (lyophilized products). The nanocapsules were prepared by interfacial deposition of preformed polymer. As the results, it was possible to prepare poly(Ɛ-caprolactone) NC suspensions and palm oil (PO/PCL) or Eudragit® RS100 and coconut oil (OC/EUD) containing idebenone (1.0 mg/mL) with appropriate physico-chemical characteristics. Parameters such as the proportion of aqueous phase/organic phase, type of both surfactant (low HLB) and polymer influenced the optimization of these systems. For comparison, corresponding formulations were prepared with medium chain triglycerides (TCM/PCL or TCM/EUD), using the same conditions. The suspensions had an average diameter between 166 and 216nm, low polydispersity index (0.085 to 0.142), positive or negative zeta potential, depending on the characteristics of the polymer, and high encapsulation efficiency. The maintenance of average particle diameter and low polydispersity index have be verified during stability study (room temperature and exposed or not to light) for 75 days. However, the idebenone content significantly decreased in this period, with influence on the type of polymer. Thereafter, photostability study has shown that the suspensions NC OP/PCL (UVC/UVA) and TCM/PCL (UVA) were able to significantly reduce the degradation of idebenone (content: 53,7-76,1%) compared to an aqueous micellar (content: 31,2-63,1%) dispersion containing the drug. In addition, these systems were able to promoting drug controlled release (t1/2 26 h), without burst effect, showing monoexponential profile (t1/2< 3.0 h for free drug). The lyophilization of suspensions, employing trehalose as soluble carbohydrate, resulted in suitable and redispersible products (content of 96-100%, less than 3.6% moisture; 0.8-1.2 index), presenting several spherical structures, including in colloidal range, featuring the presence of NC in these dried products. In the stability study (room temperature/protection from light and moisture), it was observed that the lyophilized products were able to delay or decrease the degradation of idebenone compared to suspensions of origin, regardless of the both type of polymer (PCL/EUD) and oil (OP/OC/TCM). In conclusion, the developed systems are promising for the controlled release of neuroprotective drug idebenone. / A idebenona é um antioxidante, derivado sintético da coenzima Q10, com várias aplicações, como em neuroproteção. No entanto, este fármaco possui baixa solubilidade em água, potencial irritativo e instabilidade química, fato que tem despertado o interesse em sua associação a sistemas nano-organizados. Dentre estes, destacam-se as nanocápsulas poliméricas (NC). Óleos vegetais, contendo compostos antioxidantes, como óleo de coco e de palma, podem ser interessantes para a composição destas partículas. Neste sentido, o objetivo deste trabalho foi desenvolver suspensões de NC contendo diferentes óleos como núcleo (palma, coco ou triglicerídeos de cadeia média), almejando à veiculação do neuroprotetor idebenona, de forma a comparar o comportamento dos sistemas quanto à estabilidade físico-química, fotoestabilidade, controle de liberação, além da conversão em formas farmacêuticas sólidas redispersíveis (liofilizados). As NC foram preparadas pelo método de deposição interfacial de polímero pré-formado. Conforme os resultados, foi possível preparar suspensões de NC de poli(ε-caprolactona) e óleo de palma (OP/PCL) ou de Eudragit® RS100 e óleo de coco (OC/EUD), contendo idebenona (1,0 mg/mL), com características físico-químicas adequadas, sendo que fatores como proporção das fases aquosa/orgânica, tipo de tensoativo de baixo EHL e de polímero influenciaram a otimização dos sistemas. Para fins comparativos, formulações correspondentes foram preparadas com triglicerídeos de cadeia média (TCM/PCL ou TCM/EUD), empregando as mesmas condições. As suspensões apresentaram diâmetros médios entre 166 e 216 nm, baixos índices de polidispersão (0,085-0,142), potencial zeta positivo ou negativo, dependendo das características do polímero e elevada eficiência de encapsulamento. Quando estas suspensões foram submetidas a estudo de estabilidade, à temperatura ambiente e expostas ou não à luz, durante 75 dias, verificou-se manutenção dos diâmetros médios de partículas e baixos índices de polidispersão. Entretanto, o teor de idebenona decaiu significativamente neste período, com influência significativa do tipo de polímero. Após, estudo de fotoestabilidade demonstrou que as suspensões de NC OP/PCL (UVC/UVA) e TCM/PCL (UVA) foram capazes de reduzir significativamente a degradação da idebenona (teor remanescente: 53,7-76,1%) em comparação a uma dispersão micelar aquosa contendo o fármaco (teor remanescente: 31,2-63,1%), além de promoverem liberação controlada da mesma (t1/2 26 h), sem efeito burst, com perfil ajustado ao modelo monoexponencial (t1/2<3,0 h para fármaco livre). A liofilização das suspensões, empregando trealose, um carboidrato solúvel, resultou em produtos adequados (teor entre 96-100 %; umidade inferior a 3,6 %), redispersíveis (índice de ressuspensão entre 0,8-1,2) e com a presença de inúmeras estruturas esféricas, inclusive na faixa coloidal, caracterizando a presença das NC nestes produtos secos. No estudo de estabilidade (temperatura ambiente/proteção da luz e da umidade), observou-se que os produtos liofilizados foram capazes de retardar ou diminuir significativamente a degradação da idebenona em comparação às suspensões de origem, independentemente do tipo de polímero (PCL/EUD) e de óleo (OP/OC/TCM). Sendo assim, os sistemas desenvolvidos são promissores para a liberação controlada do neuroprotetor idebenona.

Made available in DSpace on 2014-06-11T19:31:39Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-28Bitstream added on 2014-06-13T18:42:35Z : No. of bitstreams: 1 pedro_mam_dr_sjrp.pdf: 1284122 bytes, checksum: 45709686cf62bab3c06f4aeffcf8c502 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Os objetivos deste trabalho foram analisar a influência do tipo e da quantidade de aditivos, além de diferentes métodos de secagem da polpa de maracujá em pó, nas isotermas, propriedades termodinâmicas de sorção e nos atributos de qualidade do produto obtido. No capítulo 1 descreve-se o efeito de diferentes aditivos - maltodextrina DE 10 e goma arábica - sobre as isotermas de sorção nas temperaturas de 20, 30, 40 e 50 ºC de polpa de maracujá em pó obtida por secagem a vácuo. O modelo de GAB se ajustou aos dados de sorção. As isotermas apresentaram comportamento da curva do tipo II, na classificação de Brunauer. Observou-se que a adição de maltodextrina DE 10 e de goma arábica à polpa de maracujá desidratada reduziu a umidade de equilíbrio em relação à umidade da polpa pura e não houve diferença considerável entre as umidades de equilíbrio das amostras da polpa com 18% de goma arábica e polpa com 18% ou 55% de maltodextrina. O aumento da concentração da maltodextrina não teve influência sobre os valores de umidade de equilíbrio. O calor isostérico de sorção da polpa em pó aumentou com o decréscimo da umidade, ao mesmo tempo em que apresentou menores valores para a polpa em pó com aditivos do que os observados para a polpa pura. Através da teoria da compensação isocinética, pode-se concluir que o processo de sorção de água pela polpa de maracujá em pó é um processo espontâneo e controlado pela entalpia para todas as amostras testadas. No capítulo 2 foi analisada a influência de três métodos de secagem: em estufa a vácuo (60 ºC), spray drying (140 ºC) e liofilização sobre as isotermas da polpa de maracujá em pó com 55% de maltodextrina DE 10. O pó produzido em spray dryer apresentou maior capacidade de sorção em relação aos pós desidratados em estufa a vácuo e em liofilizador. No capítulo 3 foi avaliada a influência... / The objectives of this work were to analyze the influence of type and quantity of additives, in addition to different drying methods, on the production of powdered passion fruit pulp, on its water sorption isotherms and on its themodynamical properties, as well as evaluating the quality attributes of the obtained product. Chapter 1 describes the effect of different additives - maltodextrin DE 10 and Arabic gum - on the sorption isotherms at temperatures of 20, 30, 40 e 50 ºC of passion fruit pulp powder obtained by vacuum drying. The sorption data were well adjusted by GAB model. The isotherms presented behavior of type II curves according to the Brunauer classification. The addition of maltodextrin DE 10 and Arabic gum to the passion fruit pulp powder decreased the equilibrium water content when compared to the pure powdered pulp and no considerable differences between the equilibrium moisture content of samples with 18% of arabic gum and with 18% or 55% of maltodextrin were observed. The increase in maltodextrin concentration did not affect the equilibrium water contents. The isosteric heat of sorption of the powdered pulp increased with decreasing water content, at the same time that lower values were obtained to powdered pulp with additives than to pure powdered pulp. Through the isokinetic compensation theory it could be concluded that the water sorption process by the powdered passion fruit pulp is an enthalpy controlled, spontaneous process for all tested samples. In chapter II, the influence of three drying methods: vacuum drying (60 ºC), spray drying (140 ºC) and freeze drying over the powdered passion fruit pulp isotherms with 55% of maltodextrin DE 10, was analyzed. The passion fruit pulp powder produced by spray drying presented higher sorption ability than vacuum dried and freeze dried pulp. In chapter 3, the influence of different concentrations and different dextrose... (Complete abstract click electronic access below)

Made available in DSpace on 2014-06-11T19:24:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-12Bitstream added on 2014-06-13T20:13:00Z : No. of bitstreams: 1 catelam_kt_me_sjrp.pdf: 2505612 bytes, checksum: 6d1f12a789582003771152e325b4032a (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Este projeto teve como objetivo estudar a influência de diferentes processos de desidratação (secagem em leito pulso-fluidizado, atomizador – “spray dryer” e em liofilizador) de polpa de maracujá na qualidade do produto final em pó. Todos estes processos visam à obtenção do produto em pó, apresentando vantagens e desvantagens em nível de manuseio e custos. Entretanto, são escassos na literatura estudos que comparem estes processos com foco na qualidade do produto final. O leite desnatado foi utilizado para avaliar sua eficiência na substituição de parte dos aditivos comumente utilizados na produção deste tipo de produto, como, por exemplo, a maltodextrina e a goma Arábica, os quais têm como função a diminuição das dificuldades tecnológicas encontradas na secagem de sucos de frutas e outros produtos com alta quantidade de açúcar devido à higroscopicidade, termoplasticidade e capacidade de caramelização. Inicialmente, realizaram-se as análises físico-químicas da polpa de maracujá e do leite desnatado, onde foram obtidos resultados muito próximos aos da literatura, sendo que as pequenas diferenças obtidas foram atribuídas à variedade do maracujá utilizado, época e local de cultivo e no caso do leite em pó desnatado, devido provavelmente às diferentes marcas comerciais analisadas na literatura. A secagem da polpa de maracujá sem aditivos, em diversas condições operacionais, levou a um rendimento praticamente nulo, fazendo com que o processo fosse considerado inviável nestas condições. Conseguiu-se obter o pó com a polpa de maracujá e os aditivos no secador por atomização (“spray dryer”). Utilizando a maltodextrina como aditivo, o maior rendimento (23.32%) obtido foi para a proporção de 1:4:4 (polpa de maracujá:maltodextrina:leite desnatado) ou seja, 50% dos sólidos de aditivo substituído por leite desnatado... / The aim of this research was to study the influence of different drying methods (pulsed fluid bed dryer, spray dryer and freeze dryer) of passion fruit pulp in the quality of final powder product. All these processes have the purpose to obtain a powder product, showing advantages and disadvantages in terms of handmade and costs. Nonetheless, the literature has a few studies related to comparison between these processes, focusing final product quality. Skim milk was utilized to evaluate its efficiency on partial substitution of additives commonly used in this kind of processes like maltodextrin and Arabic gum, which have the function of minimizing technologies difficulties in drying fruit juices and other products with high quantity of sugar due to hygroscopicity and termoplasticity in high temperatures and humidity. Initially, physicochemical analysis of passion fruit pulp and skim milk showed values close to those described by literature, with little differences due to passion fruit varieties used, time and place of culture. For skim milk the differences can be explain due to existence of a lot of commercial marks. Drying of passion fruit pulp without additives in many operations conditions had a small yield, becoming process impracticable in these conditions. It was obtained powdered passion fruit and additives in spray dryer. Using maltodextrin the greater yield (23.32%) was obtained for 1:4:4 ratio (passion fruit pulp:maltodextrin:skim milk) that is 50% of solids from additives substituted by skim milk. To Arabic gum the best results (21.96%) was obtained to 1:2:6 (passion fruit pulp:Arabic gum:skim milk) with 75% of solids from additives substituted by skim milk. The total substitution of additives (maltodextrin or Arabic gum) by skim milk also showed good results (15.5%). These better yield were obtained in 120°C and feed flow 0.4 l/h considering ratio of pulp... (Complete abstract click electronic access below)

Resumo: Este projeto teve como objetivo estudar a influência de diferentes processos de desidratação (secagem em leito pulso-fluidizado, atomizador - "spray dryer" e em liofilizador) de polpa de maracujá na qualidade do produto final em pó. Todos estes processos visam à obtenção do produto em pó, apresentando vantagens e desvantagens em nível de manuseio e custos. Entretanto, são escassos na literatura estudos que comparem estes processos com foco na qualidade do produto final. O leite desnatado foi utilizado para avaliar sua eficiência na substituição de parte dos aditivos comumente utilizados na produção deste tipo de produto, como, por exemplo, a maltodextrina e a goma Arábica, os quais têm como função a diminuição das dificuldades tecnológicas encontradas na secagem de sucos de frutas e outros produtos com alta quantidade de açúcar devido à higroscopicidade, termoplasticidade e capacidade de caramelização. Inicialmente, realizaram-se as análises físico-químicas da polpa de maracujá e do leite desnatado, onde foram obtidos resultados muito próximos aos da literatura, sendo que as pequenas diferenças obtidas foram atribuídas à variedade do maracujá utilizado, época e local de cultivo e no caso do leite em pó desnatado, devido provavelmente às diferentes marcas comerciais analisadas na literatura. A secagem da polpa de maracujá sem aditivos, em diversas condições operacionais, levou a um rendimento praticamente nulo, fazendo com que o processo fosse considerado inviável nestas condições. Conseguiu-se obter o pó com a polpa de maracujá e os aditivos no secador por atomização ("spray dryer"). Utilizando a maltodextrina como aditivo, o maior rendimento (23.32%) obtido foi para a proporção de 1:4:4 (polpa de maracujá:maltodextrina:leite desnatado) ou seja, 50% dos sólidos de aditivo substituído por leite desnatado... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The aim of this research was to study the influence of different drying methods (pulsed fluid bed dryer, spray dryer and freeze dryer) of passion fruit pulp in the quality of final powder product. All these processes have the purpose to obtain a powder product, showing advantages and disadvantages in terms of handmade and costs. Nonetheless, the literature has a few studies related to comparison between these processes, focusing final product quality. Skim milk was utilized to evaluate its efficiency on partial substitution of additives commonly used in this kind of processes like maltodextrin and Arabic gum, which have the function of minimizing technologies difficulties in drying fruit juices and other products with high quantity of sugar due to hygroscopicity and termoplasticity in high temperatures and humidity. Initially, physicochemical analysis of passion fruit pulp and skim milk showed values close to those described by literature, with little differences due to passion fruit varieties used, time and place of culture. For skim milk the differences can be explain due to existence of a lot of commercial marks. Drying of passion fruit pulp without additives in many operations conditions had a small yield, becoming process impracticable in these conditions. It was obtained powdered passion fruit and additives in spray dryer. Using maltodextrin the greater yield (23.32%) was obtained for 1:4:4 ratio (passion fruit pulp:maltodextrin:skim milk) that is 50% of solids from additives substituted by skim milk. To Arabic gum the best results (21.96%) was obtained to 1:2:6 (passion fruit pulp:Arabic gum:skim milk) with 75% of solids from additives substituted by skim milk. The total substitution of additives (maltodextrin or Arabic gum) by skim milk also showed good results (15.5%). These better yield were obtained in 120°C and feed flow 0.4 l/h considering ratio of pulp... (Complete abstract click electronic access below) / Orientador: Javier Telis Romero / Coorientador: Carmen Sílvia Fávaro Trindade / Banca: João Borges LAurindo / Banca: Célia Maria Landi Franco / Mestre

Made available in DSpace on 2014-12-17T15:01:29Z (GMT). No. of bitstreams: 1 ErlyMMAN_DISSERT.pdf: 2763165 bytes, checksum: 02d0a064f93f95db42ddc7fc2c52410e (MD5) Previous issue date: 2012-03-30 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Brazil, one of the largest agricultural producers in the world, has managed in recent years to significantly improve its production. However, in response to this advance in the agro-industrial sector, the generation of agro-industrial residues has also increased. New technological alternatives have to be implemented in order to bring economic and rational use of this material and drying is one of the possible choices. Considering the great importance that bioactive compounds present for food science and technology, this research aims to evaluate the air-drying process of acerola residue in a tray convective drier under controlled temperature (60, 70 e 80?C), air velocity (4.0, 5.0 e 6.0 m/s) and material width (0.5, 0.62 e 0.75 cm) by applying an experimental planning 23 + 3. Based on that, the impact on physical-chemical characteristics, color, bioactive compounds concentration and antioxidant activity of dried acerola waste was evaluated, having the in natura and freeze dried waste as control groups. Dried acerola residue presented natural pigments, mainly carotenoids (143.68 - 68.29 mg/g) and anthocyanins (290.92 - 90.11 mg/100 g), which explain the red and yellow instrumental color parameters observed. The acerola residue powder is also rich in phenolic compounds (3261.11 -2692.60 mgGAEeq/100g), proanthocyanidins (61.33-58.46 eq/100g), ascorbic acid (389.44 739.29 mg/100 g) and DPPH antioxidant activity (20.91 24.72 ?g Trolox eq/g). Results show decreased concentration of phenolic compounds, anthocyanins, carotenoids, proanthocyanidins and ascorbic acid caused by the air-drying process. However, even after the observed drying losses, the acerola residue powder can be considered a high value food ingredient, considering the high bioactive compounds concentration found in the final product, as well as the colorimetric characterization and microbiological stability of the dried powder / O Brasil, um dos maiores produtores agr?colas atuais, tem conseguido aumentar sua produ??o agroindustrial nos ?ltimos anos. Em conseq??ncia a isso a gera??o de res?duos tamb?m aumentou. Dessa forma, torna-se relevante a pesquisa de alternativas de uso racional e econ?mico para esse tipo de mat?ria prima, incluindo opera??es unit?rias de transforma??o como a secagem. Diante da import?ncia que os compostos bioativos apresentam para a ?rea de ci?ncia e tecnologia de alimentos, esta pesquisa objetivou avaliar a secagem do res?duo agroindustrial da acerola em secador convectivo de bandejas sob condi??es controladas de temperatura de trabalho (60; 70 e 80?C), velocidade do ar (4,0; 5,0 e 6,0 m/s) e espessura do material (0,5; 0,62 e 0,75 cm), mediante aplica??o de planejamento experimental do tipo fatorial 23 + 3 pontos centrais. A partir disso, o impacto da secagem sobre as caracter?sticas f?sico-qu?micas, cor, concentra??o de compostos bioativos selecionados e atividade antioxidante do res?duo da acerola s?o abordados, tomando os res?duos in natura e liofilizado como grupos-controle. Os p?s do res?duo desidratado de acerola apresentaram presen?a de pigmentos naturais, com colora??o vermelha e amarela, sobretudo caroten?ides (143,68 a 68,29 mg/g), antocianinas (290,92 a 90,11 mg/100 g), al?m de elevado teor de compostos fen?licos (3261,11 a 2692,60 mg GAE eq/100 g amostra), proantocianidinas (61,33 a 58,46 eq/100 g amostra) e ?cido asc?rbico (389,44 a 739,29 mg/100 g), bem como expressiva atividade antioxidante obtida pelo m?todo DPPH (20,91 a 24,72 ?g Trolox eq/g amostra). Os dados experimentais mostraram diminui??o da concentra??o de compostos fen?licos, antocianinas, caroten?ides, proantocianidinas e ?cido asc?rbico ocasionada pela secagem nas condi??es estudadas. No entanto, a concentra??o final desses compostos detectada no produto desidratado, bem como a caracteriza??o colorim?trica e a estabilidade microbiol?gica alcan?ada, caracteriza o p? do res?duo de acerola como ingrediente com elevado potencial bioativo

Preparation of biological samples for transmission electron microscopy is not a trivial task. The samples must withstand a vacuum environment present inside a microscope, and it is often necessary to use non-physiological procedures for their processing. These procedures usually involve aldehyde-based fixation, replacing water with alcohol (i.e. dehydration/substitution), and embedding into a resin, which creates support for the subsequent preparation of thin sections that can be placed into the microscope. In the last decade, the method of cryo-fixation (vitrification) using ultra-fast high-pressure freezing followed by freeze substitution and low-temperature resin embedding gained a dominant position in the cell biology research. In this way, a range of biological samples with a thicknesses up to several hundreds of micrometers was successfully vitrified to a state that was closely related to their in vivo structures. The cryo-fixation of isolated biological objects (with a limited thickness up to several micrometers) is possible in a thin layer of vitrified water by plunge freezing at ambient pressure. In combination with electron cryo-microscopy, this method has become the most effective and fundamental principle for the high-resolution studies and image analysis of fully hydrated samples...

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / The mangrove crab, Ucides cordatus is one of the most shellfish produced in Brazil, but his consumption becomes scarce during closed season. This study aimed development of freezedried products of the mangrove crab stored at ambient temperature and analyze the effect of lyophilization in relation to physicalchemical, microbiological, nutritional and sensory characteristics. Two products were developed: a "freeze-dried crab meat" and "freeze-dried crab cone". The product quality was evaluated through sensory tests, microbiological, TBARS, water activity, water holding capacity, centesimal composition, nutritional value, fatty acids content, and amino acid profile of volatile compounds. The best formulation of the "freeze-dried crab cone", acceptance by the tasters, corresponded to that contained only crab meat and dehydrated condiments. The lyophilized products were stored in two different packages (laminated polyethylene terephthalate) in the period 0 to 120 days of storage at ambient temperature. Both products did not suffer microbiological and sensory changes during this period, occurring only a slight increase in water activity and moisture. As to biochemical characteristics, freeze-dried products showed all essential amino acids in quantities greater than those recommended by FAO. In the freeze-dried products was higher concentration of fatty acids when compared to the fresh beef. The volatile compounds were detected in highest concentrations after rehydration of the product in heated water ( 100  C), mainly in relation to groups of aldehydes (hexanal and pentanal) and alcohol (2-methyl-3- phenyl-propanal and 3,7-dimethyl-1,6-octadien-3-ol). In general, the total volatile compounds were lowered after 240 days of storage at ambient temperature. Therefore, with this research was observed the feasibility of developing lyophilized products ("land crab freeze-dried meat" and "freeze-dried crab cone") the basis of land crab meat can be stored at ambient temperature with sensory attributes, physicalchemical and microbiological characteristics acceptable. / O caranguejo-uÃÃ, Ucides cordatus à um dos crustÃceos mais produzido no Brasil, porÃm o seu consumo torna-se escasso no perÃodo do defeso da espÃcie. Desta forma, o objetivo deste trabalho foi o desenvolvimento de produtos liofilizados do caranguejo-uÃa armazenados à temperatura ambiente e analisar o efeito da liofilizaÃÃo em relaÃÃo Ãs caracterÃsticas fÃsicoquÃmicas, microbiolÃgicas, nutricionais e a sensoriais. Foram desenvolvidos dois produtos: a âcarne de caranguejo liofilizadaâ e âcasquinha de caranguejo liofilizadaâ. A qualidade dos produtos foi avaliada, atravÃs de anÃlises sensoriais, microbiolÃgicas, TBARS, atividade de Ãgua, capacidade de retenÃÃo de Ãgua, composiÃÃo centesimal, valor nutricional, teor de Ãcidos graxos, perfil de aminoÃcidos e dos compostos volÃteis. A formulaÃÃo da âcasquinha de caranguejo liofilizadaâ de melhor aceitaÃÃo pelos degustadores correspondeu Ãquela que continha somente carne de caranguejo e condimentos desidratados. Os produtos liofilizados foram acondicionados em dois tipos de embalagens (laminada e tereftalato de polietileno) no perÃodo de 0 a 120 dias de armazenamento à temperatura ambiente. Ambos os produtos, nÃo sofreram alteraÃÃes microbiolÃgicas e sensoriais, neste perÃodo, ocorrendo apenas um leve aumento da atividade de Ãgua e umidade. Quanto Ãs caracterÃsticas bioquÃmicas, os produtos liofilizados apresentaram todos os aminoÃcidos essenciais em quantidades superiores Ãs recomendadas pela FAO. Nos produtos liofilizados houve maior concentraÃÃo dos Ãcidos graxos quando comparados com a carne in natura. Os compostos volÃteis foram detectados em maiores concentraÃÃes apÃs a reidrataÃÃo dos produtos, em Ãgua aquecida (Â100 ÂC), principalmente, no que se refere aos grupos dos aldeÃdos (hexanal e pentanal) e alcoÃis (2- metil-3-fenil-propanal e 3,7-dimetil-1,6-octadien-3-ol). De modo geral, o total dos compostos volÃteis foi reduzido apÃs 240 dias de armazenagem à temperatura ambiente. Portanto, com essa pesquisa observou-se a viabilidade de desenvolver produtos liofilizados (âcarne de caranguejo-uÃà liofilizadaâ e uma âcasquinha de caranguejo liofilizadaâ) a base de carne de caranguejo-uÃà que podem ser estocados a em temperatura ambiente com caracterÃsticas sensÃrias, fÃsico-quimica e microbiolÃgica aceitÃveis.

Ce travail de thèse concerne les verres bioactifs purs et dopés pour des applications en tant que biomatériaux en site osseux. Ils sont synthétisés par fusion dans le système SiO₂-CaO-Na₂O-P₂O₅. Quatre éléments métalliques (Zn, Ti, Cu et Ag), présentant des caractéristiques chimiques et physiologiques intéressantes, ont été introduits dans la matrice vitreuse. Leur réactivité chimique et leur cytotoxicité ont été évalués lors de tests in vitro. L'introduction de ces éléments métalliques influe sur les caractéristiques thermiques des verres ainsi que sur la dissolution de la matrice vitreuse, la cinétique et la cristallisation de la couche d'hydroxyapatite. Une bonne prolifération cellulaire a été mise en évidence. En parallèle, une méthode de synthèse d'une vitrocéramique, présentant une microporosité, a été développée par réaction entre TiN et ZnO. Des essais in vitro ont montré un caractère bioactif après 60 jours d'immersion et une absence de cytotoxicité. Ce biomatériau a ensuite été implanté au niveau de la diaphyse fémorale de lapins. Différentes études structurales ont montré la résorption progressive du biomatériau jusqu'à 6 mois d'implantation. Des scaffolds chitosan / verre bioactif ont également été synthétisés et obtenus par lyophilisation. Ils ont été étudiés lors d'essais in vitro. Ils ont servi de support pour la vectorisation de gentamicine. Les résultats obtenus montrent que les teneurs en chitosan et en verre bioactif ont une influence sur la cristallisation de l'hydroxyapatite et le relargage du médicament. Les modèles mathématiques établis montrent que le temps de relaxation des scaffolds dépend de la concentration de départ en gentamicine. / This research work focuses on the pure and doped bioactive glasses for use as bone biomaterial. They are synthesized by the melting method in the system SiO₂-CaO-Na₂O-P₂O₅. Four metallic elements, presenting interesting chemical and physiological properties, have been introduced in the amorphous matrix. Their chemical reactivity and their cytotoxicity have been evaluated during in vitro assays in simulated body fluid and cell culture media. The introduction of these metallic elements influences their thermal characteristics, the glass matrix dissolution, the kinetic and the crystallization of the hydroxyapatite layer. A good cells proliferation have been showed. In parallel, a method of synthesis of a glass-ceramic, having a microporosity, have been developed by reaction between TiN and ZnO. In vitro assays have showed a bioactive character after 60 days of immersion and a non-cytotoxicity. This biomaterial was implanted in the femoral dyaphisis of rabbits. Different structural studies have showed the gradual resorption of the biomaterial up to 6 months of implantation. Finally, scaffolds chitosan/bioactive glass, obtained by freeze-drying, have also been studied during in vitro assays. They were used as support for the vectorization of gentamicin. The obtained results show that the content of chitosan and bioactive glass have an impact on the crystallization of hydroxyapatite et the release of drug. Mathematic models show that the relaxation time depend on the starting concentration of gentamicin.

On s'intéresse dans le présent travail au comportement au gel des sols fins limono-argileux traités à la chaux seule, sols valorisables qui sont couramment rencontrés sur les chantiers de terrassement. Trois sols appartenant aux classifications A1, A2, A3 selon la norme NF P 11300, ont été choisis pour cette étude. Ces sols sont traités à 3 dosages en chaux correspondant à 3 objectifs : 1) amélioration (dosage en chaux minimal), 2) stabilisation et insensibilité à l'eau (dosage en chaux intermédiaire), 3) stabilisation et résistance au gel (dosage en chaux le plus élevé). Les sols traités sont ensuite conservés pendant quatre périodes de cure : 7 jours, 28 jours, 90 jours et 365 jours. Les deux processus de gel - le géligonflement et la gélifraction sont étudiés, parallèlement à l'évaluation des performances mécaniques, hydrauliques et microstructurales. Les résultats expérimentaux ont montré que les propriétés hydrauliques (la succion au front de gel, sp et la conductivité hydraulique à l'état non-saturé, kunsat) sont les paramètres qui gouvernent le phénomène de géligonflement des sols, traités ou non. Les résultats ont également mis en évidence le lien direct existant entre la microstructure (la distribution porale) et les propriétés hydrauliques du sol, principalement en termes de capacité de rétention d'eau et conductivité hydraulique. Le traitement augmente les performances mécaniques des sols d'une part, et amène d'autre part à des modifications de leur microstructure ; ceci induit des changements vis-à-vis de leur sensibilité au gel. Les sols sont plus gélifs directement après le traitement, cette sensibilité au gel diminuant avec le temps de cure. Une modélisation simple permettant d'estimer le gonflement au gel à partir de la succion au front de gel et de la valeur de conductivité hydraulique à l'état non-saturé a été proposée et validée. Vu que la détermination de la conductivité hydraulique à l'état non-saturé n'est pas un essai couramment pratiqué au sein de la plupart des laboratoires, un critère basé sur la succion au front de gel, sp, et la conductivité hydraulique à l'état saturé, ksat a été proposé pour évaluer la sensibilité des sols au gel. L'essai de gélifraction consiste à évaluer un coefficient de résistance de l'éprouvette de sol après 10 cycles de gel/dégel, RFT (%) - « retained strength factor after freeze-thaw testing ». Les résultats expérimentaux montrent que la valeur RFT des sols traités varie de 0% (lorsque les éprouvettes de sol perdent totalement leur résistance à la compression simple et sont détruites après 10 cycles de gel/dégel) à 90%. Quand RFT ≥ 60%, aucune dégradation visuelle de la surface des éprouvettes des sols traités n'est constatée. Ainsi, cette valeur est proposée comme critère d'acceptation des matériaux constitutifs d'une couche de forme subissant le gel avant son recouvrement. L'étude de l'effet du nombre des cycles de gel/dégel montre une diminution importante de la performance mécanique (RFT) durant trois premiers cycles de gel/dégel, et ce paramètre se stabilisant après 10 cycles. A l'aide de la technique de µ Tomographie X, l'endommagement interne des éprouvettes de sol ayant subi des cycles de gel/dégel a été quantifié. Une corrélation directe entre la diminution de performance mécanique et l'augmentation de l'indice de l'endommagement de l'éprouvette a été mise en évidence. Enfin, un modèle d'endommagement permettant d'évaluer la dégradation de la performance mécanique avec l'augmentation de l'indice d'endommagement a été établi / The present work deals with the behaviour of fine-grained silty and clayey soils treated with lime under frost. Those soils are frequently encountered in earthworks. Three soils corresponding to A1, A2, A3 classes according French NF P 11-300 standard were chosen for this study. These soils were treated with 3 lime dosages corresponding to three objectives: 1) improvement (minimum dosage), 2) stabilization and insensitivity to water (intermediate dosage), 3) stabilization and frost resistance (highest dosage). Lime-treated soils were subsequently cured for different times: 7, 28, 90, 365 days. Two frost processes, frost heave and freeze-thaw cycles, were applied in parallel with the assessment of mechanical, hydraulic and microstructural properties. Experimental results evidenced that it is the hydraulic properties (suction at frost front, sp and unsaturated hydraulic conductivity, kunsat) that govern the frost heave phenomenon of soils, treated or not. In addition, this study demonstrates the direct link between the microstructure (the pore size distribution) and the hydraulic properties (water retention curve and hydraulic conductivity). The treatment on one hand improves the mechanical performances of soils, and on the other hand modify their microstructure, and thus changes their frost sensitivity. The frost susceptibility increases directly after treatment, and then decreases with curing time. Based on the suction at frost front and the unsaturated hydraulic conductivity, a simple model was proposed and validated allowing to estimate the frost heave. Considering that the determination of unsaturated hydraulic conductivity is not a test commonly performed by most laboratories, a criterion based on the suction at frost front and the saturated hydraulic conductivity was proposed to estimate the frost sensibility of soils. The second frost resistance test consists of measuring the retained strength factor after 10 freeze-thaw cycles, RFT (%). The results obtained show that RFT of lime treated soil varies from 0% (when soil specimen completely loses its resistance and collapses after 10 freezethaw cycles) to 90%. When RFT is higher than 60%, no visual damage was observed on the specimen surface; consequently, this value is proposed as a criterion for acceptance of lime treated soil in capping layer before covering. In addition, the study of effect of freeze-thaw cycles showed a significant decrease of mechanical performance (RFT) during the first three cycles, and a stabilization after 10 cycles. Using X-ray Tomography, the intern damage of specimens due to freeze-thaw cycles was quantified. A correlation between the decrease of mechanical performance and the increase of damage index was evidenced. A model was then developed to evaluate the degradation of mechanical performance with the increase of damage index