Spelling suggestions: "subject:"freezedrying."" "subject:"predrying.""
121 |
Development and Validation of a Light Weight, Energy Dense, Ready to Eat (RTE) BarHeick, Jacob Wilhelm-Maria 01 December 2010 (has links) (PDF)
DEVELOPMENT AND VALIDATION OF A LIGHT WEIGHT, ENERGY DENSE, READY TO EAT (RTE) BAR
Jacob Wilhelm-Maria Heick
Providing additional calories in the form of an RTE bar to endurance athletes will increase performance and muscle re-synthesis, reduce muscle breakdown, and shorten recovery time. An RTE bar containing a blend of dairy proteins and carbohydrates will create a product with superior functionality, including bioactive and immunity enhancing properties from dairy derived ingredients. The protein will provide benefits in the form of easily digestible calories, essential amino acids and physical satiate.
A formulation was developed and optimized, resulting in a final product that meets the required nutritional profile: 400kcal, 25grams protein per 100 gram serving size. The desired physical characteristics were achieved through processing by both conventional baking and freeze drying. The latter method improves the stability and functionality of the RTE bar.
In order to meet the protein requirements of the RTE bar without compromising sensory properties, a unique protein source was developed. Using high concentrations of conventional protein sources like Whey Protein Concentrate (WPC) resulted in stale off-flavors and unappealing textures. Milk Protein Precipitate (MPP) was developed for this formulation. MPP is a curd-like ingredient created through the combined heat and acid precipitation of dairy proteins. MPP can be used effectively in high concentrations provides a subtle dairy flavor. MPP delivers a balance of casein and whey, similar to that found in milk.
The effectiveness of the RTE bar formulation as a post exercise recovery food was evaluated in a human studies experiment conducted on the Cal Poly campus. The human subjects study utilized 34 Cal Poly students in a single-blind cross-over design experiment. The study compared the effects of this high protein RTE bar against a calorically equal carbohydrate bar. The bars were administered after subjects completed the pre-assigned hikes on three consecutive days. Following the cross-over design, subjects received the alternate bar in the second period of the experiment. Several blood markers involved in metabolism and inflammation were measured before and after the two treatment periods. No blood marker showed a statistically significant difference between bars, but several trends were observed. Body weight and fat percent were also unaffected by bar composition.
|
122 |
Évaluation d'une forme galénique à base d'alpha cyclodextrine et d'huile végétale pour l'administration par voie orale de molécules actives peu solubles dans l'eau / Beads made of cyclodextrin and oil for oral delivery of lipophilic drugsHamoudi, Mounira Cherifa 13 July 2012 (has links)
L’objectif général de cette thèse a été d’étudier le potentiel de billes à base de molécules d’α-cyclodextrine et d’huile de soja, pour l’administration orale de principes actifs peu solubles dans l’eau.Nous avons tout d’abord vérifié qu’il était possible d’encapsuler dans les billes des molécules actives (la progestérone et l’indométacine) autres que les rétinoïdes et le diazépam, avec une teneur élevée et un rendement de fabrication satisfaisant. L’étude du comportement des billes nues lyophilisées, en termes de stabilité et de libération dans des milieux digestifs simulés, nous a permis de proposer un mécanisme de libération de la molécule encapsulée qui se déroule en plusieurs étapes: i) hydratation des billes, ii) dissolution de la matrice hydrophile d’α-cyclodextrine, iii) libération de gouttelettes d’huile contenant le principe actif puis de la fraction dissoute dans l’huile par un phénomène de partage, iiii) fragmentation des billes fragilisées et libération totale de l’huile. La présence de sels biliaires dans le milieu, accélère à la fois la libération et la quantité dissoute, en fragilisant les billes et en réduisant la valeur du coefficient de partage du principe actif entre l’huile et le milieu digestif. Nous avons montré in vitro et in vivo qu’il est possible de moduler la libération d’un principe actif à partir d’une même formulation de départ, en jouant sur l’organisation du système (émulsion sèche, billes nues, billes coquées par un nouvel ajout d’α-cyclodextrine sur les billes nues). Les études in vivo chez le rat ont révélé que l’émulsion sèche se comporte comme une forme à libération immédiate, les billes coquées comme une forme à libération prolongée et les billes nues comme une forme à libération intermédiaire. Enfin, la libération du principe actif encapsulé peut également être modulée en modifiant le mode de séchage des billes. Comparativement à la lyophilisation, le séchage à l’étuve modifie les propriétés des billes en augmentant leur résistance dans les milieux digestifs simulés et prolonge la libération de la molécule encapsulée. / The general aim of this thesis was the study of the potential of beads, made of α-cyclodextrin and soybean oil, for the oral delivery of poorly water soluble drugs. We have first verified that it was possible to encapsulate in beads, active molecules (progesterone and indomethacin), other than retinoid and diazepam, with a high drug loading and a satisfying yied. The study of the behaviour of freeze-dried naked beads, in terms of stability and drug release in simulated gastro-intestinal fluids, allowed to propose a mechanism for the release of the encapsulated drug, involving several steps: i) hydration of the freeze-dried beads, ii) dissolution of α-CD hydrophilic matrix, iii) release of oily droplets containing the active drug and then of the fraction of drug dissolved in oil, following a partition phenomenon, iiii) fragmentation of the weakened beads and at last the total release of oil. The presence of bile salts in the medium accelerates both the release and the dissolved amount, by weakening the beads and reducing the partition coefficient value of the active molecule between oil and digestive medium.We have shown in vitro as well as in vivo that it is possible to modulate the release of a model drug from the same initial formulation, according to the degree of organization of the system (dry emulsion, naked beads, coated beads obtained by an additional amount of α-cyclodextrine to the preformed naked beads). In vivo studies in rats have highlighted that dry emulsion behaves as a fast release formulation, the coated beads as a sustained release formulation and the naked beads as an intermediate one. Finally, the release of the encapsulated drug can also be modulated by modifying the drying method of the beads. Compared to freeze-drying, oven-drying modifies the properties of the beads by increasing their resistance in simulated gastro-intestinal fluids and sustaining the release of the encapsulated drug.
|
123 |
Desenvolvimento tecnológico e secagem de sistemas lipídicos incorporando óleo essencial de Lippia sidoides / Technological development and drying of lipid systems containing essential oil of Lippia sidoidesBaldim, Iara 26 April 2017 (has links)
Óleos essenciais (OEs) constituem misturas complexas de várias moléculas voláteis hidrofóbicas produzidas pelo metabolismo secundário de plantas. Eles são empregados em diversos setores industriais, como por exemplo, o farmacêutico, alimentício, cosmético, agricultura e pecuária, em virtude de suas comprovadas ações bactericida, virucida, fungicida, antiparasitária, inseticida, analgésica, sedativa, anti-inflamatória, espasmolitica e anestésica local. Também têm sido utilizados na proteção de alimentos (como antioxidantes e conservantes), e incorporados em embalagens ativas. Os OEs podem apresentar problemas de instabilidade quando expostos ao calor, umidade, oxigênio e luminosidade. A reduzida solubilidade em água e sua elevada volatilidade são outras limitações para seu uso. A microencapsulação e nanoencapsulação dos OEs são estratégias viáveis e eficientes à proteção e modulação da liberação dos compostos bioativos, promovendo o aumento da estabilidade físico-química, proteção contra fatores ambientais, redução da volatilidade, aumento da solubilidade, biodisponibilidade, atividade biológica, redução da toxicidade, entre outros. A encapsulação em carreadores lipídicos micro e nanoestruturados tem recebido significativa atenção nos setores farmacêutico e alimentício, em face de várias vantagens, como baixa toxicidade, facilidade de escalonamento, baixo custo de produção e capacidade de encapsular compostos hidrofílicos e lipofílicos. Este trabalho teve como objetivo estudar a formação e secagem de sistemas lipídicos micro e/ou nanoestruturados contendo óleo essencial de Lippia sidoides, empregando diferentes processos tecnológicos e avaliar a influência destes nas propriedades apresentadas pelo produto líquido e seco obtido (propriedades físico-químicas, estabilidade, atividade antimicrobiana e retenção do timol, composto ativo majoritário no OE). Os resultados mostraram que a composição das formulações, as condições e o processo de secagem tiveram efeitos significativos nas propriedades físico-químicas e na estabilidade do produto, além de influenciarem também a retenção de timol. Este trabalho permitiu obter informações relevantes sobre os processos de secagem das formulações lipídicas por spray drying e liofilização e também sobre as características apresentadas pelos pós obtidos / Essential oils (EOs) are complex mixtures of various volatile molecules (hydrophobic) produced by the plants secondary metabolism. Essential oils have high importance in various industrial sectors, such as pharmaceutical, food, cosmetic, health, agriculture and livestock; mainly due to its proved biological activity as bactericidal, virucidal, fungicidal, antiparasitic, insecticidal, analgesic, sedative, anti-inflammatory, spasmolytic and local anesthetic activities. Essential oils have also been used in food protection (as antioxidants and preservatives), and embedded in active food packaging. It is also characteristic of EOs present problems of instability when exposed to heat, moisture, oxygen and light. The reduced water solubility and high volatility are another limitation for the use of EOs. The micro and nanoencapsulation technologies of EOs arises as a viable and effective solution, increasing the product physicochemical stability, furnishing protection against environmental factors, reducing volatility, modulate the release, increasing bioavailability, reducing toxicity, among others. Encapsulation in lipid carriers has received significant attention in the pharmaceutical and food sectors, mainly due to the several attributed advantages such as low toxicity, capability to encapsulate hydrophilic and lipophilic compounds, low production costs and easy scale up. The objective of this work was to study the formation and drying of micro and/or nanostructured lipid systems loaded with essential oil of Lippia sidoides using different technological processes and to evaluate their influence on the properties presented by the liquid and dry product obtained (physicochemical properties, stability, antimicrobial activity and retention of thymol, major active compound in EO). The results showed that the composition of the formulations, the conditions and the drying process had significant effects on the physicochemical properties and the stability of the product, besides also influencing the retention of thymol. This work allowed to obtain relevant information on the drying processes of the lipid formulations by spray and freeze drying and also on the characteristics presented by the obtained powders
|
124 |
Perfil lipídico do concentrado com liofilizado de leite humano para alimentação de recém-nascidos pré-termo de muito baixo peso / Fatty acids profile from the concentrate with human milk freeze-dried for feeding very low birth weight preterm infantsBomfim, Vanessa Silva 24 May 2018 (has links)
Introdução Os recém-nascidos de muito baixo peso (<1.500g) necessitam de aporte adequado de nutrientes para desenvolver-se satisfatoriamente. O leite humano é fundamental na sua alimentação, já que possui uma composição nutricional balanceada que inclui nutrientes essenciais, tais como os ácidos graxos poli-insaturados, incluindo os ácidos ômega 3 e 6, de extrema importância para o desenvolvimento do sistema nervoso central e retina. No entanto, apenas o leite materno pode não ser suficiente para suprir essas necessidades, necessitando, portanto, de suplementação. Atualmente, surgiu a possibilidade de adequação do leite humano acrescido de um concentrado com liofilizado do próprio leite humano, que foi desenvolvido neste trabalho. Objetivos determinar a quantidade de lipídios totais e o perfil lipídico do Leite Humano Baseline (LHB) e dos Concentrados com o liofilizado de Leite Humano em diferentes momentos (Leite Humano concentrado no período imediato - LHCI, Leite Humano concentrado no período de 3 meses - LHC3m e Leite Humano concentrado no período de 6 meses - LHC6m). Métodos Foram obtidas 50 amostras de leite humano de mulheres doadoras do Banco de Leite Humano da FMRP-USP que aceitaram participar do estudo. A quantificação de lipídeos ocorreu pelo Analisador de Leite Humano MIRIS® e o perfil de ácidos graxos foi determinado por CG-FID, SHIMADZU®. Resultados Houve uma concentração de lipídios totais no LHCI em relação ao LHB; a concentração (% em relação ao total de ácidos graxos) dos ácidos foi de: palmítico (C16:0) 22,30% LHB, 21,46% LHCI, 21,54% LHC3m e 21,95% LHC6m (p<0,01); oleico (C18:1n-9) 30,41% LHB, 30,47% LHCI, 30,55% LHC3m e 29,79% LHC6m (p=0,46); linoléico (C18:2 n-6) 19,62% LHB, 19,88% LHCI, 19,49% LHC3m e 19,45% LHC6m (p=0,58); araquidônico (C20:4 n-6) 0,35% LHB, 0,16% LHCI, 0,13% LHC3m e 0,15% LHC6m (p<0,01); ?- linolênico (C18:3 n-3) 1,32% LHB, 1,37% LHCI, 1,34% LHC3m e 1,34% LHC6m (p=0,14); docosahexaenóico (C22:6 n- 3) 0,10% LHB, 0,06% LHCI, 0,05% LHC3m e 0,06% LHC6m (p<0,01). Há modificações específicas em alguns ácidos graxos, no entanto a somatória de ácidos graxos por suas classes estruturais não apresentam diferenças. Conclusão Apesar das pequenas diferenças encontradas no perfil lipídico, o concentrado com leite humano liofilizado é um alimento que pode vir a atender as necessidades do recém-nascido, já que houve aumento dos lipídios totaise preservação dos nutrientes essenciais presentes apenas no leite materno, mas estudos clínicos ainda precisam ser feitos para avaliar a segurança e eficácia do concentrado como alimentação dos recém-nascidos de muito baixo peso. / Introduction Very low birth weight infants (<1,500 g) require adequate nutrient intake to develop satisfactorily. Human milk is essential in its diet, since it has a balanced nutritional composition that includes essential nutrients, such as polyunsaturated fatty acids, including omega 3 and 6 acids, of extreme importance for the development of the central nervous system and retina. However, only breast milk may not be sufficient to meet these needs, thus requiring supplementation. Nowadays, the possibility of adapting the human milk plus a concentrate with lyophilized from the human milk itself, which was developed in this work, has arisen. Objectives To determine the amount of total lipids and the lipid profile of Human Baseline Milk (LHB) and Concentrates with human milk lyophilized at different times (Human Milk Concentrated in the immediate period - LHCI, Concentrated Human Milk in the 3-month period - LHC3m and Human Milk Concentrated in the 6-month period - LHC6m). Methods Fifty samples of human milk from women donors of the Human Milk Bank of FMRP-USP who were accepted to participate in the study were obtained. Lipid quantification was performed by the MIRIS® Human Milk Analyzer and the fatty acid profile was determined by CG-FID, SHIMADZU®. Results There was a total lipid concentration in LHCI relative to LHB; the concentration (% of total fatty acids) of the acids was: palmitic (C16: 0) 22.30% LHB, 21.46% LHCI, 21.54% LHC3m and 21.95% LHC6m (p <0) , 01); oleic acid (C18: 1n-9) 30.41% LHB, 30.47% LHCl, 30.55% LHC3m and 29.79% LHC6m (p = 0.46); linoleic acid (C18: 2 n-6) 19.62% LHB, 19.88% LHCI, 19.49% LHC3m and 19.45% LHC6m (p = 0.58); arachidonic (C20: 4 n-6) 0.35% LHB, 0.16% LHCl, 0.13% LHC3m and 0.15% LHC6m (p <0.01); ?-linolenic acid (C18: 3 n-3) 1.32% LHB, 1.37% LHCI, 1.34% LHC3m and 1.34% LHC6m (p = 0.14); (C22: 6 n-3) 0.10% LHB, 0.06% LHCl, 0.05% LHC3m and 0.06% LHC6m (p <0.01). There are specific modifications in some fatty acids, however the sum of fatty acids by their structural classes do not present differences. Conclusion Despite the small differences found in the lipid profile, the concentrate with freeze-dried human milk is a food that can meet the needs of the newborn, since there was an increase in total lipids and preservation of essential nutrients present only in breast milk, butclinical studies still need to be done to evaluate the safety and efficacy of concentrate as a feed for very low birth weight infants.
|
125 |
Perfil lipídico do concentrado com liofilizado de leite humano para alimentação de recém-nascidos pré-termo de muito baixo peso / Fatty acids profile from the concentrate with human milk freeze-dried for feeding very low birth weight preterm infantsVanessa Silva Bomfim 24 May 2018 (has links)
Introdução Os recém-nascidos de muito baixo peso (<1.500g) necessitam de aporte adequado de nutrientes para desenvolver-se satisfatoriamente. O leite humano é fundamental na sua alimentação, já que possui uma composição nutricional balanceada que inclui nutrientes essenciais, tais como os ácidos graxos poli-insaturados, incluindo os ácidos ômega 3 e 6, de extrema importância para o desenvolvimento do sistema nervoso central e retina. No entanto, apenas o leite materno pode não ser suficiente para suprir essas necessidades, necessitando, portanto, de suplementação. Atualmente, surgiu a possibilidade de adequação do leite humano acrescido de um concentrado com liofilizado do próprio leite humano, que foi desenvolvido neste trabalho. Objetivos determinar a quantidade de lipídios totais e o perfil lipídico do Leite Humano Baseline (LHB) e dos Concentrados com o liofilizado de Leite Humano em diferentes momentos (Leite Humano concentrado no período imediato - LHCI, Leite Humano concentrado no período de 3 meses - LHC3m e Leite Humano concentrado no período de 6 meses - LHC6m). Métodos Foram obtidas 50 amostras de leite humano de mulheres doadoras do Banco de Leite Humano da FMRP-USP que aceitaram participar do estudo. A quantificação de lipídeos ocorreu pelo Analisador de Leite Humano MIRIS® e o perfil de ácidos graxos foi determinado por CG-FID, SHIMADZU®. Resultados Houve uma concentração de lipídios totais no LHCI em relação ao LHB; a concentração (% em relação ao total de ácidos graxos) dos ácidos foi de: palmítico (C16:0) 22,30% LHB, 21,46% LHCI, 21,54% LHC3m e 21,95% LHC6m (p<0,01); oleico (C18:1n-9) 30,41% LHB, 30,47% LHCI, 30,55% LHC3m e 29,79% LHC6m (p=0,46); linoléico (C18:2 n-6) 19,62% LHB, 19,88% LHCI, 19,49% LHC3m e 19,45% LHC6m (p=0,58); araquidônico (C20:4 n-6) 0,35% LHB, 0,16% LHCI, 0,13% LHC3m e 0,15% LHC6m (p<0,01); ?- linolênico (C18:3 n-3) 1,32% LHB, 1,37% LHCI, 1,34% LHC3m e 1,34% LHC6m (p=0,14); docosahexaenóico (C22:6 n- 3) 0,10% LHB, 0,06% LHCI, 0,05% LHC3m e 0,06% LHC6m (p<0,01). Há modificações específicas em alguns ácidos graxos, no entanto a somatória de ácidos graxos por suas classes estruturais não apresentam diferenças. Conclusão Apesar das pequenas diferenças encontradas no perfil lipídico, o concentrado com leite humano liofilizado é um alimento que pode vir a atender as necessidades do recém-nascido, já que houve aumento dos lipídios totaise preservação dos nutrientes essenciais presentes apenas no leite materno, mas estudos clínicos ainda precisam ser feitos para avaliar a segurança e eficácia do concentrado como alimentação dos recém-nascidos de muito baixo peso. / Introduction Very low birth weight infants (<1,500 g) require adequate nutrient intake to develop satisfactorily. Human milk is essential in its diet, since it has a balanced nutritional composition that includes essential nutrients, such as polyunsaturated fatty acids, including omega 3 and 6 acids, of extreme importance for the development of the central nervous system and retina. However, only breast milk may not be sufficient to meet these needs, thus requiring supplementation. Nowadays, the possibility of adapting the human milk plus a concentrate with lyophilized from the human milk itself, which was developed in this work, has arisen. Objectives To determine the amount of total lipids and the lipid profile of Human Baseline Milk (LHB) and Concentrates with human milk lyophilized at different times (Human Milk Concentrated in the immediate period - LHCI, Concentrated Human Milk in the 3-month period - LHC3m and Human Milk Concentrated in the 6-month period - LHC6m). Methods Fifty samples of human milk from women donors of the Human Milk Bank of FMRP-USP who were accepted to participate in the study were obtained. Lipid quantification was performed by the MIRIS® Human Milk Analyzer and the fatty acid profile was determined by CG-FID, SHIMADZU®. Results There was a total lipid concentration in LHCI relative to LHB; the concentration (% of total fatty acids) of the acids was: palmitic (C16: 0) 22.30% LHB, 21.46% LHCI, 21.54% LHC3m and 21.95% LHC6m (p <0) , 01); oleic acid (C18: 1n-9) 30.41% LHB, 30.47% LHCl, 30.55% LHC3m and 29.79% LHC6m (p = 0.46); linoleic acid (C18: 2 n-6) 19.62% LHB, 19.88% LHCI, 19.49% LHC3m and 19.45% LHC6m (p = 0.58); arachidonic (C20: 4 n-6) 0.35% LHB, 0.16% LHCl, 0.13% LHC3m and 0.15% LHC6m (p <0.01); ?-linolenic acid (C18: 3 n-3) 1.32% LHB, 1.37% LHCI, 1.34% LHC3m and 1.34% LHC6m (p = 0.14); (C22: 6 n-3) 0.10% LHB, 0.06% LHCl, 0.05% LHC3m and 0.06% LHC6m (p <0.01). There are specific modifications in some fatty acids, however the sum of fatty acids by their structural classes do not present differences. Conclusion Despite the small differences found in the lipid profile, the concentrate with freeze-dried human milk is a food that can meet the needs of the newborn, since there was an increase in total lipids and preservation of essential nutrients present only in breast milk, butclinical studies still need to be done to evaluate the safety and efficacy of concentrate as a feed for very low birth weight infants.
|
126 |
Etapas críticas na liofilização do pericárdio bovino / Critical steps during bovine pericardium freeze-dryingVirgilio Tattini Junior 02 September 2008 (has links)
Em um sistema biológico, a água é responsável por inúmeras reações metabólicas, assim como pela estabilidade estrutural dos constituintes celulares do material. A liofilização é um processo de secagem comumente utilizado para a conservação de materiais biológicos. Entretanto, devido a complexidade do processo e às mudanças térmicas aplicadas ao material, se as etapas da liofilização não forem bem conduzidas, poderão ocorrer danos estruturais irreversíveis. Este projeto tem como objetivo determinar as etapas críticas na liofilização do pericárdio bovino. Através das técnicas de caracterização térmica por calorimetria exploratória diferencial (DSC) e microscopia óptica acoplada a liofilização (FDM) determinaram-se as principais transições de fases do pericárdio bovino visando o aprimoramento do processo e a qualidade final do produto. Após a liofilização do material, utilizando-se diferentes protocolos de congelamento, concluiu-se que o pericárdio bovino apresenta suporte físico suficiente para ser liofilizado acima da temperatura de transição vítrea sem apresentar sinais de colapso estrutural. O protocolo de liofilização utilizando-se congelamento lento com o emprego do tratamento térmico apresentou os melhores resultados de umidade residual, tempo de liofilização e manutenção da estrutura conformacional do colágeno. / In biological system, water is responsible for many metabolic reactions as well as for structural stability of the material cellular constituents. Freeze-drying or lyophilization is a drying technique commonly used for the preservation of biological materials. However, given to the process complexity and to the thermal changes applied to the material, if all freeze-drying steps are not well determined and controlled, irreversible structural damages on the material may occur. The aim of this project is to determine the critical steps on the bovine pericardium tissue freeze-drying. Through two different thermal analysis techniques, Differential Thermal Analysis (DSC) and Freeze-drying microcopy (FDM), it was determined the main phase transitions of bovine pericardium to optimize the freeze-drying process and the quality of dried product. After freeze-drying under different freezing protocols it was concluded that bovine pericardium showed enough physical support to be dried above the glass transition temperature without showing any signs of structural collapse. The freeze-drying protocol using slow freezing rate and annealing showed the best results regarding residual moisture content, freeze-drying time and maintenance of the collagen conformational structure.
|
127 |
Etapas críticas na liofilização do pericárdio bovino / Critical steps during bovine pericardium freeze-dryingTattini Junior, Virgilio 02 September 2008 (has links)
Em um sistema biológico, a água é responsável por inúmeras reações metabólicas, assim como pela estabilidade estrutural dos constituintes celulares do material. A liofilização é um processo de secagem comumente utilizado para a conservação de materiais biológicos. Entretanto, devido a complexidade do processo e às mudanças térmicas aplicadas ao material, se as etapas da liofilização não forem bem conduzidas, poderão ocorrer danos estruturais irreversíveis. Este projeto tem como objetivo determinar as etapas críticas na liofilização do pericárdio bovino. Através das técnicas de caracterização térmica por calorimetria exploratória diferencial (DSC) e microscopia óptica acoplada a liofilização (FDM) determinaram-se as principais transições de fases do pericárdio bovino visando o aprimoramento do processo e a qualidade final do produto. Após a liofilização do material, utilizando-se diferentes protocolos de congelamento, concluiu-se que o pericárdio bovino apresenta suporte físico suficiente para ser liofilizado acima da temperatura de transição vítrea sem apresentar sinais de colapso estrutural. O protocolo de liofilização utilizando-se congelamento lento com o emprego do tratamento térmico apresentou os melhores resultados de umidade residual, tempo de liofilização e manutenção da estrutura conformacional do colágeno. / In biological system, water is responsible for many metabolic reactions as well as for structural stability of the material cellular constituents. Freeze-drying or lyophilization is a drying technique commonly used for the preservation of biological materials. However, given to the process complexity and to the thermal changes applied to the material, if all freeze-drying steps are not well determined and controlled, irreversible structural damages on the material may occur. The aim of this project is to determine the critical steps on the bovine pericardium tissue freeze-drying. Through two different thermal analysis techniques, Differential Thermal Analysis (DSC) and Freeze-drying microcopy (FDM), it was determined the main phase transitions of bovine pericardium to optimize the freeze-drying process and the quality of dried product. After freeze-drying under different freezing protocols it was concluded that bovine pericardium showed enough physical support to be dried above the glass transition temperature without showing any signs of structural collapse. The freeze-drying protocol using slow freezing rate and annealing showed the best results regarding residual moisture content, freeze-drying time and maintenance of the collagen conformational structure.
|
128 |
PECTINAMETILESTERASE EM EXTRATO DO ALBEDO DE MARACUJÁ-AMARELO (Passiflora edulis f. flavicarpa)Meneguzzo, Adeline Chaicouski 14 April 2014 (has links)
Made available in DSpace on 2017-07-21T18:53:23Z (GMT). No. of bitstreams: 1
Adeline Chaicouski Meneguzzo.pdf: 1276340 bytes, checksum: 02b7c8e69340d28ceb45b8fabb4d2651 (MD5)
Previous issue date: 2014-04-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The pectic substances, carbohydrates found in plant cell wall, are involved in the change of texture in the ripening process under action of pectinolytic enzymes, among which pectinmethylesterase. The production and consumption have increased the passion, also indicating an increase in the amount of waste generated, among which the albedo. The objective of this study was to evaluate the enzymatic activity of the crude extract obtained pectinametileserase albedo yellow passion fruit. The sequence of experiments was to determine the extraction protocol of the enzyme and characterization of the enzyme activity in the crude extract obtained from the albedo of yellow passion fruit, as the stage of maturation, NaCl concentration and substrate storage time, pH and temperature. When comparing the level of passion fruit in green and ripe, fresh and lyophilized maturation, the best result was found in green lyophilized samples. Among the five extraction methods used, two of them stood out and were adapted, and made the triple rinsing the material with cold water to remove soluble substances, followed by extraction with pectinmethylesterase PVPP and NaCl. The best salt concentration for higher activity obtained with NaCl 1,0 mol L- 1, both in the extraction, as in the determination of pectin methyl esterase activity. The best substrate concentration found was 1,0 % citrus pectin. The influence of the storage period of raw material showed that the freeze-dried fruit enzyme activity remained for a longer period, followed by the frozen sample and then refrigerated. The optimum pH was found to be 8 and the optimum temperature of 50 °C. The enzyme was heat-stable. The ideal range of precipitation with ammonium sulphate was 40-60 % of the salt. With the studies was possible to detect and study the pectinmethylesterase in extracts obtained from samples of albedo yellow passion fruit, with influence of various factors such as salt concentration and pH. / As substâncias pécticas, carboidratos presentes na parede celular de vegetais, estão envolvidas na mudança da textura no processo de amadurecimento, sob atuação das enzimas pectinolíticas, dentre as quais a pectinametilesterase. A produção e o consumo do maracujá têm aumentado, indicando também aumento na quantidade de resíduos gerados, dentre os quais o albedo. O objetivo deste trabalho foi avaliar a atividade enzimática da pectinametileserase em extrato bruto obtido do albedo de maracujá-amarelo. A sequência dos experimentos foi determinação do protocolo de extração da enzima e caracterização da atividade enzimática em extrato bruto obtido do albedo de maracujá-amarelo, quanto ao estádio de maturação, concentração de NaCl e substrato, período de armazenamento, pH e temperatura. Quando comparados os maracujás em estádio de maturação verde e maduro, fresco e liofilizado, o melhor resultado foi encontrado em amostras verdes liofilizadas. Dentre os cinco métodos de extração utilizados, dois deles se destacaram e foram adaptados, sendo realizada a tripla lavagem do material com água gelada para remoção de substâncias solúveis, seguida da extração da pectinametilesterase com PVPP e NaCl. A melhor concentração salina para maior atividade foi obtida com NaCl 1,0 mol L-1, tanto na extração, quanto na determinação da atividade da pectinametilesterase. A melhor concentração de substrato encontrada foi 1,0 % de pectina cítrica. A influência do período de armazenamento da matéria-prima mostrou que o fruto liofilizado manteve a atividade enzimática por um período maior, seguido da amostra congelada e depois a refrigerada. O pH ótimo encontrado foi de 8 e a temperatura ótima de 50 ºC. A enzima mostrou-se termoestável. A faixa ideal de precipitação com sulfato de amônio foi de 40-60 % do sal. Com os estudos realizados foi possível detectar e estudar a pectinametilesterase em extratos obtidos de amostras de albedo de maracujá-amarelo, com influência de vários fatores tais como concentração de NaCl e pH do meio.
|
129 |
Water Management Efficiency in the Food and Beverage IndustryReyes Torres, Maria Del C 01 January 2016 (has links)
Water is critical for food production, food security, and health. Water quality management influences freshwater sustainability, land, and energy administration. Global agriculture accounts for more than 70% of all water consumption; the fertilizer, manure, and pesticide overspills are chief sources of water pollution worldwide. On a global scale, food-related waste directly impacts local food production and water resource management. The purpose of this multiple-case study on the food and beverage (FB) industry in the State of Georgia was to identify successful strategies for improving water management efficiency. The concepts of systems thinking, adaptive resource management, and integrated water resource management provided the conceptual framework for the study. Data were collected via personal interviews with 2 global supply chain leaders in the FB industry and 1 water expert in the public water utility system in Georgia. The findings showed 10 themes: sustainability; mission-driven culture; ethical responsibility; water quality and governance; food safety and sanitation; water conservation and climatic trends; waste management; nutrition and the freeze drying method; knowledge sharing and collaboration; and water detention and retention systems. The study results are intended to contribute to social change by providing information to global supply chain leaders, policy makers, entrepreneurs, and sustainability leaders to implement sustainability beyond the environmental value; these findings will also help achieve a positive posture on resource overconsumption and waste management for efficient and complex decision making within a worldwide spectrum.
|
130 |
Heuristic algorithm for multistage scheduling in food processing industryJuwono, Cynthia P. 16 March 1992 (has links)
A multistage production system consists of a number of
production stages that are interrelated, that is the output
from one stage forms input to the next stage. There are
constraints associated with each stage as well as constraints
imposed by the overall system. Besides, there are multiple
objectives that need to be satisfied, and in numerous cases,
these objectives conflict with each other. What is required is
an efficient technique to allocate and schedule resources so
as to provide a balance between the conflicting objectives
within the system constraints.
This study is concerned with the problem of scheduling
multistage production systems in food processing industry. The
system and products have complex structure and relationships.
This makes the system difficult to be solved analytically.
Therefore, the problem is solved by developing a heuristic
algorithm that considers most of the constraints. The output
generated by the algorithm includes a production schedule
which specifies the starting and completion times of the
products in each stage and the machines where the products are
to be processed. In addition, a summary of system performances
including throughput times, resources' utilizations, and tardy
products is reported. / Graduation date: 1992
|
Page generated in 0.2496 seconds