Tesi sul tema "Extrudates"

Orientador: Fernanda Paula Collares Queiroz
Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Neste trabalho, foram desenvolvidos, pelo processo de extrusão termoplástica, salgadinhos expandidos à base de farinha de milho enriquecidos com a incorporação de farinha de quinoa, visando o aumento do valor nutricional. O milho é muito utilizado na fabricação de salgadinhos pelo fato de expandir com facilidade. A quinoa (Chenopodium quinoa) é um pseudocereal de importante potencial agronômico e alto valor nutricional, apresentando elevado teor de proteína, com expressivos níveis do aminoácido lisina. As matérias-primas foram caracterizadas quanto às propriedades físicas, químicas e nutricionais. Para verificar quais parâmetros influenciariam as propriedades dos salgadinhos expandidos, primeiramente foi realizado um delineamento fatorial fracionado 25-1, cujas variáveis independentes foram: (i) umidade inicial da amostra; (ii) teor de farinha de quinoa; (iii) temperatura da 4ª zona do extrusor; (iv) temperatura da 5ª zona do extrusor e (v) velocidade da rosca. As variáveis dependentes avaliadas foram: (i) índice de expansão, (ii) dureza e (iii) lisina biodisponível. As variáveis que influenciaram significativamente pelo menos uma das respostas, considerando p<0,20, foram: (i) umidade inicial da amostra, (ii) teor de farinha de quinoa e (iii) temperatura da 5ª zona do extrusor. Na sequência, foi executado um Delineamento Composto Central Rotacional (DCCR), com essas três variáveis independentes, alterando as faixas de estudos em função do impacto que as mesmas apresentaram sobre as respostas. Não foi possível gerar modelos matemáticos válidos que descrevessem a tendência da dureza e da lisina biodisponível nas faixas de variação estudadas (umidade de 15 a 20%, teor de farinha de quinoa entre 15 e 50% e temperatura da 5ª zona do extrusor de 110 a 160ºC). O aumento destas três variáveis independentes promoveu a redução do índice de expansão. Pela análise de superfície de resposta, observou-se que as condições para a produção de salgadinhos extrudados com alta expansão foram: umidade inicial da amostra em 17,5%, adição de 22% de farinha de quinoa e temperatura de 110ºC na 5ª zona do extrusor. Nestas condições, foram produzidos salgadinhos expandidos apenas de milho (padrão) e salgadinhos com incorporação de 22 e 43% de quinoa, que foram caracterizados, aromatizados e submetidos a uma avaliação sensorial de aceitação e intenção de compra. Os salgadinhos expandidos de milho e quinoa apresentaram dureza e diâmetros similares aos disponíveis no mercado, indicando que as condições do processo de extrusão foram adequadamente escolhidas. Do ponto de vista nutricional, os salgadinhos com quinoa apresentaram maior teor de proteína, aminoácidos essenciais (treonina, cisteína, isoleucina, lisina e triptofano) e lisina biodisponível, em relação ao salgadinho apenas de milho, mostrando a viabilidade da adição de farinha de quinoa em produtos à base de milho para aumentar o seu valor nutricional. O salgadinho expandido com 22% farinha de quinoa apresentou boa aceitação e alta intenção de compra, enquanto o salgadinho com 43% não foi bem aceito, por apresentar menor expansão, escurecimento e sabor residual
Abstract: In this work, expanded snacks made from corn flour enriched by incorporating quinoa flour with the aim of increasing the nutritional value, were developed and processed by thermoplastic extrusion. Corn is widely used in snack production since it expands easily. Quinoa (Chenopodium quinoa) is a pseudocereal with important agronomic potential and a high nutritional value, containing an elevated protein content and expressive amount of the amino acid lysine. The raw materials were characterized with respect to their physical, chemical and nutritional properties. Initially a 25-1 Fractional Factorial Design was used to determine which parameters influenced the properties of the expanded snacks, the independent variables being: (i) initial moisture content; (ii) amount of quinoa flour; (iii) temperature of the 4th extruder zone; (iv) temperature of the 5th extruder zone and (v) screw speed. The dependent variables evaluated were: (i) expansion ratio; (ii) hardness and (iii) available lysine. The independent variables that significantly influenced at least one of the responses, considering p<0.20, were: (i) initial moisture content; (ii) amount of quinoa flour; and (iii) temperature of the 5th extruder zone. In sequence, a Central Composite Rotatable Design (CCRD) was carried out with the above three independent variables, altering the range of the study considering the impact they had on the responses. It was not possible to obtain valid mathematical models to describe the trends with respect to hardness and available lysine in the range of variation studied (moisture content from 15 to 20%, quinoa flour content from 15 to 50% and temperature in the 5th extruder zone from 110 to 160ºC). Increases in these three independent variables resulted in a reduction in the expansion ratio. From the analysis of the response surface, it was observed that the conditions required to produce highly expanded extruded snacks were: initial moisture content of 17.5%, addition of 22% of quinoa flour and a temperature of 110ºC in the 5th extruder zone. Under these conditions, expanded snacks were produced with 100% corn (standard) and with the incorporation of 22 and 43% of quinoa flour, and subsequently characterized, aromatized and subjected to a sensory evaluation for acceptance and purchasing intention. The expanded corn and quinoa snacks showed values for hardness and diameter similar to those available on the market, indicating that the extrusion process conditions were suitably chosen. From the nutritional point of view, the snacks with the incorporation of quinoa showed higher protein and essential amino acid (threonine, cysteine, isoleucine, lysine and tryptophan) contents and available lysine, as compared to the 100% corn snacks, demonstrating the feasibility of adding quinoa flour to corn products to increase their nutritional value. The expanded snack with 22% of quinoa flour was well accepted and showed high purchasing intention, whereas the snack with 43% was not well accepted because it showed less expansion, darkening and an aftertaste
Doutorado
Tecnologia de Alimentos
Doutor em Tecnologia de Alimentos

Parmi les procédés de fabrication continue, l’extrusion par fusion à chaud est une technique dont l’intérêt dans le domaine pharmaceutique est grandissant. Ce procédé permet la formation des dispersions solides des substances actives au sein des matrices polymériques ou lipidiques. En fonction de l’excipient et de la substance active, cela peut être largement utilisé pour la conception des systèmes: (i) pour une libération immédiate, (ii) pour une libération modifiée et (iii) pour le masquage de goût. Les systèmes à libération modifiée sont des dispositifs intéressants qui permettent d’améliorer la biodisponibilité de la substance active, son efficacité ainsi que l’observance des patients. En fonction de la nature de l’excipient, différents systèmes avec des mécanismes de libération variés peuvent être produit, notamment des matrices inerte, érodable ou gonflante. Le poly éthylène oxide est un polymère semi- cristallin et hydrophile qui peut être utilisé pour la libération contrôlée. Son point de fusion compris entre 63 et 67 °C le rend adapté pour l’extrusion. Surtout, ses capacités de gonflement permettent d’administrer la substance active de façon contrôlée en fonction du poids moléculaire du poly éthylène oxide. Les objectifs de ce travail sont (i) d’étudier l’impact des paramètres critiques du procédé (température d’extrusion et vitesse des vis d’extrudeuse) sur le profil de libération de la substance active, (ii) de déterminer l’impact des paramètres de formulations (poids moléculaire du poly éthylène oxide, charge et type de la substance active) sur le profil de libération de la substance active et (iii) d’évaluer des formes galéniques solides conçues par le procédé d’extrusion à celui de la compression directe. Il a été montré que la variation de la température d’extrusion et de la vitesse des vis altérait l’apparence de l’extrudat et ainsi la distribution de la substance active au sein de l’extrudat. Il s’est avéré dans notre étude que la libération de la substance active n’était pas particulièrement affectée par ces changements de température et vitesse de vis de l’extrudeuse. De plus, cette étude a permis de fixer les paramètres pour les projets suivants: température 100 °C ; vitesse des vis 30 rpm ; longueur de la forme galénique 1 cm. Des extrudats de poly ethylène oxide contenant 10 % de théophylline et du poly éthylène oxide de 100 à 7000 kDa ont été utilisés dans ce travail. Il a été observé que lorsque le poids moléculaire du poly ethylène oxide augmente de 100 à 600 kDa, la libération en substance active diminue de façon importante alors qu’une augmentation jusqu’à 7000 kDa ne diminue que légèrement la libération. Des études du gonflement ont montré que ce phénomène corrélait aux variations de volume de la partie opaque de l’extrudat (gel non transparent et cœur solide)
Among continuous manufacturing processes, hot melt extrusion is a technique with growing interest in the pharmaceutical field. This process enables the formation of solid dispersions of many drugs within a polymeric or lipidic carrier. Hot melt extrusion can be widely used for different issues using the appropriate carrier and drug. Here are the mostly used concepts in pharmaceutical solid dosage forms: (i) immediate release, (ii) modified release and (iii) taste masking. Modified release systems have been taken into account to be very interesting devices for the improvement of drug- bioavailability, drug- efficacy as well as the patient compliance. Various systems with different release mechanisms can be manufactured, depending on the nature of the carrier (inert, erodible, and swelling matrices). Poly ethylene oxide is a semi crystalline and hydrophilic polymer which can be used to control drug delivery. The poly ethylene oxide melting point ranging from 63 to 67 °C makes it suitable for hot melt extrusion. Importantly, the swelling capacities of the hydrophilic poly ethylene oxide matrices are able to deliver drug in a time controlled manner, in respect of the poly ethylene oxide molecular weights. The purposes of this work were (i) to study the impact of critical process parameters (extrusion temperature and screw speed) on the drug release behavior, (ii) to determine the impact of formulation parameters (poly ethylene oxide molecular weight, nature of drug and drug loading) on drug release kinetics, and (iii) to evaluate solid dosage forms prepared by hot melt extrusion versus direct compression. Interestingly, the variation of the extrusion temperature and the screw speed leads to the altering of the extrudate appearance and thus the distribution of drug into the extrudate. However, this changing has not influenced the drug release remarkably. Thus, this study was useful to set the parameters for the following projects (temperature 100 °C; screw speed 30 rpm; dosage form size 1 cm). Poly ethylene oxide hot melt extrudates containing 10 % theophylline and based on 100 - 7,000 kDa poly ethylene oxide are used for this thesis. Importantly, the drug release decreased substantially with the increase of the poly ethylene oxide molecular weight from 100 to 600 kDa. However, further increasing of the molecular weights leads to only a slight decrease in the release rate. Swelling studies have shown that this phenomenon correlated with the change in volume of the opaque part of the extrudates (non-transparent gel and solid core)

The factors determining the generation of aroma in starch extrudates containing added ingredients with aroma precursors were elucidated. Analyses were performed using headspace analysis of raw materials and extrudates and subsequent analysis by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Olfactometry (GC-O. Study I described the volatile, amino acid and fatty acid profiles of Hydrolised vegetable protein (HVP)and Soy protein isolate (SPI). Studies II, III and IV descibed the volatiles developed from extrusion of different feedstocks under mild and extreme processing conditions. Wheat starch was chosen as the carrier.A comparison of the influence of the three different ingredients HVP, SPI and glucose, added to the starch feed, showed the formation of Strecker aldehydes and Maillard-type compounds were significantly affected by the addition of these ingredients. The work in this thesis demonstrated that the addition of ingredients such as HVP, SPI, glucose, cysteine, cysteine-HCI, modifies the aroma of wheat starch extrudates. Furthermore, it showed the changes in conditions of extrusion and pH will greatly influence the aroma profile of the products.
Doctor of Philosophy (PhD)

Structural characterisation, mechanical properties and acoustic properties of solid biopolymer food foams {starch extrudates) are the major subject areas studied through this thesis. Initial stages involved the development of a method for capturing mechanical destruction acoustic emissions. Consideration was given to mechanical test parameters, vibrations from the test rig, extrudate geometry and ensuring frequency spectra acoustic differences occur. Structural characterisation was developed using x-ray microtomography (XMT). Pore size distributions, volume fraction porosity and average oell wall thickness were taken from XMT images. A three dimensional watershed algorithm was successfully applied to the three dimensional XMT images to segment interconnected-regions into recognisable cells. This stage is required due to the open-cell nature ofextrudate porosity. In order to obtain samples of differing porosity but all other parameters constant an expansion control chamber (ECC) was used. The ECC alters the pressure differential across the extruder die face whilst leaving extrusion conditions constant Considering extrusion pressures, extrusion temperatures and extrudate skeletal material density the effect of the ECC on the extrusion process (and hence skeletal material) has been evaluated. The effect ofthe ECC on extrudate structure/porosity is also discussed. Modelling of the approximate vibration frequencies ofcell walls was carried out using simple models. The aim was to find if these vibrations are responsible for the frequency peaks seen in the mechanical destruction frequency spectra. This provides an understanding of what needs to be altered during production for control ofacoustic emissions. Relationships between pore structure and mechanical measures were considered as well as those between acoustic emissions and mechanical measures.

The factors determining the generation of aroma in starch extrudates containing added ingredients with aroma precursors were elucidated. Analyses were performed using headspace analysis of raw materials and extrudates and subsequent analysis by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Olfactometry (GC-O. Study I described the volatile, amino acid and fatty acid profiles of Hydrolised vegetable protein (HVP)and Soy protein isolate (SPI). Studies II, III and IV descibed the volatiles developed from extrusion of different feedstocks under mild and extreme processing conditions. Wheat starch was chosen as the carrier.A comparison of the influence of the three different ingredients HVP, SPI and glucose, added to the starch feed, showed the formation of Strecker aldehydes and Maillard-type compounds were significantly affected by the addition of these ingredients. The work in this thesis demonstrated that the addition of ingredients such as HVP, SPI, glucose, cysteine, cysteine-HCI, modifies the aroma of wheat starch extrudates. Furthermore, it showed the changes in conditions of extrusion and pH will greatly influence the aroma profile of the products.

Thesis (Ph.D.) -- University of Western Sydney, 2001.
"A thesis submitted for the degree of Doctor of Philosophy" "Supervisory panel, Food Science Australia: Robert L. Johnson, Frank B. Whitfield, University of Western Sydney: Paul A. Baumgartner, Grant Wyllie" Bibliography : leaves 179-192.

Sago starch is extracted from the trunk of sago palm (Metroxylon spp.), which is found throughout South East Asia. In Indonesia sago is considered an underutilised crop and moreover Iron Deficiency Anaemia (IDA) is prevalent among particularly women and children. Creation of a ready to eat product from sago, which was fortified with iron, would address issues of food security both in terms of nutrition and as a non-imported carbohydrate source. With this aim studies for the manufacture of a thermomechanical directly expanded snack product using a commercial source of sago starch were conducted. Composition and properties of sago starch were analysed and compared with rice and cassava. Sago starch differed in several aspects from the two other starches widely processed in Asia. Sago starch had large granules, had the highest amylose levels and gelatinisation temperature (76 °C). X-ray diffraction suggested an A-type packing for all samples, including the sago where literature suggest a C-type ordering. Conversion of the starches (30% moisture) and their flow were studied in a capillary rheometer. A stable extruded product was achieved, but it did not expand. Capillary rheometer data showed pseudoplastic behaviour of the moistened sago starch. With increasing temperature viscosity decreased and no impact of the presence of iron (ferrous sulphate heptahydrate 800 ppm) on the flow behaviour was found, but the inclusion of iron made the extrudates brown in colour. The losses of crystallinity were measured on the extrudates from the rheometer. Levels of order loss were predicted from the state diagram and by comparison with the DSC enthalpy changes for uncooked sago at higher moisture contents. When processed at 70 °C the samples showed more amorphous material than anticipated. When processed at 100 °C still 30% of the order remained. This indicated that shear and moisture levels are critical in the processing of the starch. Thermomechanical extrusion was carried out on a twin screw pilot scale machine (Thermo Fisher, Prism). The screw and die configuration and feed rate for the sago starch (8 kg/h) were fixed. The impact of variable processing parameters of water feed rate (16.5 to 25% wwb), screw speed (200, 300 and 400 rpm) and die temperature (120, 140 and 160 °C) on the physical and physicochemical properties of extruded sago starch were investigated. At the lower water feed rates expansion occurred as the product left the extruder to form a stable extrudate with multiple air cells, which gave a crispy texture. The specific mechanical energies needed to create the expanded product were high at 400-500Whr/kg. The properties of the extrudates were more affected by water feed rate than by alterations in screw speed or die temperature. In order to reduce discolorations, iron-fortified sago starch extrudates were made using iron and ascorbic acid (1:6 ratio). The presence of additives at low water feed rate had no detrimental impact on the extrudates. The recommended extrusion parameters for the manufacture of an extruded sago starch product would be: feed rate of 8 kg/h, screw speed of 300 rpm, die temperature at 140 °C, and water feed rate at 4 mL/min (equivalent to 16.5% wwb), and it is possible that machine settings that produce even higher SME values may allow a more expanded product. From this work it appears that an iron fortified directly expanded sago product could be manufactured. Its nutritional properties and commercial applicability would need to be ascertained.

Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2003.
Includes bibliographical references (leaves 120-125). Also available in electronic version. Access restricted to campus users.

No
Hot melt extrusion is a continuous process with wide industrial applicability. Till current date, there have been no reports on the formulation of extrudates for topical treatment of dermatological diseases. The aim of the present work was to prepare and characterize medicated hot melt extrudates based on Soluplus polymer and nicotinamide, and to explore their applicability in acne treatment. The extrudates were characterized using DSC, FTIR, XRD, and DVS. The extrudates were also tested for their skin adhesion potential, ability to deposit nicotinamide in different skin layers, and their clinical efficacy in acne patients. The 10% nicotinamide extrudates exhibited amorphous nature which was reserved during storage, with no chemical interaction between nicotinamide and Soluplus. Upon contrasting the skin adhesion and drug deposition of extrudates and nicotinamide gel, it was evident that the extrudates displayed significantly higher adhesion and drug deposition reaching 4.8 folds, 5.3 folds, and 4.3 folds more in the stratum corneum, epidermis and dermis, respectively. Furthermore, the extrudates significantly reduced the total number of acne lesions in patients by 61.3% compared to 42.14% with the nicotinamide gel. Soluplus extrudates are promising topical drug delivery means for the treatment of dermatological diseases.

This thesis presents four different studis describing the characteristics and processing opportunities of two widely available biopolymers: chitosan and wheat gluten. The interest in these materials is mainly because they are bio-based and obtained as co- or by-products in the fuel and food sector In the first study, high solids content chitosan samples (60 wt.%) were successfully extruded. Chitosan extrusion has previously been reported but not chitosan extrusion with a high solids content, which decreases the drying time and increases the production volume. An orthogonal experimental design was used to assess the influence of formulation and processing conditions, and the optimal formulation and conditions were determined from the orthogonal experimental analysis and the qualities of the extrudates. The mechanical properties and processing-liquid mass loss of the optimized extrudates showed that the extrudates became stable within three days. The changes in the mechanical properties depended on the liquid mass loss. In a separate study, monocarboxylic (formic, acetic, propionic, and butyric) acid uptake and diffusion in chitosan films were investigated. It is of importance in order to be able to optimize the production of this material with the casting technique. The time of the equilibration uptake in the chitosan films exposed to propionic and butyric acid was nine months. This long equilibration time encouraged us study the exposed films further. The uptake and diffusivity of acid in the films decreased with increasing acid molecular size. A two-stage absorption curve was observed for the films exposed to propionic acid vapour. The films at the different stages showed different diffusivities. The acid transport was also affected by the structure of the chitosan films. X-ray diffraction suggested that the crystal structure of the original films disappeared after the films had been dried from their acid-swollen state, and that the microstructure of the dried films depended on the molecular size of the acid. Compared with the original films, the dried films retained their ductility, although a decrease in the molecular weight of the chitosan was detected. The water resistance of the acid-exposed films was increased, even though the crystallinity of these films was lower. The third study was devoted to chitosan/wheat gluten blend films cast from aqueous solutions. Different solvent types, additives and drying methods were used to examine their effects on the microstructures of the blended films. Chitosan and wheat gluten were immiscible in the aqueous blend, and the wheat gluten formed a discrete phase, and the homogeneity of the films was improved by using a reducing agent, compared with films prepared using only water/ethanol as cast media. Adding urea and surfactants resulted in a medium homogeneity of the films compared to those prepared with the reducing agents or with only water/ethanol. An elongated wheat gluten phase was observed in a film using glyoxal, in contrast to pure chitosan/wheat gluten blends. The opacity of the different films was studied. The mechanical properties and humidity uptake of the films increased with increasing chitosan content. The films containing 30 wt.% of wheat gluten showed the most promising mechanical properties, close to those of the pristine chitosan films. The final part describes the preparation and properties of a bio-foam composed of a blend of chitosan and wheat gluten. This foam was prepared without any porogen or frozen liquid phase to create porosity. A unique phase distribution of the chitosan and wheat gluten solutions formed without any agitation, and the foam was obtained when the liquid phase were withdrawn under vacuum. These foams showed high mass uptake of n-hexane and water in a short time due to their open pores and high porosity. The maximum uptake of n-hexane measured was 20 times the initial mass of the foam. The foams showed a high rebound resilience (94 % at 20 % compression strain) and they were not broken when subjected to bending.

QC 20150825

An apparatus was designed and constructed to allow a molten polymer extrudate under tension - or draw-down - to pass through a volume of liquid metal alloy in order that the extrudate would rapidly reach the temperature of the metal and be fully quenched on leaving the medium. The temperature of the medium could be controlled to an accuracy of +/- 0.5°C and the molten extrudates could be subjected to a wide range of draw-downs whilst maintaining a continuous production of extrudate. High density polyethylene (HOPE) extrudates were prepared from three dies - circular, strip and flat-film - at a range of liquid metal alloy temperatures (111 - 123°C) and over a wide range of draw-downs. The effect of processing on the HOPE extrudates was analysed by tensile testing, cyclic strain recovery, shrinkage testing, density measurements and annealing in air and liquid metal at 117°C. It was found that the level of draw-down and the temperature of the quenching medium had a profound effect upon the resultant properties of the extrudate. Extrudates prepared using a low level of orientation and low bath temperature are similar to those quenched in air, i.e. having a pronounced yield point, whereas those prepared using a high level of orientation and a high bath temperature exhibited properties similar to those of amorphous samples, i.e. high modulus and low extension at break. However, if the extrudate remains in the bath longer than is necessary to quench it, this effect is reversed. A possible mechanism was proposed to explain the relationship between the values of the processing parameters used, the morphology of the resultant HDPE extrudates and their properties.

The study presented here was firstly to investigate the physiochemical properties of native sago starch (obtained from Metroxylon sp. and designated as sago INA), in comparison with those of Metroxylon sago starch obtained from a different source, sago starch derived from Arenga sp. palms, wheat, corn, and tapioca starches. The properties analysed were chemical composition, total starch content, apparent amylose content, pasting properties, endothermic thermal behaviour, starch paste clarity, freeze-thaw stability, hardness of gel, and microscopic structure of the granules. The results obtained indicated that sago INA starch sample contained less fat and protein, compared to cereal starches. The sago starch sample had larger sized granules and had a more transparent paste. The gels of the starch were harder, and showed a relatively better stability to freeze-thaw treatment. The other part of the study was extrusion of sago INA starch both in the absence and presence of enzyme by utilising a response surface design. In the absence of the enzyme, the experiment was conducted to establish the extrusion process conditions including moisture contents, melt temperature, and screw speed. The extruded products were then analysed for degree of molecular degradation, light microscopic structure, reducing sugars of the water soluble materials, water absorption index, water solubility index, enzyme susceptibility, and gelatinisation endothermic energy. Increased mechanical and thermal energy input received by the products in the extruder resulted in a significant degradation of the molecular weight of the macromolecules. Light photomicrographs also suggested that the granule structures of the extrudates have been reshaped. All extrudate samples had a very low gelatinisation endothermic energy compared to its native starch. The specific mechanical energy received by the products in the extruder was calculated and related to the process variables. The possibility of using the products in food application was also discussed.
Doctor of Philosophy (PhD)

Doctor of Philosophy
Department of Grain Science and Industry
Sajid Alavi
Extrusion processing is a technology widely used to make ready-to-eat snack and breakfast cereal products. The raw materials that result in optimal texture and consumer acceptance are mainly those with high levels of starch, which greatly limits the nutritional value of these products. One alternative to enhance the nutritional value is the incorporation of fruits and vegetables. Fruits and vegetables are consistently under-consumed by the American population and incorporation into extruded products may help increase the intake of important nutrients, such as dietary fiber. In the first part of this study a lab-scale twin screw extruder was used for processing directly expanded products based on corn flour and apple pomace (0-28%), resulting in a total dietary fiber content of 1.1-22.5%. Apple pomace increased nucleation and favored axial expansion. The change in cell size and alignment explained the higher mechanical resistance caused by apple pomace. The objective of the second part was to study the effect of preconditioning regimen on the extent of matrix transformation and impact on texture, microstructure and digestibility. The material was processed on a pilot scale extruder. The results showed that increasing the opportunity for hydration increased starch gelatinization at all pomace levels. Apple pomace promoted milder extrusion conditions, resulting in less starch gelatinization and solubilization and reduced starch digestibility. Digestibility was also affected by structure, with a strong correlation between the available starch fraction and cell wall thickness/cell size ratio (r=0.90). The third part of this study was designed to gain a better understanding of the impact of the individual cell wall components (cellulose, lignin, xyloglucan and pectin) on expansion and structure formation. The results suggest that compatibility with starch is critical for good dispersion in the matrix, therefore good expansion and structure forming properties.

The study presented here was firstly to investigate the physiochemical properties of native sago starch (obtained from Metroxylon sp. and designated as sago INA), in comparison with those of Metroxylon sago starch obtained from a different source, sago starch derived from Arenga sp. palms, wheat, corn, and tapioca starches. The properties analysed were chemical composition, total starch content, apparent amylose content, pasting properties, endothermic thermal behaviour, starch paste clarity, freeze-thaw stability, hardness of gel, and microscopic structure of the granules. The results obtained indicated that sago INA starch sample contained less fat and protein, compared to cereal starches. The sago starch sample had larger sized granules and had a more transparent paste. The gels of the starch were harder, and showed a relatively better stability to freeze-thaw treatment. The other part of the study was extrusion of sago INA starch both in the absence and presence of enzyme by utilising a response surface design. In the absence of the enzyme, the experiment was conducted to establish the extrusion process conditions including moisture contents, melt temperature, and screw speed. The extruded products were then analysed for degree of molecular degradation, light microscopic structure, reducing sugars of the water soluble materials, water absorption index, water solubility index, enzyme susceptibility, and gelatinisation endothermic energy. Increased mechanical and thermal energy input received by the products in the extruder resulted in a significant degradation of the molecular weight of the macromolecules. Light photomicrographs also suggested that the granule structures of the extrudates have been reshaped. All extrudate samples had a very low gelatinisation endothermic energy compared to its native starch. The specific mechanical energy received by the products in the extruder was calculated and related to the process variables. The possibility of using the products in food application was also discussed.

MAST Carbon are scaling up production of activated carbon honeycomb monoliths, to which there are two major barriers. Firstly the extrusion process suffered from an unacceptably high rejection rate (around 50%) of monoliths due to malformation of channels and tearing at the surface and interior of the structure. Pastes were characterised using the Benbow Bridgwater paste flow model and it was shown that the parameters of this model could be controlled by the careful addition of various extrusion aids to the formulation. It has also been shown that the extrusion profile can be predicted from the extrusion die geometry and the Benbow Bridgwater parameters. These discoveries led to a new paste formulation, specifically designed to produce defect free monoliths with MAST Carbon’s extrusion dies, reducing the rate of monolith rejection to zero. Secondly, the monoliths required 10 days to dry at ambient conditions; a serious bottleneck in the production process. A forced drying regime was introduced which reduced the drying time to less than 24 hours without causing any internal cracks. A model describing the drying and shrinkage behaviour of the monoliths was developed and used to predict the shape of the stress field in the monolith.

This thesis focusses on the measurement and prediction of extrudate (or die) swell of molten polymers. The overall aim of this work is to understand extrudate swell for complex, industrially relevant systems. This is performed by first understanding the causes of swelling for well defined, monodisperse polymers at a molecular level. The systems are then gradually built up in complexity from bidisperse to very polydisperse and/or branched samples. At each stage predictions for extrudate swell are obtained using the \textit{flowSolve} fluid dynamics package combined with a molecular constitutive equation and are compared to extrusion experiments using a novel Multi-Pass-Rheometer setup. The effects of both molecular weight and temperature can be ignored when shear rates are scaled by Rouse Weissenberg number as extrudate swell is a chain stretch controlled phenomenon. For monodisperse systems theoretical predictions using the Rolie-Poly constitutive equation match experimental results up to a $W_R$=7 above which simulations over-predict swelling ratios. This is justified in this work using reduction of monomeric friction at high deformation rates. Extrudate swell of polydisperse polystyrenes is successfully predicted up to high Weissenberg numbers using the Rolie-Double-Poly equation when combined with monomeric friction reduction. A slight under-prediction is seen at low Weissenberg number where the chain stretch times of long polymer chains are increased by dilution with shorter chains. Qualitatively correct but quantitatively poor predictions are obtained for highly polydisperse polyethylenes where the low shear extrudate swell is under-predicted. Branched polymers behave differently experimentally to linear samples, exhibiting extrudate swell below the Rouse time of the polymer backbone. A small amount of branching increases swelling ratios versus the linear case but moderate increases in branching above this point have little effect on the experimentally observed swelling ratios. Significantly branched polyethylenes swell more than this, especially at high shear rates. There is a similar trend in simulated results using the XPP model but only a partial agreement between simulated and experimental extrudate swell is observed.

Extrudate swell is an important phenomenon in polymer extrusion, affecting many polymer processes. The ability of predicting swell, using rheological properties of the resin, would help the design and operation of plastics processing equipment. Different techniques for predicting swell are reviewed.
A computer program has been written to predict steady-state, isothermal extrudate swell in annular and circular dies. The equations of motion and continuity have been solved along with selected constitutive relations. Newtonian, power-law and the viscoelastic Maxwell and Giesekus rheological models were chosen. The Galerkin formulation of the Finite Element Method has been used to solve the system of differential equations.
The predictions for Newtonian, power-law and Maxwell models have been verified with existing experimental or numerical results when available. The results for the swell of Maxwell and Giesekus fluids have been compared at the same levels of elasticity. The effects of inertia and gravity on extrudate position and swell have been studied. Different geometries of an annular die (converging, diverging) were also examined.

The purpose of this study is to identify and quantify factors governing extrudate swell and melt fracture. In the first part, the factors which control the extrudate swell of carbon black (N330) filled styrene-butadiene rubber (SBR) compounds at various states-of-mix were investigated. State-of-mix is quantified by effective filler volume fraction (EFVF), based on an estimate of the amount of rubber immobilised in the carbon black agglomerates. Extrudate swell was found to be dominated by recoverable strain and relaxation time, which are controlled by EFVF. In contrast, shear rate and the rubber-carbon black tridimensional transient network were not found to influence extrudate swell significantly. In the second part, melt fracture of the rubber compounds was investigated in terms of surface texture wavelength. The longer the wavelength, the greater the severity of the surface disruption. It was found that wavelength was controlled strongly by state-of mix (or by EFVF). In addition, a mechanism for melt fracture of the compounds studied has been proposed, based on average energy at the extrudate surface (t.E). Lastly, the influences of additives; paraffinic processing oil, stearic acid or a mixture of predominantly calcium fatty acid soaps on extrudate swell and melt fracture were investigated. For the rubber compounds with paraffinic processing oil or stearic acid, EFVF was found to play an important role in extrudate swell. The mixture of fatty acid soaps was shown to reduce significantly extrudate swell due to the presence of wall slip. The influence of the fatty acid soaps on extrudate swell is more noticeable for extrudates obtained from long dies, in which flow is dominated by shear. The major factors shown to exert a significant influence on melt fracture for the compounds with paraffinic processing oil or stearic acid are EFVF and green strength of the extrudate. Wall slip, promoted by a mixture of fatty acid soaps, was also found to decrease the melt fracture severity, particularly for long dies in which shear stresses are dominant.

The analysis of extrudate swell in polymer melts is of great importance in many polymer processing operations and has been the subject of interest both experimentally and numerically. The main objectives of this research work are to obtain systematic and reliable extrudate swell data of a high molecular weight HDPE, to identify a suitable constitutive model that can precisely represent extrudate swell phenomena and to predict extrudate swell accurately under various processing and operating conditions. A novel extrudate swell measuring system with an online data acquisition system is designed for the present work. This system allows one to measure extrudate swell profile under different conditions such as steady state or transient, gravity free, isothermal and non-isothermal conditions. Further, the set-up is suitable for both capillary and slit extrudates. A comprehensive analysis on the applicability and validity of various rheological (integral and differential/molecular) models in describing extrudate swell of a highly viscoelastic HDPE polymer over a broad range of shear rates (5 to 100s-¹) is carried out using FEM based ANSYS POLYFLOW®. The simulation results indicated that the integral constitutive equations of K-BKZ type can account for the significant memory effects of viscoelastic polymer melts such as HDPE. Overprediction of extrudate swell by the integral K-BKZ model invoked the importance of obtaining non-linear viscoelastic properties for a broader range of deformations/deformation rates. The newly available CPP fixture from AntonPaar is used to procure such non-linear viscoelastic data and thus to determine the accurate damping function. The simulation results of extrudate swell in capillary and slit dies are in good agreement with the experimental measurements using the newly determined damping function. In addition, non-isothermal extrudate swell of the HDPE polymer is studied using the pseudo-time integral K-BKZ Wagner (i.e., the non-isothermal form) model with the differential Nakamura equation for the crystallization kinetics. The model is implemented in ANSYS POLYFLOW®. Extrudate swell measurements are obtained by extruding the polymer melt at 200ºC through long capillary and slit dies to ambient air at 25ºC and 110ºC. The numerical results are found to be in very good agreement with the experimental observations.
Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnologico, Programa de Pós-Graduação em Ciência e Engenharia de Materiais, Florianópolis, 2010
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O setor da indústria de cerâmica estrutural é um nicho para a inovação formal e à aplicação dos produtos extrudados, visíveis para além da aplicação como elementos estruturais, tornando-os visíveis, com aplicação estética e decorativa. O Design, enquanto atividade projetual, de caráter científico e criativo, pode equacionar, sistematicamente, os conhecimentos que envolvem os aspectos formais de produtos industriais, buscando as tendências que influenciam na criação de produtos cerâmicos em uma metodologia do seu processo. Os requisitos metodológicos partem do uso do material cerâmico processado por extrusão, fazendo o caminho inverso da seleção de materiais, com investigação acerca do material e do processo. Este estudo objetiva promover a inovação formal na indústria de cerâmica extrudada por meio desta proposta metodológica de design, estreitando a relação entre o design e a engenharia, tratando-se de um trabalho de interface entre conhecimentos. O foco deste estudo é dar suporte à inovação no desenvolvimento de produtos cerâmicos extrudados que atendam os requisitos formais, científico-tecnológicos e sócio-econômicos, com diversas possibilidades de aplicação em decoração de ambientes.

A estimação de parâmetros de equações constitutiva viscoelásticas, tipicamente efetuada através de diferentes tipos de reômetros, pode ser uma tarefa árdua, especialmente no que diz respeito à estimação de parâmetros não lineares. Nas últimas décadas houve grande progresso no desenvolvimento de novas metodologias para caracterização de fluidos viscoelásticos na região de comportamento viscoelástico não linear e na simulação de escoamentos de fluidos viscoelásticos nesta região. Este trabalho tem como objetivo apresentar uma metodologia de estimação de parâmetros reológicos de equações constitutivas viscoelásticas baseada na comparação recursiva entre valores originados em experimentos com a modelagem em fluidodinâmica computacional do escoamento de referência. Esta metodologia apresenta como vantagem a possibilidade de estimar parâmetros a partir de dados originados em escoamentos mais representativos dos processos industriais, resultando em parâmetros com maior potencial de representar adequadamente o comportamento viscoelástico de um dado material nas suas condições típicas de aplicação. Dois estudos de caso foram implementados de forma a testar a metodologia: o escoamento de um fluido newtoniano entre placas paralelas e o escoamento de um fluido viscoelástico na saída do capilar. A estimação da viscosidade newtoniana foi baseada na comparação entre valores analíticos e numéricos para o gradiente de pressão ao longo do escoamento. A estimação do parâmetro não linear da equação constitutiva viscoelástica de Phan-Thien-Tanner (PTT) foi baseada na diferença entre os perfis de diâmetro numéricos com relação aos valores experimentais para o fenômeno de inchamento do filete de fluido ao emergir da saída do capilar, conhecido como inchamento do extrusado. O erro final obtido para o valor estimado da viscosidade newtoniana foi de 9 % com relação ao valor de referência. Para o parâmetro não linear do modelo PTT o erro para o valor estimado foi de 0,75 % com relação ao valor de referência obtido pela técnica de reometria rotacional.
The estimation of viscoelastic constitutive equations parameters, typically performed through different types of rheometers, can be an arduous task, especially as regards the estimation of nonlinear parameters. In recent years, there has been great progress in developing new methods for the characterization of viscoelastic fluids beyond the linear region and in the simulation of viscoelastic fluid flows in general. This work aims to present a methodology for estimation of rheological parameters of viscoelastic constitutive equations. The methodology is based on recursive comparison between experimentally measured fields with numerically computed ones by a computational fluid dynamics (CFD) model. This methodology has the advantage of estimating parameters through data coming from more representative flows of industrial processes, resulting in parameters with higher potential to represent the viscoelastic behavior of a given material under its typical conditions of application. Two case studies have been used to test this methodology: a steady state shear flow between two parallel plates of a Newtonian fluid and a viscoelastic fluid flow in a capillary. The estimation of Newtonian viscosity was based on the comparison between analytical and numerical values for the pressure gradient along the flow. The estimation of the nonlinear parameter of the viscoelastic constitutive equation Phan-Thien-Tanner was based on the difference between the experimental and numerical diameter profiles of the swelling of the fluid emerging from the capillary opening, known as extrudate swell. The final error obtained for the estimated value of Newtonian viscosity was 9 % compared to the reference value. For nonlinear parameter of PTT model, the error of the estimated value was 0.75 % compared to the reference value obtained through rotational rheometer technique.

O desenvolvimento de ligas de alumínio de propriedades mecânicas intermediárias possibilitou a extrusão de alumínio a participar de grandes mercados como a construção civil, transportes, automobilística, estruturas, entre outras. O conhecimento do processo de extrusão propicia o aumento de produtividade com melhor desempenho e precisão dimensional do produto acabado. Neste trabalho, procurou-se analisar as características de conformação de perfis sólidos das ligas de alumínio AA6063 e AA6082 com razão de extrusão (RE) variando de 2,0 a 27,8 e tubular com RE de 8,7. A partir da extrusão realizada em uma prensa industrial de 3300 toneladas de força, compararam-se os resultados obtidos da tensão média de escoamento (\"sigma\") em função da temperatura de deformação e do parâmetro de Zener-Hollomon (Z) e este último em função do tamanho de subgrão observado no produto extrudado. Foram obtidos, em condições industriais, para estas ligas os valores da constante \"alpha\" que relaciona a RE com a pressão de fim de extrusão. Foram realizadas observações metalográficas e constatadas regiões de recristalização e de não recristalização diferentes para as ligas estudadas, bem como as relações do parâmetro Z e o tamanho do subgrão do produto sólido e tubular na liga AA6082. Em termos de textura foi possível obter as figuras de pólo e do tipo FDO no perfil extrudado ilustrando a presença de fibras do tipo \"beta\" (característica de produto conformado) e cubo (característica de produto recristalizado/recuperado). Os resultados confirmam valores próximos àqueles encontrados na literatura.
The development of medium strength aluminum alloys enabled aluminum extrusions to take part of the large world markets, associated with the building, transport and automotive industries, amongst several applications. The knowledge of the extrusion process details enables the productivity increase with better performance and higher dimensional accuracy of the finished extrusion product. In the present study the deformation characteristics of solid extrusion profiles in the AA6063 and AA6082 alloys with extrusion ratios (ER) in the range of 2.0 to 27.8 and for solid and tubular of 8.7 sections were studied. Extrusions were carried out in an industrial 3300 ton press. Results are compared in terms of average flow stress as a function of extrusion temperature and of the Zener-Hollomon (Z) parameter; the latter one also as a function of the observed subgrain size in the final product. Under industrial conditions, for the studies alloys, the values of the \"alpha\"-constant (which relates the end pressure to the extrusion ratio), has been evaluated. Metallographic observations have been conducted to study the recrystallised and unrecrystallised regions in the studied alloys, as well as the relationship between the Z parameter and the subgrain size of the end extrusion, both for the solid and tubular products, mainly for the AA6082 alloy. In terms of texture components it has been observed that the pole figures and the ODF´s of the extruded product presented the \"beta\" (characteristic of rolled/worked products) and cube (characteristic of recrystallised/recovered products). The results obtained confirmed those reported in the literature.

Quality protein maize (QPM), high protein corn (HPC) and food grade maize (FGM) were processed into tortillas and direct expanded extruded snacks. QPM had similar test weight, density and kernel size with 45% more lysine and 38% more tryptophan compared to FGM. HPC had the largest kernel with density and test weight similar to FGM. During alkaline cooking, HPC absorbed water faster than QPM and FGM. White QPM required shorter cooking time and had less dry matter losses compared to FGM. All corn varieties had excellent pericarp removal at the optimum cooking time. Tortillas from QPM had better pliability and rollability after storage compared to FGM and HPC. HPC tortillas had lower rupture force after storage. The use of QPM for tortilla production may reduce energy and sewage cost, and could produce a tortilla with longer shelf stability with improved nutritional value. Decorticated and non-decorticated QPM, FGM and HPC grain were processed into corn meal and direct expanded snacks. A modified short scale dry milling system was used to produce the corn meal. QPM produced more coarse meal with greater fat content compared to FGM. Decortication decreased fiber content and coarse meal yield. Non-decorticated meal had greater protein, fiber and fat content compared to decorticated meal. The modified short flow milling system provides reduced lost fractions for extrusion into nutritionally improved products. Extrusion was performed in a low cost friction extruder. QPM extruded faster than FGM and HPC. FGM required greater specific mechanical energy than QPM. Extrudates from FGM were the most expanded followed by QPM and HPC. Extrudates from the three corn varieties were acceptable to the panelists and decortication did not affect acceptability. The improved nutritional value of QPM, was retained during dry milling and extrusion. Current QPM varieties can be processed into tortillas with longer shelf stability and meal for extrusion into a wide variety of snacks and other foods. These may have application in specialty health foods and in developing countries where maize is a staple food.

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Universidade Federal de Sao Carlos
Polymer profiles extrusion shows some peculiarity due to the flow behavior of these materials during the processing. On the other hand, the profile die design and tooling has been more a result of professional s expertise than an engineering project in essence. In the present work, it was aimed to combining concepts of computer s aided engineering to rheological behavior of wood thermoplastic composites on profile die design. The prepared formulation where comprised of 60%wt HDPE, with and without a coupling agent, compounded with up to 40%wt wood flour and lubricant. Rheological properties in capillary and oscillatory rheometry were investigated. Due to experimental difficulties found in such rheometry methods when large particle size fillers are present or in highly loaded systems, a systematic approach for data collecting from a torque rheometer was evaluated, together with a mathematical model for power law parameters evaluation, where the results has been found in agreement to the data of capillary and oscillatory rheometry for neat polymers. For the composites, the results of torque and capillary rheometry virtually coincide, but the viscosities are lower than those measured in oscillatory rheometry. Simulation software was employed both in the die design and experimental data explanation. A cooled land die attached to a single screw extruder was employed for profile extrusion. Once steady extrusion conditions were achieved, temperature, pressure and linear output were monitored and profile s samples were cut for mechanical properties evaluation in flexural mode. The results shown that linear output and profile s properties were influenced by a combination of factors associated to composite formulation, processing conditions and die cooling. The optimum processing conditions for uniform profile extrusion could be reproduced by computer simulation.
A extrusão de perfis poliméricos apresenta algumas peculiaridades decorrentes do comportamento de fluxo destes materiais durante o processamento. Por outro lado, o projeto e construção de matrizes para perfis ainda tem sido mais resultado da experiência dos profissionais envolvidos do que um projeto de engenharia na sua essência. Neste trabalho, procurou-se aliar conceitos de engenharia auxiliada por computador ao comportamento reológico de compósitos termoplásticos reforçados com madeira no projeto de matrizes para perfis. As formulações preparadas foram constituídas de 60% em peso de PEAD, com e sem compatibilizante, compostos com até 40% de farinha de madeira e lubrificante. Propriedades reológicas em reometria capilar e oscilatória foram investigadas. Devido a dificuldades experimentais encontradas nestes métodos de reometria quando na presença de cargas de grande tamanho médio de partículas ou em sistemas altamente carregados, uma abordagem sistemática para coleta de dados a partir de um reômetro de torque foi avaliada, junto a um modelo matemático para obtenção de parâmetros de Lei das Potências, onde os resultados estiveram em concordância em relação às medidas obtidas em reometria capilar e oscilatória para polímeros puros. Para os compósitos, os resultados de reometria de torque e capilar virtualmente coincidem, porém as viscosidades são inferiores àquelas medidas em reometria oscilatória. Softwares de simulação foram empregados no projeto de matrizes e na interpretação dos dados experimentais. Uma matriz com região do paralelo resfriada acoplada a uma extrusora de rosca única foi utilizada para a extrusão dos perfis. Uma vez alcançadas condições estáveis de extrusão, a temperatura, pressão e a produtividade linear foram monitoradas e amostras dos perfis foram cortadas para determinação de propriedades mecânicas em flexão. Os resultados indicaram que a descarga linear e as propriedades dos perfis foram influenciadas por uma combinação de fatores associados à formulação do compósito, condições de processo e resfriamento da matriz. As condições ótimas de processo para obtenção de perfis uniformes puderam ser reproduzidas através da simulação.

L'objectif de cette thèse est d'observer la modification du comportement rhéologique dedifférents polyéthylènes branchés, suite à un traitement de cisaillement. Après avoir décrit lesmatériaux et les moyens utilisés, nous avons caractérisé le plus complètement possible lecomportement rhéologique des différents matériaux, aussi bien en cisaillement qu'en élongation.Nous avons également déterminé des données calorimétriques et des informations sur lescaractéristiques moléculaires, permettant entre autres de définir la masse entre enchevêtrements.Nous avons ensuite mesuré l'évolution de la viscosité dans différentes conditions de pré‐cisaillement,en faisant varier le temps et le taux de cisaillement dans un rhéomètre cône‐plan et dans unegéométrie de Couette montée en amont d'un rhéomètre capillaire. Nous avons montré que lesmécanismes de désenchevêtrement sont complexes et qu'ils ne sont pas directement explicables parun seul paramètre, comme la masse entre enchevêtrements. Enfin, l'observation des extrudats à lasortie de la filière nous a permis de mettre en évidence la modification des défauts d'extrusion sousl'effet d'un pré‐cisaillement.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O politereftalato de etileno (PET) é um poliéster termoplástico com ampla utilização em diversos seguimentos industriais, especialmente o de bebidas, que quando descartado inadequadamente, torna-se um passivo ambiental, podendo ocasionar a poluição ambiental, perda da biodiversidade local e até mesmo a proliferação de vetores de doenças. Na busca de opções para a minimização de impactos ambientais provenientes do descarte de materiais poliméricos, surge como alternativaa produção de blendas poliméricas, que, ainda pode agregar valor a outros subprodutos industriais, como a lignina. A lignina é um dos biopolímeros predominantes em plantas, como a celulose e hemicelulose, possui grande disponibilidade, e pode ser obtida por meio de resíduos da indústria de papel e celulose. Com o objetivo agregar valor a estes resíduos, neste estudo, foram utilizadasembalagens de PET virgem cristal, obtidos de pré-formas, triturados e higienizados, e lignina kraft (LK), obtida por meio da purificação do licor negro, resíduo da indústria de papel e celulosepara a formação de blendas.As blendas foram extrudadas em teores de 1, 2, 5 e 10% de LK/PET (m/m). Posteriormente investigaram-se as características térmicas, por meio da análise termogravimétrica (TGA) e da calorimetria exploratória diferencial (DSC) e as características químicas e morfológicas com a difração de raios X (DRX), espectroscopia no infravermelho (FTIR) e microscopia eletrônica de varredura (MEV). Constatou-sesob as condições deste estudo,que ossistemas PET/LK inferiores a 10%, apresentaram melhor estabilidade mecânica, menor alteração do perfil cristalino, interação e miscibilidade nas blendas. Sendo que a utilização da massa residual de indústrias de papel (lignina kraft) torna-se uma alternativa promissora na produção de substitutos para a madeira, devido a relativa facilidade e o baixo custo de obtenção, assim como a quantidade de matéria prima disponível, tanto da LK quanto de PET descartado, resultando na valorização destes dois resíduos.
Polyethylene terephthalate (PET) is a thermoplastic polyester widely used in a variety of industrial processes, especially beverages, which, when improperly disposed of, becomes an environmental liability, leading to environmental pollution, loss of local biodiversity and even Proliferation of disease vectors. In the search for options to minimize environmental impacts from the disposal of polymeric materials, the production of polymer blends is an alternative, which can still add value to other industrial byproducts, such as lignin. Lignin is one of the predominant biopolymers in plants, such as cellulose and hemicellulose, has high availability, and can be obtained through waste from the paper and cellulose industry. In order to add value to these residues, in this study, crystal virgin PET containers, obtained from preforms, crushed and sanitized, and kraft lignin (LK) obtained by purification of black liquor, Paper and pulp for the formation of blends. The blends were extruded at contents of 1, 2, 5 and 10% LK/PET (m/m). Subsequently, the thermal characteristics were investigated by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) and chemical and morphological characteristics with X-ray diffraction (XRD), infrared spectroscopy (FTIR) and electron microscopy of Scanning (SEM). Under the conditions of this study, PET/LK systems lower than 10% showed better mechanical stability, less alteration of the crystalline profile, interaction and miscibility in the blends. Since the use of the residual mass of paper industries (kraft lignin) becomes a promising alternative in the production of substitutes for wood, due to the relative ease and the low cost of obtaining, as well as the amount of raw material available, both of LK and of PET discarded, resulting in the valorization of these two residues.

Orientador: Fernanda Paula Collares
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: O presente trabalho visou avaliar a aplicação de farinha de Yacon (Polymnia sonchifolia) em produtos à base de cereais como bolo inglês, biscoito tipo "Champurrada" e snacks à base de arroz obtidos por extrusão termoplástica. Para tanto, a incorporação de farinha de Yacon nos snacks e a substituição parcial da farinha de trigo pela farinha de Yacon no bolo e no biscoito foram analisadas quantificando-se a magnitude das mudanças físicas e sensoriais nestes produtos. Para os três estudos, utilizou-se a metodologia de superfície de resposta com um delineamento estatístico do tipo composto central rotacional (com 2 variáveis independentes no caso do bolo e biscoito, e 3 variáveis independentes para o estudo dos snacks). As variáveis independentes no estudo do bolo foram as concentrações de farinha de Yacon e de farinha de linhaça. Já, para o biscoito, as variáveis foram as concentrações de farinha de Yacon e de aveia em flocos. Em se tratando dos snacks, as variáveis foram: umidade da farinha de alimentação; temperatura na 4ª e 5ª zona do extrusor; e teor de farinha de Yacon incorporada. Os bolos e os biscoitos foram analisados quanto à textura e cor instrumental (Hunterlab), densidade da massa, volume específico, além das avaliações sensoriais. Por sua vez, as variáveis dependentes no estudo dos snacks foram: propriedades físico-químicas (textura e cor instrumental, índice de absorção de água e de solubilidade em água, e índice de expansão) e sensoriais. Para o bolo, as superfícies geradas sugeriram que concentrações de farinha de Yacon variando entre 0,0% e 3,45% e teores de farinha de linhaça entre 3,18% e 6,0% resultaram em um produto de menor dureza. Para os parâmetros de cor, com concentrações mínimas de farinha de Yacon e linhaça (0,0% e 3,18%, respectivamente), obteve-se um bolo mais claro, de coloração mais amarelada e a densidade da massa atingiu valores mínimos quando o teor de linhaça foi de 6,0%, sendo que o teor de farinha de Yacon não apresentou influência sobre este parâmetro. No estudo do biscoito, a superfície de resposta indicou que quando a concentração de Yacon foi de 3,45% ou superior, e a de aveia de 6,82%, o parâmetro L* atingiu seu valor máximo. O maior valor de intenção de compra ocorreu para uma concentração de Yacon de 3,45% e de aveia de 1,18% e 6,82%. Dessas observações pode-se inferir que a concentração recomendada de incorporação de farinha de Yacon seria 3,45% e de aveia de 6,82%, considerando a faixa de valores estudada. Os snacks que apresentaram maior expansão foram obtidos a 120ºC, com teor de umidade da matéria-prima igual a 17% e concentração da farinha de Yacon de 12%. As superfícies geradas para os atributos sensoriais textura e intenção de compra, mostraram que o valor máximo para estes dois atributos ocorreram para as mesmas condições de temperatura, umidade da farinha de alimentação e teor de farinha de Yacon que propiciaram o maior índice de expansão. A utilização da farinha de Yacon (Polymnia sonchifolia) como um ingrediente funcional em produtos panificados (bolo e biscoito) e extrudados (snacks de arroz) mostrou-se viável. Os fruto-oligossacarídeos (FOS), objeto central no desenvolvimento de um produto funcional, foram conservados no processamento do Yacon até a obtenção da farinha e permaneceram em concentrações satisfatórias, de modo a suprir a ingestão nutricional de acordo com padrões difundidos na literatura
Abstract: This study aimed at evaluating the application of yacon (Polymnia sonchifolia) flour in cereal-based products such as pound cake, "Champurrada" type biscuits and rice-based snacks produced by a thermoplastic extrusion process. Thus the effect of incorporating yacon flour into the snacks and the partial substitution of wheat flour by yacon flour in the cake and biscuit were analysed, quantifying the magnitude of the physical and sensory changes in these products. Response surface methodology was used in the three studies, with a rotatable central-composite experimental design (with 2 independent variables for the cake and biscuit, and 3 independent variables for the snacks). The independent variables for the cake study were the yacon flour and flaxseed flour concentrations, and for the biscuit, the yacon flour and oat flake concentrations. For the snacks, the variables were: moisture content of the feed flour; temperature in the 4th and 5th extruder zones; and amount of yacon flour incorporated. The cakes and biscuits were analysed for instrumental texture and colour (Hunterlab), dough density and specific volume, as well as the sensory analyses. On the other hand the dependent variables for the snacks were: the physical (instrumental texture and colour, water solubility index, water absorption index and expansion ratio) and sensory properties. For the cake, the surfaces generated suggested that concentrations of yacon flour between 0.0% and 3.45% and of flaxseed flour between 3.18% and 6.0% resulted in a cake with reduced hardness. For the colour parameters, the minimum yacon and flaxseed flour concentrations (0.0% and 3.18%, respectively), produced lighter coloured cakes with a yellowish colour. The dough density reached minimum values when the concentration of flaxseed was 6.0%, whilst the yacon flour concentration showed no influence on this parameter. In the biscuit study, the response surface indicated that when the yacon flour concentration was 3.45% or above and that of the oat flakes 6.82%, the L* parameter reached its maximum value. The highest value for purchasing intention was obtained with a Yacon flour concentration of 3.45% and an oats concentration between 1.18% and 6.82%. These observations inferred that the recommended concentrations for the yacon flour and oat flakes would be 3.45% and 6.82%, respectively, considering the range of values studied. The most expanded snacks were obtained under the following conditions: 17% moisture content in the feed flour, a temperature of 120ºC and the incorporation of 12% yacon flour. The surfaces generated for the sensory attributes of texture and purchasing intention, showed that the maximum values for these two attributes were obtained under the same conditions of temperature, feed flour moisture content and yacon flour incorporation that propitiated the greatest expansion values. The use of yacon flour (Polymnia sonchifolia) as a functional ingredient in bakery products (cake and biscuit) and extruded products (rice snacks) was shown to be viable. The fructooligosaccharides (FOS), central object of the development of a functional product, were conserved during the processing of the yacon to obtain the flour, remaining in satisfactory concentrations, sufficient to supply the recommended values for ingestion according to standards divulged in the literature
Mestrado
Mestre em Tecnologia de Alimentos

[ES] Las microalgas son organismos unicelulares fotosintéticos microscópicos que se encuentran en gran variedad de ambientes y son muy eficientes en la transformación de energía solar en biomasa. Los estudios realizados hasta el momento hacen referencia a posibles beneficios de la incorporación de microalgas en la dieta, por la mejora del sistema cardiovascular, las propiedades adelgazantes y energizantes, capacidad antioxidante, o la reducción del colesterol y los triglicéridos. La forma más habitual de consumir las microalgas es como suplemento dietético en forma de tabletas, cápsulas o polvo. La incorporación de biomasa de microalgas en productos tradicionales se ha enfrentado al reto de la aparición de colores verdes fuertes, así como su consistencia pulverulenta que puede afectar la textura y percepción del producto. Todos estos aspectos constituyen las principales áreas de mejora para conseguir un mayor grado de aceptación de productos con microalgas, y son la base del reto de este proyecto. El objetivo de la presente tesis doctoral fue el desarrollo de nuevos productos alimentarios incorporando las propiedades nutricionales de la biomasa de microalgas, incrementando o mejorando con ello, las propiedades nutricionales del alimento original. Para conseguir este objetivo se evaluaron a nivel fisicoquímico, reológico y textural, la incorporación de diferentes especies de microalgas (Arthrospira platensis (Spirulina), Chlorella vulgaris, Dunaliella salina y Nannochloropsis gaditana) en distintas matrices alimentarias (productos horneados, emulsiones y extrusionados). Por otra parte, se evaluó y caracterizó la incorporación de las microalgas utilizando diferentes tecnologías como la impresión 3D o la extrusión. Además de cómo afecta la incorporación de las microalgas a los productos obtenidos, se evaluaron los aspectos nutricionales de su incorporación, en cuanto al aporte de minerales y su biodisponibilidad. Las propiedades reológicas de las masas y emulsiones enriquecidas con microalgas (Spirulina, Chlorella y Dunaliella) indicaron que su comportamiento viscoelástico fue modificado y mejorado, mostrando características aptas para este tipo de productos. La adición de microalgas (Spirulina y Chlorella) a las masas utilizadas para la impresión 3D de galletas y snacks, permitió una mejor extrusión o impresión de éstas, obteniendo muestras impresas en 3D de forma cilíndrica, más precisas en cuanto a sus dimensiones con respecto a la estructura cilíndrica diseñada. Además, las muestras impresas presentaron mayor estabilidad y resistencia, antes y después del proceso de horneado comparadas con la muestra control. Para los productos horneados, tanto para las rosquilletas como los snacks impresos en 3D, la adición de microalgas (Spirulina y Chlorella) permitió mayor estabilidad en términos de textura. Ligeros cambios en los parámetros fisicoquímicos y de expansión se produjeron por la adición de Spirulina y Chlorella en los productos extrusionados. Además, los extrusionados enriquecidos con Nannochloropsis, mostraron parámetros similares a los de la muestra de control. Todos los productos presentaron colores luminosos y apariencias innovadoras y atractivas. En cuanto a los minerales, se observó un aumento de P, K, Ca, Na, Mg, Fe y Se con la adición de Spirulina y Chlorella, junto con el aumento de la concentración adicionada de microalgas. Siguiendo la normativa sobre etiquetado nutricional de los alimentos, el enriquecimiento con microalgas en rosquilletas se puede clasificar como un alimento "rico en hierro (Fe)". De igual forma, las rosquilletas y galletas enriquecidas con microalgas pueden considerarse un alimento "alto en selenio (Se)". Además, la incorporación de Spirulina y Chlorella en las formulaciones de galletas, permitió una mayor bioaccesibilidad del contenido de P, K, Ca, Mg, Fe, Zn y Se para la absorción en el cuerpo comparado con las muestras control.
[CAT] Les microalgues són organismes unicellulars fotosintètics microscòpics. Són molt eficients a l'hora de transformar l'energia solar en biomassa. Els estudis realitzats fins ara fan referència a possibles beneficis de la incorporació de microalgues en la dieta per produir una millora del sistema cardiovascular, per presentar propietats per aprimar i donar energia, per mostrar capacitat antioxidant o per afavorir una reducció del colesterol i els triglicèrids. La forma més habitual de consumir microalgues és com a suplement dietètic en forma de tauleta, càpsula o en pols. La incorporació de biomassa de microalgues en productes tradicionals s'ha afrontat al repte de l'aparició d'un color verd fosc i d'una consistència polsosa que pot afectar a la textura i, per tant, a la percepció del producte. Aquests aspectes constituïxen les principals àrees de millora per aconseguir un major grau d'acceptació de productes amb microalgues i són la base del repte d'aquest projecte. L'objectiu d'aquesta tesi doctoral és el desenvolupament de nous productes alimentaris que incorporen les propietats nutricionals de la biomassa de microalgues, de manera que s'incrementen o es milloren les propietats nutricionals de l'aliment original. Per aconseguir aquest objectiu s'avaluaren a escala fisicoquímica, reològica i de textura la incorporació de diferents espècies de microalgues (Arthrospira platensis (Spirulina), Chlorella vulgaris, Dunaliella salina i Nannochloropsis gaditana) en diferents matrius alimentàries (productes fornejats, emulsions i extrudits). D'altra banda, s'avaluà i caracteritzà la incorporació de les microalgues utilitzant diferents tecnologies com la impressió en 3D o l'extrusió. A banda de valorar com afecta la incorporació de microalgues als productes elaborats, s'avaluaren els aspectes nutricionals, pel que fa a l'aportació i biodisponibilitat de minerals. Les propietats reològiques de les masses i emulsions enriquides amb microalgues (Spirulina, Chlorella i Dunaliella) indicaren que el seu comportament viscoelàstic fou modificat i millorat, de tal manera que mostrà característiques aptes per aquest tipus de productes. L'addició de microalgues (Spirulina i Chlorella) en les masses utilitzades per a la impressió 3D de galetes i snacks permeté una millor impressió, ja que s'obtingueren mostres impreses de forma cilíndrica amb unes dimensions més precises respecte a l'estructura cilíndrica dissenyada. A més, les mostres impreses presentaren una major estabilitat i resistència abans i després del procés de fornejat en comparació amb la mostra control. Respecte als productes fornejats, l'addició de microalgues (Spirulina i Chlorella) a les rosquilletes i els snacks impresos en 3D permeté una major estabilitat en termes de textura. Lleugers canvis als paràmetres fisicoquímics i d'expansió es produïren per l'addició d'Spirulina i Chlorella en els productes extrudits. A més, els extrudits que foren enriquits amb Nannochloropsis mostraren paràmetres similars als de la mostra control. Tots els productes presentaren colors lluminosos i aparences innovadores i atractives. Pel que fa als minerals, s'observà un augment de P, K, Ca, Na, Mg, Fe i Se quan s'afegí Spirulina i Chlorella, directament relacionat amb l'augment de la concentració de microalgues. Seguint la normativa sobre etiquetatge nutricional dels aliments, l'enriquiment amb microalgues en rosquilletes ens permet classificar-les com a aliment "ric en ferro (Fe)". De la mateixa manera, les rosquilletes i galetes enriquides amb microalgues poden considerar-se un aliment "alt en seleni (Se)". A més a més, la incorporació de Spirulina i Chlorella en les formulacions de galetes, permeté una major bioaccessibiltat del contingut de P, K, Ca, Mg, Fe, Zn i Se comparat amb les mostres control.
[EN] Microalgae are microscopic unicellular and photosynthetic organisms that can be found in a wide variety of environments. These microorganisms are very efficient when transforming solar energy into biomass, due to their cellular structure, which is completely submerged in an aqueous medium, forming an adequate surface for the exchange of nutrients and gases. Microalgae compounds are now known to exhibit cardioprotective, immunomodulatory, anti-proliferative, anti-inflammatory, cognitive, neurobehavioral and antimicrobial properties, amongst others. Researchers have shown possible benefits of the incorporation of microalgae in the diet so far. The most common way to consume microalgae is as a dietary supplement in the form of tablets, capsules or powder. The incorporation of microalgae biomass in traditional products has faced the challenge of the appearance of strong green colours, as well as its powdery consistency that can affect the texture and perception of the product. All these aspects constitute the main areas for improvement the development of microalgae-based products, and they are the challenges faced of this project. The main objective of this PhD Thesis was the development of novel food products incorporating the nutritional properties of microalgae biomass, thereby increasing or improving the nutritional properties of the original food matrix. To achieve this goal, the effect of the addition of different species of microalgae (Arthrospira platensis (Spirulina), Chlorella vulgaris, Dunaliella salina and Nannochloropsis gaditana) on the physicochemical, rheological and textural properties of different food matrices (baked products, emulsions and extrudates) was evaluated. Furthermore, the effect of the incorporation of microalgae using different technologies such as 3D printing or extrusion to obtain food products was studied. In addition, how the incorporation of microalgae affects the nutritional aspects of the food products in terms of the contribution of minerals and their bioavailability was also evaluated. The rheological properties of doughs, batters and emulsions enriched with microalgae (Spirulina, Chlorella and Dunaliella) indicated that their viscoelastic behaviour was modified and improved, showing characteristics suitable for this type of products. The addition of microalgae (Spirulina and Chlorella) to the doughs and batters used for the 3D printing of cookies and snacks, allowed a better extrusion or printing behaviour. This allowed obtaining cylindrical 3D printed samples, more precise in terms of their dimensions with respect to the designed cylindrical structure. In addition, the 3D microalgae-printed sample structures presented greater stability and resistance, before and after the baking process compared to the control sample. For baked products, both for breadsticks and 3D printed snacks, the addition of microalgae (Spirulina and Chlorella) allowed greater stability in terms of texture. Slight changes in the physicochemical and expansion parameters were produced by the addition of Spirulina and Chlorella in the extruded products. In addition, the extrudates enriched with Nannochloropsis, showed similar parameters to those of the control sample. Microalgae-enriched obtained products showed bright colours with appealing appearances. Regarding minerals, an increase in P, K, Ca, Na, Mg, Fe and Se was observed with the addition of Spirulina and Chlorella, along the increase of concentration of microalgae addition. Following the regulations on nutrition labelling for food stuffs, breadstick enrichment with microalgae are a food "high in iron (Fe)" In the same way, breadsticks and cookies enriched with microalgae can be considered a "high in selenium (Se)" food. Going a step further, Spirulina and Chlorella vulgaris incorporation in cookie formulations allowed for greater bioaccessibility of P, K, Ca, Mg, Fe, Zn, and Se content for absorption in the body than control cookies.
Uribe Wandurraga, ZN. (2020). Microalgae as novel ingredients for the formulation of food products [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/158743
TESIS

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CAPES
Whey is one the most polluting by-products of the food industry and their perishability does not allow storage for long periods, then it's necessary to find appropriate destination. The whey protein have potential anticarcinogenic, activities hypocholesterolemic, anti-inflammatory, immunomodulatory action, among others. The rice consists mainly of starch, and this structure contributes to the production of snacks high technological quality. The objective of this study was develop and characterize mixed extruded flour of rice and whey protein concentrate aiming use in the manufacture nutritional and practical products. The parameters used in the processing of thermoplastic extrusion were: formulation (% whey protein concentrate), moisture content and temperature of the last heating zone. The extrudates were subjected to physical characterization and functional technology assessment. The highest rates of growth were observed for the tests with up to 4 % whey protein concentrates in their formulations and were processed with low humidity generally less than 20 % and milder temperatures, generally at or below 140 ?C. Through the visual characterization of extruded and the micrographs it was observed that the samples processed with low moisture content (16.64 and 18%) were more homogeneous cells. The X-ray diffraction showed that the profile of the crystal samples is characteristic of type "A" due to the presence of crystalline domains in its structure. The flours viscosity profile is consistent with the characteristics of pre- gelatinized products, being dissolved without needing to cook. The pre-gel flour with blends of rice and whey protein concentrate present viscous, homogeneous and with low capacity of retrogradation. The addiction protein concentrate in rice flour increased the ash and proteins, indicating that the mineral and amino acid composition of the mixed flours may also have a nutritional improvement. Generally, the processing conditions do not significantly affect the nutritional value of the flours blends. The acceptance test performed with the cookies prepared with the mixed flours 8, 10 and 16 (6, 7.36 and 4 % whey protein concentrate, respectively) indicated that the biscuit with a higher content of protein concentrate showed better overall evaluation, taste and purchase intent. The porridges were produced with pre-gelatinized flour containing 2, 4 and 7.36% whey protein concentrate and sensory analysis evaluated the attributes appearance, flavor and consistency, plus purchase intent. The results showed that for most of the evaluated attributes and purchase intent, the sample with higher content of protein concentrate showed the best results. The porridges were produced with pre-gelatinized flour containing 2, 4 and 7.36% whey protein concentrate and sensory analysis evaluated the attributes appearance, flavor and consistency, plus purchase intent. The results showed that for most of the evaluated attributes and purchase intent, the sample with higher content of protein concentrate showed the best results. We conclude that it is possible to produce pre-gel flours containing rice and whey protein concentrate with good nutritional, microbiological and technological features for the production of cookies and porridges rapid dissolution.
O soro de leite ? um dos subprodutos mais poluentes da ind?stria de alimentos e sua natureza perec?vel n?o permite a estocagem por per?odo prolongado, sendo necess?rio encontrar destino adequado aos volumes produzidos. Atribuem-se ?s prote?nas do soro de leite poss?veis atividades anticarcinog?nica, hipocolesterol?mica, anti-inflamat?ria, a??o imunomoduladora, entre outras. O arroz ? constitu?do principalmente por amido, e devido a sua estrutura, contribui para a produ??o de snacks de elevada qualidade tecnol?gica. O objetivo desse trabalho ? desenvolver e caracterizar farinhas mistas pr?-gelatinizadas de arroz e concentrado proteico de soro de leite bovino, obtidas por extrus?o termopl?stica, visando utiliza??o na elabora??o de produtos nutritivos e pr?ticos. Foram consideradas como vari?veis independentes: formula??o (% de concentrado proteico de soro de leite na mistura com farinha de arroz), umidade da mistura da farinha no processamento e temperatura da ?ltima zona de aquecimento. Os extrudados elaborados foram submetidos ? caracteriza??o f?sica e avalia??o tecnol?gica funcional. Os melhores ?ndices de expans?o foram observados para os ensaios com at? 4 % de concentrado proteico e que foram processados com baixa umidade e temperaturas mais brandas. Atrav?s da caracteriza??o visual dos extrudados e das micrografias foi poss?vel observar que as amostras processadas com baixo conte?do de umidade (16,64 % e 18 %) apresentaram c?lulas mais homog?neas. Por meio da difratometria de raios X verificou-se que o perfil das amostras ? caracter?stico ao cristal do tipo "A", devido ? presen?a de dom?nios cristalinos em sua estrutura. As farinhas mistas extrudadas se destacaram por possuir elevada viscosidade a frio, baixa viscosidade a quente (95?C) e baixo poder de retrograda??o. Os resultados observados nos par?metros de viscosidade avaliados mostram correla??o destas propriedades com as caracter?sticas de f?cil reconstitui??o e boa solubiliza??o em meio aquoso, sem a necessidade de cozimento. A incorpora??o de concentrado proteico na farinha de arroz promoveu incremento no teor de cinzas e prote?nas, indicando melhoria na composi??o mineral e de amino?cidos das farinhas mistas. De modo geral, as condi??es de processamento utilizadas n?o afetaram de forma significativa o valor nutricional da maior parte das farinhas mistas produzidas. O teste de aceita??o realizado com os biscoitos elaborados com as farinhas mistas referentes aos ensaios 8, 10 e 16 (6, 7,36 e 4 % de concentrado proteico, respectivamente) indicou que o biscoito com maior teor de concentrado proteico apresentou melhor avalia??o global, sabor e inten??o de compra. Os mingaus foram produzidos com farinhas pr?-gelatinizadas contendo 2, 4 e 7,36 % de concentrado proteico e submetidos ? an?lise sensorial. Para a maior parte dos atributos avaliados e para a inten??o de compra, a amostra com maior teor de concentrado proteico apresentou os melhores resultados. Conclui-se que ? poss?vel produzir farinhas mistas pr?-gelatinizadas de arroz e concentrado proteico de soro de leite bovino com boas caracter?sticas nutricionais, microbiol?gicas e tecnol?gicas tanto para a elabora??o de biscoitos quanto para a produ??o de mingaus de r?pida dissolu??o.

In einer Zeit, in der eine Zunahme von ernährungsbedingten Erkrankungen in steigendem Maße zu beobachten ist, wird dem Getreide als Grundlage der menschlichen Ernährung erhöhte Aufmerksamkeit gewidmet. Ein hoher Verzehr von Ballaststoffen ist ein wesentlicher Aspekt in der präventiv-medizinischen Ernährung. Die von der Deutschen Gesellschaft für Ernährung vorgeschlagene tägliche Ballaststoffzufuhr liegt bei 30 g. Die Aufnahme von Ballaststoffen ist jedoch in Deutschland deutlich unterhalb dieser empfohlenen Menge.

Getreideprodukte, besonders vom Vollkorntyp, sind die wichtigste Quelle für Ballaststoffe. Deshalb sollten im Rahmen dieser Arbeit direkt verzehrsfähige, Ballaststoff-angereicherte Haferprodukte (vorwiegend Extrudate) mit hohen Gehalten an b-Glucanen und resistenter Stärke hergestellt, analysiert und nachfolgend auf relevante ernährungsphysiologische Wirkungen geprüft werden. Als Basis für die Produkte wurden Hafermehl und Haferkleie eingesetzt.
Der erste Teil der Arbeit beschäftigte sich mit der Analyse der Haferprodukte. Diese wiesen eine hohe Wasserbindungskapazität auf. Bei den Untersuchungen am Tiermodell wurde gezeigt, dass im Dünndarm eine größere Menge an Wasser durch die Haferprodukte gebunden wurde, was zu einem höheren Feuchtigkeitsanteil der gastrointestinalen Inhalte der Tiere führte, die ballaststoffreiches Futter erhielten.

Trotz der hydrothermischen Behandlung während der Extrusion wurden Produkte gewonnen, deren β-Glucane im hochmolekularen Zustand erhalten blieben und somit eine hohe Viskosität in wässrigen Lösungen beibehielten. In rheologischen Untersuchungen wurde bestätigt, dass die aus Haferprodukten isolierten β-Glucane ein pseudoplastisches Fließverhalten besitzen. Demgegenüber führte ein Autoklavieren der Produkte zu einer starken Depolymerisation der b-Glucane, was sich in einer Änderung der funktionellen Eigenschaften der b-Glucane widerspiegelte.

Im Mittelpunkt der Untersuchungen standen ernährungsphysiologische In-vitro- und In-vivo-Experimente mit Extrudaten und Proben auf der Basis von Hafer, die einen erhöhten Anteil an Ballaststoffen, speziell an b-Glucan und an resistenter Stärke, besaßen und die direkt verzehrbar sind. Diese Haferprodukte zeigten eine Reihe von ernährungsphysiologisch vorteilhaften und protektiven Wirkungen in In-vitro-Experimenten. So traten sie mit Gallensäuren unter den Bedingungen des Dünndarms in Wechselwirkung und waren gut mit Faecesflora vom Menschen fermentierbar. Die In-vitro-Verdauung von Maisstärke durch Pankreatin, wurde durch die ballaststoffreichen Haferprodukte partiell gehemmt. Dieser Befund lässt eine Abschwächung des postprandialen Glukoseanstieges erwarten.

In einem sechswöchigen Fütterungsversuch erhielten Ratten Diäten, die zu 50 % aus ballaststoffreichen Haferprodukten bestanden. Diese Haferprodukte bewirkten einen erhöhten Transport von Gallensäuren und neutralen Sterolen in den unteren Intestinaltrakt sowie deren verstärkte Ausscheidung. Durch den Verzehr der ballaststoffreichen Haferprodukte kam es zu Veränderungen in der Mikroflora, wobei sich besonders die coliformen Keime verminderten und die Keimzahlen der Lactobacillen sowie die Bifidobakterien erhöhten. Die Fermentation der Ballaststoffe führte zur erhöhten Bildung von kurzkettigen Fettsäuren einschließlich von Butyrat. Die Bildung der kurzkettigen Fettsäuren geht mit einer pH-Wert-Absenkung im Caecum und Colon einher, die wiederum für eine geringere Bildung von sekundären Gallensäuren verantwortlich ist.

Die Ergebnisse des Fütterungsversuchs an Ratten wurden prinzipiell durch eine vierwöchige Pilotstudie am Menschen, in der Probanden täglich 100 g Haferextrudat erhielten, bestätigt. Das Extrudat wurde von den Probanden gut akzeptiert. In der 4. Woche wurden eine geringe Abnahme der Cholesterolfraktionen im Serum, höhere Keimzahlen für Lactobacillen, Bifidobacterien und Bacteroides, geringere pH-Werte und Trockenmassegehalte in den Faeces, eine Zunahme der individuellen und Gesamt-SCFA sowie des Butyratanteils in den Faeces, eine erhöhte Ausscheidung an Steroiden, eine Zunahme der primären Gallensäuren und eine Abnahme des prozentualen Anteils an sekundären Gallensäuren sowie der Cholesterol-Metaboliten gefunden. Diese Parameter gingen 2 Wochen nach Beendigung der Intervention mit dem Haferextrudat wieder in Richtung der Ausgangswerte (0. Woche) zurück.

Die untersuchten Haferprodukte erwiesen sich als gut fermentierbare Substrate für die intestinale Mikroflora und können deshalb als ein Präbiotikum mit Ballaststoffcharakter eingeschätzt werden. Diese Produkte, die mit einem erhöhten Anteil an resistenter Stärke und wertvollen Haferballaststoffen hergestellt wurden, können dazu beitragen, die Ballaststofflücke in unserer Ernährung zu schließen und positive ernährungsphysiologische Effekte zu bewirken.
Cereal products, particularly from whole grains, are the most important source of dietary fibre in the western diet. A high intake of dietary fibre, which is an essential component in nutrition, is positively related to several physiological and metabolic effects. However, the daily intake of dietary fibre is below the recommended levels (30d/day) in most industrials country. Oat (Avena sativa L.) products are well accepted in human nutrition. Oats is an excellent source of different dietary fibre types, such as β-glucan, arabinoxylans and cellulose, and it contains high levels of proteins, lipids, vitamins, antioxidants and minerals.
A series of extrudates was prepared from oat meal, oat bran and Novelose 330®, differing in concentrations of individual dietary fibre components, such as β-glucan and resistant starch, as well as total dietary fibre.

The cereal dietary fibre, β-glucan, has outstanding functional and nutritional properties, because of its viscosity in aqueous systems and in the intestinal tract. The rheological behaviour of β-glucan (concentrations: 2% and 4%) isolated from extruded oat meal and from oat bran was evaluated using oscillatory and rheological measurements. In frequency sweep, the storage and loss moduli G′ and G″ of β-glucan preparations from extruded meal and from bran increased continuously with increasing frequency, showing a dominantly viscous behaviour. With increasing frequency, the elastic properties improved.

After simulated digestion, the digested dietary fibre-rich oat-based extrudates were used to evaluate their physiological effects in vitro. A strong interaction occurred between the digested extrudates and bile acids. The binding of bile acids increased with increasing proportions of oat bran, total dietary fibre, insoluble dietary fibre and β-glucan in the extrudates. Dihydroxy-bile acid was more strongly bound to the extrudates than trihydroxy- bile acid. Interactions at pH 5.0 were greater than at pH 6.5. During fermentation of digested extrudates with human faecal samples, concentrations of short-chain fatty acid formed and the molar proportion of butyrate increased continuously. Higher short-chain fatty acid concentrations were found when extrudates contained more oat bran, soluble and insoluble dietary fibre and β-glucan. Extrudates, on the basis of oat, have several beneficial nutritional and protective effects in vitro. Therefore, physiological effects occurring in the small and large intestine are also related to the dietary fibre composition of the cereal products.

The results found in vitro was examined in feeding experiments with animal models and in nutritional studies with human subjects.

Male Wistar rats were fed either an oat-free diet (control group) or diet containing 50% oat-based products (test groups) for 6 week. In most of the test group, following effects were observed compared with control group: higher water intake; slightly decreased total and LDL cholesterol in serum; higher count of Bifidobacteria as well as lower count numbers of Coliforms; greater mass of cecum walls and cecal contents; lower pH values in intestinal contents; higher concentration of acetate, propionate and butyrate in cecal contents and greater excretion of short-chain fatty acids; significantly more total bile acids in cecal contents; higher excretion of total bile acids and primary bile acids; lower proportion of secondary bile acids as well as higher concentration of neutral sterols in cecal contents, colonic contents and feces.

In the human study 12 volunteers consumed 100 g fiber-rich oat-based product (to the habitually diet) daily for 4 week. Following results were observed in the week 4 compared with the beginning of the experiment: higher water intake; slightly decreased total cholesterol in serum; lower pH values in feces; higher concentration of acetate, propionate and butyrate in feces; higher excretion of total bile acids and primary bile acids; lower proportion of secondary bile acids as well as higher concentration of neutral sterols in feces.

In conclusion, application of the dietary fiber-rich oat-based diets had a variety of beneficial physiological and protective effects in rats and human depending on their composition and amount, their technological pre-treatment and their functional properties. The major effects connected whit fermentation of dietary fibre components and their high formation of short-chain fatty acids as well as with higher excretion of steroids.

Este trabalho tem como objetivo o desenvolvimento de um método numérico para simular escoamentos viscoelásticos tridimensionais com superfícies livres governados pelo modelo constitutivo Giesekus. As equações governantes são resolvidas pelo método de diferenças finitas numa malha deslocada. A superfície livre do fluido é modelada por partículas marcadoras, possibilitando assim a visualização e localização da superfície livre do fluido. A equação constitutiva de Giesekus é resolvida utilizando as seguintes formulações: método de Runge-Kutta de segunda ordem (também conhecido como método de Euler modificado) e transformação logarítmica do tensor conformação. O método numérico apresentado é verificado comparando-se os resultados obtidos por meio de refinamento de malha para os escoamentos em um tubo e de um jato incidindo em uma placa plana. Resultados de convergência foram obtidos por meio de refinamento de malha do escoamento totalmente desenvolvido em um tubo. Os resultados numéricos obtidos incluem a simulação de um jato incidindo em uma caixa vazia e a simulação do inchamento do extrudado (dieswell) para vários números de Weissenberg utilizando diferentes valores do fator de mobilidade do fluido. Resultados adicionais incluem simulações do fenômeno delayed dieswell para altos números de Weissenberg e altos valores do número de Reynolds. Uma comparação qualitativa com resultados experimentais é apresentada.
In this work, a numerical method for simulating viscoelastic free surface flows governed by the Giesekus constitutive equation is developed. The governing equations are solved by the finite difference method on a staggered grid. The fluid free surface is approximated by marker particles which enables the visualization and location of the free surface fluid. The Giesekus constitutive equation is solved by the following techniques: second-order Runge-Kutta, conformation tensor and logarithmic transformation of the conformation tensor. The numerical method is verified by comparing the numerical solutions obtained on a series of embedding meshes of the flow in a tube and by the flow produced by a jet flowing onto a planar surface. Additional verification and convergence results are obtained by solving tube flow employing several meshes. Results obtained include the simulation of a jet flowing into a three dimensional container and the simulation of extrudate swell using several values of the Reynolds and Weissenberg numbers and different values of the mobility parameter a. Furthermore, we present results from the simulation of the phenomenon know as delayed dieswell using highWeissenberg and Reynolds numbers. Comparisons with experimental results are given.

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Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES
The extrusion technology enables energy-efficient, with minimal waste and continuously, the processing of cereals. This technology has been used to generate low nutritional and caloric value products, low in dietary fiber, high fat and sugars. The use of raw materials based on whole grain rice, maize and sorghum for the production of products ready for consumption, besides being an excellent source of fiber, it is a good alternative for patients celiac and / or gluten restriction. The objective of this work was to study the effect of the mixture of whole grains (rice, maize and sorghum), submitted to the thermoplastic extrusion process. These mixtures were processed on a single screw lab extruder in the following conditions, which were held constant: Moisture mixtures of 14%, screw rotational speed of 200 rpm, tempera-ture of the heating zones of the extruder (feeding zone until the output of the matrix): 1st Zone - 50 ? C, 2nd - and 3rd 100 - 130, the vertical feeder screw rotation of 15 rpm at (-5 kg / hr). As experimental design, various fractions of whole grain flours were used (corn, rice, sor-ghum). Treatment 1 (T1) consisted of 70% corn; 15% rice, and 15% sorghum; T2: (15%; 70%; 15%); T3: (15%; 15%; 70%); T4: (42.5%; 42.5%; 15%); T5: (42.5%; 15%; 42.5%); T6: (15%; 42.5%; 42.5%); T10: (33.3%; 33.3%; 33.3%); T7 and T10 central points. The whole grain flour for each of the cereals were analyzed for their proximate composition and particle size distribution. The response variables during the extrusion process were: feed rate of mix-tures and specific mechanical energy (EME); bulk density; Expansion indices (radial, longitu-dinal and volume); characterization by images; instrumental texture; paste viscosity; absorp-tion index (WAI) and water solubility (ISA). Variations between treatments were mainly at-tributed to their composition, in particular the dietary fiber content of each sample. It was ob-served that increasing fiber content in the mixture led to the reduction in radial expansion of extruded, as expected. Mixtures with more brown rice content (T2 and T4 treatments) were those who had higher radial expansion, which was attributed to lower this fiber content in rice flour, as expected. The best result was shown EME the treatment with higher corn meal con-tent and sorghum (T5). The instrumental texture analysis also highlighted the crispness (high-er Nsr) treatments more rice portion (T2 and T4). Treatment with higher fraction of corn (T1), achieved the highest paste viscosity. But the T2 treatment, also pointed to present low value for ISA. The treatment of central point (T8) has the greatest value. It could be obtained from mixtures of T2 and T4, more crispness product, expansion and better distribution of the inter-nal air cells; It is therefore recommended treatment for producing extruded.
A tecnologia de extrus?o permite com efici?ncia energ?tica, com m?nima de res?duos e, de forma cont?nua, o processamento de cereais. Este tecnologia tem sido usada para gerar produtos de baixo valor nutricional e cal?ricos, com baixo teor de fibra alimentar, altos teores de gorduras e a??cares. A utiliza??o de mat?rias primas ? base de gr?os integrais de arroz, milho e sorgo, para a elabora??o de produtos para pronto consumo, al?m de ser excelente fonte de fibras, se faz uma boa alternativa para doentes cel?acos e/ou com restri??o a gl?ten. O objetivo deste trabalho foi estudar o efeito da mistura dos cereais integrais (arroz, milho e sorgo), submetidos ao processo de extrus?o termopl?stica. Tais misturas foram processadas em um extrusor de laborat?rio de rosca simples nas seguintes condi??es, as quais foram mantidas constantes: umidade das misturas a 14%, velocidade de rota??o do parafuso a 200 rpm, temperatura das zonas de aquecimento do extrusor (da zona de alimenta??o at? a sa?da da matriz): 1? zona ? 50?C, 2? - 100 e 3? - 130, alimentador vertical helicoidal na rota??o de 15 rpm (~5 kg/h). Como delineamento experimental, foram utilizadas fra??es variadas das farinhas dos cereais integrais (milho, arroz, sorgo). O Tratamento 1 (T1) foi composto de 70% de milho; 15% de arroz e 15% de sorgo; T2: (15%; 70%; 15%); T3: (15%; 15%; 70%); T4: (42,5%; 42,5%; 15%); T5: (42,5%; 15%; 42,5%); T6: (15%; 42,5%; 42,5%); T10: (33,3%; 33,3%; 33,3%); sendo T7 a T10 pontos centrais. As farinhas integrais de cada um dos cereais foram analisadas quanto a sua composi??o centesimal e distribui??o granulom?trica. As vari?veis respostas durante o processamento de extrus?o foram: vaz?o de alimenta??o das misturas e energia mec?nica espec?fica (EME); densidade aparente; ?ndices de expans?o (radial, longitudinal e volum?trico); caracteriza??o por imagens; textura instrumental; viscosidade de pasta; ?ndices de absor??o (IAA) e solubilidade em ?gua (ISA). As varia??es entre os tratamentos foram principalmente atribu?das ? composi??o centesimal, em particular, o teor de fibra alimentar de cada amostra. Observou-se que o aumento do teor de fibra na mistura, levou ? redu??o da expans?o radial dos extrudados, como esperado. As misturas com maior teor de arroz integral (Tratamentos T2 e T4) foram aquelas que apresentaram maior expans?o radial, o que foi atribu?do ao menor teor de fibra presente na farinha de arroz, como esperado. O maior resultado de EME foi evidenciado no tratamento com maior teor de farinha de milho e de sorgo (T5). A an?lise de textura instrumental tamb?m destacou a croc?ncia (maior Nsr) dos tratamentos com maior por??o de arroz (T2 e T4). O tratamento com maior fra??o de milho (T1), alcan?ou a maior viscosidade de pasta. J? o tratamento T2, se destacou tamb?m por apresentar baixo valor para ISA. O tratamento do ponto central (T8) foi o de maior valor. Foi poss?vel obter a partir das misturas dos tratamentos T2 e T4, produtos de maior croc?ncia, expans?o e melhor distribui??o interna das c?lulas ar; sendo, portanto, os tratamentos recomendados para produ??o de extrudados.

Les systèmes à base de biopolymères à faible teneur en humidité sont couramment rencontrés dans les aliments. Bien entendu, il est primordial de comprendre les bases physiques de leur qualité: texture, performances dans le temps ou en fonction de leur composition. Le vieillissement physique des systèmes composites rend les changements survenant dans le stockage des produits comestibles difficiles à prévoir. Les objectifs de ce travail étaient d'évaluer l'incidence de la présence de saccharose et de la teneur en eau de fabrication sur les propriétés physico-chimiques du produit fini. La stabilité physique de ces matériaux a été contrôlée grâce à une étude à différentes échelles moléculaires. Ensuite, les relations entre les données multi-échelles ont été examinées. L'effet du saccharose (0 à 20%) et de l'eau d'alimentation (10 et 15%) sur les mélanges d'extrusion a été étudié à l'aide d'un extrudeur double vis conduit dans les mêmes conditions. Les propriétés physiques et microstructurales des produits extrudés expansés ont été examinées sous diverses conditions d'humidité relative. La réduction des teneurs en sucre et en eau d’alimentation a fait augmenter la pression et l’énergie mécanique spécifique, ce qui a réduit la dégradation de l’amidon et augmenté la viscosité dans l’extrudeur en particulier à la teneur en eau la plus élevée. L'augmentation de la pression dans l’extrudeur a entraîné une expansion plus importante des extrudés. Par contre, la technique d'imagerie neutronique montré que le saccharose réduisait la taille des pores, et donc augmentait la densité apparente et ce qui était particulièrement évident en utilisant. Cette technique a été appliquée pour la première fois sur des produits extrudés. Les images de tomographie 2D ont indiqué des différences structurelles internes entre les extrudés à différentes teneurs en saccharose et stockés à humidité relative différente. Toutefois, l'analyse d'images 3D a montré que l'impact de ces facteurs sur la distribution de la taille des pores et le taux de porosité n'était pas significatif. En fin d'extrusion, les échantillons étaient à l'état amorphe à la suite de la gélatinisation de l'amidon et de la fonte du sucre. Leursrs propriétés thermiques ont été analysées par analyse enthalpique différentielle (AED) et les températures e transition vitreuse ont été étudiées. Les thermogrammess d’AED ont été minutieusement étudiés via une déconvolution de la dérivée première de la variation d’enthalpie. Cette approche a mis en évidence que les systèmes composites étudiés présentaient des phases multiples avec des transitions vitreuses distinctes. Ces dernières sont associées à une phase riche en polymère (amidon principalement) et / ou à une phase riche en plastifiant (sucre) dont le comportement dépendait de la teneur en eau de l'échantillon. Les isothermes de sorption ont montré qu’aux faibles Aw et pour une valeur donnée, a la teneur en eau des extrudés diminuait avec l’augmentation des teneurs en saccharose et que l'effet inverse était observé aux aw élevées. L’étude de la cinétique apparente de lala diffusion de l'eau a mis en évidence deux sites de sorption différents. Le premier est caractérisé par une cinétique quasi constante qui pourrait correspondre à un phénomène d'adsorption à la surface. Le second site présente d’abord un ralentissement initial de la cinétique de sorption, tandis qu’une forte augmentation est constatée lorsque la teneur en eau était plus élevée. Ce comportement peut être lié à un effondrement de la structure. Une étude par RMN à cyclage de champ rapide à basse fréquence a montré que les temps de relaxation dépendaient de la teneur en saccharose et en eau. Une carte de stabilité a été tracée pour modéliser les évolutions rhéologiques des matrices avec la teneur en eau en lien avec les transitions de phases des matériaux (...)
Low-moisture biopolymer-based systems are commonly encountered in food. Obviously, understanding the physical basis of their quality: e.g texture, or performance over time or as a function of their composition is of primary importance. The objectives of this work were to evaluate how the presence of sucrose and water content affects physico-chemical properties. The physical stability of these materials were monitored through an insight at different molecular scales. Then the relations between the multi-scale studies were investigated. The effect of sucrose (0–20%) and feed water (10 and 15%) on extrusion blends was studied using a twin screw extruder under the same processing settings. The physical and microstructural properties of extruded products were examined at various RH. Reducing both sugar levels and feed water increased die pressure and specific mechanical energy, as a consequence, it reduced starch degradation and increased in viscosity. The effect was more pronounced with increasing feed water content. The increased die pressure resulted in higher expansion of the porous extrudates. Sucrose was shown to increase the bulk density and reduce the pore size, this was particularly evident by using neutron imaging technique. This technique was applied for the first time in extrudate. 2D tomography images indicated internal structural differences between extrudates containing different sucrose content and stored at low and high % RH, while 3D image analysis showed impact of these factors on pore size distribution and % porosity were not significant. The extruded samples were in the amorphous state as a result of starch gelatinization and sugar melting. Their thermal properties were analyzed with DSC and their Tg were studied. The DSC thermograms were thoroughly studied through a Gaussian deconvolution of the first derivative of their heat low. This approach evidenced a multiple phase behavior with different glass transitions in composite systems. They were associated with either a polymer-rich phase and/or a plasticizer-rich phase which behavior depended on the sample water content. Physical aging accompanied with an increase in rigidity at low aw, resulted in an increased bulk density and more pronounced with increasing sucrose content. Sorption isotherms showed the water content of extrudates decreased when product contains high sucrose at low aw range and the inverse effect was observed at high aw. Apparent kinetics of water diffusion showed two different sorption sites, the first kinetics was almost constant and could be adsorption phenomena at the surface. The second one reflected first an initial slowing in dynamics whereas a sharp increase was found at higher water content. Addition of sucrose or water decreased both Tgs in extrudates. Young's modulus showed water acts as anti-plasticizer at low aw, while it shows a plasticizing effect at high aw. A stability map can explain the brittle-ductile transition occurred below Tg. Fast field cycling NMR study at low frequency highlighted that T1 depended on sucrose and water content. T1 and T2 measured using Low field NMR decrease as a function of water content, while the impact pf sucrose were not significant. T2 showing a minimum probably indicating the exchange of protons of water and macromolecules in composite system. The impact of sucrose content was not significant for T1 and for T2 at low water content. FFC NMR showed T1 results consistent with the LF NMR measurement.In conclusion, physicochemical studies of the influence of water and sucrose content on glassy materials showed that the material properties can be investigated at different levels from the macro- to the microscopic scale and these results clearly presented the need for complementary techniques to probe the dynamics in the glassy state of heterogeneous food systems that could be facilitated to manage the stability during storage of this type of dry products

Introdução: A doença celíaca não tem cura e apresenta como único tratamento a dieta isenta de glúten. Frequentemente observa-se a má absorção de cálcio em celíacos, consequência dos menores níveis de transportadores de cálcio no enterócito desses indivíduos. Os celíacos têm dificuldade em dar sequência ao tratamento dietético devido à escassez de produtos isentos de glúten, tornando fundamental o desenvolvimento de produtos para esta população. Isso pode ser feito por meio do uso de matérias primas isentas de glúten e com valor nutritivo agregado, como o grão de amaranto, e de ingredientes que contribuem para o aumento da absorção de cálcio através de absorção passiva nos colonócitos, como os frutanos inulina e oligofrutose. Objetivo: Desenvolver e otimizar as propriedades nutricionais e sensoriais de produtos à base de amaranto enriquecidos com frutanos, para intervenção nutricional em celíacos. Metodologia: Foram elaborados snacks à base de milho e amaranto (50, 75 e 100%), barras e pães sem glúten, enriquecidos com 4 gramas de frutanos/ porção. Para maximizar a aceitabilidade das barras foi utilizado um planejamento experimental para misturas de amaranto extrusado, estourado e laminado. Para maximizar o valor nutritrivo e a aceitabilidade do pão sem glúten foi utilizado o planejamento experimental para misturas de farinha de arroz, fécula de batata e farinha de amaranto. Os produtos foram caracterizados quanto a composição centesimal, o índice glicêmico (IG) e a carga glicêmica (CG). Também foram avaliadas as propriedades físicas e a aceitabilidade (escala hedônica estruturada de nove pontos) durante o período de armazenamento. Resultados e discussão: Os snacks foram aceitos e apresentaram estabilidade de suas características físicas e da aceitabilidade durante os 135 dias de armazenamento. O efeito combinado do amaranto e dos frutanos gerou redução de 19% do IG e de 56% da CG dos snacks. O amaranto estourado e laminado apresentaram interações sinérgicas para a aceitabilidade das barras (R2(aj)>92%, p=0,00). A formulação à base de amaranto estourado e laminado (½,½) foi diversificada em seis diferentes sabores e apresentou estabilidade de suas propriedades físicas e da aceitabilidade durante os seis meses de armazenamento. A estimativa da resposta glicêmica revelou IG moderado e CG baixa das barras. Pães com 33 e 45% de farinha de amaranto apresentaram destacado valor nutritivo e aceitabilidade. A incorporação de amaranto e de frutanos ocasionou redução de 20% do IG e de até 53% da CG do pão sem glúten. Conclusão: Os produtos desenvolvidos (snacks, barras e pães sem glúten) apresentaram destacado valor nutritivo em relação aos produtos convencionais, atenuação da resposta glicêmica e alta aceitabilidade pelo consumidor, podendo contribuir para uma maior variação e adequação da dieta dos celíacos e também para auxiliar no aumento da absorção de cálcio
Introduction: Celiac disease does not have a cure and the only scientifically proven treatment is strict lifelong adherence to a gluten-free diet. Calcium malabsorption is frequently found in celiac, possibly due to negligible amounts of calcium-binding protein in their enterocytes. Compliance with dietary treatment is often difficult due to the lack of gluten-free products, so it is essential to develop specific products for this population. This can be done through the use of gluten-free raw materials of great nutritional value, such as amaranth grain, and ingredients that contribute to the calcium absorption increasement through passive absorption in colonocytes, such as the fructans inulin and oligofructose. Objective: Develop and optimize the nutritional and sensory properties of amaranth based products enriched with fructans, for nutritional intervention in celiac. Methods: Snacks from blends of corn and amaranth (50, 75 and 100%), amaranth bars and gluten-free bread, all enriched with 4 grams of fructans/ portion, were prepared. A mixture experiment of extruded, popped and flaked amaranth was used to optimize the sensory acceptability of the bars. A mixture experiment of rice flour, potato starch and amaranth flour was used to maximize the nutritional value and sensory acceptability of gluten-free bread. Products chemical composition, glycemic index (GI) and glycemic load (GL), were evaluated. The physical properties and sensory acceptability (nine point hedonic scale) were assessed during the storage time. Results and discussion: Snacks were sensory accepted and maintained their physical characteristics and sensory acceptability during the 135 days of storage. The combined effect of amaranth and fructans resulted in 19% reduction of GI and 56% of GL of snacks. Popped and flaked amaranth present synergistic interactions to sensory acceptability of the bars (R2(adj)>92%, p=0,00). Bars were produced with popped and flaked amaranth (½,½) in six different flavors and its physical properties and sensory acceptability were stable during the six months of storage. The predicted glycemic response showed moderate GI and low GL bars. Breads with 33 and 45% of amaranth flour had higher nutritional value and sensory acceptability. Amaranth and fructans addition led to a reduction of approximately 20% of GI and up to 53% of the GL of gluten-free breads. Conclusion: The developed products (snacks, bars and gluten-free breads) had superior nutritional composition than conventional products, reduced glycemic response, high consumer sensory acceptability, great potential to contribute to variation and adequacy of celiac diet and also help to increase calcium absorption.

Trabalho Final de Mestrado Integrado, Ciências Farmacêuticas, Universidade de Lisboa, Faculdade de Farmácia, 2014
The hot-melt extrusion (HME) technology has recently demonstrated to have great potentials for the production of pharmaceutical dosage forms that may also allow for a new design of the well-established process development and for the introduction of continuous manufacturing process of dosage forms. The present work is dedicated to the study of HME for the production of extrudates with different types of hydroxypropylcellulose (LF, GF and MF) and the evaluation of the differences between each polymer through the release of paracetamol, used as the model drug. The influence of the extent of the surface area on the drug release was rated using extrudates prepared with HPC GF. Extrusion was carried out with a counter-rotating twin screw extruder at different temperatures for each type of HPC, maintaining the same processing conditions. Then, all the extrudates obtained were characterized by visual characterization, API content, differential scanning calorimetry (DSC) and release test. In order to select the processing conditions for the extrusion process, preliminary data were collected using placebo formulations. The use of HPC LF required the lowest processing temperature (130ºC) and HPC MF required the highest (150ºC), which is coherent with the increase in the molecular weight of the polymer, directly related to the melt viscosity of the celluloses ethers. When paracetamol was introduced in the formulation the extrusion process was easier, probably due to a plasticization effect of the API on the molten mass. The API content showed a decrease of paracetamol in all the extrudates; however, all of them were homogeneous. The release tests showed, as expected, a faster release of the drug from extrudates containing HPC LF and a slower release from those containing HPC GF or MF. For preparing controlled drug release systems, HPC GF and MF would be recommended. In a second stage of the work, a study on the influence of the surface area on the drug release was achieved. Only HPC GF was used and the extrudates had different diameters and lengths. The API content showed a more pronounced decrease of paracetamol on the extrudates with 2 mm diameter. As expected, the extrudates with bigger total surface area released the drug faster than the others.
A extrusão por fusão (HME), utilizada na produção de formas farmacêuticas, tem mostrado ter um grande potencial no desenvolvimento de novas concepções dessas mesmas formas farmacêuticas. Este trabalho teve como objectivo produzir extrudidos através de HME, utilizando diferentes tipos de hidroxipropilcelulose (LF, GF E MF), e avaliar as diferenças entre elas através da libertação de paracetamol, usado como fármaco modelo. Foi também avaliada a influência da área de superfície na libertação do fármaco, utilizando extrudidos com HPC GF como excipiente. A extrusão realizou-se recorrendo a um extrusor equipado com dois parafusos contra-rotativos, a diferentes temperaturas para cada HPC, mantendo as mesmas condições de processo. Posteriormente, todos os extrudidos foram caracterizados visualmente bem como através de ensaios de doseamento do fármaco, calorimetria diferencial de varrimento (DSC) e ensaios de dissolução. De modo a seleccionar as condições de processo ideais para o processo de extrusão, inicialmente utilizou-se apenas formulações placebo. Verificou-se que a HPC LF necessitou de uma menor temperatura para ser extrudida (130ºC), ao contrário da HPC MF que necessitou de uma maior temperatura (150ºC); o que nos permite verificar que um aumento na massa molecular do polímero está directamente relacionado com um aumento na temperatura de viscosidade destas celuloses. Todos os extrudidos que continham paracetamol na formulação foram mais facilmente extrudidos que aqueles que continham apenas a HPC, provavelmente devido ao efeito plasticizante do API na massa fundida. O doseamento do fármaco mostrou uma diminuição na percentagem de paracetamol em todos os extrudidos, no entanto, todos eles eram homogéneos. Por último, o ensaio de dissolução ocorreu de acordo com o esperado, tendo sido verificada uma rápida libertação do fármaco com os extrudidos que continham HPC LF e uma libertação mais lenta com os extrudidos que continham HPC GF ou MF. Assim, para uma libertação mais controlada do fármaco, a utilização das HPCs GF ou MF será a mais indicada. Numa segunda parte do trabalho, foi avaliada a influência da área de superfície na libertação do fármaco, recorrendo a um ensaio de dissolução. Apenas se utilizou a HPC GF e os extrudidos foram produzidos com diferentes diâmetros e tamanhos. O ensaio de doseamento do fármaco mostrou que os extrudidos com 2 mm de diâmetro apresentam uma diminuição da quantidade de paracetamol mais acentuada. Após realizar o ensaio de dissolução verificou-se que os extrudidos com maior área total de superfície libertam o fármaco mais rapidamente que os restantes.
University of Milan, Faculty of Pharmacy, Department of Pharmaceutical Sciences.

碩士
國立中興大學
農業機械工程學系
82
Rice flour was used to study the effects of process variables on physical properties in single-screw extrusionystem.The response surface methodology with rotable design was introduced in this research.The process variables were barrel temperature, screw speed , and additives, and five levels were designed for each variable.The physcial properties of extrudatesuch as moisture content, specific volume,shear force ,expansion ratio and color changes were investigated. Experimental results showed that: (1) The moisture content of extrudates increased with increasing its sugar content,but decreased with increasing its salt content. (2) The specific volume of extrudates was maximum at theonditions of screw speed at 560 rpm and 1% salt content ,or 120℃ barrel temperature and 2% salt content. (3) The expansion ratio increased with increasing barrelemperature and screw speed.The maximum expansion ratio occurred at 320 rpm screw speed with both 3% sugar and 2% salt content. (4) The minimum whiteness index and maximum color difference and b-value occurred at 320 rpm screw speed and 2% salt content.

博士
國立臺灣大學
食品科技研究所
89
This study was to investigate the expansion behavior of rice pellets. To understand the role of amylose content, three different flours (TS10, TG9, TSG1)and reconstituted flour from TS10 and TSG1 were used to prepare pellet by single screw extrusion at 50% feeding moisture. The Tg and Te of pellets were determined using DSC and non-contact infrared thermometer, respectively. The results showed that amylose content did not significantly affect Tg and Te. But the increase in amylose content results in the decrease in both transparency and expansion ratio. The pellet exhibited maximum expansion ratio at equilibrium moisture of 10%. Addition of dextrin resulted in the decrease in intrinsic viscosity, Tg and Te. The addition of dextrin and increase in feeding moisture resulted in more transparent pellet with higher expansion ratio. The data illustrated that the transparency can be an index of quality control. Te increased linearly (r2=0.95) with Tg, which appeared to be a good reference temperature for studying expansion behavior. Te was about 20~100℃ higher than Tg. The expansion appeared to occur at rubbery state. The Tg of binary-mixture pellet (rice flour, water) can be estimated by using Gordon-Taylor equation. The method to estimate Tg for ternary-mixture pellet ( rice flour, dextrin, water) has also been discussed. Heating method affected the temperature rising rate and water loss rate, which were important factors affecting the expansion of pellet. High temperature rising rate softened the pellet that can be expanded by the pressure exerted by water vapor. Low temperature rising was not able to generate flexible material resulted in burned out of the pellet. The established of phase diagram would be helpful to understand the roles of Tg, Te and heating method on expansion of pellet.

Trabalho Final de Mestrado Integrado, Ciências Farmacêuticas, Universidade de Lisboa, Faculdade de Farmácia, 2014
Originally used in plastic industry, the Hot-Melt Extrusion (HME) technique has received considerable attention by pharmaceutical industries in the last years. The main goal of this project was the production of extrudates by HME, using hydroxypropylcellulose (HPC) as a carrier polymer. To the base polymer it was added other excipients – PEG 8000, HPMC K4M, Eudragit E PO, sodium bicarbonate and sorbitol – in order to observe some changes during the extrusion process and in the release of paracetamol, the model drug. After extrudates production, visual characterization and characterization tests were performed like dissolution, rheological and mechanical tests, differential scanning calorimetry (DSC) and API content assay. The extrusion was performed in a counter-rotating twin-screw extruder. For each formulation it was tested different conditions and different percentages of excipient to yield the best extrudates. During the characterization, all samples showed a lower content of paracetamol comparing to the theorical value (20%). All the dissolution profiles revealed a sustained and complete release of paracetamol and the DSC studies showed some samples with characteristics peaks. Both mechanical and rheological tests led to inconsistent results and further research should be done in this field.
Inicialmente utilizada na produção de plástico, a extrusão por fusão ou Hot-Melt Extrusion (HME) tem, nos últimos anos, recebido especial atenção pela indústria farmacêutica. O estudo realizado teve como objectivo a produção de extrudidos por HME, utilizando como polímero base a hidroxipropilcelulose (HPC). A este foram adicionados outros excipientes - PEG 8000, HPMC K4M, Eudragit E PO, bicarbonato de sódio e sorbitol – com o intuito de observar as alterações provocadas durante a extrusão e na libertação do paracetamol, fármaco usado como modelo. Depois de produzidos, todos os extrudidos foram caracterizados visualmente e através de ensaios de dissolução, testes reológicos e mecânicos, calorimetria diferencial de varrimento (DSC) e conteúdo em API. O processo de extrusão foi realizado num extrusor com dois parafusos contra-rotativos. Para cada formulação foram testadas diferentes condições de extrusão, assim como diferentes percentagens de excipiente até serem obtidos os extrudidos com melhores características. Durante a caracterização, observou-se um conteúdo em paracetamol inferior ao valor teórico (20%) em todas as amostras. Os perfis de dissolução revelaram um prolongamento da libertação do fármaco e no estudo de DSC algumas amostras apresentaram picos característicos. Tanto os testes reológicos como os mecânicos levaram a resultados inconsistentes, sendo necessária mais investigação nesta área.

碩士
國立中興大學
農業機械工程學系
84
Feed corn was used as the raw material to study the effects of process parameters on extrudates residence time distributions, physical and chemical properties by using a single-screw extruder. The process parameters were barrel temperature, screw speed and feed rate. The physical and chemical properties were moisture content, cross-sectional expansion ratio, longitudinal expansion ratio, bulk density, shear force, whiteness index, saturation index, water solubility index, water absorption index, degree of gelatinization, starch digestibility, and browning reaction. The experiment was a 3×3×3 factorial design. Results indicated that : 1. Barrel temperature, screw speed and feed rate were influential in mean residence time. Mean residence time was significantly affected by the feed rate. Decreasing of the feed rate raised the mean residence time. 2. The changing of barrel temperature had the greatest effect on extrudates physical and chemical properties. The feed rate was the second important factor affecting the extrudates physical and chemical properties. The screw speed only provided the negative correlation with the extrudates saturation index. 3. The optimum operating conditions for the feed corn by using the single-screw extruder were 80℃-80℃-80℃ barrel temperature, 73.3rpm screw speed, and 15.53kg／h feed rate.