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Enrione, Javier. "Mechanical stability of intermediate moisture starch-glycerol systems." Thesis, University of Nottingham, 2005. http://eprints.nottingham.ac.uk/11634/.
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There is conflicting information on the mechanical properties and ageing kinetics of starch-water-glycerol systems. This makes understanding the changes occurring on storage of edible products difficult to predict. The work described in this thesis looks at model systems consisting of thermomechanically extruded plasticized starches (waxy maize, rice and wheat) and commercial products. The objectives of the work were to evaluate how the presence of polyols effects glass transition temperature (Tg), sorption isotherms, diffusion rates and texture parameters and to create models that could be used to predict behaviour. Very similar results were obtained for the starch samples except that monolayer (ma) values were higher for the waxy maize starch than for the wheat and rice. The waxy maize also was more brittle at equivalent moisture content when compared to the other two starches. Glycerol had a major impact on the water absorption. For RHs > 70% more water absorbed up by samples containing glycerol while the opposite occurred at RHs <60%. Monolayer values for GAB and BET confirmed this finding. The behaviour could be predicted if an interaction factor <1 was used in weight fraction models. Tg of the samples was measured by DSC and also by using predictive models, where the ten-Brinke Karas equation was found to give the best predictions. A value that was found to be most beneficial for the prediction of retrogradation was (storage temperature minus Tg). Change in texture was associate with (T-Tg), although the brittle ductile transition occurred 40°C below T-Tg=O. Diffusivity values increased with plasticizer level up to 8*10 3 m'z/s. There was an apparent fall in values when the samples were above Tg. However, it is suggested that this is due to sample geometry change rather than a change in diffusion mechanism. The Tg values also were found to be a good predictor of the type of change occurring in the model systems and food products during storage. Below Tg physical aging (enthalpy relaxtion) could be seen in the samples and retrogradation of the starch occurred above Tg. The rates of retrogradation were not affected by glycerol content directly and knowledge of Tg and storage temperature were sufficient to predict the retrogradation. Products became stiffer on storage and this was associated with molecular reassociation of the starchy component, but control of the moisture was also critical as water still dominated product behaviour even in the presence of glycerol.
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Al-Muhtaseb, Ala'A. "Moisture sorption isotherms and drying characteristics of starch materials." Thesis, Queen's University Belfast, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.403272.
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Zondag, Meredith Dara. "Effect of microwave heat-moisture and annealing treatments on buckwheat starch characteristics." Online version, 2003. http://www.uwstout.edu/lib/thesis/2003/2003zondagm.pdf.
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Ellingson, Jordan M. "Starch Resin Moisture Level Effect on Injection Molding Processability and Molded Part Mechanical Properties with Pure Starch Resin and Polymer Blends." BYU ScholarsArchive, 2013. https://scholarsarchive.byu.edu/etd/3782.
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The current and forecasted global consumption of plastic packaging and products through the 21st century combined with the already reported and growing negative impact of plastics on the environment due to plastics being synthesized from nonrenewable resources that do not biodegrade is of serious concern. However, recent advances in starch technology including the development of thermoplastic starch (TPS) materials —polymers that are both renewable and biodegradable—have brought hope to reducing this impact. The mechanical properties of thermoplastic starch have often been improved by blending with synthetic polymers. One issue that arises with blending is volatilization of the melt from moisture in the TPS materials. Ecostarch™ a proprietary, pelletized thermoplastic starch resin formulated from potato starch, was processed and tested to observe injection molding processability at various moisture levels, in pure TPS as well as various blend ratios with high-density polyethylene (HDPE) and polypropylene (PP). This study evaluated and analyzed the effects of the TPS pellet moisture content on void formation in the plastic pre-injection melt and subsequent molded part mechanical properties. Statistical analysis of the test results showed that moisture had a significant effect on void formation in the plastic melt. In TPS/HDPE blends, voids percent (as measured by cross section area) increased by 300-350% from 0.6% to 1.4% moisture levels. In unblended TPS, void percent increased by 150% from 0.4% to 1.4% moisture levels. In the unblended TPS parts, impact strength (energy in ft-lb) was decreased by 1% from 0.6% to 1.4% moisture level. In the TPS/HDPE and TPS/PP blends, there was no significant effect on impact strength due to the moisture percent levels of the TPS. Modulus decreased by 25% from 0.4% to 1.4% moisture level in unblended TPS parts. From 0.6% to 1.4% change in TPS moisture content, the modulus of the TPS/HDPE blend decreased by 9% at a 30% TPS/70% HDPE blend and decreased by 14% at a 70% TPS/30% HDPE blend. Though the moisture of TPS did not have a significant impact on the tensile strength of TPS/HDPE blends, the tensile strength of TPS/PP blend samples were significantly affected: a change from 0.6% to 1.4% moisture increased tensile strength 34% at a 70% TPS/30% PP blend and increased tensile strength by 22% at a 30% TPS/70% PP blend. Thus the results of this study highlight the relationships between moisture, voids, and mechanical performance of TPS and TPS/Polymer blends.
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Vu, Thanh Hien Thi. "Preparation, characterization, and evaluation of sorghum flour with increased resistant starch content." Thesis, Kansas State University, 2014. http://hdl.handle.net/2097/32171.
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Master of ScienceDepartment of Grain Science and Industry
Yong-Cheng Shi
Sorghum flour is a gluten-free ingredient and can be used to prepare foods for celiac patients. In addition, sorghum flour is a good source of fiber in the form of resistant starch. The objectives of this research were to develop an effective process to increase resistant starch content of sorghum flour and investigate the effects of sorghum protein matrix on starch digestibility. Samples of white sorghum flour (28.9% amylose content) with different moisture contents (0%, 12.5%, 20%, and 30%) were treated at different temperatures (100, 120, and 140 [degrees]C) for different times (1, 2, and 4 h). Samples after heat treatments were tested for starch digestibility, protein digestibility, differential scanning calorimetry (DSC), size-exclusion chromatography (SEC), and X-ray diffraction. The sample treated with 20% moisture at 100[degrees]C for 4 h had high resistant starch (RS) content (22.1% compared with 5.6% of the native sample) and low protein digestibility (8.4% compared with 68.3% of the native sample). The same heat-moisture treatment on isolated sorghum starch showed no significant change in RS content. DSC showed a very low degree of gelatinization for samples treated at moisture contents 20% and below. X-ray diffraction also suggested minimal change in starch crystallinity after heat treatment at low moisture contents (20% and below). Sorghum protein solubility after heat treatment was reduced, suggesting that protein structure was altered during the heat treatments. In conclusion, heat-moisture treatments were successful in increasing resistant starch content of sorghum flour by altering sorghum protein without gelatinizing the starch to retain starch functionality in food product applications. Sorghum flour with increased resistant starch content after heat treatment was evaluated and compared with normal sorghum flour for starch digestibility using the Integrated Total Dietary Fiber method, and for food applications in tortillas.
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Perera, Chandani. "Effect of hydroxypropylation on the structure and physicochemical properties of native, defatted and heat-moisture treated potato starches." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ36211.pdf.
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Szegda, Damian. "Experimental investigation and computational modelling of the thermoforming process of thermoplastic starch." Thesis, Brunel University, 2009. http://bura.brunel.ac.uk/handle/2438/3445.
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Plastic packaging waste currently forms a significant part of municipal solid waste and as such is causing increasing environmental concerns. Such packaging is largely non-biodegradable and is particularly difficult to recycle or to reuse due largely to its complex compositions. Apart from limited recycling of some easily identifiable packaging wastes that can be separated economically, such as bottles, most packaging waste ends up in landfill sites. In recent years, in an attempt to address this problem in plastic packaging, the development of packaging materials from renewable plant resources has received increasing attention and a wide range of bioplastic materials based on starch are now available. Environmentally these bioplastic materials also reduce reliance on oil resources and have the advantage that they are biodegradable and can be composted upon disposal to reduce the environmental impact. Many food packaging containers are produced by thermoforming processes in which thin sheets are inflated under pressure into moulds to produce the required thin -wall structures. Hitherto these thin sheets have almost exclusively been made of oilbased polymers and it is for these that computational models of thermoforming processes have been developed. Recently, in the context of bioplastics, commercial thermoplastic starch sheet materials have been developed. The behaviour of such materials is influenced both by temperature and, because of the inherent hydrophilic characteristics of the materials, by moisture content. Both of these aspects affect the behaviour of bioplastic sheets during the thermoforming process. This thesis describes experimental work and work on the computational modelling of thermoforming processes for thermoplastic starch sheets using a commercially available material. The experimental work has been carried in order to characterise the deformation behaviour of the material with regard to different temperature, moisture contents and strain rates. Thermoforming of the material was performed and samples produced were used for comparison and verification of the computational modelling of the thermoforming process. In the first attempt to model the thermoforming process, a hyperelastic constitutive equation was established to approximate the material behaviour taking account of the combined effects of temperature and moisture content and a simple ii membrane model with constrained deformation was used to model an axisymmetric case of thermoforming. Simulations with this model showed that moisture content mostly affects the pressure required to push the sheet into the mould while moisture variation during thermoforming has little effect on the final thickness distribution of the product. Considerable discrepancies were found in the thickness distribution between the predictions from the model and the experimental measurements. Further attempts were made to take account of the elasto-plastic behaviour of the material and a more complex three-dimensional FE model was developed using ANSYS/LS-DYNA. Based on the findings in the simpler modelling work, no attempt was made to incorporate the moisture content effect on material behaviour but the material parameters for the elasto-plastic constitutive equation were obtained from high speed tensile tests so that moisture variation during thermoforming could be minimised and neglected. The predictions from this model have led to significant improvements in prediction of the thickness distribution which has become much closer to the experimental measurements in comparison with the hyperelastic model. This work provides some important insights into thermoforming of thermoplastic starch materials: a) Deformation behaviour of such materials depends strongly on the moisture content and the temperature, both of which affect behaviour during thermoforming processes, including the preheating stage; b) moisture variation during the thermoforming process has a significant effect on the pressure required for the deformation. This also leads to variation of moisture content distribution in the final product, which in turn affects the material properties such as ductility or impact strength at different positions in the thermoformed structure; c) thermoforming of thermoplastic starch materials can be simulated more accurately by an elasto-plastic model and the LS-DYNA algorithm in comparison with a hyperelastic membrane model. This work has provided useful information on thermoforming of thermoplastic starch materials with particular reference to the design of thermoforming tools and to the careful control of processing conditions including preheating. It has also laid a solid foundation for future work on how the moisture variation impacts on the formation of defects such as incomplete forming due to material hardening and fracture due to loss of ductility.
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Kumar, Rajesh. "Non-traditional grains in low and high moisture extrusion applications –residence time, physico-chemical properties and resistant starch." Thesis, Kansas State University, 2017. http://hdl.handle.net/2097/38210.
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Master of ScienceDepartment of Grain Science and Industry
Sajid Alavi
Sorghum, millets and teff are important staple crops worldwide, especially in semi-arid regions of Africa and India because of their drought tolerance. However, lack of research and other limitations have restricted their usage in food products. This study is focused on extrusion processing of low and high tannin sorghum varieties, millet and teff for high and low moisture applications, and to investigate process characteristics such as residence time distribution and specific mechanical energy, physico-chemical properties of resultant food products (such as pre-cooked pasta and expanded snacks) and their resistance starch content. Results from preliminary lab scale extrusion, including optimization of starch type and level for pre-cooked pasta and in-barrel moisture for expanded snacks, were used to design pilot-scale studies on a twin-screw extruder. In the first pilot-scale experiment, decorticated white sorghum blends prepared with addition of mono-glycerides (0.5%, 1% and1.5%) and salt (1%) were processed at three different in-barrel moisture contents 40%, 44% and 48% (wet basis) for processing of precooked pasta. The optimum formulation containing 1% mono-glycerides and process conditions corresponding to 48% in-barrel moisture were also used to develop precooked teff and millet pasta. The non-traditional grain based pastas were investigated for cooking quality, thermal characteristics using differential scanning calorimeter, pasting properties using rapid visco analyzer and texture profile analysis. In general, increasing in-barrel moisture led to reduction in solid losses (ranging from 4.0-8.2% for all treatments), indicating improvement in cooking quality. On the other hand, increase in mono-glycerides concertation led to higher cooking losses, and also affected pasting and textural properties significantly. Sorghum-based precooked pasta was of best quality while millet pasta was poorest in cooking quality, visual and textural attributes. Cooking loss for control pre-cooked pasta produced in this experiment using semolina was 4.5%, and commercial semolina pasta was 3.2%. Residence time distribution in pilot-scale twin screw extruder, during high moisture process conditions used for pre-cooked pasta, was also investigated at three different in-barrel moistures (40%, 44% and 48%) and monoglycerides/ lipid (0.5, 1% and 1.5%) concentrations. Increase in in-barrel moisture significantly decreased mean residence time. For example, mean residence time was 4.47 min at 40% moisture, 3.89 min at 44% and 3.74 min at 48%. On the contrary, residence time significantly increased with lipid level. For example, mean residence time was 3.87 min at 0.5% concentration of mono-glycerides, 4.48 min at 1% and 4.70 min 1.5%. In the second experiment focusing on low moisture applications, pilot-scale twin screw extrusion was used to process decorticated white sorghum and high tannin sumac sorghum for expanded snacks. The addition of sumac bran decreased the specific mechanical energy input (366-578 kJ/kg) and expansion ratio (6.4-7.9), and resulted in higher piece density of extrudates. Use of sumac bran and sumac flour led to increase in resistant starch content, although it was less than 1% for all treatments. Therefore, extrusion with ingredients having high tannin content does not provide value, despite tannins being associated with resistant starch at least in raw materials.
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Souza, Carla Giselly de [UNESP]. "Degradabilidade de grãos secos e ensilados de sorgo, com e sem tanino, submetidos à granulometrias." Universidade Estadual Paulista (UNESP), 2009. http://hdl.handle.net/11449/92400.
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Universidade Estadual Paulista (UNESP)
O objetivo desse trabalho foi avaliar o efeito da granulometria (moagem) nos grãos de dois híbridos de sorgo (com e sem tanino), conservados secos ou ensilados úmidos, sobre a degradabilidade in situ da matéria seca (MS) e proteína bruta (PB) em ovinos. Foram utilizados três ovinos adultos, fistulados no rúmen, distribuídos em um delineamento experimental em blocos, com arranjo fatorial de 2 x 2 x 3 , sendo dois híbridos de sorgo (com e sem tanino), duas formas de conservação (seco e ensilado), três granulometrias (inteiro, moído grosso e moído fino), e o tempo como sub parcela. Recomenda-se a moagem dos grãos de sorgo, pois proporciona aumento da degradabilidade ruminal e efetiva da matéria seca, proteína bruta e amido. A presença do tanino no grão de sorgo alterou a degradabilidade potencial da proteína bruta e amido. Pelos resultados inferidos recomenda-se a moagem dos grãos de sorgo, por aumentar a degradabilidade ruminal e efetiva da matéria seca, proteína bruta e amido. O melhor tratamento foi a moagem grossa no grão sem tanino armazenado na forma de grãos secos.
The main research purpose was evaluate the grinding effect on two sorghum genotypes grain with and without tannin, in dry grain or humid silage conservation above the dry matter in situ degradability and crude protein. Three rumen fistulated sheep was used, in a bloc design, in a 2 x 2 x 3 factorial out line, with two sorghum genotypes (with and without tannin), two conservation ways (dry grain and high moisture grains silage) and three grinding ways (role, thick grinding and fine grinding) and time like sub-portion. To sorghum grains is recommended the grinding just because increases the dry matter and crude protein, ruminal and effective degradability. The tannins presence depressed the crude protein effective degradability, in a soft way. The fine grinding became a huge increasing in dry matter degradability rate. In this way the better treatment was the fine grinding without tannin in dry grain. We recommend the grinding, to sorghum grains independent the conservation way or utilized genotype, just because increase the ruminal and effective ruminal degradability. Mainly to without tannin genotype in dry grain way.
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Souza, Carla Giselly de 1980. "Degradabilidade de grãos secos e ensilados de sorgo, com e sem tanino, submetidos à granulometrias /." Botucatu : [s.n.], 2009. http://hdl.handle.net/11449/92400.
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Resumo: O objetivo desse trabalho foi avaliar o efeito da granulometria (moagem) nos grãos de dois híbridos de sorgo (com e sem tanino), conservados secos ou ensilados úmidos, sobre a degradabilidade in situ da matéria seca (MS) e proteína bruta (PB) em ovinos. Foram utilizados três ovinos adultos, fistulados no rúmen, distribuídos em um delineamento experimental em blocos, com arranjo fatorial de 2 x 2 x 3 , sendo dois híbridos de sorgo (com e sem tanino), duas formas de conservação (seco e ensilado), três granulometrias (inteiro, moído grosso e moído fino), e o tempo como sub parcela. Recomenda-se a moagem dos grãos de sorgo, pois proporciona aumento da degradabilidade ruminal e efetiva da matéria seca, proteína bruta e amido. A presença do tanino no grão de sorgo alterou a degradabilidade potencial da proteína bruta e amido. Pelos resultados inferidos recomenda-se a moagem dos grãos de sorgo, por aumentar a degradabilidade ruminal e efetiva da matéria seca, proteína bruta e amido. O melhor tratamento foi a moagem grossa no grão sem tanino armazenado na forma de grãos secos.Abstract: The main research purpose was evaluate the grinding effect on two sorghum genotypes grain with and without tannin, in dry grain or humid silage conservation above the dry matter in situ degradability and crude protein. Three rumen fistulated sheep was used, in a bloc design, in a 2 x 2 x 3 factorial out line, with two sorghum genotypes (with and without tannin), two conservation ways (dry grain and high moisture grains silage) and three grinding ways (role, thick grinding and fine grinding) and time like sub-portion. To sorghum grains is recommended the grinding just because increases the dry matter and crude protein, ruminal and effective degradability. The tannins presence depressed the crude protein effective degradability, in a soft way. The fine grinding became a huge increasing in dry matter degradability rate. In this way the better treatment was the fine grinding without tannin in dry grain. We recommend the grinding, to sorghum grains independent the conservation way or utilized genotype, just because increase the ruminal and effective ruminal degradability. Mainly to without tannin genotype in dry grain way.
Orientador: Jozivaldo Prudêncio Gomes de Morais
Coorientador: Ciniro Costa
Coorientador: Wagner dos Reis
Banca: Paulo Roberto de Lima Meireles
Banca: Luciana Thie Seki
Mestre
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Lopes, Ana Beatriz Rocha de Castro. "Efeito de métodos de preservação dos grãos úmidos de milho e de sorgo sobre a estrutura do endosperma, dos grânulos de amido e desempenho de leitões /." Botucatu : [s.n.], 2004. http://hdl.handle.net/11449/104121.
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Orientador: Dirlei Antonio BertoResumo: Para avaliar os efeitos da ensilagem e da preservação química dos grãos úmidos de milho e sorgo sobre as modificações no endosperma e nos grânulos de amido, foram estudados os seguintes tratamentos (T): T1- Milho seco (variedade A) inteiro; T2- Milho seco (variedade A) moído; T3- Milho úmido (variedade A) moído e ensilado, T4- Milho úmido(variedade A) moído, acidificado com 1,2% de propionato de cálcio e ensilado; T5- Milho úmido (variedade B) moído e ensilado; T6 - Milho úmido (variedade B) moído e preservado quimicamente (2,4% de propionato de cálcio); T7- Sorgo seco (baixo tanino) moído, T8- Sorgo seco (alto tanino) moído; T9- Sorgo úmido (baixo tanino) moído e ensilado;. T10- Sorgo úmido (alto tanino) moído e ensilado. Os processamentos de ensilagem e preservação química dos grãos úmidos, determinaram redução no teor de amido em relação ao milho ou sorgo secos. No processo de ensilagem ocorreu rompimento da matriz protéica que envolve os grânulos de amido e alterações estruturais nos grânulos, como aumento no diâmetro dos poros e concavidade central, semelhante ao que ocorre nos processos de digestão enzimática, sendo que estas alterações foram mais intensas nos grânulos de amido de milho do que de sorgo. A temperatura máxima no interior do silo não é suficiente para geleificar o amido.
Abstract: To evaluate the effect of ensiling or chemical preservation of high-moisture corn and sorghum grain on the modifications occurring in the endosperm and starch granules, the following treatments (T) were studied were studied: T1 - whole dry corn grain (variety A); T2 - ground dry corn grain (variety A); T3 - high-moisture corn grain(variety B), ground and ensiled; T4 - high-moisture corn grain (variety A), ground, acidified with 1.2 % calcium propionate and ensiled; T5 - high-moisture corn grain (variety B), ground and ensiled; T6 - high-moisture corn grain (variety B), ground and chemically preserved with 2.4 % calcium propionate; T7 - dry and ground low-tannin sorghum; T8 - dry and ground high-tannin sorghum; T9 - high-moisture, low-tannin sorghum, ground and ensiled; T10 - high-moisture, high-tannin sorghum, ground and ensiled. Ensiling or chemically preserving reduced the starch content, as compared to dry corn or sorghum. A rupture of the protein matrix (which covers the starch granules) was observed during the ensiling process; structural changes were also detected, such as the increase in pore diameters and in the central concavity, similar to what occurs during enzymatic digestion. These changes were more intense in the corn starch granules than in the sorghum granules. Even the highest temperature detected inside the silos was not enough to gelatinize starch.
Doutor
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Thomaz, Luísa. "Caracterização da dupla modificação física em propriedades termoanalíticas, físico-químicas, estruturais e de pasta da fração amilácea de taro (colocasia esculenta l. schott) orgânico." Universidade Estadual de Ponta Grossa, 2018. http://tede2.uepg.br/jspui/handle/prefix/2491.
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Conselho Nacional de Desenvolvimento Científico e Tecnológico
O taro (Colocasia esculenta L. Schott) é um tubérculo que apresenta até 80 % de material amiláceo em sua composição (base seca), possuindo grânulos pequenos, medindo de 1 μm a 6 μm, enquanto que outras fontes chegam a 100 μm. Amidos nativos podem apresentar limitações tecnológicas e, portanto, modificações físicas, químicas e biológicas são realizadas para ampliar a gama de sua utilização. Neste estudo foi utilizado o amido de taro orgânico, o qual foi modificado por tratamento hidrotérmico (HMT) a partir da variação do teor de umidade (13, 19 e 25 %) e tempo (45, 60 e 75 min), mantendo fixa a temperatura (120 °C). Após esses tratamentos foi aplicado o ultrassom em todas as amostras durante 30 min e amplitude de 60 % (frequência fixa de 20 kHz). Para avaliação e caracterização da amostra nativa e das modificadas foram obtidas imagens por microscopia eletrônica de varredura por efeito de campo (MEV/FEG), as propriedades de pasta por viscoamilografia (RVA), decomposição térmica por termogravimetria (TG), evento de gelatinização por calorimetria exploratória diferencial (DSC) e padrão de cristalinidade por difratometria de raios X (DRX). Houve alteração significativa na cristalinidade relativa, variando de 26,9 % a 32,7 %. O perfil de pasta obteve redução em todos os parâmetros de viscosidade e, no evento de gelatinização, foi observado um aumento de entalpia para todas as condições de HMT, chegando a 14,88 J/g (amostra nativa: 9,45 J/g), além de um alargamento do pico, sugerindo uma maior estabilidade frente ao aquecimento. Devido a esta característica, estudos sugerem aplicação do amido hidrotermicamente tratado em produtos enlatados e congelados. As amostras duplamente modificadas promoveram um encurtamento do evento de gelatinização e redução da entalpia, tendo como menor valor 4,1 J/g; tais resultados ocorreram devido a maior hidratação e menor inchamento do grânulo, o que sugere uma boa dispersibilidade, com possível aplicação em filmes biodegradáveis.
Taro (Colocasia esculenta L. Schott) is a tuber that possesses up to 80% of starchy material in its composition (dry basis) and the size of its granules ranges from 1 μm to 6 μm, while other fonts may have granules up to 100 μm. Native starches can present technological processing limitations, and thus, physical, chemical and biological modifications are performed to improve its application range. In this study, organic taro starch was modified by heat-moisture treatment (HMT), with different moisture levels (13, 19 and 25%) and different time intervals (45, 60 and 75 min). All treatments were performed at 120 °C followed by ultrasound (US) for dual modification. The US was applied for 30 min and 60% of amplitude, at a fixed frequency of 20 kHz, for all samples. The morphology of the native and modified samples where evaluated by scanning electron microscopy (SEM), the pasting properties by viscoamilography (RVA), the gelatinization event by differential scanning calorimeter (DSC) and cristallinity pattern by X-ray difratometry. The major differences where in the relative crystallinity that increased from 26.9% to 32.7%. Additionally, the pasting profile showed a decrease in all parameters. The gelatinization showed an enthalpy increase for all HMT-modified samples, up to 14.88 J/g (native sample: 9.45 J/g). Moreover, a peak broadening was observed, suggesting higher heating stability. Due to this, previous studies suggest that HMT starch can be used in canned and frozen food. The dual modified samples resulted in gelatinization shortening and had a decrease in enthalpy, reaching 4.1 J/g at the minimum. This is due to the higher hydration and lower swelling power of the granule, which indicates a good dispersibility. This gives the taro potential to be used in biodegradable films. Keywords: modified starch, ultrasound, heat-moisture treatment, non-convetional starch.
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Lopes, Ana Beatriz Rocha de Castro [UNESP]. "Efeito de métodos de preservação dos grãos úmidos de milho e de sorgo sobre a estrutura do endosperma, dos grânulos de amido e desempenho de leitões." Universidade Estadual Paulista (UNESP), 2004. http://hdl.handle.net/11449/104121.
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Universidade Estadual Paulista (UNESP)
Para avaliar os efeitos da ensilagem e da preservação química dos grãos úmidos de milho e sorgo sobre as modificações no endosperma e nos grânulos de amido, foram estudados os seguintes tratamentos (T): T1- Milho seco (variedade A) inteiro; T2- Milho seco (variedade A) moído; T3- Milho úmido (variedade A) moído e ensilado, T4- Milho úmido(variedade A) moído, acidificado com 1,2% de propionato de cálcio e ensilado; T5- Milho úmido (variedade B) moído e ensilado; T6 - Milho úmido (variedade B) moído e preservado quimicamente (2,4% de propionato de cálcio); T7- Sorgo seco (baixo tanino) moído, T8- Sorgo seco (alto tanino) moído; T9- Sorgo úmido (baixo tanino) moído e ensilado;. T10- Sorgo úmido (alto tanino) moído e ensilado. Os processamentos de ensilagem e preservação química dos grãos úmidos, determinaram redução no teor de amido em relação ao milho ou sorgo secos. No processo de ensilagem ocorreu rompimento da matriz protéica que envolve os grânulos de amido e alterações estruturais nos grânulos, como aumento no diâmetro dos poros e concavidade central, semelhante ao que ocorre nos processos de digestão enzimática, sendo que estas alterações foram mais intensas nos grânulos de amido de milho do que de sorgo. A temperatura máxima no interior do silo não é suficiente para geleificar o amido.
To evaluate the effect of ensiling or chemical preservation of high-moisture corn and sorghum grain on the modifications occurring in the endosperm and starch granules, the following treatments (T) were studied were studied: T1 - whole dry corn grain (variety A); T2 - ground dry corn grain (variety A); T3 - high-moisture corn grain(variety B), ground and ensiled; T4 - high-moisture corn grain (variety A), ground, acidified with 1.2 % calcium propionate and ensiled; T5 - high-moisture corn grain (variety B), ground and ensiled; T6 - high-moisture corn grain (variety B), ground and chemically preserved with 2.4 % calcium propionate; T7 - dry and ground low-tannin sorghum; T8 - dry and ground high-tannin sorghum; T9 - high-moisture, low-tannin sorghum, ground and ensiled; T10 - high-moisture, high-tannin sorghum, ground and ensiled. Ensiling or chemically preserving reduced the starch content, as compared to dry corn or sorghum. A rupture of the protein matrix (which covers the starch granules) was observed during the ensiling process; structural changes were also detected, such as the increase in pore diameters and in the central concavity, similar to what occurs during enzymatic digestion. These changes were more intense in the corn starch granules than in the sorghum granules. Even the highest temperature detected inside the silos was not enough to gelatinize starch.
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Vieira, Fabiana do Carmo. "Efeito do tratamento com calor e baixa umidade sobre características físicas e funcionais dos amidos de mandioquinha-salsa (Arracacia xanthorrhiza), de batata - doce (Ipomoea batatas) e de gengibre (Zingiber officinale)." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/11/11141/tde-23112004-170358/.
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O objetivo do presente trabalho foi o de obter maiores informações acerca das modificações causadas pelo tratamento com calor e baixa umidade (TCBU) sobre a estrutura granular e propriedades funcionais dos amidos extraídos de mandioquinha-salsa, gengibre e batata-doce, fontes alternativas desse carboidrato. Os amidos foram extraídos desses vegetais e caracterizados quanto à composição macromolecular, substâncias acompanhantes, tamanho e forma dos grânulos. Para avaliar o efeito do tratamento térmico e baixa umidade (100°C, 27% de umidade, 16 horas), os amidos foram submetidos a processo de digestão enzimática pela alfa-amilase de Bacillus sp e amiloglucosidase de Rhizopus mold. As amostras obtidas foram avaliadas quanto ao modo de ataque das enzimas aos grânulos em microscópio eletrônico de varredura (MEV), padrão de cristalinidade por difração de raios-x e propriedades da pasta em Rapid Visco Analyser (RVA). O amido de mandioquinha-salsa apresentou 17% de amilose e 0,032% de fósforo, tamanho médio de grânulo de 12,5 x 17,3µm, padrão B de cristalinidade e 38% de hidrólise enzimática. O amido de batata-doce apresentou 22% de amilose, 0,027% de fósforo, tamanho médio de grânulo de 20,4 x 26,2µm, padrão A de cristalinidade e 72% de hidrólise. O amido de gengibre apresentou 25% de amilose, 0,022% de fósforo, tamanho médio de grânulos de 17,6 x 23,2µm, padrão A de cristalinidade e 15% de hidrólise. O tratamento com calor e baixa umidade nas condições do estudo provocou aumento na suscetibilidade à ação enzimática em todos os amidos, mas principalmente no de mandioquinha-salsa. Com este tratamento ocorreram também alterações na intensidade dos picos nos difratogramas de raios-x, entretanto, os padrões de cristalinidade dos amidos não foram alterados. Os perfis e valores dos viscoamilogramas dos amidos estudados foram substancialmente alterados com o tratamento térmico em baixa umidade, havendo elevação da temperatura de pasta e do tempo para ocorrência do pico, redução nos valores de viscosidade e extinção da quebra, ou seja, estabilização da viscosidade dos amidos quando sob temperaturas elevadas e agitação mecânica. O tratamento térmico sob baixa umidade, nas condições do estudo, promoveu alterações que apontam para um rompimento seguido de rearranjo das associações internas na estrutura granular do amido fazendo com que ocorra redução da cristalinidade e aumento significativo de sua área acessível à ação enzimática.The goal of this work is to obtain more information about the modifications caused by heat-moisture treatment (TCBU) on the granular structure and functional properties extracted of starch Peruvian carrot, sweet potato and ginger, sources alternative sources of this carbohydrato. The starches were extracted of these vegetables and how characterized macromolecular composition, non-starch components, size and form of granules. To evaluate effect of heat-moisture treatment (HMT- 100°C, 27% of humidity, 16 hours), starches had been submittedby to enzymatic digestion with alpha-amilase of Bacillus sp and amiloglucosidase of Rhizopus mold. The samples had been evaluated about the way of enzymes attack to granules in scanning electron microscope (SEM), pattern of cristallinity for rays-x diffraction and properties of the paste in Rapid Visco Analyser (RVA). The peruvian carrot starch presented amylose content of 17% and phosphorus content of 0,032%, granule average size of 12,5 x 17,3µm, standard B of cristallinity and 38% of enzymatic hydrolysis. The sweet potato starch presented of amylose content of 22%, phosphorus content of 0,027%, granule average size of 20,4 x 26,2µm, standard A of cristallinity and 72% of hydrolysis. The ginger starch presented amylose content of 25%, phosphorus content of 0,022%, granule average sizes of 17,6 x 23,2µm, standard A of cristallinity and 15% of hydrolysis. Heat-moisture treatment (HMT), in this work , caused increase in susceptibility to enzymatic action in all studied starches, but mainly in peruvian carrot starch. With this treatment had also occurred alterations in rays-x diffraction peaks intensity, however, starches patterns of cristallinity had not been modified. The heat-moisture treatment, in this conditions, changed in the profiles and values of viscosity and increase of susceptibility to enzymatic hydrolysis, what probably, it was caused by the breached crystal rearrangement, starch chain association and disruption of double helices in the amorphous regions.
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Umurigirwa, Benitha Sandrine. "Élaboration et caractérisation d'un agromatériau chanvre-amidon pour le Bâtiment." Thesis, Reims, 2014. http://www.theses.fr/2014REIMS017/document.
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Afin de diminuer les consommations énergétiques, plusieurs pays Européens, y compris la France, ont mis au point de nouvelles normes permettant d'optimiser les performances énergétiques de l'enveloppe du bâtiment. Ceci peut entraîner l'augmentation de l'humidité relative, ce qui peut nuire à la santé des occupants et dégrader la structure du bâtiment. Utiliser des éco-matériaux tel que le béton de chanvre est une solution prometteuse permettant d'assurer le confort à l'intérieur du bâtiment, en régulant l'humidité relative. L'objectif principal de cette thèse est d'élaborer, optimiser et caractériser un agromatériau à base de la chènevottes défibrée avec un liant d'amidon de blé. La formulation du chanvre-amidon est étudiée en variant le rapport massique amidon/chanvre et son impact sur les propriétés mécaniques. Le coefficient d'absorption acoustique est mesuré pour la composition optimale. Pour améliorer les propriétés d'adhésion à l'interface chanvre/amidon, un traitement de surface à base d'hydroxyde de sodium NaOH suivi par un agent de couplage (3-glycidyloxypropyl) triméthoxysilane ont été effectués. L‘influence du traitement de surface sur les fibres de chanvre a été analysée au microscope électronique à balayage (MEB), par la calorimétrie différentielle à balayage (DSC), l'analyse thermographique (ATG) et par la spectroscopie infrarouge à transformée de Fourier (FTIR). Les propriétés hygrothermiques du matériau chanvre-amidon avec et sans traitement de fibres sont également étudiées. Ces propriétés comprennent la courbe d'isotherme de sorption, la perméabilité à la vapeur d'eau, la conductivité thermique et la capacité tampon hydrique du matériauIn order to control energy consumption, several European countries including France, adopted regulations to optimize the energy performance of the building envelope. This fact could increase the level of indoor relative humidity which can affect the health of the occupants and causes material damage. Using eco-friendly materials such as hemp concrete which can buffer indoor moisture levels might contribute to maintain high indoor comfort.The main purpose of this thesis is to optimise and characterize a construction material made of hemp hurds and wheat starch binder.The formulation of the hemp-starch is studied by varying starch/hemp ratio and its impact on mechanical properties. Sound absorption coefficient is measured for optimal composition. To improve the adhesion between hemp fibers and starch matrix, alkali treatment with sodium hydroxide was performed to solubilize hemicelluloses and lignin seal surrounding the cellulose bundle in the first step and then a silane coupling agent (3-glycidyloxypropyl) trimethoxylsilane was used to provide a stable bond between hemp fibres and starch matrix. The influence of the treatments were investigated by scanning electron microscopy (SEM), differential thermal analysis (DTA), thermogravimetric analysis (TGA) and attenuated total reflectance spectroscopy (ATR). After the treatments, mechanical properties of hemp-starch material were studied.Hygrothermal properties of hemp-starch material with and without fibre treatment were also measured. These properties include sorption isotherm curve, water vapour permeability, thermal conductivity and moisture buffering value
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Souza, Juliane Alves de. "ESTUDO TERMOANALÍTICO, REOLÓGICO E ESTRUTURAL DE AMIDO DE TRIGO MODIFICADO POR UMIDADE E TEMPERATURA CONTROLADAS (HMT)." UNIVERSIDADE ESTADUAL DE PONTA GROSSA, 2014. http://tede2.uepg.br/jspui/handle/prefix/642.
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Previous issue date: 2014-12-12Cereals have an important role in human nutrition. Wheat is one of the most cultivated and consumed cereals in the world being used in the preparation of the enormous diversity of products. The wheat flour fortification with iron and folic acid is obligatory in Brazil in according with current legislation. Starch is a reserve polysaccharide of vegetable consisting essentially of amylose and amylopectin. It is a matter abundant and replaceable material being the main source of carbohydrate in diet human. Starches in their native form have limited features for industrial use so it is important modification aiming to acquire improved stability, rheological properties, paste, gel texture, water retention, among others. The chemical modification, still very used, is not considered as safe a one way of modification, so the physical modification is well regarded by food industry. Heat Moisture Treatment (HMT) in starch is considered a natural method and is conducted with a moisture content of 30% and a maximum temperature of 120 ° C. Were studied native wheat and modified starches with presence and absence of folic acid and iron, by HMT at 121 °C for a period of 1 hour. The effects of HMT were studied using the following techniques: thermogravimetry and derivative thermogravimetry (TG/DTG), differential scanning calorimetry (DSC), x-ray diffraction (DRX), atomic force microscopy (NC-AFM), rapid visco analysis (RVA), the flame atomic absorption spectrometry (FEAA) and reflectance photocolorimetry. From the TG and DTG curves was observed that for the physically treated starches, the values of weight loss for starch in the presence of folic acid iron in the first and third stages decreased and the second increased as increased moisture. The DSC, modified starches, the temperatures at which the event occurred and the enthalpy of gelatinization decreased and the higher the moisture treatment was lower enthalpy. All starches showed bimodal distribution and irregularities in the micro-images of AFM with changes in average diameter and roughness, after physical modification. For all starches DRX peaks did not undergo pronounced displacement, however there was a decrease in crystallinity after modification. All starches showed high paste temperature and low peak viscosity. Was determined absence iron concentration to starch without folic acid and iron and little change for the presence of starch with these nutrients. With respect to color analysis for all samples studied, there was little variation in color between them, with causing a trend mainly to yellow after modification.
Cereais possuem importante papel na alimentação humana. O trigo é um dos cereais mais cultivados e consumidos no mundo sendo utilizado na elaboração de enorme diversidade de produtos. A fortificação da farinha de trigo com ferro e ácido fólico é obrigatória no Brasil de acordo com a legislação vigente. O amido é um polissacarídeo de reserva vegetal constituído basicamente por amilose e amilopectina. É uma matéria prima abundante e renovável sendo a principal fonte de carboidrato na alimentação humana. Amidos na forma nativa possuem características limitadas para uso industrial por isso torna-se importante sua modificação visando adquirir melhor estabilidade, propriedades reológicas, de pasta, textura de géis, retenção de água entre outros. A modificação química, ainda muito utilizada, não é considerada uma forma tão segura de modificação, por isso a modificação física é bem vista pela indústria alimentícia. A modificação por umidade e temperatura controladas (HMT) em amido é considerada um método natural e é conduzida com teor de umidade de até 30% e temperatura máxima de 121 ºC. Foram estudados amidos trigo nativos e modificados, com presença e ausência de ácido fólico e ferro, por HMT a 121°C por um período de 1 hora. Os efeitos do HMT foram estudados utilizando as seguintes técnicas: termogravimetria e termogravimetria derivada (TG/DTG), calorimetria exploratória diferencial (DSC), difração de raios X (DRX), microscopia de força atômica (NC-AFM), análise viscoamilográfica rápida (RVA), espectrometria de absorção atômica com chama (FEAA) e refletância fotocolorimetria. A partir das curvas TG e DTG, observou-se que para os amidos tratados fisicamente, os valores de perda de massa para o amido em presença de ácido fólico e ferro, nas primeiras e terceiras etapas diminuíram e da segunda aumentaram, conforme aumento da umidade. Após a análise de DSC, os amidos modificados, as temperaturas em que ocorreu o evento e o valor da entalpia de gelatinização diminuíram e quanto maior a umidade de tratamento menor foi à entalpia. Os amidos deste estudo apresentaram distribuição bimodal e irregularidades nas microimagens de AFM, com alterações nos diâmetros médios e rugosidade, após a modificação física. Para todos os amidos os picos de DRX não sofreram deslocamento acentuado, porem houve redução da cristalinidade após a modificação. Todos os amidos apresentaram alta temperatura de pasta e baixo pico de viscosidade. Foi determinada ausência de ferro para o amido sem ácido fólico e ferro e pouca alteração para o amido com presença desses nutrientes. Com relação a análise de cor, para todas as amostras estudadas, houve pouca variação de cor entre elas, com tendência ao amarelamento após a modificação.
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Fideles, Marília Cândido. "Modificação física de farinha de araruta para aplicação em massa alimentícia enriquecida com coprodutos agroindustriais." Universidade Federal de Goiás, 2019. http://repositorio.bc.ufg.br/tede/handle/tede/9260.
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Arrowroot is a plant that has abundant starch content and does not present gluten in its composition, arousing the interest of its use in the production of pasta. However, gluten substitution must be provided through the use of techniques, such as the arrowroot flour modification through physical processes. Starch is the highest percentage of arrowroot composition, so enrichment of the dough is an interesting alternative, and a fortification with agroindustrial coproducts sources of fiber and protein, such as passion fruit peel and bovine rumen, may be viable. The objective of this study is to produce flours from agroindustrial coproducts, to modify by different methods (ultrassonic and heat-moisture treatment) the starch of arrowroot obtained and determine the viability technological and nutritional aspects of the use of modified flours and agroindustrial coproducts, source of fiber and protein, in the production of different types of pasta. The hydration, paste and thermal properties of raw and modified flours were evaluated. The results of the ultrasound treatments vary with the temperature between 35.83 and 62% with time between 5 and 15 minutes. For heat-moisture treatment, the best results were those using the lowest temperature (105 ° C) and shorter times (15 and 30 minutes). Taking into account the use of modified flours in the production of pasta, ultrasonic treatments with parameters of intensity of 43.5% and time of 15 min and heat-moisture treatment with 105 ° C for 15 min were selected. With the technological techniques of the pasta produced, it was possible to analyze and choose the best parameters to obtain a pasta with less cooking time, loss of solids, intermediate increase of pasta, and small values of firmness, angle Hue and C* chromaticity. The proximal composition of the pasta was satisfactory, being able to be characterized as a food with high protein content and high fiber content. The pastas with the greatest desirability are a good sensory acceptance. The results obtained have the possibility to develop and improve the pasta formulated with raw and modified arrowroot flour and agroindustrial coproducts.
A araruta é uma planta que apresenta conteúdo abundante de amido e não glúten em sua composição, despertando o interesse da sua utilização na produção de massas alimentícias. Porém a substituição do glúten deve ser suprida através da utilização de diferentes técnicas, como, por exemplo, a modificação da farinha por meio de processos físicos. O amido é o maior percentual da composição da araruta, portanto o enriquecimento da massa é uma alternativa interessante, e a fortificação com coprodutos agroindustriais fontes de fibra e proteína, como a casca de maracujá e o rúmen bovino, pode ser viável. O objetivo deste trabalho é produzir farinhas a partir de coprodutos agroindustriais, modificar por métodos distintos (ultrassom e tratamento térmico em baixa umidade - TTBU) o amido da farinha de araruta obtida e determinar a viabilidade tecnológica e nutricional da utilização das farinhas de araruta modificadas e de coprodutos agroindustriais na produção de diferentes tipos de massas alimentícias. Foram avaliadas as propriedades de hidratação, de pasta e térmicas das farinhas cruas e modificadas. Os melhores resultados dos tratamentos com ultrassom são os com intensidade variando entre 35,83 e 62% com tempo entre 5 e 15 minutos. Já para o TTBU os melhores resultados da modificação são os que utilizaram menor temperatura (105°C) e menores tempos (15 e 30 minutos). Levando em consideração o uso das farinhas modificadas na produção de massas alimentícias, foram selecionados os tratamentos de ultrassom com parâmetros de intensidade 43,5% e tempo 15 min e TTBU com temperatura de 105°C por 15 min. Através das análises tecnológicas das massas alimentícias produzidas foi possível analisar e escolher os melhores parâmetros para se obter uma massa com menor tempo ótimo de cozimento, perda de sólidos, intermediário aumento de massa, e menores valores de firmeza, ângulo Hue e cromaticidade C*. A composição proximal das massas foi satisfatória, podendo ser caracterizada como um alimento com alto teor de proteína e alto teor de fibra, de acordo com a legislação. As massas com maior desejabilidade apresentaram uma boa aceitação sensorial. Os resultados encontrados indicam a possibilidade de se desenvolver e aperfeiçoar massas alimentícias formuladas com farinha de araruta crua e modificadas e coprodutos agroindustriais.
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RIBEIRO, VILAS BOAS MARTA SOFIA. "Caratteristiche Fisiche e Chimiche che Influenzano la Digeribilità dell'Amido nei Ruminanti." Doctoral thesis, Università Cattolica del Sacro Cuore, 2010. http://hdl.handle.net/10280/778.
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L’amido è la maggiore fonte di energia per i ruminanti e la sua efficienza di utilizzazione nel tratto gastro-intestinale è importante per soddisfare i fabbisogni energetici dell’animale. La degradabilità dell’amido è misurata da diversi metodi (i.e., metodi in vivo, in situ, in vitro con inoculo ruminale e/o metodi enzimatici) e appare essere influenzata dal tipo di cereale, dai metodi di lavorazione e conservazione degli alimenti, dalla dimensione delle particelle, dal tipo di endosperma, etc.). La tesi è consistita di 4 esperimenti: Esperimento 1) la degradabilità dell’amido di diversi alimenti è stata valutata con un metodi condotto in situ ed il metodo in vitro proposto da Tilley&Terry: entrambi sono stati capaci di differenziare gli alimenti in base alla diversa degradabilità dell’amido. Esperimento 2) Un approccio enzimatico è stato studiato per determinare la quantità di amido degradato. Esperimento 3) Il metodo enzimatico ed il metodo Tilley&Terry sono stati comparati e sono risultati essere ben correlati, evidenziando la possibilità di utilizzare l’approccio enzimatico per studiare i fattori che influenzano la degradabilità dell’amido. Dato che pochi lavori scientifici hanno confrontato la degradabilità dell’amido di granelle e pastoni di mais, nell’Esperimento 4) sono stati raccolti campioni di mais conservati con diverse modalità (i.e., farina di mais, pastoni di granella e pastoni integrali di mais) per verificare quali le caratteristiche chimiche che influenzano la degradabilità dell’amido.
I fattori che maggiormente condizionano la valutazione enzimatica della degradabilità dell’amido sono il contenuto in prolamine e l’umidità dei campioni. In conclusione, il metodo enzimatico può essere routinariamente utilizzato dai laboratori commerciali per la rapida valutazione della degradabilità dell’amido negli alimenti destinati all’uso animale.Starch is the main energy source for ruminants and its efficient utilization in gastro-intestinal tract is important to meet animal energy requirements. The starch degradability is determined by several methods (i.e., in vivo, in situ, in vitro ruminal and/or enzymatic methods) and is affected by type of grain, processing and conservation methods, particle size, type of endosperm, etc.. Four experiments were conducted: Experiment 1) starch degradability of different feeds was evaluated with in-situ and in-vitro Tilley&Terry methods: both are able to differentiate starch degradability among feeds. Experiment 2) An in-vitro enzymatic approach was studied to determine the amount of starch degradation. Experiment 3) Enzymatic and Tilley-Terry methods were compared, resulting well correlated and highlighting the possible application of enzymatic method to investigate the factors affecting starch degradability. Because few works compared the starch degradability of dry-ground and high-moisture corns, in Experiment 4) a data set of different conserved corn samples (i.e., dry, high-moisture and high-moisture-ear corns) was produced and chemical factors affecting starch degradability were studied. The most important factors influencing the enzymatic starch degradability were prolamin and moisture. Concluding, the enzymatic method could be used by commercial laboratories as a routine method for rapid determination of feed starch degradability.
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Manuel, Heather J. "The effect of heat-moisture treatment on the structure & physicochemical properties of legume starches." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1996. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/mq25864.pdf.
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Yost, Douglas Arlen. "Gelatinization of low moisture wheat starch." 1985. http://hdl.handle.net/2097/27628.
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Lin, Jia-Jing, and 林佳靜. "Effect Of Heat-Moisture Treatment On Physicochemical Properties Of Starch." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/r5sd84.
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Walker, Shane Bruce. "Physicochemical Transformations in Low-Moisture Dough During Baking." Thesis, 2013. http://hdl.handle.net/10214/6656.
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Transformations in the properties of low-moisture dough products (cookies and crackers) during baking have been studied under idealized conditions in pilot facilities and laboratories. However, little research is published that describes dough development within the context of complex industrial baking processes. A process mapping approach was adopted, in which oven parameters were profiled and matched against changes in dough. In cookies, changes to starch A-granules, including loss of granule birefringence, disruption to granule borders and increased gel viscosity were observed. Development of acrylamide in cookies was seen to trail colour development, suggesting options for mediating acrylamide content. In crackers, the presence of additional water allowed significant changes to starch A-granules to occur, including: swelling similar to the early stages of gelatinization in bread, reduced pasting ability, a drop in enthalpy, and a loss of crystallinity. Emulation of low-moisture dough baking at the benchtop level, based upon internal product temperature data from industrial processes, was found to be limited in its ability to produce crackers having appropriate leavening and internal structure development. The determination of isosteric heat of desorption values for cookies and crackers, modeled on industrial processes at temperatures > 100°C, gave values of 44.3 and 42.7 kJ/mol, respectively. This data will be useful for establishing energy requirements in industrial baking processesMITACS, OMAFRA
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Huang, Shun-Ting, and 黃舜廷. "Effect of Microwave Heat-Moisture Treatment on Physicochemical Properties of Starch." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/32101680923043570134.
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碩士國立宜蘭大學
食品科學系碩士班
101
Starch has been widely used in the food industry. In many applications the properties of native starch are not optimal; therefore, starch is often chemically and physically modified to improve its performance. However, current market trends are driving producers towards more natural food components, so there is interest in finding new ways to improve the properties of native starches without using chemical modification. Hydrothermal treatment (HTT) is a physical modification technique that is commonly processed at a specific moisture content and temperature. Traditional hydrothermal treatment required a long processing time. Microwave can improve this obstacle. However, there is little research for the microwave hydrothermal treatment (MHTT) of starch. The objective of this study is to understand the physicochemical properties of starch after MHTT. The results showed damage starch content, apparent amylose content and cold water soluble starch were increased but cold water insoluble starch decreased with the increase of temperature after MHTT. At 135oC for 12 minutes and 4oC retrogradation 7 days have the highest content resistant starch content. White index (WI) measured by hunter colormeter indicated MHTT modified starch decreased in whiteness but still more than 90.
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Wen, Chia-ying, and 溫嘉盈. "Effect of acid-ethanol and heat-moisture dual modification on resistant starch content and physicochemical properties of different corn starch." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/33620754490009169591.
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碩士靜宜大學
食品營養研究所
98
Corn starches differing in amylose content (24.7%, 51.9% and 62.7% for normal, Hylon V and Hylon VII, respectively) were treatment in ethanol containing 0.36% HCl at 45 oC for 1-360 h to prepare starch with different molecular sizes. The acid-ethanol-treated starch was then heat-moisture treatment with 30% moisture content at 100 oC for 80 min, and the granule morphology, gelatinization thermal properties, relative double helix content, relative crystallinity, resistant starch (RS) content and digestibility of starch before and after heat-moisture treatment were determined for elucidating the effect of molecular size on the heat-moisture treatment of corn starch. Results showed that starch granules did not show significant change after either modification, except for the merge of some starch granules. The gelatinization peak temperature (Tp) and enthalpy (ΔH) of native corn starch and acid-ethanol-treated starch after heat-moisture treatment were higher than those of the counterpart starch before heat-moisture treatment. After heat-moisture treatment, Hylon V and Hylon VII starches differing in molecular size showed increase in boiling-stable RS content with the decrease of molecular size. There the combination of acid-ethanol and heat-moisture treatments increased the thermal stability of starch granules. The rapid digestible starch (RDS), slow digestible starch (SDS) and RS contents of the three corn starches studied varied with the period of acid-ethanol treatment. Starch being acid-ethanol- treated for less than 24 h showed comparable contents of RDS, SDS, and RS. Whereas the RS content of starch being acid-ethanol-treated for more than 24 h increased with decreasing molecular size. The change of RS content of starch with molecular size, either before or after heat-moisture treatment, is more obvious for Hylon V and Hylon VII starches than that of normal corn starch. Results indicated that the RS content of starch depended on not only the amylose content of starch and the presence of heat-moisture treatment, but also the molecular size of starch. The degradation of starch, causing by acid-ethanol treatment, resulted in the decrease of molecular size and the alteration of granular structure of starch, which further increased the susceptibility of starch to enzyme. Moreover, acid-ethanol treatment increased the movement and rearrangement of starch chains within granules, which further increased the realignment of starch chains during heat-moisture treatment and consequently increased the RS content of starch.
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Chatakanonda, Pathama. "Water and starch chain mobility in cassava starch as monitored by NMR: Effects of heat-moisture treatments, growth conditions and harvest time." 2003. https://scholarworks.umass.edu/dissertations/AAI3078673.
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This study focuses on applying Nuclear Magnetic Resonance (NMR) to differentiate heterogeneous domains of starch Mobility and distribution of water and starch chains in cassava starch from crops grown in drought and rainy reasons, harvested at 6 months and 12 months, were investigated by deuterium (2H) solid state NMR and proton (1H) spin-spin relaxation time (T 2) distributions. Changes in water and starch chain mobility with heating, freezing, and acid hydrolysis were also studied. In a very low moisture range (<5% dry basis), all water present was immobile (rigid) in both drought and rainy cassava (A-type crystals), and potato starches (B-type crystal). Thus, the amount of bound water was irrespective of degrees of crystallinity and crystal types. The “Monolayer” value estimated from water sorption isotherms (7–9% dry basis) over-estimated the level of bound water in starch (when compared with NMR data). With increasing water content, T, decreased to a minimum at a moisture range of 14–17% (dry basis) marking its onset of molecular plasticization of the starch chains. Packed beds of starch granules (54% water, dry basis) were subjected to heating and freezing treatments. NMR T2 distributions of water and starch protons were characterized with a continuous model. Intragranular water (T2 ∼ 3 ms, disappeared below 0°C) and extragranular water (T2 ∼ 20 ms) were observed. An extra long T2 (∼100 ms) population (postulated as water associated with leached amylose) was developed upon gelatinization. The swelling and melting of starch from the drought crop were shifted to a higher temperature than those from the rainy crop resulting from a possible closer packing of rigid amylopectin and/or amylose chains. Upon gelatinization, rigid amylopectin (T2 ∼ 10 μs) disappeared, while the mobile amylopectin (in the amorphous region of semicrystalline lamellae, T2 ∼ 1 ms) increased. An additional fraction with very long T 2 (∼50 ms) emerged at 65°C and above indicating an increase in mobile/soluble starch. This study demonstrated a possible use of NMR to monitor changes in starch chains and related water mobility in intact starch granules, which is a unique feature not offered by other methods.
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Mathobo, Vhulenda Melinda. "Influence of head-moisture treatment on functional, colour and thermal properties of bambara ground-nut starch." Diss., 2019. http://hdl.handle.net/11602/1457.
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MSCFSTDepartment of Science and Technology
Heat-moisture treatment (HMT) is a physical modification that alters the physicochemical properties of starch without changing its molecular structure. The objective of the study was to investigate the influence of HMT on the functional, colour and thermal properties of bambara groundnut (BG) starch. A central composite rotatable design comprising two independent factors (temperature and time) was used for the study. The central composite rotatable design was generated using Design-Expert software version 8.0.1.0. Bambara starch extraction was done by milling BG into flour (5 Kg), suspension in 15 L, 0.3% sodium hydroxide and centrifugation followed by washing using distilled water. The starch was then HMT treated in an air oven at 80 - 120 °C for 30 - 90 min under 15 % moisture content (MC) (HMT 15), 25% MC (HMT 25) and 35% MC (HMT 35). The highest L* and WI values for HMT treated BG starch were observed at HMT 80 °C for 30 min under 15% MC; 100 °C for 60 min (25% MC); and 100 °C for 17.57 min (35% MC) while the lowest was observed in HMT 100 °C for 102.43 min (15% MC); 120 °C for 90 min (25% MC); and 120 °C for 90 min (35% MC). In HMT 15-BG starch, the gelatinisation parameters onset (To), peak (Tp) and concluding temperature (Tc) of the samples decreased as treatment time and temperature increased whereas gelatinisation enthalpy of BG starch increased with increase in HMT treatment temperature and time. In HMT 25-BG starch Tp, and gelatinisation enthalpy of the starch increased with increase in HMT treatment temperature and time. While in HMT 35-BG starch, To, Tp, Tc and gelatinisation enthalpy of the starches decreased with increase in HMT treatment temperature and time. In HMT 15-BG starch, the water absorption capacity (WAC), solubility and swelling power (SP) decreased as treatment time and temperature increased while oil absorption capacity (OAC) of the starch increased with increase in HMT treatment temperature and time. In terms of HMT 25-BG starch, the WAC and OAC increased as HMT treatment time and temperature increased while SP and solubility of the starch decreased with increase in HMT treatment temperature and time. In HMT 35-BG starch, OAC, solubility and SP decreased as treatment time and temperature increased while WAC of the starch increased with increase in HMT treatment temperature and time. The optimum HMT conditions for BG starch were found to be 80 °C for 30 min (HMT 15), 105.74 °C for 30 min (HMT 25), and 113.16 °C for 30 min (HMT 35). Desirability of the obtained optimum conditions were 0.63 (HMT 15), 0.56 (HMT 25) and 0.64 (HMT 35). Information obtained from scanning electron micrograph indicates oval and round shape for bambara starch granules, with varying sizes. The range of the granule size width was 4.2 – 4.7 mm and 10 μm for length. The modified starches showed some changes in granule morphology as they seem to disintegrate with application of HMT. Unmodified and HMT - BG starches showed characteristic FTIR bands linked with common starches. All the samples displayed complex vibrations in the region below 1000 cm-1 due to the skeletal vibrations of the glucose pyranose ring. Statistical analysis on colour, thermal and functional properties of HMT 15-BG, HMT 25-BG and HMT 35-BG starch showed that effects of temperature and treatment time had no significant (p ≥ 0.05) effect on these properties of HMT-BG starch. However, treatment time had a significant linear effect (p ≤ 0.05) on swelling power, for HMT 15-BG starch. In HMT 35-BG starch, WAC was significantly affected by quadratic effect of temperature and time while solubility was significantly affected by linear effect of time and quadratic effect of temperature.
NRF
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Gunaratne, D. M. Anil. "The effect of heat-moisture treatment on the structure and physicochemical properties of tuber and root starches /." 2001.
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Su, Wei-chen, and 蘇瑋琛. "Effect of osmotic pressure and simultaneous heat-moisture and phosphorylation treatments on the resistant starch content and physicochemical properties of mung bean and water caltrop starches." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/84883170619958436112.
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碩士靜宜大學
食品營養研究所
99
The resistant starch is defined by Food and Agriculture Organization of the United Nations as “The small intestine of healthy people can not be absorbing and degradation products which can enhance the probiotics, decreasing the functional colonic disease and reducing calorie ingestion and then control the body weight”. The purpose of this study were to investigate the effect of osmotic pressure treatment (OPT) and simultaneous heat-moisture phosphorylation treatment (HMPT) on the physicochemical properties, resistant starch content and estimated glycemic index of high amylase starches. Two local starches, including mung bean and water caltrop, and high amylase corn starch (Hylon VII) were treated by both treatment methods for 15-60 min, respectively, in this experiment. The results indicated that the content of resistant starch increased with the increase of processing time in all three tested samples. The treatment of OPT and HMPT promoted the gelatinization temperature (To, Tp, Tc) but decreased the gelatinization enthalpy and pasting viscosity of tested starches. The results also observed that the swelling power and solubility decreased as the treatment time increased on three tested starches. The hardness of mung bean and water caltrop starch gel decreased as those starches were treated by OPT but increased in HMPT mung bean gel. According to X-ray diffraction, the relative crystallinity of starch increased as the starches were treated by OPT and HMPT. The crystal type of Hylon VII corn starch was changed from B-type to Ca-type after OPT treatment. The changes of particle size were observed that the particle size of three tested starches decreased with the increase of HMPT processing time. Moreover, the surface of mung bean starch particle appeared concavity when mung bean starch was processed by OPT. The estimated glycemic index of all processed starches by OPT and HMPT decreased as compared with rice starch
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高崇烈. "Effects of Screw Speed, Feed Moisture Content, and Addition of Corn Starch on the Physical Properties of Extruded Rice Noodles." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/75484930533184851346.
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碩士國立屏東科技大學
食品技術研究所
86
The conventional manufacturing process of rice noodles is laborious and time-consuming. The quality and sanitation of the product are also difficult to be maintained. However, the method of continuous cooking extrusion by a locally-made single-screw extruder can be used to process the pre-conditioned rice dough to produce rice noodles. Not only the disadvantages of the conventional process of rice noodles can be improved, but also the quality and sanitation of the product are more possibly to be maintained. Food extrusion is influenced by many variables. The objective of this study is to investigate the effects of process variables on the extruded rice noodles, while the rice noodles is being produced by a loccally made single screw extruder. Specifically, the effects of screw speed, feed moisture content, and addition of corn starch on the physical properties of extruded rice noodles were studied. According to the results, process variables, i. e., screw speed, feed moisture content, and addition of corn starch,significantly affected the strength, expansion ratio, density, cooking loss, water absorption, colors, texture and structure of extruded rice noodles, The strength of extruded rice noodles increased with the increasing screw speed, feed moisture content, and addition of corn starch The expansion ratio of extruded rice noodles increased with the increasing screw speed and feed moisture content. The density of dried extruded rice noodles increased with increasing scrow speed.The cooking loss of dried extruded rice noodles decreased with increasing screw speed and feed moisture content. The water absorption of dried extruded rice noodles decreased with increasing feed moisture content and addition of corn starch. In addition, the white index of extruded rice noodles decreased with increasing screw speed, but increased with increasing addition of corn starch.
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Vamadevan, Varatharajan. "Organization of Glucan Chains in Starch Granules as Revealed by Hydrothermal Treatment." Thesis, 2013. http://hdl.handle.net/10214/7240.
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Regular starches contain two principal types of glucan polymers: amylopectin and amylose. The structure of amylopectin is characterized according to the unit chain length profile and the nature of the branching pattern, which determine the alignment of glucan chains during biosynthesis. The organization of glucan chains in amylopectin and their impact on the structure of starch are still open to debate. The location of amylose and its exact contribution to the assembly of crystalline lamellae in regular and high-amylose starch granules also remain unknown. The primary focus of this thesis is the organization and flexibility of glucan chains in crystalline lamellae.
The organization and flexibility of glucan chains in native, annealed (ANN), and heat-moisture treated (HMT) normal, waxy, hylon V, hylon VII, and hylon VIII corn starches were examined. This study has shown for the first time that increased amounts of apparent amylose in B-type starches hinder the polymorphic transition (from B to A+B) during HMT. The research has also demonstrated that an iodine-glucan complex transformed the B-type polymorphic pattern of hylon starches into a V-type pattern. The differential scanning calorimetry (DSC) results showed that ANN- and HMT-induced changes were most pronounced in hylon starches. These findings suggest that the glucan tie chains influences the assembly of crystalline lamellae in high-amylose starches.
The relationship between the internal unit chain composition of amylopectin, and the thermal properties and annealing of starches from four different structural types of amylopectin was investigated by DSC. The onset gelatinization temperature (To) correlated negatively with the number of building blocks in clusters (NBbl) and positively with the inter-block chain length (IB-CL). The enthalpy of gelatinization (∆H) correlated positively with the external chain length of amylopectin. Annealing results showed that starches with a short IB-CL were most susceptible to ANN, as evidenced by a greater increase in the To and Tm. The increase in enthalpy was greater in starches with long external chains and IB-CLs. These data suggest that the internal organization of glucan chains in amylopectin determines the alignment of chains within the crystalline lamellae and thereby the thermal properties and annealing of the starch granules.
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Chi, Hsin-Yi, and 紀欣儀. "Effect of heat-moisture treatments on the digestibility and physicochemical properties of Tainung No.57 and Tainung No.66 sweet potato starches." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/52w4c2.
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碩士國立中興大學
食品暨應用生物科技學系所
106
In the present study, the effects of heat-moisture treatment( HMT, under 20%, 25% and 30% moisture level, 105℃, 2 hours) on physicochemical and structure properties of Tainung No.57 and Tainung No.66 sweet potato starches originated from Longjing were investigated. The water content of Tainung No.57 and Tainung No.66 sweet potato was 67.32% and 75.27%, and the yield of its starch was 67.32% and 23.89%(dry base), respectively. The results showed that the birefringence of HMT starch samples of two spices was not changed, but it had pore at hilum and found concavity on granule surface after heat-moisture treatment under different moisture level. As moisture level of heat-moisture treatment increased, the content of damage starch increased gradually, and the content of resistant starch decreased gradually. Furthermore, the crystalline pattern of native and HMT starch samples changed from Ca type into A type gradually, and compared native starch with HMT starch samples, the relative crystallinity increased and then decreased. Moreover, the HMT starch samples of two exhibited increased pasting temperature, reduced viscosities, and no longer exhibited traditional pasting profiles for lack of a true peak viscosity and no breakdown. The swelling power and solubility of all starches increased while temperature increased, as moisture level of heat-moisture treatment increased, the swelling power and solubility decreased when exceeded gelatinization temperature. Rheological behavior of 10% sweet potato starch paste belongs to shear-thinning fluid. Dynamic viscoelastic results also revealed that the sweet potato paste belonged to weak gels, as moisture level of heat-moisture treatment increased, sweet potato starch paste changed into strong gel and the modulus of 10% sweet potato paste increased.