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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Properties of extruded starch and its technological implication

Alias, Abd Karim January 1994 (has links)
No description available.
2

Analysis of the colour of an intermediate moisture Mailland system

Bates, Lisa January 1996 (has links)
No description available.
3

Influence of ascorbic acid on starch conversion

Sriburi, Pensiri January 1999 (has links)
No description available.
4

Bubble growth and starch conversion in extruded and baked cereal systems

Fan, Jintian January 1994 (has links)
No description available.
5

Mechanical oil expression from selected oilseeds under uniaxial compression

Bargale, Praveen Chandra 01 January 1997 (has links)
Mechanical pressing of soybean is highly desirable as it provides, at low cost, non-contaminated, protein-rich, low-fat soyflour which can be further processed into nutritious edible foods. Unfortunately, mechanical pressing of this low-fat oilseed ($<$20%) yields only 50-70% of the available oil, in contrast to the solvent extraction method which recovers over 98% of the oil. The main focus of the study was to maximize the oil recovery from soybean using mechanical oil expression by applying two pretreatments, enzymatic hydrolysis and extrusion cooking of soybeans, and by varying the pressing conditions including three applied pressures (20, 40 and 60 MPa), three pressing temperatures (22, 60 and 90°C) and two sample sizes (10 and 20 g). To characterize the material properties affecting mechanical oil expression from soybean a mathematical simulation of uniaxial compression was developed which incorporated the time dependent variation of soybean properties. The mathematical simulation was based on Terznaghi's theory of consolidation for soils and was solved using measured values of the coefficients of permeability, volume change and consolidation. A compression-permeability test cell was specifically developed for these measurements. For validation of the model, in addition to extruded soy, sunflower seeds (oil content ca. 45%) were also compressed under the same pressing conditions. Improvements in oil recovery due to enzymatic pretreatment of soybean were small, while the extrusion pretreatment increased the oil recovery from only a trace for raw soybean to 90.6%. Such oil recovery using mechanical pressing of soybean has not been reported in the past. The measured values of oil recovery, coefficients of permeability, volume change and consolidation for soybean and sunflower seeds were found to vary significantly $(P<0.05)$ with time of pressing, applied pressure, pressing temperature and the size of the sample. For extruded soy samples, the developed model predicted the values of oil recovery versus pressing time with an average error of 15%, while for sunflower seed samples the average prediction error was 40%. The high error values were attributed to the presence of hulls in the sunflower seed samples, as well as error during measurement of the coefficient of permeability. The coefficient of consolidation was found to have the greatest influence on oil recovery. The incorporation of time dependent material properties in the developed simulation was demonstrated to give more accurate and consistent prediction in trends of oil recovery as compared to using constant material properties. The correlationship developed between the oilseed material properties and the oil recovery obtained from uniaxially compressed oilseeds would help researchers and designers to better evaluate the mechanical oil expression equipment and systems. To the extent that the developed model adequately predicted oil recoveries from both sunflower and soybean oilseeds, the model is expected to be applicable to other oilseeds as well.
6

Twin-Screw Extrusion for the Production of Lipid Complexed Pea Starch as a Functional Food Ingredient / Twin-Screw Extrusion for a Functional Food Ingredient

Ciardullo, Sarah Kristi January 2018 (has links)
Canada is a major global producer of pulse products including pulse starch, which notably contributes to a healthy diet. Strategically, Canada is taking steps to research methods of adding greater value to these crop products, and functional foods like resistant starch are particularly interesting. The primary objectives of this study were to develop an effective reactive extrusion process to produce gelatinized lipid complexed pea starches with enhanced enzyme resistance and examine the effects of bulk lipid complexing conditions on physicochemical and functional properties of extruded pea starches. One type of commercially available pea starch, Nutri-Pea, was chosen as the research subject in this study. A number of methods including; Englyst digestion method, differential scanning calorimetry (DSC), infrared spectroscopy (FTIR), contact angle, titrations, residence time distribution (RTD) and rapid visco analysis (RVA) were used to characterize the properties of extruded pea starches. The effects of feed formulation and extrusion conditions on lipid complexing and Englyst digestion profiles were systematically examined on two mixing devices. An extensive kinetics study was conducted on a lab scale twin-screw compounder, DSM-Xplore. The process was then scaled up to produce bulk lipid complexed pea starch on a Leistritz twin-screw extruder. The results showed that lipid complexing and digestion profiles were highly dependent on feed moisture and induced screw shear. Reactive extrusion of pea starches under optimized conditions achieved a significant but moderate increase in either resistant starch (RS) content (from 13.3% to 20.2%) or slowly digestible starch (SDS) content (from 7.85% to 23.3%) compared to their native counterparts. However, RS and SDS content could not be improved simultaneously based on the pea starch and extrusion process in this study. Increased degree of substitution (DS) was found for myristic acid complexed pea starches (nominal DS= ~0.8) when compared to palmitic acid complexed pea starch (nominal DS= ~0.5). Contact angle measurements, FTIR and DSC thermograms confirmed the presence of lipids. Lipid complexed starch films showed increasing hydrophobicity with increasing lipid content. As an alternative product compared to functional foods, the modified starch was considered as a biodegradable film for industrial applications. The material was produced at the highest moisture content for extruded native starch and two concentrations of lipid complexed starch using an intensive screw design. Preliminary results show that increasing lipid content and adding 1% glycerol to samples decreases the force per film thickness required to puncture films. However further investigation is required to determine effect of heat and moisture deformation. / Thesis / Master of Applied Science (MASc) / Incorporation of pulses into food products has been a major area of Canadian research for its potential to create new avenues of enzyme resistant food starches. Extrusion cooking is commonly used in industry for producing various food products such as snacks and cereals but little research has been reported on using an extruder to rapidly produce resistant pulse starches as a functional ingredient on a large scale; resistant starch is a functional food beneficial to humans in the same manner as insoluble fiber but exhibits improved textural properties. This study aimed to develop an effective reactive extrusion process to produce lipid complexed pea starches with enhanced enzyme resistance (i.e. increased slowly digestible starch (SDS) and resistant starch (RS) content) by an examination of the effects of reaction conditions on the properties of extrusion products. The lipid complexed pea starches under optimized conditions achieved a significant but moderate increase in either RS content or SDS content depending on the sample formulation compared to their native counterparts. However, RS and SDS content could not simultaneously be improved in this study.
7

Efeito das farinhas de jatobá-do-cerrado (Hymenaea stigonocarpa Mart.) in natura e extrusada no metabolismo lipídico e parâmetros fermentativos em hamsters e resposta glicêmica em humanos após a extrusão / [Effect of jatobá-do-cerrado flour (Hymenaea stigonocarpa Mart.) in natura and extruded in lipid metabolism and fermentation parameters in hamsters and glycemic response in humans after extrusion,

Olivieri, Camila Mattos Rocha 29 April 2016 (has links)
Introdução: A polpa farinácea do jatobá-do-cerrado (Hymenaea stigonocarpa Mart.) apresenta alto teor de fibra alimentar, em média 60 g/100 g, que são importantes para a redução do risco e controle de doenças crônicas não transmissíveis (DCNT). A extrusão termoplástica neutraliza aromas intensos, proporciona a formação de amido resistente, aumenta a fibra alimentar solúvel e melhora a textura do produto final. Objetivo: Estudar o efeito das farinhas de jatobá-do-cerrado in natura (FIN) e extrusada (FE) no metabolismo lipídico e parâmetros fermentativos em hamsters, bem como verificar a resposta glicêmica em humanos após a extrusão. Métodos: Processo de extrusão: velocidade de 200 rpm; matriz com 4 mm de diâmetro; taxa de compressão 3:1; alimentação constante de 70 gramas/minuto; temperatura de 150 °C; proporção farinha de jatobá-do-cerrado e amido de milho: 70:30 por cento e umidade a 25 por cento . Foi realizado um experimento animal com hamsters durante 21 dias, em que se analisou alguns parâmetros do metabolismo lipídico e colônico (fermentativos) dos animais, divididos em quatro grupos experimentais, se diferenciando pela dieta. As dietas controle (GC), in natura (GFI) e extrusada (GFE) eram hipercolesterolemizantes (13,5 por cento de gordura de coco e 0,1 por cento de colesterol) e a dieta referência (GR) com óleo de soja como fonte lipídica, não. Todas as dietas apresentavam 15 por cento de fibra alimentar, sendo que as dietas GR e GC tinham como fonte de fibra a celulose, e as dietas GFI e GFE tiveram as próprias fibras como fonte. A resposta glicêmica em humanos foi verificada por meio do ensaio do índice glicêmico e carga glicêmica da FE, com dez voluntários saudáveis que consumiram 25 gramas de carboidratos disponíveis do alimento teste (farinha extrusada) ou do pão branco como alimento controle. Resultados: Não foi observada diferença significativa entre o peso final, ingestão diária média e total, ganho de peso e CEA entre os animais dos quatro grupos. A concentração de triglicerídeos foi menor em 41 por cento e 38 por cento nos animais que receberam as dietas GFI e GFE, em relação aqueles que receberam a dieta GC, assim como também para o colesterol total (55 por cento e 47 por cento ), LDL-c (70 por cento e 53 por cento ) e não-HDL-c (63 por cento e 49 por cento ) séricos, lipídeos totais hepáticos (39 por cento e 45 por cento ) e o peso dos fígados dos animais também foi menor (21 por cento em ambos os grupos). Não houve diferença no colesterol hepático e excretado nas fezes dos animais dos quatro grupos. Os animais do GFE excretaram 57 por cento mais ácidos biliares nas fezes que os animais do GC. Com relação aos parâmetros fermentativos, observou-se maior excreção de fibras (1,24 ± 0,08 e 1,52 ± 0,09 gramas) nos animais dos grupos GR e GC respectivamente, em relação aos do GFI e GFE (0,50 e 0,48 gramas), porém o escore fecal (3,50 ± 0,19 e 3,38 ± 0,18) e o grau de fermentação (54 e 52 por cento ) foi maior nos animais dos grupos GFI e GFE. Houve uma maior produção de AGCC no ceco dos animais dos grupos GFI e GFE (80 e 57,5 µmol/g de ceco respectivamente) e maior diminuição do pH no conteúdo cecal nos animais do grupo GFI (7,49 ± 0,10), em relação ao GC (8,06 ± 0,13). Os ácidos acético e propiônico, estiveram presentes em maior quantidade no ceco dos animais dos grupos GFI (58,5 e 6,1 µmol/g de ceco) e GFE (42,5 e 6,6 µmol/g de ceco) e os animais do GFI produziram mais ácido butírico (15 µmol/g de ceco), em relação aos demais grupos. Quanto à resposta glicêmica da farinha pós extrusão, não houve diferença entre a área de resposta glicêmica da farinha extrusada e do pão branco, o índice glicêmico da farinha extrusada (glicose como controle) foi classificado como moderado, e a carga glicêmica (na porção de 30 gramas), baixa. Conclusão: As FIN e FE favoreceram a redução do colesterol total, LDL-c, não-HDL-c e dos triglicerídeos séricos, além da diminuição do acúmulo de lipídeos hepáticos. Foi observado também aumento expressivo na formação de AGCC e no grau de fermentação. A FE proporcionou um aumento na excreção de ácidos biliares nas fezes e apresentou índice glicêmico moderado e baixa carga glicêmica. / Introduction: The mealy pulp of jatobá-do-cerrado (Hymenaea stigonocarpa Mart.) has high dietary fiber content, on average 60 g/100 g, which is important for reducing risk and control chronic non-communicable diseases (NCDs). The thermoplastic extrusion neutralizes intense flavors, formation of resistant starch, increases soluble dietary fiber and improves the texture of the final product. Objectives: Check the effect of jatobá-do-cerrado flour in natura (IF) and extruded (EF) on lipid metabolism and fermentation parameters in hamsters as well as the glycemic response in humans after extrusion. Methods: Extrusion cooking: speed of 200 rpm; 4 mm die diameter; compression ratio 3:1; constant feed rate 70 g/min; temperature 150 °C; ratio of jatobá-do-cerrado flour to corn starch: 70:30 per cent and 25 per cent moisture. A 21-day biological experiment with hamsters was conducted, in which parameters of the animals lipid metabolism and colonic (fermentation) were analyzed; they were divided into four groups, differing by diet. The control diets (CG), in natura (IFG) and extruded (EFG) were hypercholesterolemic (13.5 per cent coconut fat and 0.1 per cent cholesterol), and the reference diet (RG) with soybean oil as a lipid source was not. All diets had 15 per cent of dietary fiber, being that RG and CG diets had the cellulose fiber source, and IFG and EFG diets had the fibers themselves as a source. The glycemic response in humans was evaluated by the glycemic index and glycemic load test of EF, with ten healthy volunteers who consumed 25 grams of available carbohydrate food test (extruded) or white bread as food control. Results: There was no significant difference between final weight, average total and daily intake, weight gain and FER between animals of the four groups. The values of triglycerides were lower by 41 per cent and 38 per cent in the animals receiving the IFG and EFG diets, for those who received the CG diet, as well as for total cholesterol (55 per cent and 47 per cent ), LDL-c (70 per cent and 53 per cent ) and non-HDL-c levels (63 per cent and 49 per cent ) serum, liver lipids (39 per cent and 45 per cent ) and the animals\' livers weight was lower (21 per cent in both groups). There was no difference in hepatic cholesterol and excreted in feces of animals of the four groups. The animals of the EFG group excrete 57 per cent more bile acids in stool than animals CG. Regarding the fermentation parameters, we observed increased excretion of fibers (1.24 ± 0.08 and 1.52 ± 0.09 g) in animals of RG and CG respectively, in relation to IFG and EFG (0.50 and 0.48 grams), but the fecal score (3.50 ± 0.19 and 3.38 ± 0.18) and the degree of fermentation (54 and 52 per cent ) were higher in animal IFG and EFG groups. There was a greater production of SCFA in the caecum of animals IFG groups and EFG (80 to 57.5 µmol/g caecum respectively) and greater decrease in pH in the cecal contents of IFG animals group (7.49 ± 0.10) compared to the control group (8.06 ± 0.13). The acetic and propionic acids were present in higher amounts in the caecum of animals IFG groups (58.5 and 6.1 µmol/g caecum) and EFG (42.5 and 6.6 µmol/g caecum) and the animals of IFG group produced more butyric acid (15 µmol/g caecum), compared to other groups. Concerning the glycemic response of flour after extrusion, there was no difference between the glycemic response area of extruded flour and white bread, the glycemic index of extruded flour (glucose as a control) was classified as moderate and glycemic load (the portion of 30 grams) low. Conclusion: IF and EF aided in the reduction of total cholesterol, LDL-c, non-HDL-c and triglycerides, as well as decreased the accumulation of liver lipids. A significant increase in the SCFA and degree of fermentation was also observed. The EF increased the excretion of bile acids in stool, and presented moderate glycemic index and low glycemic load.
8

Efeito das farinhas de jatobá-do-cerrado (Hymenaea stigonocarpa Mart.) in natura e extrusada no metabolismo lipídico e parâmetros fermentativos em hamsters e resposta glicêmica em humanos após a extrusão / [Effect of jatobá-do-cerrado flour (Hymenaea stigonocarpa Mart.) in natura and extruded in lipid metabolism and fermentation parameters in hamsters and glycemic response in humans after extrusion,

Camila Mattos Rocha Olivieri 29 April 2016 (has links)
Introdução: A polpa farinácea do jatobá-do-cerrado (Hymenaea stigonocarpa Mart.) apresenta alto teor de fibra alimentar, em média 60 g/100 g, que são importantes para a redução do risco e controle de doenças crônicas não transmissíveis (DCNT). A extrusão termoplástica neutraliza aromas intensos, proporciona a formação de amido resistente, aumenta a fibra alimentar solúvel e melhora a textura do produto final. Objetivo: Estudar o efeito das farinhas de jatobá-do-cerrado in natura (FIN) e extrusada (FE) no metabolismo lipídico e parâmetros fermentativos em hamsters, bem como verificar a resposta glicêmica em humanos após a extrusão. Métodos: Processo de extrusão: velocidade de 200 rpm; matriz com 4 mm de diâmetro; taxa de compressão 3:1; alimentação constante de 70 gramas/minuto; temperatura de 150 °C; proporção farinha de jatobá-do-cerrado e amido de milho: 70:30 por cento e umidade a 25 por cento . Foi realizado um experimento animal com hamsters durante 21 dias, em que se analisou alguns parâmetros do metabolismo lipídico e colônico (fermentativos) dos animais, divididos em quatro grupos experimentais, se diferenciando pela dieta. As dietas controle (GC), in natura (GFI) e extrusada (GFE) eram hipercolesterolemizantes (13,5 por cento de gordura de coco e 0,1 por cento de colesterol) e a dieta referência (GR) com óleo de soja como fonte lipídica, não. Todas as dietas apresentavam 15 por cento de fibra alimentar, sendo que as dietas GR e GC tinham como fonte de fibra a celulose, e as dietas GFI e GFE tiveram as próprias fibras como fonte. A resposta glicêmica em humanos foi verificada por meio do ensaio do índice glicêmico e carga glicêmica da FE, com dez voluntários saudáveis que consumiram 25 gramas de carboidratos disponíveis do alimento teste (farinha extrusada) ou do pão branco como alimento controle. Resultados: Não foi observada diferença significativa entre o peso final, ingestão diária média e total, ganho de peso e CEA entre os animais dos quatro grupos. A concentração de triglicerídeos foi menor em 41 por cento e 38 por cento nos animais que receberam as dietas GFI e GFE, em relação aqueles que receberam a dieta GC, assim como também para o colesterol total (55 por cento e 47 por cento ), LDL-c (70 por cento e 53 por cento ) e não-HDL-c (63 por cento e 49 por cento ) séricos, lipídeos totais hepáticos (39 por cento e 45 por cento ) e o peso dos fígados dos animais também foi menor (21 por cento em ambos os grupos). Não houve diferença no colesterol hepático e excretado nas fezes dos animais dos quatro grupos. Os animais do GFE excretaram 57 por cento mais ácidos biliares nas fezes que os animais do GC. Com relação aos parâmetros fermentativos, observou-se maior excreção de fibras (1,24 ± 0,08 e 1,52 ± 0,09 gramas) nos animais dos grupos GR e GC respectivamente, em relação aos do GFI e GFE (0,50 e 0,48 gramas), porém o escore fecal (3,50 ± 0,19 e 3,38 ± 0,18) e o grau de fermentação (54 e 52 por cento ) foi maior nos animais dos grupos GFI e GFE. Houve uma maior produção de AGCC no ceco dos animais dos grupos GFI e GFE (80 e 57,5 µmol/g de ceco respectivamente) e maior diminuição do pH no conteúdo cecal nos animais do grupo GFI (7,49 ± 0,10), em relação ao GC (8,06 ± 0,13). Os ácidos acético e propiônico, estiveram presentes em maior quantidade no ceco dos animais dos grupos GFI (58,5 e 6,1 µmol/g de ceco) e GFE (42,5 e 6,6 µmol/g de ceco) e os animais do GFI produziram mais ácido butírico (15 µmol/g de ceco), em relação aos demais grupos. Quanto à resposta glicêmica da farinha pós extrusão, não houve diferença entre a área de resposta glicêmica da farinha extrusada e do pão branco, o índice glicêmico da farinha extrusada (glicose como controle) foi classificado como moderado, e a carga glicêmica (na porção de 30 gramas), baixa. Conclusão: As FIN e FE favoreceram a redução do colesterol total, LDL-c, não-HDL-c e dos triglicerídeos séricos, além da diminuição do acúmulo de lipídeos hepáticos. Foi observado também aumento expressivo na formação de AGCC e no grau de fermentação. A FE proporcionou um aumento na excreção de ácidos biliares nas fezes e apresentou índice glicêmico moderado e baixa carga glicêmica. / Introduction: The mealy pulp of jatobá-do-cerrado (Hymenaea stigonocarpa Mart.) has high dietary fiber content, on average 60 g/100 g, which is important for reducing risk and control chronic non-communicable diseases (NCDs). The thermoplastic extrusion neutralizes intense flavors, formation of resistant starch, increases soluble dietary fiber and improves the texture of the final product. Objectives: Check the effect of jatobá-do-cerrado flour in natura (IF) and extruded (EF) on lipid metabolism and fermentation parameters in hamsters as well as the glycemic response in humans after extrusion. Methods: Extrusion cooking: speed of 200 rpm; 4 mm die diameter; compression ratio 3:1; constant feed rate 70 g/min; temperature 150 °C; ratio of jatobá-do-cerrado flour to corn starch: 70:30 per cent and 25 per cent moisture. A 21-day biological experiment with hamsters was conducted, in which parameters of the animals lipid metabolism and colonic (fermentation) were analyzed; they were divided into four groups, differing by diet. The control diets (CG), in natura (IFG) and extruded (EFG) were hypercholesterolemic (13.5 per cent coconut fat and 0.1 per cent cholesterol), and the reference diet (RG) with soybean oil as a lipid source was not. All diets had 15 per cent of dietary fiber, being that RG and CG diets had the cellulose fiber source, and IFG and EFG diets had the fibers themselves as a source. The glycemic response in humans was evaluated by the glycemic index and glycemic load test of EF, with ten healthy volunteers who consumed 25 grams of available carbohydrate food test (extruded) or white bread as food control. Results: There was no significant difference between final weight, average total and daily intake, weight gain and FER between animals of the four groups. The values of triglycerides were lower by 41 per cent and 38 per cent in the animals receiving the IFG and EFG diets, for those who received the CG diet, as well as for total cholesterol (55 per cent and 47 per cent ), LDL-c (70 per cent and 53 per cent ) and non-HDL-c levels (63 per cent and 49 per cent ) serum, liver lipids (39 per cent and 45 per cent ) and the animals\' livers weight was lower (21 per cent in both groups). There was no difference in hepatic cholesterol and excreted in feces of animals of the four groups. The animals of the EFG group excrete 57 per cent more bile acids in stool than animals CG. Regarding the fermentation parameters, we observed increased excretion of fibers (1.24 ± 0.08 and 1.52 ± 0.09 g) in animals of RG and CG respectively, in relation to IFG and EFG (0.50 and 0.48 grams), but the fecal score (3.50 ± 0.19 and 3.38 ± 0.18) and the degree of fermentation (54 and 52 per cent ) were higher in animal IFG and EFG groups. There was a greater production of SCFA in the caecum of animals IFG groups and EFG (80 to 57.5 µmol/g caecum respectively) and greater decrease in pH in the cecal contents of IFG animals group (7.49 ± 0.10) compared to the control group (8.06 ± 0.13). The acetic and propionic acids were present in higher amounts in the caecum of animals IFG groups (58.5 and 6.1 µmol/g caecum) and EFG (42.5 and 6.6 µmol/g caecum) and the animals of IFG group produced more butyric acid (15 µmol/g caecum), compared to other groups. Concerning the glycemic response of flour after extrusion, there was no difference between the glycemic response area of extruded flour and white bread, the glycemic index of extruded flour (glucose as a control) was classified as moderate and glycemic load (the portion of 30 grams) low. Conclusion: IF and EF aided in the reduction of total cholesterol, LDL-c, non-HDL-c and triglycerides, as well as decreased the accumulation of liver lipids. A significant increase in the SCFA and degree of fermentation was also observed. The EF increased the excretion of bile acids in stool, and presented moderate glycemic index and low glycemic load.

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