The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Denis Lourdin - One of the best experts on this subject based on the ideXlab platform.
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Mechanical behaviour of Corn Flour and starch-zein based materials in the glassy state: A matrix-particle interpretation
Carbohydrate Polymers, 2006Co-Authors: Helene Chanvrier, Guy Della Valle, Denis LourdinAbstract:Starch–zein systems were characterised by their dynamic mechanical behavior. Although the main relaxation temperatures were located in the same range of temperature for the various zein contents, significant differences were observed for the tan δ peak amplitude. They were related to the morphology of the system, i.e., dispersed zein aggregates in starch matrix or dispersed amorphous starch in zein matrix, the phase inversion domain, determined by image analysis, being in the (17–34%) phase concentration interval. When testing processed Corn Flour under different thermomechanical conditions, at a moisture content of 12.0% (wb), higher values of tan δ peak were found when starch transformation was increased. For the same trend, values of E′ modulus in the rubbery state continuously decreased which was attributed to the reduction of remaining starch granules within the Flour. The application of models of composites materials points out the matrix–particles behaviour of processed Corn Flour and starch–zein blends, whatever the particles composition. The quality of adhesion between starch and zein is inferred for the mechanical properties of their blends.
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structure and mechanical behaviour of Corn Flour and starch zein based materials in the glassy state
Carbohydrate Polymers, 2005Co-Authors: Helene Chanvrier, Paul Colonna, Guy Della Valle, Denis LourdinAbstract:Abstract Corn Flour and starch–zein based samples were prepared by extrusion and thermomoulding and then analysed at a moisture content of 12.0% (wb). Starch–zein blends (5–50% zein, db) were used to study the influence of starch–zein ratio on material properties. Glass transition temperatures were determined by differential scanning calorimetry and molecular relaxations by dynamic mechanical thermal analysis. Behaviour at large deformations was examined by the three-point bending test. The behaviour of materials made from glassy Corn Flour and starch–zein blends was compared to the behaviour of their components. Amorphous starch was ductile whereas blends and Corn Flour samples were brittle. This difference could not be explained by molecular mobility. Blend morphology observed by confocal scanning light microscopy (CLSM) showed that proteins undergo aggregation during thermomechanical processing, which largely conditioned their mechanical properties. The consequences of processing on the morphology of the protein phase in the Corn Flour were also discussed.
Helene Chanvrier - One of the best experts on this subject based on the ideXlab platform.
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Mechanical behaviour of Corn Flour and starch-zein based materials in the glassy state: A matrix-particle interpretation
Carbohydrate Polymers, 2006Co-Authors: Helene Chanvrier, Guy Della Valle, Denis LourdinAbstract:Starch–zein systems were characterised by their dynamic mechanical behavior. Although the main relaxation temperatures were located in the same range of temperature for the various zein contents, significant differences were observed for the tan δ peak amplitude. They were related to the morphology of the system, i.e., dispersed zein aggregates in starch matrix or dispersed amorphous starch in zein matrix, the phase inversion domain, determined by image analysis, being in the (17–34%) phase concentration interval. When testing processed Corn Flour under different thermomechanical conditions, at a moisture content of 12.0% (wb), higher values of tan δ peak were found when starch transformation was increased. For the same trend, values of E′ modulus in the rubbery state continuously decreased which was attributed to the reduction of remaining starch granules within the Flour. The application of models of composites materials points out the matrix–particles behaviour of processed Corn Flour and starch–zein blends, whatever the particles composition. The quality of adhesion between starch and zein is inferred for the mechanical properties of their blends.
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structure and mechanical behaviour of Corn Flour and starch zein based materials in the glassy state
Carbohydrate Polymers, 2005Co-Authors: Helene Chanvrier, Paul Colonna, Guy Della Valle, Denis LourdinAbstract:Abstract Corn Flour and starch–zein based samples were prepared by extrusion and thermomoulding and then analysed at a moisture content of 12.0% (wb). Starch–zein blends (5–50% zein, db) were used to study the influence of starch–zein ratio on material properties. Glass transition temperatures were determined by differential scanning calorimetry and molecular relaxations by dynamic mechanical thermal analysis. Behaviour at large deformations was examined by the three-point bending test. The behaviour of materials made from glassy Corn Flour and starch–zein blends was compared to the behaviour of their components. Amorphous starch was ductile whereas blends and Corn Flour samples were brittle. This difference could not be explained by molecular mobility. Blend morphology observed by confocal scanning light microscopy (CLSM) showed that proteins undergo aggregation during thermomechanical processing, which largely conditioned their mechanical properties. The consequences of processing on the morphology of the protein phase in the Corn Flour were also discussed.
Joyce I Boye - One of the best experts on this subject based on the ideXlab platform.
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protein rich extruded products prepared from soy protein isolate Corn Flour blends
Lwt - Food Science and Technology, 2013Co-Authors: Hosahalli S Ramaswamy, Joyce I BoyeAbstract:Abstract Protein rich extruded products were prepared from soy protein isolate and Corn Flour blends using a twin screw extruder and the physical properties of the extruded product were evaluated and related to process variables: soy protein isolate (SPI) (32.2–66.6 g protein/100 dry matter), feed moisture (31.6–48.4 g/100 g) and process temperature (126.4–193.6 °C). A central composite rotate design (CCRD) and response surface methodology was used to evaluate the significance of independent and interaction effects of extrusion process variables on the product’s various physical properties (breaking stress, bulk density, expansion ratio, water solubility index, rehydration rate and color). Second order polynomial regression equations were developed to relate the product responses to process variables as well as to obtain the response surfaces plots. The independent variables had significant (p ≤ 0.05) effects on physical properties of extrudates: (i) higher SPI and feed moisture contents increased the breaking stress and bulk density, but decreased the expansion ratio, water solubility index, and rehydration rate, (ii) higher SPI content decreased the color L value, whereas higher feed moisture content increased it, (iii) higher temperatures increased breaking stress, expansion ratio, rehydration rate and L value, but decreased the bulk density and water solubility index.
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twin screw extrusion of Corn Flour and soy protein isolate spi blends a response surface analysis
Food and Bioprocess Technology, 2012Co-Authors: Hosahalli S Ramaswamy, Joyce I BoyeAbstract:The effects of feed moisture, screw speed, and barrel temperature on physical properties of extruded Corn Flour and soy protein isolate (SPI) blends were investigated in a co-rotating twin-screw extruder using a response surface methodology. Corn Flour and SPI were mixed with a ratio of 4:1. The screw speed was set at five levels between 60 and 140 rpm, barrel temperature between 140 °C and 180 °C, and feed moisture between 18% and 38%. All physical properties of the extruded material evaluated—included expansion ratio, bulk density, breaking strength, water solubility index, rehydration ratio, and color—were significantly (p < 0.05) affected by the three process variables. Feed moisture was the most significant variable with quadratic effects on most of the physical properties. Response surface regression models were established to correlate the physical properties of the extruded product to the process variables. Understanding the effect of these variables on the product physical properties was deemed useful for the development of protein-rich extruded products.
Guy Della Valle - One of the best experts on this subject based on the ideXlab platform.
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Mechanical behaviour of Corn Flour and starch-zein based materials in the glassy state: A matrix-particle interpretation
Carbohydrate Polymers, 2006Co-Authors: Helene Chanvrier, Guy Della Valle, Denis LourdinAbstract:Starch–zein systems were characterised by their dynamic mechanical behavior. Although the main relaxation temperatures were located in the same range of temperature for the various zein contents, significant differences were observed for the tan δ peak amplitude. They were related to the morphology of the system, i.e., dispersed zein aggregates in starch matrix or dispersed amorphous starch in zein matrix, the phase inversion domain, determined by image analysis, being in the (17–34%) phase concentration interval. When testing processed Corn Flour under different thermomechanical conditions, at a moisture content of 12.0% (wb), higher values of tan δ peak were found when starch transformation was increased. For the same trend, values of E′ modulus in the rubbery state continuously decreased which was attributed to the reduction of remaining starch granules within the Flour. The application of models of composites materials points out the matrix–particles behaviour of processed Corn Flour and starch–zein blends, whatever the particles composition. The quality of adhesion between starch and zein is inferred for the mechanical properties of their blends.
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structure and mechanical behaviour of Corn Flour and starch zein based materials in the glassy state
Carbohydrate Polymers, 2005Co-Authors: Helene Chanvrier, Paul Colonna, Guy Della Valle, Denis LourdinAbstract:Abstract Corn Flour and starch–zein based samples were prepared by extrusion and thermomoulding and then analysed at a moisture content of 12.0% (wb). Starch–zein blends (5–50% zein, db) were used to study the influence of starch–zein ratio on material properties. Glass transition temperatures were determined by differential scanning calorimetry and molecular relaxations by dynamic mechanical thermal analysis. Behaviour at large deformations was examined by the three-point bending test. The behaviour of materials made from glassy Corn Flour and starch–zein blends was compared to the behaviour of their components. Amorphous starch was ductile whereas blends and Corn Flour samples were brittle. This difference could not be explained by molecular mobility. Blend morphology observed by confocal scanning light microscopy (CLSM) showed that proteins undergo aggregation during thermomechanical processing, which largely conditioned their mechanical properties. The consequences of processing on the morphology of the protein phase in the Corn Flour were also discussed.
Hosahalli S Ramaswamy - One of the best experts on this subject based on the ideXlab platform.
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residence time distribution of soy protein isolate and Corn Flour feed mix in a twin screw extruder
Journal of Food Processing and Preservation, 2014Co-Authors: Yang Meng, Hosahalli S Ramaswamy, Joyce I OyeAbstract:The residence time distribution (RTD) of soy protein isolate (SPI) and Corn Flour mixture through a twin-screw extruder under different conditions was evaluated. A full-factorial design of experiments was used to select the variables at different levels. The feed mixture was prepared by blending Corn Flour and SPI in the ratio of 4:1 (20% SPI content). The effect of screw speed (75, 100 and 125 rpm), feed mixture moisture content (25, 30 and 35%) and die diameter (3 and 5 mm) were investigated. All factors were found to have a significant (P < 0.05) effect on the mean resident time and its variance (square of standard deviation). Higher screw speed, higher initial moisture content and larger die diameter resulted in a shorter mean residence time. Two conventional flow models were used to represent the RTD profile in the extruder – the frequency model (F-distribution) and the cumulative RTD model (E distribution). The parameters of these models – the half-concentration internal age and particle accumulation rate – were determined by a nonlinear regression. The parameters of these models were responsive and related to process variables and both F- and E-distributions were well predicted. Practical Applications Residence time distribution (RTD) is an important parameter that describes the time spent by particles through any continuous processing system. RTD study is important with respect to extrusion processing because the properties of extruded product depend on the shear, pressure, time and temperature history of the product in the extruder. The study is aimed at evaluating RTD of a protein-rich formulation obtained by different blends of soy protein isolates and Corn Flour which are prepared for producing protein-rich soy-based products. The study is important because it examines the influence of selected process and product variables on the residence time of particles in the twin-screw extrusion system.
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protein rich extruded products prepared from soy protein isolate Corn Flour blends
Lwt - Food Science and Technology, 2013Co-Authors: Hosahalli S Ramaswamy, Joyce I BoyeAbstract:Abstract Protein rich extruded products were prepared from soy protein isolate and Corn Flour blends using a twin screw extruder and the physical properties of the extruded product were evaluated and related to process variables: soy protein isolate (SPI) (32.2–66.6 g protein/100 dry matter), feed moisture (31.6–48.4 g/100 g) and process temperature (126.4–193.6 °C). A central composite rotate design (CCRD) and response surface methodology was used to evaluate the significance of independent and interaction effects of extrusion process variables on the product’s various physical properties (breaking stress, bulk density, expansion ratio, water solubility index, rehydration rate and color). Second order polynomial regression equations were developed to relate the product responses to process variables as well as to obtain the response surfaces plots. The independent variables had significant (p ≤ 0.05) effects on physical properties of extrudates: (i) higher SPI and feed moisture contents increased the breaking stress and bulk density, but decreased the expansion ratio, water solubility index, and rehydration rate, (ii) higher SPI content decreased the color L value, whereas higher feed moisture content increased it, (iii) higher temperatures increased breaking stress, expansion ratio, rehydration rate and L value, but decreased the bulk density and water solubility index.
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twin screw extrusion of Corn Flour and soy protein isolate spi blends a response surface analysis
Food and Bioprocess Technology, 2012Co-Authors: Hosahalli S Ramaswamy, Joyce I BoyeAbstract:The effects of feed moisture, screw speed, and barrel temperature on physical properties of extruded Corn Flour and soy protein isolate (SPI) blends were investigated in a co-rotating twin-screw extruder using a response surface methodology. Corn Flour and SPI were mixed with a ratio of 4:1. The screw speed was set at five levels between 60 and 140 rpm, barrel temperature between 140 °C and 180 °C, and feed moisture between 18% and 38%. All physical properties of the extruded material evaluated—included expansion ratio, bulk density, breaking strength, water solubility index, rehydration ratio, and color—were significantly (p < 0.05) affected by the three process variables. Feed moisture was the most significant variable with quadratic effects on most of the physical properties. Response surface regression models were established to correlate the physical properties of the extruded product to the process variables. Understanding the effect of these variables on the product physical properties was deemed useful for the development of protein-rich extruded products.