| 1. |
- Gallstedt, Mikael, et al.
(author)
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Film Extrusion of Crambe abyssinica/Wheat Gluten Blends
- 2017
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In: Journal of Visualized Experiments. - : JOURNAL OF VISUALIZED EXPERIMENTS. - 1940-087X. ; :119
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Journal article (peer-reviewed)abstract
- Crambe abyssinica is a plant with potential for use in industrial (non-food) plant oil production. The side stream from this oil production is a high-protein crambe meal that has limited value, as it is not fit for food or feed use. However, it contains proteins that could potentially make it a suitable raw material for higher-value products. The purpose of this study was to find methods of making this side stream into extruded films, showing that products with a higher value can be produced. The study mainly considered the development of material compositions and methods of preparing and extruding the material. Wheat gluten was added as a supportive protein matrix material, together with glycerol as a plasticizer and urea as a denaturant. The extrudate was evaluated with respect to mechanical (tensile testing) and oxygen barrier properties, and the extrudate structure was revealed visually and by scanning electron microscopy. A denser, more homogeneous material had a lower oxygen transmission rate, higher strength, and higher extensibility. The most homogeneous films were made at an extruder die temperature of 125-130 degrees C. It is shown here that a film can be extruded with promising mechanical and oxygen barrier properties, the latter especially after a final compression molding step.
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| 2. |
- Hedenqvist, Mikael S., et al.
(author)
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Extrusion of protein plastics
- 2017
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In: Abstracts of Papers of the American Chemical Society. - : American Chemical Society (ACS). - 0065-7727. ; 253
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Journal article (other academic/artistic)
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| 3. |
- Kuktaite, Ramune, et al.
(author)
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Gluten Biopolymer and Nanoclay-Derived Structures in Wheat Gluten-Urea-Clay Composites: Relation to Barrier and Mechanical Properties
- 2014
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In: ACS Sustainable Chemistry & Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 2:6, s. 1439-1445
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Journal article (peer-reviewed)abstract
- Here, we investigated the structure of natural montmorillonite (MMT) and modified Cloisite C15A (MMT pre-intercalated with a dimethyl-dehydrogenated tallow quaternary ammonium surfactant) nanoclays in the wheat gluten-urea matrix in order to obtain a nanocomposite with improved barrier and mechanical properties. Small-angle X-ray scattering indicated that the characteristic hexagonal closed packed structure of the wheat gluten-urea matrix was not found in the CISA system and existed only in the 3 and 5 wt % MMT composites. SAXS/WAXS, TGA, and water vapor/oxygen barrier properties indicated that the dispersion of the C15A clay was somewhat better than the natural MMT clay. Confocal laser scanning microscopy showed MMT clay clusters and C15A clay particles dispersed in the protein matrix, and these were preferentially oriented in the extrusion direction only at 5 wt % of the CIS clay. The water vapor/oxygen barrier properties were improved with the presence of clay. Independent of the clay content used, the stiffness decreased and the extensibility increased in the presence of C15A due to the surfactant induced changes on the protein. The opposite "more expected" clay effect (increasing stiffness and decreasing extensibility) was observed for the MMT composites.
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| 4. |
- Kuktaite, Ramune, et al.
(author)
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Structure and Morphology of Wheat Gluten Films : From Polymeric Protein Aggregates toward Superstructure Arrangements
- 2011
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In: Biomacromolecules. - : American Chemical Society (ACS). - 1525-7797 .- 1526-4602. ; 12:5, s. 1438-1448
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Journal article (peer-reviewed)abstract
- Evaluation of structure and morphology of extruded wheat gluten (WG) films showed WG protein assemblies elucidated on a range of length scales from nano (4.4 angstrom and 9 to 10 angstrom, up to 70 angstrom) to micro (10 mu m). The presence of NaOH in WG films induced a tetragonal structure with unit cell parameters, a = 51.85 angstrom and c = 40.65 angstrom, whereas NH4OH resulted in a bidimensional hexagonal close-packed (HCP) structure with a lattice parameter of 70 angstrom. In the WG films with NH4OH, a highly polymerized protein pattern with intimately mixed glutenins and gliadins bounded through SH/SS interchange reactions was found. A large content of beta-sheet structures was also found in these films, and the film structure was oriented in the extrusion direction. In conclusion, this study highlights complexities of the supramolecular structures and conformations of wheat gluten polymeric proteins in biofilms not previously reported for biobased materials.
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| 5. |
- Muneer, Faraz, et al.
(author)
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Innovative Gliadin/Glutenin and Modified Potato Starch Green Composites : Chemistry, Structure, and Functionality Induced by Processing
- 2016
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In: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 4:12, s. 6332-6343
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Journal article (peer-reviewed)abstract
- In this study, we combined two wheat proteins, gliadin (Gli)/glutenin (GT), and modified potato starch (MPS) into composites using extrusion. In the Gli/GT MPS composites, we studied the structural dynamics of proteins and starch, protein starch interactions, protein properties, and composite morphology in relation to mechanical and barrier properties. Materials with different ratios of Gli/GT and MPS were extruded using either glycerol or glycerol water at 110 and 130 degrees C. For the first time, a hierarchical hexagonal structure of Gli proteins was observed in Gli MPS composite at both extrusion temperatures. The higher temperature (130 degrees C) induced a higher degree of protein cross-links, an increase in the polymer size, and formation of beta-sheets compared to 110 degrees C. The combination of plasticizers (glycerol and water) favored a micro-structural morphology with improved gelatinization of starch, processability, as well as strength, stiffness, and extensibility of GT MPS composites. The highest amount of the oxidized proteins was observed in the samples with the highest protein content and at high extrusion temperature. The Gli- and GT MPS (30/70) samples showed promising oxygen barrier properties under ambient testing conditions. These findings provide in-depth information for tailoring the structural functional relationship of the Gli/GT-potato starch composites for their promising use in designing various green materials.
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| 6. |
- Newson, William R., et al.
(author)
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Commercial potato protein concentrate as a novel source for thermoformed bio-based plastic films with unusual polymerisation and tensile properties
- 2015
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In: RSC Advances. - 2046-2069. ; 5:41, s. 32217-32226
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Journal article (peer-reviewed)abstract
- Commercial potato protein concentrate (PPC) was investigated as a source of thermoformed bio-based plastic film. Pressing temperatures of 100 to 190 degrees C with 15 to 25% glycerol were used to form PPC films. The shape of the tensile stress-strain curve in thermoformed PPC was controlled by glycerol level and was independent of processing temperature. Tensile testing revealed that elongation at break increased with processing temperature while Young's modulus was unaffected by processing temperature, both in contrast to previous results in protein based systems. Also in contrast to previous studies, Young's modulus was found to be only sensitive to glycerol level. Maximum tensile stress increased with increasing processing temperature for PPC films. Maximum stress and strain at break correlated with the extractable high molecular weight protein content of the processed films measured with size exclusion chromatography. Infrared absorption indicated that the content of beta-sheet structure increased from the commercial protein concentrate to that pressed at 100 degrees C, but did not further develop with increasing press temperature. Changes in structural arrangements were observed by small angle X-ray scattering indicating the development of different correlation distances with processing temperature but with no clear long range order at the supramolecular level. The novel Young's modulus behaviour appears to be due to constant secondary structure or the effect of aggregated protein structure formed during protein production. Unique strain at break behaviour with processing temperature was demonstrated, likely due to new connections formed between those aggregates.
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| 7. |
- Rasheed, Faiza, et al.
(author)
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Macromolecular changes and nano-structural arrangements in gliadin and glutenin films upon chemical modification Relation to functionality
- 2015
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In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 79, s. 151-159
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Journal article (peer-reviewed)abstract
- Protein macromolecules adopted for biological and bio-based material functions are known to develop a structured protein network upon chemical modification. In this study, we aimed to evaluate the impact of chemical additives such as, NaOH, NH4OH and salicylic acid (SA), on the secondary and nano-structural transitions of wheat proteins. Further, the effect of chemically induced modifications in protein macromolecular structure was anticipated in relation to functional properties. The gliadin-NH4OH-SA film showed a supramolecular protein organization into hexagonal structures with 65 angstrom lattice parameter, and other not previously observed structural entities having a characteristic distance of 50 angstrom. Proteins in gliadin-NH4OH-SA films were highly polymerized, with increased amount of disulfide crosslinks and beta-sheets, causing improved strength and stiffness. Glutenin and WG proteins with NH4OH-SA showed extensive aggregation and an increase in beta-sheet content together with irreversible crosslinks. Irreversible crosslinks hindered a high order structure formation in glutenins, and this resulted in films with only moderately improved stiffness. Thus, formation of nano-hierarchical structures based on beta-sheets and disulfide crosslinks are the major reasons of high strength and stiffness in wheat protein based films.
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| 8. |
- Rasheed, Faiza, et al.
(author)
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Mild gluten separation - A non-destructive approach to fine tune structure and mechanical behavior of wheat gluten films
- 2015
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In: Industrial Crops and Products. - : Elsevier BV. - 0926-6690 .- 1872-633X. ; 73, s. 90-98
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Journal article (peer-reviewed)abstract
- Despite the increasing production of wheat gluten (WG) for industrial use, minor attention has been given to the impact of the separation procedure on the gluten quality. The purpose of the present study was to probe the effect of the separation treatments (harsh vs mild) on gluten structure, morphology, and performance in bio-based films. The harshly separated industrial WG showed aggregated and pre-cross linked structure in the starting material most likely due to shear forces during gluten separation from flour and heat effect during the drying procedures. Further, when the harshly separated WG was processed into films the pre-crosslinked starting material restricted new crosslinks formation and structural rearrangements at nano-scale. The mechanical integrity of the film was also affected resulting in films with low Young's modulus and strength. WG (from cultivars Diskette, Puntari, and Sleipner) recovered from mild separation showed relatively "native" non-destructed crosslinking pattern and not previously observed structural morphology at nano-scale. When processed into films the mildly separated WG showed well polymerized intimately crosslinked proteins both with disulfide and other covalent crosslinks. The nano-scale morphology showed lamellar and hexagonal arrangements, not reported so far in any study. The structural rearrangements among films from mildly separated WG resulted in materials with improved mechanical integrity as compared to films from harshly separated WG. The present study showed that the quality of WG is significantly affected by the separation procedure which also affects protein polymerization, nano-scale morphology, and tensile properties of films. (C) 2015 Elsevier B.V. All rights reserved.
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| 9. |
- Rasheed, Faiza, et al.
(author)
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The use of plants as a "green factory" to produce high strength gluten-based materials
- 2016
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In: Green Chemistry. - : Royal Society of Chemistry. - 1463-9262 .- 1463-9270. ; 18:9, s. 2782-2792
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Journal article (peer-reviewed)abstract
- The aim of the present study was to develop an understanding of how wheat plants can be used as a "green factory" by the modulation of genotype (G) and environmental (E) interactions to fine-tune the structure and increase the strength of gluten based materials. Two wheat genotypes (5 + 10 and 2 + 12) were grown under four nitrogen and two temperature regimes to obtain gluten of various characteristics. Protein microstructure morphology revealed by confocal laser scanning microscopy suggested a higher polymerisation of proteins in glycerol plasticized films from the 5 + 10 compared to the 2 + 12 genotype. Also, films with the highest Young's modulus and maximum stress were obtained from the 5 + 10 genotype, which might be explained by the higher number of cysteine residues and consequently more disulphide crosslinks in this genotype compared to the 2 + 12 one. The presence of two nano-scaled morphologies, hexagonal and lamellar structures and their internal relations were found to be of relevance for formation of beta-sheets and also to be related to performance (strength) of the material. Thus, plants could be used as a "green factory", avoiding the use of chemicals, to tune the tensile properties of the materials. Structural properties such as relatively low protein aggregation, high beta-sheet content and a high hexagonal to lamellar structural ratio at the nano-scale were found to yield films with high stiffness and strength.
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| 10. |
- Rasheed, Faiza, et al.
(author)
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The use of plants as a “green factory” to produce high strength gluten-based materials
- 2016
-
In: Green Chemistry. - 1463-9270. ; 18:9, s. 2782-2792
-
Journal article (peer-reviewed)abstract
- The aim of the present study was to develop an understanding of how wheat plants can be used as a “green factory” by the modulation of genotype (G) and environmental (E) interactions to fine-tune the structure and increase the strength of gluten based materials. Two wheat genotypes (5 + 10 and 2 + 12) were grown under four nitrogen and two temperature regimes to obtain gluten of various characteristics. Protein microstructure morphology revealed by confocal laser scanning microscopy suggested a higher polymerisation of proteins in glycerol plasticized films from the 5 + 10 compared to the 2 + 12 genotype. Also, films with the highest Young’s modulus and maximum stress were obtained from the 5 + 10 genotype, which might be explained by the higher number of cysteine residues and consequently more disulphide crosslinks in this genotype compared to the 2 + 12 one. The presence of two nano-scaled morphologies, hexagonal and lamellar structures and their internal relations were found to be of relevance for formation of β-sheets and also to be related to performance (strength) of the material. Thus, plants could be used as a “green factory”, avoiding the use of chemicals, to tune the tensile properties of the materials. Structural properties such as relatively low protein aggregation, high β-sheet content and a high hexagonal to lamellar structural ratio at the nano-scale were found to yield films with high stiffness and strength.
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