| 1. |
- Bishnoi, Shahana, et al.
(författare)
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Adjustable polysaccharides-proteins films made of aqueous wheat proteins and alginate solutions
- 2022
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Ingår i: Food Chemistry. - : Elsevier BV. - 0308-8146 .- 1873-7072. ; 391, s. 133196-
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Tidskriftsartikel (refereegranskat)abstract
- Large amount of wheat proteins by-products are produced during wheat starch manufacture. This work aimed to develop edible films of cast aqueous wheat proteins (WP) and alginate (Al) solutions. The investigation of the microstructure of Al/WP films revealed a more compacted cross-section and homogeneous surface, comparatively to Al films. Those properties could be modified with the increase of WP concentration from 4 to 8 % w/v, as result of electrostatic interactions between WP and Al. Furthermore, the incorporation of WP provided UltraViolet-blocking behaviour (4-fold decrease in the Ultra-Violet-B region). Additionally, the incorporation of WP in the films reduced the water solubility of the Al films. It was also found that by incorporating different amounts of WP the mechanical and Water Vapor Transmission rate (WVTR) properties could also be modified, so the film composition could be adjusted to suit different types of foods and applications (e.g. coatings and packaging).
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| 2. |
- España Giner, Jose Manuel, et al.
(författare)
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Antioxidant effects of natural compounds on green composite materials
- 2012
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Ingår i: Plastics Research Online. - Bethel, United States : Society of Plastics Engineers. ; , s. 1-3
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Naturally-occurring antioxidant compounds can improve the thermal resistance of a bio-composite, increasing the degradation temperature of the material by as much as 130%.
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| 3. |
- Johansson, Mathias, et al.
(författare)
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Effect of starch and fibre on faba bean protein gel characteristics
- 2022
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Ingår i: Food Hydrocolloids. - : Elsevier BV. - 0268-005X .- 1873-7137. ; 131
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Tidskriftsartikel (refereegranskat)abstract
- Faba bean is a promising alternative to soybean for production of protein-rich plant-based foods. Increased understanding of the gelling behaviour of non-soy legumes can facilitate development of novel plant-based foods based on other legumes, such as faba bean. A mixture design was used in this study to evaluate the effect of different proportions of protein, starch and fibre fractions extracted from faba beans on gelation properties, texture and microstructure of the resulting gels. Large deformation properties, in terms of fracture stress and fracture strain, decreased as fibre and/or starch replaced protein. In contrast, Young's modulus and storage modulus increased with substitution of the protein. Light microscopy revealed that for all gels, protein remained the continuous phase within the region studied (65–100% protein fraction, 0–35% starch fraction, 0–10% fibre fraction in total flour added). Swollen and deformed starch granules were distributed throughout the mixed gels with added starch. Leaked amylose aggregated on starch and fibre surfaces and in small cavities (<1 μm) throughout the protein network. No clear difference between samples in protein network structure was observed by scanning electron microscopy. The reduction in large deformation properties was tentatively attributed to inhomogeneities created by the added starch and fibre. The increase in small deformation properties was hypothesised to be affected by water adsorption and moisture stability through the starch and fibre, increasing the effective protein concentration in the surrounding matrix and enhancing the protein network, or potentially by starch granules and fibre particles acting as active fillers reinforcing the gel structure.
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| 4. |
- Kittikorn, Thorsak, et al.
(författare)
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Enhancement of interfacial adhesion and engineering properties of polyvinyl alcohol/polylactic acid laminate films filled with modified microfibrillated cellulose
- 2020
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Ingår i: Journal of plastic film & sheeting (Print). - : SAGE Publications Ltd. - 8756-0879 .- 1530-8014. ; 36:4, s. 368-390
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Tidskriftsartikel (refereegranskat)abstract
- This work was done to improve the interfacial adhesion and engineering performance of polyvinyl alcohol/polylactic acid laminate film by altering the polyvinyl alcohol phase surface properties via incorporating microfibrillated cellulose modified by propionylation. Incorporating the modified microfibrillated cellulose into polyvinyl alcohol film improved adhesion between film layers during the laminating process. Improved peel strength and tensile properties confirmed that modified microfibrillated cellulose can produce better bonding between polyvinyl alcohol and polylactic acid via mechanical interlocking and cohesive forces at the film interface. Modified microfibrillated cellulose (3 wt%) increased the peel strength by 40% comparing with the neat polyvinyl alcohol/polylactic acid laminate film.The reduction of both moisture absorption and diffusion rate of the modified microfibrillated cellulose–polyvinyl alcohol/polylactic acid to 20 and 23%, respectively, also indicated that the modified microfibrillated cellulose could inhibit moisture permeation across the film. This was because the modified microfibrillated cellulose is hydrophobic. Furthermore, the addition of modified microfibrillated cellulose also increased the decomposition temperature of the laminate film up to 10% as observed at 20% of remaining weight, while the storage modulus substantially increasing to 72% relative to the neat laminate film.The superior interfacial adhesion between the polylactic acid and modified microfibrillated cellulose–polyvinyl alcohol layers, observed by scanning electron microscopy, confirmed the improved compatibility between the polyvinyl alcohol and polylactic acid phases.
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| 5. |
- Mendoza, Ana, et al.
(författare)
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Image analysis of PDMS/ZnO nanocomposite surfaces for optimized superhydrophobic and self-cleaning surface design
- 2023
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Ingår i: Surfaces and Interfaces. - : Elsevier B.V.. - 2468-0230. ; 37
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Tidskriftsartikel (refereegranskat)abstract
- Optimized superhydrophobic and self-cleaning nanocomposite surfaces were obtained by spraying surface modified ZnO nanoparticles (NPs) onto PDMS, using octadecylphosphonic acid and octadecanethiol as hydrophobic modifiers. In this study, it is the first time to our knowledge that surface parameters such as topography, morphology, superhydrophobicity, and self-cleaning are correlated to particle surface distribution and agglomeration parameters obtained by image analysis. The topography, morphology, and wettability of the surfaces were analyzed using atomic force microscopy, scanning electron microscopy, static contact angle (SCA), and contact angle hysteresis measurements. Image analysis was performed using the new enhanced graphical user interface of a previously self-developed Matlab® algorithm. Both hydrophobization methodologies increased the NPs’ surface coverage and the hierarchical rough structure formation on the substrates, resulting in more homogenous superhydrophobic self-cleaning surfaces. A higher coated fraction and lower degree of interconnected uncoated PDMS paths are correlated to an increase in SCA. The combination of a higher agglomerates fraction, lower agglomerate radius, and lower distance between agglomerates obtained for the surfaces with hydrophobized ZnO-NPs rendered self-cleaning surfaces. The observed correlations increase the understanding of the design and modelling of superhydrophobic self-cleaning PDMS/ZnO nanocomposite surfaces for use in high voltage outdoor insulators.
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| 6. |
- Moriana-Torró, Rosana, et al.
(författare)
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Thermal characterisation of photo-oxidized HDPE/Mater-Bi and LDPE/Mater-Bi blends buried in soil
- 2008
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Ingår i: Journal of Applied Polymer Science. - : Wiley. - 0021-8995 .- 1097-4628. ; 109:2, s. 1177-1188
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Tidskriftsartikel (refereegranskat)abstract
- Blends of high and low density polyethylene with a commercial biodegradable material (Mater-Bi) were subjected to an accelerated soil burial test. A set of samples was previously photo-oxidized to evaluate the effects of UV-irradiation on the degradation in soil process of these blends. Thermogravimetric as well as calorimetric analysis were performed to study the biodegradation, photo-degradation and their synergetic effects. Differential scanning calorimetry was carried out to analyze the morphological changes as a consequence of the photo-oxidation process. UV-irradiation slightly modifies the crystalline content of HDPE/Mater-Bi blends, increasing the heterogeneity of this blend. Criado master curves were plotted to analyses the degradation kinetic model. Broido and Coats-Redfern methods have been used for calculating the Ea of the thermal decomposition mechanisms. Thermogravimetric results reveal that noncomplexed starch is more affected by biodegradation than the polyethylene matrix and the starch/EVPH complexes chains from Mater-Bi. However, the effects of both photo-oxidation and biodegradation processes on the thermal decomposition of Mater-Bi is influenced by the polymeric matrix used. Previous photo-oxidation finds to slow down the degradative effects caused by the soil burial test on the HDPE/Mater-Bi blends. © 2008 Wiley Periodicals, Inc.
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| 7. |
- Norberg Samuelsson, Lina, et al.
(författare)
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Model-free rate expression for thermal decomposition processes : The case of microcrystalline cellulose pyrolysis
- 2015
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 143, s. 438-447
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Tidskriftsartikel (refereegranskat)abstract
- We explore the possibility to derive a completely model-free rate expression using isoconversional methods. The Friedman differential method (Friedman, 1964) and the incremental integral method by Vyazovkin (2001) were both extended to allow for an estimation of not only the apparent activation energy but also the effective kinetic prefactor, defined as the product of the pre-exponential factor and the conversion function. Analyzing experimental thermogravimetric data for the pyrolytic decomposition of microcrystalline cellulose, measured at six different heating rates and three different initial sample masses (1.5-10 mg), revealed the presence of secondary char forming reactions and thermal lag, both increasing with increased sample mass. Conditioning of the temperature function enables extraction of more reliable prefactors and we found that the derived kinetic parameters show weak dependence on initial sample mass. Finally, by successful modeling of quasi-isothermal experimental curves, we show that the discrete rate expression estimated from linear heating rate experiments enables modeling of the thermal decomposition rate without any assumptions regarding the chemical process present. These findings can facilitate the design and optimization of industrial isothermal biomass fed reactors.
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| 8. |
- Requena, Raquel, et al.
(författare)
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Integral Fractionation of Rice Husks into Bioactive Arabinoxylans, llulose Nanocrystals, and Silica Particles
- 2019
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Ingår i: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 7:6, s. 6275-6286
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Tidskriftsartikel (refereegranskat)abstract
- Rice husk is an important agricultural by-product that has not been exploited yet to full capacity for advanced applications. The feasibility of obtaining high-value products such as bioactive hemicelluloses and cellulose nanocrystals (CNCs) from rice husk is here demonstrated in a cascade biorefinery process using subcritical water extraction (SWE) prior to bleaching and acid hydrolysis and compared to traditional alkali pretreatments. The proposed SWE process enables the isolation of bioactive arabinoxylans with phenolic acid moieties, thus preserving their antioxidant and anti- bacterial properties that are lost during alkaline conditions. Bioactive Additionally, SWE can be combined with subsequent arabinoxylan Silica particles bleaching and acid hydrolysis to obtain CNCs with large aspect ratio, high crystallinity, and thermal stability. The hydrothermal process also enables the recovery of silica particles that are lost during the alkali step but can be recovered after the isolation of the CNCs. Our biorefinery strategy results in the integral valorization of rice husk into their molecular components (bioactive arabinoxylans, cellulose nanocrystals, and silica particles), which can be used as additives for food applications and as reinforcing agents in biocomposite materials, respectively.
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| 9. |
- Rojas-Lema, Sandra, et al.
(författare)
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“Faba bean protein films reinforced with cellulose nanocrystals as edible food packaging material”
- 2021
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Ingår i: Food Hydrocolloids. - : Elsevier B.V.. - 0268-005X .- 1873-7137. ; 121
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Tidskriftsartikel (refereegranskat)abstract
- In the present work, transparent films were obtained by the solution casting method from faba bean protein isolate (FBP), reinforced with different cellulose nanocrystals (CNCs) content (1, 3, 5 and 7 wt%), obtained by acid hydrolysis of pine cone, and using glycerol as plasticizer. The influence of different CNCs loadings on the mechanical, thermal, barrier, optical, and morphological properties was discussed. Microstructurally, the FTIR and FESEM results corroborated the formation of intramolecular interactions between the CNCs and proteins that lead to more compact and homogeneous films. These interactions had a positive influence on the mechanical strength properties, which is reflected in higher tensile strength and Young's modulus in reinforced films with respect to the control film, resulting in stiffer films as the CNCs content increases. Thermal stability of the FBP films was also improved with the presence of CNCs, by increasing the characteristic onset degradation temperature. In addition, the linkages formed between the CNCs, and proteins reduced the water affinity of the reinforced films, leading to a reduction in their moisture content and water solubility, and an increase in their water contact angle, obtaining more hydrophobic films as the CNCs content in the matrix increased. The addition of CNCs in the FBP film also considerably improved its barrier properties, reducing its water vapour transmission rate (WVTR) and oxygen transmission rate (OTR). The present work shows the possibility of obtaining biobased and biodegradable films of CNC-reinforced FBP with improved mechanical, thermal and barrier properties, and low water susceptibility, which can be of great interest in the food packaging sector as edible food packaging material.
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| 10. |
- Rojas-Lema, S., et al.
(författare)
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The effect of pine cone lignin on mechanical, thermal and barrier properties of faba bean protein films for packaging applications
- 2023
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Ingår i: Journal of Food Engineering. - : Elsevier Ltd. - 0260-8774 .- 1873-5770. ; 339
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Tidskriftsartikel (refereegranskat)abstract
- In the present work, faba bean protein (FBP) films plasticized with glycerol and reinforced with different amounts (2.5, 5.0, 7.5 and 10% by weight of FBP) of lignin extracted from pine cones (PL) have been obtained by solution casting. The results obtained showed an elongation at break of 111.7% with the addition of 5% PL to the FBP film, which represents an increase of 107% compared to the FBP control film. On the other hand, it was observed by thermogravimetric analysis (TGA) that the incorporation of lignin improved the thermal stability of the FBP film, leading to an increase in the protein degradation temperature, being this increase higher in the sample film reinforced with 10% PL. The barrier properties of the FBP films were also affected by the presence of lignin, leading to a decrease in water vapor permeability (WVP) in comparison to the unreinforced film. The results show that the sample reinforced with 2.5% PL had the lowest WVP value, with a reduction of 25% compared to the control film. Chemical analysis by Fourier transform infrared spectroscopy (FTIR) confirmed the formation of intramolecular interactions between lignin and proteins which, together with the inherent hydrophobicity of lignin, resulted in a decrease of the moisture content in the films reinforced with PL. This research work has allowed the development of biobased and biodegradable films with attractive properties that could be of potential use in sectors such as packaging. © 2022 The Authors
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