| 1. |
- Li, Jingwen, et al.
(författare)
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Emerging Food Packaging Applications of Cellulose Nanocomposites : A Review
- 2022
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Ingår i: Polymers. - : MDPI AG. - 2073-4360. ; 14:19
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Forskningsöversikt (refereegranskat)abstract
- Cellulose is the most abundant biopolymer on Earth, which is synthesized by plants, bacteria, and animals, with source-dependent properties. Cellulose containing beta-1,4-linked D-glucoses further assembles into hierarchical structures in microfibrils, which can be processed to nanocellulose with length or width in the nanoscale after a variety of pretreatments including enzymatic hydrolysis, TEMPO-oxidation, and carboxymethylation. Nanocellulose can be mainly categorized into cellulose nanocrystal (CNC) produced by acid hydrolysis, cellulose nanofibrils (CNF) prepared by refining, homogenization, microfluidization, sonification, ball milling, and the aqueous counter collision (ACC) method, and bacterial cellulose (BC) biosynthesized by the Acetobacter species. Due to nontoxicity, good biodegradability and biocompatibility, high aspect ratio, low thermal expansion coefficient, excellent mechanical strength, and unique optical properties, nanocellulose is utilized to develop various cellulose nanocomposites through solution casting, Layer-by-Layer (LBL) assembly, extrusion, coating, gel-forming, spray drying, electrostatic spinning, adsorption, nanoemulsion, and other techniques, and has been widely used as food packaging material with excellent barrier and mechanical properties, antibacterial activity, and stimuli-responsive performance to improve the food quality and shelf life. Under the driving force of the increasing green food packaging market, nanocellulose production has gradually developed from lab-scale to pilot- or even industrial-scale, mainly in Europe, Africa, and Asia, though developing cost-effective preparation techniques and precisely tuning the physicochemical properties are key to the commercialization. We expect this review to summarise the recent literature in the nanocellulose-based food packaging field and provide the readers with the state-of-the-art of this research area.
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| 2. |
- Li, Jingwen, et al.
(författare)
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Nisin electroadsorption-enabled multifunctional bacterial cellulose membranes for highly efficient removal of organic and microbial pollutants in water
- 2022
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 440, s. 135922-
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Tidskriftsartikel (refereegranskat)abstract
- Membranes fabricated from bacteria-produced cellulose have many practical and technological advantages over other means of cellulose fiber production, however, their functionality for targeted applications is limited and requires complex, multi-stage processing, while the mechanisms underpinned the optimum improvements remain largely unknown. Focusing on one of the highest-demand applications in wastewater treatment, here we resolve the three persistent issues in bacterial cellulose membranes (BCMs), namely poor fibrillar network quality, insufficient functionality and unsatisfactory performance, and discover the counterintuitive, yet most effective mechanism of imparting the multifunctional properties. First, innovative application of the Hestrin-Shramm medium instead of the CM0986 medium stimulated Taonella mepensis to produce BCMs with higher yields, more uniform fibrils and developed fibrillar networks, higher crystallinity indexes, better mechanical and thermal properties. Second, a novel but facile electroadsorption method was developed to enhance BCM functionality via bonding a natural bactericidal peptide-Nisin to the deliberately activated terminals on the BCM surface, achieving great antibacterial activity, good durability, well-preserved nanoporous network, outstanding water retention and low toxicity. Third, due to the synergetic effects of surface adsorption, ionic bonding, physical retention and active microbial killing, the Nisin-decorated BCMs enabled outstanding organic dye removal and excellent disinfection performance, among the best in the available reports. Collectively, this study demonstrates that electroadsorption is a promising and potentially generic strategy to fabricate Nisin-decorated and functionalized BCMs for next-generation membrane filters toward water purification.
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| 3. |
- Piao, Xinyue, et al.
(författare)
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Inulin for surimi gel fortification : Performance and molecular weight-dependent effects
- 2023
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Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 305
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Tidskriftsartikel (refereegranskat)abstract
- Inulin is a prebiotic carbohydrate widely used in food industry due to its health benefits and unique rheological properties. For the first time, this study explores the potential of natural inulin as a sustainable food additive to enhance surimi gel characteristics, specifically focusing on understanding its molecular weight effects. The good solubility of inulin facilitates the conversion of alpha-helix to other secondary conformations which are favorable for protein denaturation and aggregation during gelation. Moreover, the abundant -OH groups at the surface of inulin can boost the chemical forces within surimi proteins to reinforce the gel network. Compared to short-chain inulin, long-chain inulin can alleviate proteolysis, enhance hydrophobic interactions and intertwine with myosin molecules, thereby reinforcing the gel network. A more viscous long-chain inulin solution formed within surimi gels fills the space between aggregated proteins and facilitates the lock of water molecules, improving the water -holding capacity (WHC). Thus, an addition of 12 % long-chain inulin leads to an enhanced hardness of surimi gel from 943 to 1593 and improved WHC from 72 % to 85 %. A new inulin-myosin interaction mechanism model is also proposed to provide useful guidelines for surimi processing and expanding the application of inulin within the food industries.
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| 4. |
- Piao, X., et al.
(författare)
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Oxidized cellulose nanofibrils-based surimi gel enhancing additives : Interactions, performance and mechanisms
- 2022
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Ingår i: Food Hydrocolloids. - : Elsevier BV. - 0268-005X .- 1873-7137. ; 133
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Tidskriftsartikel (refereegranskat)abstract
- Surimi-based products with preferred textural properties and high nutritional value are fashionable throughout the market. Enhancing surimi gel characteristics is of key importance for enabling the following processing and warranting the end-product quality, but challenging due to the lack of energy- and performance-efficient processes and the elusive mechanisms underpinned such enhancements. Focusing on enhancing surimi gel properties by introducing sustainable additives, we successfully explore functionalized cellulose nanofibrils as a textural enhancer in surimi gels and establish a new model to expound the interaction mechanisms. Firstly, TEMPO-mediated oxidation prior to homogenization harvests functionalized cellulose nanofibrils with unique fibrillary shape, uniform nano-size, high surface hydrophilicity and activated -COO- groups, highly suited for the additive use in surimi gels (Monto et al., 2021). Secondly, the innovative application of oxidized cellulose nanofibrils at a remarkably low concentrations (0.1 g/100 g surimi) greatly improve the whiteness, microstructure, water holding capacity, gel strength and thermal stability of the surimi gels, through a synergistic effect of matrix-reinforcing, water binding and entrapping, covalent interactions (disulfide bonds, amide bonds), non-covalent interactions (hydrogen bonds, ionic bonds) and favorable protein conformational changes within the network. Next, a new mechanism model toward the high-performance surimi gels is concluded to better elucidate the interactions between oxidized cellulose nanofibrils and myosin molecules. We expect that this work can provide guidelines on designing novel and high-quality cellulose-additive foods and understanding the roles of food additives in meat gel systems, for advancing the applications of new additives and gelation mechanisms in the food industry.
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| 5. |
- Pylypchuk, Ievgen, V, et al.
(författare)
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"Artificial Wood" Lignocellulosic Membranes : Influence of Kraft Lignin on the Properties and Gas Transport in Tunicate-Based Nanocellulose Composites
- 2021
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Ingår i: Membranes. - : MDPI AG. - 2077-0375. ; 11:3
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Tidskriftsartikel (refereegranskat)abstract
- Nanocellulose membranes based on tunicate-derived cellulose nanofibers, starch, and similar to 5% wood-derived lignin were investigated using three different types of lignin. The addition of lignin into cellulose membranes increased the specific surface area (from 5 to similar to 50 m(2)/g), however the fine porous geometry of the nanocellulose with characteristic pores below 10 nm in diameter remained similar for all membranes. The permeation of H-2, CO2, N-2, and O-2 through the membranes was investigated and a characteristic Knudsen diffusion through the membranes was observed at a rate proportional to the inverse of their molecular sizes. Permeability values, however, varied significantly between samples containing different lignins, ranging from several to thousands of barrers (10(-10) cm(3) (STP) cm cm(-2) s(-1) cmHg(-1) cm), and were related to the observed morphology and lignin distribution inside the membranes. Additionally, the addition of similar to 5% lignin resulted in a significant increase in tensile strength from 3 GPa to similar to 6-7 GPa, but did not change thermal properties (glass transition or thermal stability). Overall, the combination of plant-derived lignin as a filler or binder in cellulose-starch composites with a sea-animal derived nanocellulose presents an interesting new approach for the fabrication of membranes from abundant bio-derived materials. Future studies should focus on the optimization of these types of membranes for the selective and fast transport of gases needed for a variety of industrial separation processes.
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| 6. |
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| 7. |
- Quero, Franck, et al.
(författare)
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Top-down Approach to Produce Protein Functionalized and Highly Thermally Stable Cellulose Fibrils
- 2018
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Ingår i: Biomacromolecules. - : AMER CHEMICAL SOC. - 1525-7797 .- 1526-4602. ; 19:8, s. 3549-3559
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Tidskriftsartikel (refereegranskat)abstract
- Protein-functionalized cellulose fibrils, having various amounts of covalently bonded proteins at their surface, were successfully extracted from the tunic of Pyura chilensis tunicates using successive alkaline extractions. Pure cellulose fibrils were also obtained by further bleaching and were used as reference material. Extraction yields of protein-functionalized cellulose fibrils were within the range of 62-76% by weight based on the dry initial tunic powder. Fourier-transform infrared and Raman spectroscopy confirmed the preservation of residual protein at the surface of cellulose fibrils, which was then quantified by X-ray photoelectron spectroscopy. The protein-functionalized cellulose fibrils were found to have relatively high crystallinity and their cellulose I crystalline structure was preserved upon applying alkaline treatments. The extracted cellulosic materials were found to be constituted of fibrils having a ribbon-like morphology with widths ranging from 30 nm up to similar to 400 nm. These protein-functionalized cellulose fibrils were found to have outstanding thermal stability with one of them having onset and peak degradation temperatures of similar to 350 and 374 degrees C, respectively. These values were found to be 24 and 41 degrees C higher than for bleached cellulose.
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| 8. |
- Tagami, Ayumu, et al.
(författare)
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Lignin-modified tunicate cellulose nanofiber (CNF)-starch composites: impact of lignin diversity on film performance
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Lignin fractions having different molecular weights and varied chemical structures isolated from kraft lignins of both softwood and hardwood via a sequential solvent fractionation technique were incorporated into a tunicate cellulose nanofibers (CNF) - starch mixture to prepare 100% bio-based composite films. The aim was to investigate the correlation between lignin diversity and film performance. It was confirmed that lignin’s distribution in the films was dependent on the solvents used for fractionation (acetone > methanol > ethanol > ethyl acetate) and influenced the optical properties of the films. The -OH group content and molecular weight of lignin were positively related to film density. In general, the addition of lignin fractions led to the thermal stability decrease and the Young's modulus increase of the composite films. The modulus of the films was found to decrease as the molecular weight of lignin increased, and a higher amount of carboxyl and phenolic -OH groups in the lignin fraction resulted in films with higher stiffness. The thermal analysis showed higher char content formation for lignin-containing films in a nitrogen atmosphere with increased molecular weight. In an oxygen atmosphere, the phenol contents, saturated side chains and short chain structures of lignin had impacts on the maximum decomposition temperature of the films, confirming the positive relationship between the antioxidant ability of lignin and thermo-oxidative stability of the corresponding film. This study addresses the importance of lignin diversities on composite film performance, which could be helpful for tailoring lignin’s applications in bio-based materials based on their specific characteristics.
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| 9. |
- Wang, Miao, et al.
(författare)
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From hollow lignin microsphere preparation to simultaneous preparation of urea encapsulation for controlled release using industrial kraft lignin via slow and exhaustive acetone-water evaporation
- 2020
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Ingår i: Holzforschung. - : De Gruyter. - 0018-3830 .- 1437-434X. ; 74:1, s. 77-87
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Tidskriftsartikel (refereegranskat)abstract
- Lignin nano/microparticles have recently attracted growing interest for various value-additive applications of lignin, especially encapsulation. In this study, in order to establish a highly efficient and highly productive preparation process to effectively utilize technical lignin, a brand-new, slow and exhaustive solution evaporation process following a simple, self-assembly principle was developed using industrial softwood kraft lignin (SKL) from a starting acetone-water (80/20, v/v) solution to recover 100% of the lignin as homogeneous and well-shaped microspheres. The prepared microspheres had a typical average diameter of 0.81 ± 0.15 μm and were hollow with very thin shells (of nanoscale thickness). Based on this developed technique, encapsulation of urea by these lignin microspheres was directly achieved using the same process as hollow lignin microspheres with urea attached to the outside and entrapped inside of the wall. Two distinct urea release rates were observed for the urea-encapsulated microspheres: a fast release of the urea outside the shell wall and a slow (controlled) release of the urea inside the shell wall. The encapsulation efficiency was as high as 46% of the trapped urea as encapsulated inside the lignin microspheres. The slow and exhaustive solution evaporation procedure reported here is a simple and straightforward method for the valorization of industrial kraft lignin as hollow microspheres with controllable, homogeneous and desired morphologies, and especially for the direct preparation of lignin-based encapsulating fertilizers for controlled release.
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| 10. |
- Zhao, Yadong, 1985-, et al.
(författare)
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Cellulose nanofibrils-stabilized food-grade Pickering emulsions : Clarifying surface charge's contribution and advancing stabilization mechanism understanding
- 2024
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Ingår i: Food Hydrocolloids. - : Elsevier BV. - 0268-005X .- 1873-7137. ; 152
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Tidskriftsartikel (refereegranskat)abstract
- Pickering emulsions stabilized by cellulose nanofibrils (CN) have sparked significant attention, however the fundamental mechanisms underpinning the stabilization process remain insufficiently elucidated. Focusing on an academic debate of surface charge's contribution to stabilization, this study first explored how the varying carboxyl group contents of TEMPO-oxidized CN (TCNs) impacted Pickering emulsions' formation and stability. TCNs with 662 μmol/g carboxyl groups exhibited distinctive attributes, including larger particle sizes (322 nm in length), improved thermal stability (maximum decomposition temperature of 317 °C), and increased viscosity (1.57 Paִִ⋅s) compared to their counterparts with 963–1011 μmol/g charge density. Notably, the former one, with a larger three-phase contact angle (51.5°), higher interfacial tension, and greater detachment energy (21.69 × 10−18 J), resulted in a homogeneous dispersion of spherical oil droplets and super-stable Pickering emulsions with a consistent emulsifying index of 100% over 30 days. These findings clearly clarified that TCNs with a lower charge density exhibit superior emulsifying properties. In addition, for the first time, a distinct oil droplet-decorated fibrillar structure was observed, probably suggesting that TCNs might be able to serve as anchoring matrixes to guide the distribution of oil droplets. These structures seemed to impeded the migration and accumulation of the oil droplets, consequently enhancing the stability of the resulting Pickering emulsions. To sum, this study clearly elucidated the role of surface charge in stabilizing cellulose-based Pickering emulsions and proposed a new model to expound the cellulose-oil interaction mechanisms, thus providing new theoretical and practical insights on utilization of CN as highly effective emulsifier for super-stable food-grade Pickering emulsions.
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