| 1. |
- Stevanic, Jasna S., et al.
(author)
-
Wood cell wall mimicking for composite films of spruce nanofibrillated cellulose with spruce galactoglucomannan and arabinoglucuronoxylan
- 2014
-
In: Journal of Materials Science. - : Springer Science and Business Media LLC. - 0022-2461 .- 1573-4803. ; 49:14, s. 5043-5055
-
Journal article (peer-reviewed)abstract
- Two hemicelluloses (HCs), galactoglucomannan (GGM) and arabinoglucuronoxylan (AGX), and nanofibrillated cellulose (NFC) were isolated from spruce wood and used for the preparation of composite films containing high amounts of cellulose, i.e. 85 and 80 wt% of NFC, respectively. The films were prepared in two ways: (i) by the pre-sorption of HCs on NFC and (ii) by the mixing of components in the usual way. Pre-sorption was applied in an attempt to mimic the carbohydrate biosynthesis pattern during wood cell wall development, where HCs were deposited on the cellulose fibrils prior to lignification taking place. It was assumed that pre-sorption would result in a better film-forming as well as stronger and denser composite films. The mechanical, thermal, structural, moisture sorption and oxygen barrier characteristics of such composite films were tested in order to examine whether the performance of composite films prepared by pre-sorption was better, when compared to the performance of composite films prepared by mixing. The performance of composite films was also tested with respect to the HCs used. All the films showed quite similar barrier and mechanical properties. In general, stiff, strong and quite ductile films were produced. The moisture sorption of the films was comparably low. The oxygen barrier properties of the films were in the range of commercially used poly ethylene vinyl alcohol films. However, the pre-sorption procedure for the preparation of composite films resulted in no additional improvement in the performance of the films compared to the corresponding composite films that had been prepared using the mixing process. Almost certainly, the applied mixing process led to an optimal mixing of components for the film performance achieved. The GGM contributed to a somewhat better film performance than the AGX did. Indications were observed for stronger interactions between the GGM and NFC than that for the AGX and NFC.
|
|
| 2. |
- Abik, Felix, et al.
(author)
-
Potential of Wood Hemicelluloses and Their Derivates as Food Ingredients
- 2023
-
In: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 71:6, s. 2667-2683
-
Research review (peer-reviewed)abstract
- A holistic utilization of all lignocellulosic wood biomass, instead of the current approach of using only the cellulose fraction, is crucial for the efficient, ecological, and economical use of the forest resources. Use of wood constituents in the food and feed sector is a potential way of promoting the global economy. However, industrially established food products utilizing such components are still scarce, with the exception of cellulose derivatives. Hemicelluloses that include xylans and mannans are major constituents of wood. The wood hemicelluloses are structurally similar to hemicelluloses from crops, which are included in our diet, for example, as a part of dietary fibers. Hence, structurally similar wood hemicelluloses have the potential for similar uses. We review the current status and future potential of wood hemicelluloses as food ingredients. We include an inventory of the extraction routes of wood hemicelluloses, their physicochemical properties, and some of their gastrointestinal characteristics, and we also consider the regulatory route that research findings need to follow to be approved for food solutions, as well as the current status of the wood hemicellulose applications on that route.
|
|
| 3. |
- Agustin, Melissa B., et al.
(author)
-
Enzymatic crosslinking of lignin nanoparticles and nanocellulose in cryogels improves adsorption of pharmaceutical pollutants
- 2024
-
In: International Journal of Biological Macromolecules. - : Elsevier BV. - 0141-8130 .- 1879-0003. ; 266
-
Journal article (peer-reviewed)abstract
- Pharmaceuticals, designed for treating diseases, ironically endanger humans and aquatic ecosystems as pollutants. Adsorption-based wastewater treatment could address this problem, however, creating efficient adsorbents remains a challenge. Recent efforts have shifted towards sustainable bio-based adsorbents. Here, cryogels from lignin-containing cellulose nanofibrils (LCNF) and lignin nanoparticles (LNPs) were explored as pharmaceuticals adsorbents. An enzyme-based approach using laccase was used for crosslinking instead of fossil-based chemical modification. The impact of laccase treatment on LNPs alone produced surface-crosslinked water-insoluble LNPs with preserved morphology and a hemicellulose-rich, water-soluble LNP fraction. The water-insoluble LNPs displayed a significant increase in adsorption capacity, up to 140 % and 400 % for neutral and cationic drugs, respectively. The crosslinked cryogel prepared by one-pot incubation of LNPs, LCNF and laccase showed significantly higher adsorption capacities for various pharmaceuticals in a multi-component system than pure LCNF or unmodified cryogels. The crosslinking minimized the leaching of LNPs in water, signifying enhanced binding between LNPs and LCNF. In real wastewater, the laccase-modified cryogel displayed 8–44 % removal for cationic pharmaceuticals. Overall, laccase treatment facilitated the production of bio-based adsorbents by improving the deposition of LNPs to LCNF. Finally, this work introduces a sustainable approach for engineering adsorbents, while aligning with global sustainability goals.
|
|
| 4. |
- Agustin, Melissa B., et al.
(author)
-
Lignin nanoparticle-decorated nanocellulose cryogels as adsorbents for pharmaceutical pollutants
- 2023
-
In: Journal of Environmental Management. - : Elsevier BV. - 0301-4797 .- 1095-8630. ; 330
-
Journal article (peer-reviewed)abstract
- Adsorption is a relatively simple wastewater treatment method that has the potential to mitigate the impacts of pharmaceutical pollution. This requires the development of reusable adsorbents that can simultaneously remove pharmaceuticals of varying chemical structure and properties. Here, the adsorption potential of nanostructured wood-based adsorbents towards different pharmaceuticals in a multi-component system was investigated. The adsorbents in the form of macroporous cryogels were prepared by anchoring lignin nanoparticles (LNPs) to the nanocellulose network via electrostatic attraction. The naturally anionic LNPs were anchored to cationic cellulose nanofibrils (cCNF) and the cationic LNPs (cLNPs) were combined with anionic TEMPO-oxidized CNF (TCNF), producing two sets of nanocellulose-based cryogels that also differed in their overall surface charge density. The cryogels, prepared by freeze-drying, showed layered cellulosic sheets randomly decorated with spherical lignin on the surface. They exhibited varying selectivity and efficiency in removing pharmaceuticals with differing aromaticity, polarity and ionic characters. Their adsorption potential was also affected by the type (unmodified or cationic), amount and morphology of the lignin nanomaterials, as well as the pH of the pharmaceutical solution. Overall, the findings revealed that LNPs or cLNPs can act as functionalizing and crosslinking agents to nanocellulose-based cryogels. Despite the decrease in the overall positive surface charge, the addition of LNPs to the cCNF-based cryogels showed enhanced adsorption, not only towards the anionic aromatic pharmaceutical diclofenac but also towards the aromatic cationic metoprolol (MPL) and tramadol (TRA) and neutral aromatic carbamazepine. The addition of cLNPs to TCNF-based cryogels improved the adsorption of MPL and TRA despite the decrease in the net negative surface charge. The improved adsorption was attributed to modes of removal other than electrostatic attraction, and they could be 7C-7C aromatic ring or hydrophobic interactions brought by the addition of LNPs or cLNPs. However, significant improvement was only found if the ratio of LNPs or cLNPs to nanocellulose was 0.6:1 or higher and with spherical lignin nanomaterials. As crosslinking agents, the LNPs or cLNPs affected the rheological behavior of the gels, and increased the firmness and decreased the water holding capacity of the corresponding cryogels. The resistance of the cryogels towards disintegration with exposure to water also improved with crosslinking, which eventually enabled the cryogels, especially the TCNF-based one, to be regenerated and reused for five cycles of adsorption-desorption experiment for the model pharmaceutical MPL. Thus, this study opened new opportunities to utilize LNPs in providing nanocellulose-based adsorbents with additional functional groups, which were otherwise often achieved by rigorous chemical modifications, at the same time, crosslinking the nanocellulose network.
|
|
| 5. |
- Agustin, Melissa B., et al.
(author)
-
Lignin nanoparticles as co-stabilizers and modifiers of nanocellulose-based Pickering emulsions and foams
- 2023
-
In: Cellulose. - : Springer Nature. - 0969-0239 .- 1572-882X. ; 30:14, s. 8955-8971
-
Journal article (peer-reviewed)abstract
- Nanocellulose is very hydrophilic, preventing interactions with the oil phase in Pickering emulsions. This limitation is herein addressed by incorporating lignin nanoparticles (LNPs) as co-stabilizers of nanocellulose-based Pickering emulsions. LNP addition decreases the oil droplet size and slows creaming at pH 5 and 8 and with increasing LNP content. Emulsification at pH 3 and LNP cationization lead to droplet flocculation and rapid creaming. LNP application for emulsification, prior or simultaneously with nanocellulose, favors stability given the improved interactions with the oil phase. The Pickering emulsions can be freeze–dried, enabling the recovery of a solid macroporous foam that can act as adsorbent for pharmaceutical pollutants. Overall, the properties of nanocellulose-based Pickering emulsions and foams can be tailored by LNP addition. This strategy offers a unique, green approach to stabilize biphasic systems using bio-based nanomaterials without tedious and costly modification procedures.
|
|
| 6. |
- Arzami, Anis N., et al.
(author)
-
Narrow-leafed lupin (Lupinus angustifolius L.) : Characterization of emulsification and fibre properties
- 2022
-
In: FUTURE FOODS. - : Elsevier BV. - 2666-8335. ; 6
-
Journal article (peer-reviewed)abstract
- Lupin is among the most promising plant-based food protein sources due to its high protein and fibre content. The fibre fraction, especially from seed coats, is often seen as low in value (discarded as waste or as animal feed) and greater knowledge on its composition and structure are crucial to increase its usefulness. However, only one model of lupin fibre structure exists in the literature. Our sample of Finnish-grown narrow-leafed lupin seed consisted of fibre (43.3%), protein (31.3%), fat (8.1%) and starch (0.2%). According to the sugar analysis, rhamnogalacturonan-I, with branches of arabinan and galactan, constituted the main pectin population in the fibre fraction. A revised model of the overall fibre structure is proposed. At concentrations of 0.75% and 1.0%, both unrefined and defatted flour of whole lupin seeds produced stable suspensions and oil-in-water emulsions, demonstrating their application as potential emulsifiers. This study presents the knowledge and opportunity to support sustainability through the utilization of whole lupin seed for future industrial applications.
|
|
| 7. |
- de Carvalho, Danila Morais, et al.
(author)
-
Enrichment and Identification of Lignin-Carbohydrate Complexes in Softwood Extract
- 2020
-
In: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 8:31, s. 11795-11804
-
Journal article (peer-reviewed)abstract
- Lignin-carbohydrate complexes (LCCs) are hybrid structures containing covalently linked moieties of lignin and carbohydrates. The structure and behavior of LCCs affect both industrial processes and practical applications of lignocellulosic biomass. However, the identification of phenylglycoside, benzylether, and gamma (gamma)-ester LCC bonds in lignocellulosic biomass is limited due to their relatively low abundance compared to plain carbohydrate and lignin structures. Herein, we enriched the LCC bonds in softwood galactoglucomannan (GGM)-rich extract fractionated by (1) a solvent (ethanol), (2) enzymes, and (3) physical techniques. Two-dimensional nuclear magnetic resonance (NMR) spectroscopy analysis was used to identify the LCC bonds. Phenylglycoside and benzylether bonds were concentrated in the ethanol-soluble GGM fractions. A benzylether bond was concentrated into GGM fractions containing larger molecules (>500 Da) through physical techniques. The gamma-ester bond was identified in all studied GGM fractions, which is explained by its stability and possible presence in residual xylan. In summary, we demonstrated the potential of the suggested techniques to enrich LCC bonds in softwood extract and improve LCC identification. Such techniques may also enable further studies on the structure and functionality of LCC bonds and open new prospects in the engineering of biomolecules.
|
|
| 8. |
- Kisonen, Victor, et al.
(author)
-
Composite films of nanofibrillated cellulose and O-acetyl galactoglucomannan (GGM) coated with succinic esters of GGM showing potential as barrier material in food packaging
- 2015
-
In: Journal of Materials Science. - : Springer Science and Business Media LLC. - 0022-2461 .- 1573-4803. ; 50:8, s. 3189-3199
-
Journal article (peer-reviewed)abstract
- Nanofibrillated cellulose (NFC)-Norway spruce O-acetyl-galactoglucomannan (GGM) composite films were coated either with a novel succinic ester of GGM or with native GGM. NFC films were made for reference. The succinic ester of GGM was synthesised at low (GGM-Su1) and high (GGM-Su2) degree of substitution to obtain different level of water repellence. GGM and its succinic esters had good affinity with NFC substrate. This made it possible to implement the barrier functionality on the NFC network with the adequate mechanical properties. The coatings further enhanced the already excellent oxygen permeability properties, achieving 0.1 [(cm(3) A mu m)(m(2) kPa d)] as the lowest value with the NFC-GGM film double-coated with GGM-Su2. The films demonstrated pronounced stiffness by adding GGM to the NFC, as well as coating of GGM-Su2 on the NFC-GGM films at 0-90 % relative humidity. The films turned out to be impenetrable with grease even at high temperatures. NFC-GGM film with GGM-Su2 coating exhibited hydrophobic characteristics according to the water contact angle measurements. It was shown that adding 5.5 wt% of GGM to a NFC film and further 5.4 wt% of coating of GGM-Su or GGM on the film may highly enhance the feasibility of the biocomposites to be used for food packaging to replace typical oil-based non-biodegradable plastics currently used.
|
|
| 9. |
- Liu, Jun, et al.
(author)
-
Nanofibrillated cellulose originated from birch sawdust after sequential extractions : a promising polymeric material from waste to films
- 2014
-
In: Cellulose. - : Springer Science and Business Media LLC. - 0969-0239 .- 1572-882X. ; 21:4, s. 2587-2598
-
Journal article (peer-reviewed)abstract
- The residual cellulose of wood processing waste, sawdust, which was leftover after sequential hot-water extraction processes to isolate hemicelluloses and lignin in a novel forest biorefinery concept, was explored as the starting material for preparation of a highly value-added polymeric material, nanofibrillated cellulose (NFC) also widely termed as cellulose nanofiber, which has provided an alternative efficient way to upgrade sawdust waste. The residual cellulose in sawdust was converted to a transparent NFC suspension in water through the 2,2,6,6-tetramethylpiperidine-1-oxyl radical/NaClO/NaBr oxidization approach. The resultant NFC with a dimension of ca. 5 nm in width and hundreds of nanometers in length were further processed into NFC films. The morphological features of the NFC suspension and its films were assessed by transmission electron microscopy and scanning electron microscopy. Highly even dispersion of NFC fibrils in the films originated from sawdust feasibly contributes to the outstanding mechanical performance of the films. NFC suspension with higher carboxylate content and its resultant NFC films were found to show higher transmission of light.
|
|
| 10. |
|
|
