10 results
Search Results
2. Hydrophobication and characterisation of O-acetyl-galactoglucomannan for papermaking and barrier applications
- Author
-
Victor Kisonen, Jarl Hemming, Rainer Sjöholm, Vladimir Aseyev, Markku Auer, Patrik Eklund, Anna Sundberg, Andrey Pranovich, and Stefan Willför
- Subjects
Paper ,Color ,02 engineering and technology ,Benzoates ,01 natural sciences ,Biochemistry ,Benzoic anhydride ,Analytical Chemistry ,Mannans ,chemistry.chemical_compound ,Pyridine ,Transition Temperature ,Organic chemistry ,Hemicellulose ,Galactoglucomannan ,Molar mass ,010405 organic chemistry ,Organic Chemistry ,Chemical modification ,General Medicine ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Molecular Weight ,Butyrates ,Solubility ,chemistry ,Reagent ,Solvents ,Dimethylformamide ,0210 nano-technology ,Hydrophobic and Hydrophilic Interactions - Abstract
Norway spruce O-acetyl-galactoglucomannans (GGM) are water-soluble hemicelluloses that have potential to be produced in large scale as a side product of the mechanical pulping industry or by hot-water extraction of wood. Chemical modification is often needed to tailor such water-soluble polysaccharides into industrially valuable compounds. In this work, treatment of GGM with butyric and benzoic anhydride in pyridine/dimethylformamide rendered GGM derivatives, which were hydrophobic and partially soluble in organic solvents. The degree of substitution can be adjusted by varying the quantity of the reagent and reaction temperature. The dn/dc value for the benzoyl ester of GGM was determined in 0.05 M LiBr DMSO in order to obtain accurate molar mass analysis with SEC-MALLS-RI. Novel substances with adjusted hydrophobicity can thus be prepared on one step synthesis from natural hemicelluloses, which then showed a slight increase in the molar mass upon esterification.
- Published
- 2012
3. Antimicrobial, microscopic and spectroscopic properties of cellulose paper coated with chitosan sol-gel solution formulated by epsilon-poly-l-lysine and its application in active food packaging.
- Author
-
Razavi R, Tajik H, Moradi M, Molaei R, and Ezati P
- Subjects
- Anti-Bacterial Agents chemical synthesis, Anti-Bacterial Agents chemistry, Carbohydrate Conformation, Cellulose chemistry, Chitosan chemistry, Gels chemistry, Gels pharmacology, Listeria monocytogenes drug effects, Microbial Sensitivity Tests, Particle Size, Polylysine analogs & derivatives, Polylysine chemistry, Solutions, Surface Properties, Anti-Bacterial Agents pharmacology, Cellulose pharmacology, Chitosan pharmacology, Food Packaging, Paper, Polylysine pharmacology
- Abstract
Cellulose paper-chitosan (CC) double-layer films containing epsilon-poly-l-lysine (ε-PL) (0.5 and 1% w/v) were developed. FTIR analysis showed a strong association between the ε-PL and CC film. Antimicrobial activity against Listeria monocytogenes was investigated both in vitro and in the chicken breast meat. The CC films without ε-PL showed no antimicrobial activity, while the addition of ε-PL induced significant (p < 0.05) effects. During the 28 days of storage at 4
° C, no significant difference was found on the anti-listeria activity of films. When storage temperature was raised from 4 to 22° C, the antimicrobial activity was reduced. Films containing 1% ε-PL exhibited 1.5 log10 CFU/g reduction in L. monocytogenes population during 12 days storage of meat at 4° C, while no significant reduction was found in CC films with 0.5% ε-PL (p > 0.05). This study revealed an antimicrobial activity for CC films impregnated with ε-PL, to control foodborne pathogens in meat., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)- Published
- 2020
- Full Text
- View/download PDF
4. The association of water to cellulose and hemicellulose in paper examined by FTIR spectroscopy
- Author
-
Anne-Mari Olsson and Lennart Salmén
- Subjects
Paper ,Analytical chemistry ,Biochemistry ,Analytical Chemistry ,Absorbance ,chemistry.chemical_compound ,Adsorption ,Polysaccharides ,Spectroscopy, Fourier Transform Infrared ,Relative humidity ,Hemicellulose ,Cellulose ,Fourier transform infrared spectroscopy ,chemistry.chemical_classification ,Moisture ,Air ,Organic Chemistry ,Water ,Humidity ,General Medicine ,Polymer ,Wood ,chemistry ,Chemical engineering - Abstract
The nature of water sorption to different materials has always been a complex matter to address, partly due to the different possibilities of hydrogen-bond formation. For cellulosic materials this is extremely important for its product performance. In order to gain a deeper understanding of the moisture adsorption mechanisms of cellulose and hemicelluloses, the molecular interaction between moisture and paper and between moisture and some wood polymers was studied using FTIR spectroscopy under stable humid conditions. It was found that all the moisture-sorbing sites adsorbed moisture to the same relative degree, and that the rate of adsorption was the same for all these sites. It was also noticed that the moisture is adsorbed in the form of clusters. A direct relationship was found between the moisture weight gain and the increase in the absorbance peaks for humidities up to 50% relative humidity after which the moisture gain increased faster, a fact that still remains to be explained.
- Published
- 2003
5. Methylobacterium sp. isolated from a Finnish paper machine produces highly pyruvated galactan exopolysaccharide
- Author
-
Pieter de Waard, Henk A. Schols, Alphons G. J. Voragen, Matti Siika-aho, and René Verhoef
- Subjects
Pulp and paper industry ,Magnetic Resonance Spectroscopy ,slimes ,polysaccharides ,Biochemistry ,Galactans ,Analytical Chemistry ,chemistry.chemical_compound ,Pyruvic Acid ,bacteria ,Chromatography, High Pressure Liquid ,chemistry.chemical_classification ,biology ,Food Chemistry ,Chemistry ,Hydrolysis ,Polysaccharides, Bacterial ,General Medicine ,Nuclear magnetic resonance spectroscopy ,Enzymes ,Biofysica ,Methylobacterium ,Carbohydrate Sequence ,Chromatography, Gel ,chromatography ,acid ,configuration ,Pyruvate ,Paper ,Stereochemistry ,Molecular Sequence Data ,Biophysics ,Polysaccharide ,Gas Chromatography-Mass Spectrometry ,strain ,Levensmiddelenchemie ,Pink slime ,Sugar ,VLAG ,Galactan ,Organic Chemistry ,Galactose ,Methylobacterium sp ,biology.organism_classification ,NMR ,Molecular Weight ,Heteronuclear molecule ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,alpha-Galactosidase ,EPS ,Bacteria - Abstract
The slime-forming bacterium Methylobacterium sp. was isolated from a Finnish paper machine and its exopolysaccharide (EPS) was produced on laboratory scale. Sugar compositional analysis revealed a 100% galactan (EPS). However, FT-IR showed a very strong peak at 1611 cm−1 showing the presence of pyruvate. Analysis of the pyruvate content revealed that, based on the sugar composition, the EPS consists of a trisaccharide repeating unit consisting of d-galactopyranose and [4,6-O-(1-carboxyethylidene)]-d-galactopyranose with a molar ratio of 1:2, respectively. Both linkage analysis and 2D homo- and heteronuclear 1H and 13C NMR spectroscopy revealed the following repeating unit: →3)-[4,6-O-(1-carboxyethylidene)]-α-d-Galp-(1→3)[4,6-O-(1-carboxyethylidene)]-α-d-Galp-(1→3)-α-d-Galp-(1→. By enrichment cultures from various ground and compost heap samples a polysaccharide-degrading culture was obtained that produced an endo acting enzyme able to degrade the EPS described. The enzyme hydrolysed the EPS to a large extent, releasing oligomers that mainly consisted out of two repeating units.
- Published
- 2003
6. Structural elucidation of the EPS of slime producing Brevundimonas vesicularis sp. isolated from a paper machine
- Author
-
Pieter de Waard, Marjaana Rättö, Alphons G. J. Voragen, René Verhoef, Matti Siika-aho, and Henk A. Schols
- Subjects
Paper ,Magnetic Resonance Spectroscopy ,Rhamnose ,Chemical structure ,Population ,Molecular Sequence Data ,Mass spectrometry ,Biochemistry ,1H and 13C NMR analyses ,Analytical Chemistry ,chemistry.chemical_compound ,Hydrolysis ,Industrial Microbiology ,Levensmiddelenchemie ,education ,VLAG ,Alphaproteobacteria ,Pulp and Paper Industry ,education.field_of_study ,Chromatography ,Molecular mass ,Food Chemistry ,Structure elucidation ,Organic Chemistry ,Polysaccharides, Bacterial ,General Medicine ,Glucuronic acid ,Molecular Weight ,Brevundimonas vesicularis ,chemistry ,Carbohydrate Sequence ,EPS (slime) ,Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization ,Two-dimensional nuclear magnetic resonance spectroscopy - Abstract
The slime forming bacteria Brevundimonas vesicularis sp. was isolated from a paper mill and its EPS was produced on laboratory scale. After production, the exopolysaccharide (EPS) was purified and analysed for its purity and homogeneity, HPSEC revealed one distinct population with a molecular mass of more than 2,000 kDa. The protein content was around 9 w/w%. The sample was analysed to determine its chemical structure. The EPS was found to consist of rhamnose, glucose, galacturonic acid and glucuronic acid. Due to the presence of uronic acids the molar ratio between the four sugars found varies from 3:5:2:4 by sugar composition analyses after methanolysis to 1:1:1:1 found by NMR. A repeating unit with a molecular mass of 678 Da was confirmed by MALDI-TOF mass spectrometry after mild acid treatment. 13C and 1H hetero- and homonuclear 2D NMR spectroscopy of the native and partial hydrolysed EPS revealed a Download : Download full-size image repeating unit, no non-sugar substituents were present.
- Published
- 2002
7. Hydrophobication and characterisation of O-acetyl-galactoglucomannan for papermaking and barrier applications.
- Author
-
Kisonen V, Eklund P, Auer M, Sjöholm R, Pranovich A, Hemming J, Sundberg A, Aseyev V, and Willför S
- Subjects
- Benzoates chemistry, Butyrates chemistry, Color, Molecular Weight, Solubility, Solvents chemistry, Hydrophobic and Hydrophilic Interactions, Mannans chemistry, Paper, Transition Temperature
- Abstract
Norway spruce O-acetyl-galactoglucomannans (GGM) are water-soluble hemicelluloses that have potential to be produced in large scale as a side product of the mechanical pulping industry or by hot-water extraction of wood. Chemical modification is often needed to tailor such water-soluble polysaccharides into industrially valuable compounds. In this work, treatment of GGM with butyric and benzoic anhydride in pyridine/dimethylformamide rendered GGM derivatives, which were hydrophobic and partially soluble in organic solvents. The degree of substitution can be adjusted by varying the quantity of the reagent and reaction temperature. The dn/dc value for the benzoyl ester of GGM was determined in 0.05 M LiBr DMSO in order to obtain accurate molar mass analysis with SEC-MALLS-RI. Novel substances with adjusted hydrophobicity can thus be prepared on one step synthesis from natural hemicelluloses, which then showed a slight increase in the molar mass upon esterification., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2012
- Full Text
- View/download PDF
8. The association of water to cellulose and hemicellulose in paper examined by FTIR spectroscopy.
- Author
-
Olsson AM and Salmén L
- Subjects
- Adsorption, Air, Humidity, Wood, Cellulose chemistry, Paper, Polysaccharides chemistry, Spectroscopy, Fourier Transform Infrared methods, Water analysis
- Abstract
The nature of water sorption to different materials has always been a complex matter to address, partly due to the different possibilities of hydrogen-bond formation. For cellulosic materials this is extremely important for its product performance. In order to gain a deeper understanding of the moisture adsorption mechanisms of cellulose and hemicelluloses, the molecular interaction between moisture and paper and between moisture and some wood polymers was studied using FTIR spectroscopy under stable humid conditions. It was found that all the moisture-sorbing sites adsorbed moisture to the same relative degree, and that the rate of adsorption was the same for all these sites. It was also noticed that the moisture is adsorbed in the form of clusters. A direct relationship was found between the moisture weight gain and the increase in the absorbance peaks for humidities up to 50% relative humidity after which the moisture gain increased faster, a fact that still remains to be explained.
- Published
- 2004
- Full Text
- View/download PDF
9. Methylobacterium sp. isolated from a Finnish paper machine produces highly pyruvated galactan exopolysaccharide.
- Author
-
Verhoef R, de Waard P, Schols HA, Siika-aho M, and Voragen AG
- Subjects
- Carbohydrate Sequence, Chromatography, Gel, Chromatography, High Pressure Liquid, Galactans analysis, Galactose analysis, Gas Chromatography-Mass Spectrometry, Hydrolysis, Magnetic Resonance Spectroscopy, Methylobacterium isolation & purification, Methylobacterium metabolism, Molecular Sequence Data, Molecular Weight, Paper, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, alpha-Galactosidase isolation & purification, alpha-Galactosidase metabolism, Galactans chemistry, Galactose analogs & derivatives, Methylobacterium chemistry, Polysaccharides, Bacterial chemistry, Pyruvic Acid chemistry
- Abstract
The slime-forming bacterium Methylobacterium sp. was isolated from a Finnish paper machine and its exopolysaccharide (EPS) was produced on laboratory scale. Sugar compositional analysis revealed a 100% galactan (EPS). However, FT-IR showed a very strong peak at 1611 cm(-1) showing the presence of pyruvate. Analysis of the pyruvate content revealed that, based on the sugar composition, the EPS consists of a trisaccharide repeating unit consisting of D-galactopyranose and [4,6-O-(1-carboxyethylidene)]-D-galactopyranose with a molar ratio of 1:2, respectively. Both linkage analysis and 2D homo- and heteronuclear 1H and 13C NMR spectroscopy revealed the following repeating unit: -->3)-[4,6-O-(1-carboxyethylidene)]-alpha-D-Galp-(1-->3)[4,6-O-(1-carboxyethylidene)]-alpha-D-Galp-(1-->3)-alpha-D-Galp-(1-->. By enrichment cultures from various ground and compost heap samples a polysaccharide-degrading culture was obtained that produced an endo acting enzyme able to degrade the EPS described. The enzyme hydrolysed the EPS to a large extent, releasing oligomers that mainly consisted out of two repeating units.
- Published
- 2003
- Full Text
- View/download PDF
10. Structural elucidation of the EPS of slime producing Brevundimonas vesicularis sp. isolated from a paper machine.
- Author
-
Verhoef R, de Waard P, Schols HA, Rättö M, Siika-aho M, and Voragen AG
- Subjects
- Alphaproteobacteria isolation & purification, Carbohydrate Sequence, Magnetic Resonance Spectroscopy, Molecular Sequence Data, Molecular Weight, Polysaccharides, Bacterial isolation & purification, Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization, Alphaproteobacteria chemistry, Industrial Microbiology methods, Paper, Polysaccharides, Bacterial chemistry
- Abstract
The slime forming bacteria Brevundimonas vesicularis sp. was isolated from a paper mill and its EPS was produced on laboratory scale. After production, the exopolysaccharide (EPS) was purified and analysed for its purity and homogeneity, HPSEC revealed one distinct population with a molecular mass of more than 2,000 kDa. The protein content was around 9 w/w%. The sample was analysed to determine its chemical structure. The EPS was found to consist of rhamnose, glucose, galacturonic acid and glucuronic acid. Due to the presence of uronic acids the molar ratio between the four sugars found varies from 3:5:2:4 by sugar composition analyses after methanolysis to 1:1:1:1 found by NMR. A repeating unit with a molecular mass of 678 Da was confirmed by MALDI-TOF mass spectrometry after mild acid treatment. 13C and 1H hetero- and homonuclear 2D NMR spectroscopy of the native and partial hydrolysed EPS revealed a repeating unit, no non-sugar substituents were present.
- Published
- 2002
- Full Text
- View/download PDF
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