TY - JOUR
T1 - Rheological properties of water-soluble spruce O-acetyl galactoglucomannans
AU - Xu, Chunlin
AU - Willför, Stefan
AU - Holmlund, Peter
AU - Holmbom, Bjarne
N1 - Funding Information:
Many thanks to Andrey Pranovich and Jan Gustafsson for advice and helpful discussions. Thanks are also due to Krister Steinby and Rasmus Eriksson at the Department of Physical Chemistry at Åbo Akademi University for their help with the use of the Sensa tensiometer and Bohlin VOR rheometer. Financial aid was received from the Academy of Finland. Part of the work was done within the EU project WaCheUp (EU STRP 013896). This work is part of the activities at the Åbo Akademi Process Chemistry Group within the Finnish Centre of Excellence Programme (2000–2011) by the Academy of Finland, and also part of the activities within the EPNOE network (European Polysaccharide Network of Excellence).
Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2009/2/11
Y1 - 2009/2/11
N2 - The thermal and rheological properties of spray-dried, ethanol-precipitated, purified, and deacetylated spruce galactoglucomannans (GGM) were investigated by rheological measurements and differential scanning calorimetry. The shear rate dependence of viscosity and the effects of the drying method, temperature, ionic strength, and deacetylation on rheological properties were studied. GGM solutions exhibited a shear thinning behaviour. GGM solutions did not obey the Cox-Merz rule. The storage modulus of GGM solutions increased with an increase in concentration; gradually until a concentration of 5%, but rapidly at higher concentrations. Ethanol-precipitated GGM solutions showed a more elastic behaviour than spray-dried GGM solutions. Deacetylation caused an increase in apparent viscosity and more significantly in storage modulus. The storage modulus increased slightly with a decrease in temperature. A small amount addition of NaCl slightly changed the oscillatory behaviour. The effects of above factors were discussed in terms of molecular interactions. The rheological measurements of GGM solutions provide the basis of functionalities of GGM solutions.
AB - The thermal and rheological properties of spray-dried, ethanol-precipitated, purified, and deacetylated spruce galactoglucomannans (GGM) were investigated by rheological measurements and differential scanning calorimetry. The shear rate dependence of viscosity and the effects of the drying method, temperature, ionic strength, and deacetylation on rheological properties were studied. GGM solutions exhibited a shear thinning behaviour. GGM solutions did not obey the Cox-Merz rule. The storage modulus of GGM solutions increased with an increase in concentration; gradually until a concentration of 5%, but rapidly at higher concentrations. Ethanol-precipitated GGM solutions showed a more elastic behaviour than spray-dried GGM solutions. Deacetylation caused an increase in apparent viscosity and more significantly in storage modulus. The storage modulus increased slightly with a decrease in temperature. A small amount addition of NaCl slightly changed the oscillatory behaviour. The effects of above factors were discussed in terms of molecular interactions. The rheological measurements of GGM solutions provide the basis of functionalities of GGM solutions.
KW - Deacetylation
KW - Ionic strength
KW - Rheological properties
KW - Spruce galactoglucomannans
KW - Temperature effect
UR - http://www.scopus.com/inward/record.url?scp=57349105747&partnerID=8YFLogxK
U2 - 10.1016/j.carbpol.2008.08.016
DO - 10.1016/j.carbpol.2008.08.016
M3 - Article
AN - SCOPUS:57349105747
SN - 0144-8617
VL - 75
SP - 498
EP - 504
JO - Carbohydrate Polymers
JF - Carbohydrate Polymers
IS - 3
ER -