Abstract
Different fractions of water-soluble polysaccharides, all composed mainly of acetyl-galactoglucomannans, from native Norway spruce wood and thermomechanical pulp were isolated and characterised. About 65% of the mannose units in the glucomannan backbone were acetylated at either the C-2 or C-3 positions in a ratio of 2.2:1.0. Mainly the mannose units, but also some glucose units, were also partly substituted at C-6 by galactopyranose units. The number of galactose side groups at C-6 was considerably lower for acetyl-galactoglucomannans from TMP than from wood. The molar sugar unit ratios of the different fractions of dissolved acetyl-galactoglucomannans differed only slightly. Acetyl-galactoglucomannans dissolved at room temperature, as well as at 90 °C and during prolonged treatment time, contained a large proportion of mannose units. Acidic arabinogalactans were also dissolved at room temperature, while some xylans, pectins, and (1 → 5)-bonded arabinans were dissolved at higher temperatures and longer treatment times. Also the water-soluble xylans contained acetyl groups, about 0.6 per xylose unit, all attached to C-3.
Original language | English |
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Pages (from-to) | 175-187 |
Number of pages | 13 |
Journal | Carbohydrate Polymers |
Volume | 52 |
Issue number | 2 |
DOIs | |
Publication status | Published - 1 May 2003 |
MoE publication type | A1 Journal article-refereed |
Keywords
- C NMR
- H NMR
- Acetyl groups
- Apparent molar mass
- Arabinans
- Galactoglucomannans
- Gas chromatography
- Hemicelluloses
- Methanolysis
- Methylation
- Norwegian spruce
- Thermomechanical pulp
- Wood
- Xylans