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The Structural, Molecular and Functional Properties of Lignin‐Containing Beechwood Glucuronoxylan
Author(s) -
Hromádková Zdenka,
Ebringerová Anna,
Malovíková Anna
Publication year - 2005
Publication title -
macromolecular symposia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.257
H-Index - 76
eISSN - 1521-3900
pISSN - 1022-1360
DOI - 10.1002/masy.200551403
Subject(s) - chemistry , lignin , uronic acid , xylan , dissolution , ethanol precipitation , aqueous solution , molecular mass , solubility , nuclear chemistry , precipitation , sonication , ethanol , polysaccharide , chromatography , organic chemistry , physics , meteorology , enzyme
The samples of 4‐O‐methyl‐D‐glucurono‐D‐xylan (GX) with different lignin and uronic acid (MeUA) contents were prepared from beechwood by various procedures. The re‐dissolution process of the partially water‐soluble GX‐2 lyophilizate in aqueous medium depended on the content and distribution of MeUA. In contrast to the supernatant after ultracentrifugation, the sediment had a significantly lower MeUA content and showed mainly high‐molecular mass components. A part of lignin degradation products is separable by repeated dissolution and precipitation of GX in acidic and alkaline 80% ethanolic media with assistance of ultrasound. Irradiation in acidic ethanol (GX‐3/ac) showed no effect on the distribution of the UV 254 ‐absorbing component. GX‐3 sonicated in neutral and alkaline media (GX‐3/ne, GX‐3/alk) lost water solubility. The lignin‐rich GX samples showed remarkable emulsifying efficiency and protein foam stabilization effect. In addition, the presence of phenolics provided antioxidant properties to these xylan preparations indicating their potential as polymeric radical scavengers.