Xylans wheat, structure

The substitution pattern of arabinosyl side chains in AX from cereal flours and bran, based on the structural analysis of ohgomer fragments produced by xylan-degrading enzymes of known mode of action, was described by several authors [60-63], and various structural models were created [39,60]. fii a recent study [64] on the fine structure of wheat flour AX, a method was... 

Interactions with xanthan were investigated for some GAX fractions of wheat bran [109]. Whereas, for lowly substituted GaMs a synergy in viscosity was observed at low total polymer concentrations, yielding a maximum of the relative viscosity at nearly equal proportions of both polysaccharides [124], the xanthan/xylan mixtures at the same experimental conditions showed no synergy. The observed decrease in the relative viscosity values upon addition of the xylan indicates that a certain interaction with xanthan takes place, but that it leads to a contraction in the hydrodynamic volume. The authors suggested that structural and conformational differences between GaM and GAX might be the reason for this observation. 

Few further measurements have been reported. The essentially unbranched structure of a xylan from wheat straw232 and of hemicellulose-A233... 

In this publication the rese ch performed within the framework of the PhD-research concerning the characterisation of complex xylo-oligosaccharides from xylan rich by-products (2) is reviewed. The separation and structural features of differently substituted xylo-oligosaccharides obtained from hydrothermally treated wheat bran, brewery s spent grain, com cobs and Eucalyptus wood is described. 

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