Structural heterogeneity of wheat arabinoxylans revealed by Raman spectroscopy.
A set of arabinoxylan samples differing in their arabinose composition and various samples of arabino-xylo-oligosaccharide samples were analysed by Raman spectroscopy. Specific signatures for arabinose substitution were found in several spectral regions, that is, 400-600, 800-950 and 1030-1100 cm(-1). A linear relationship was observed between the peak ratio 855/895 cm(-1) of the second derivative spectra and the A/X ratio determined by chemical analysis. Moreover, spectral changes were observed in the 400-600 cm(-1) region assigned to the coupled vibrations mode in the skeleton: while the intensity of the band at 570 cm(-1) increased with the degree of substitution, that at 494 cm(-1) decreased. Similarly, a linear relationship was observed between the peak intensity ratio 570/494 cm(-1) calculated on the second derivative spectra and the composition data. Analysis of Raman spectra of arabino-xylo-oligosaccharides allowed to identify specific spectral features of disubstitution.
Barron
Cécile
C
INRA-UMR Ingénierie des Agropolymères et Technologies Emergentes, INRA-ENSAM-UMII-CIRAD, 2 place Viala, F-34060 Montpellier, France. barron@ensam.inra.fr
Robert
Paul
P
Guillon
Fabienne
F
Saulnier
Luc
L
Rouau
Xavier
X
D013059:Spectrum Analysis, Raman; D014908:Triticum; D014990:Xylans / Q000737:chemistry*
D014990:Xylans; C085118:arabinoxylan