Fig. 5
DOSY NMR analyses. Signals corresponding to water were used as reference to ease the comparison between both polysaccharides. a Superimposition of DOSY spectra from beechwood xylan (BE-X) in blue and birchwood xylan (BI-X) in red. The x-axis represents chemical shift and the y-axis shows the translational diffusion coefficient. Labels indicate the signals corresponding to the solvent (water) and the weight average of the polysaccharides. b Projection of molecular size distribution of BE-X (blue) and BI-X (red). The x-axis shows the differences at the molecular weight level in terms of translational diffusion coefficient. Labels indicate the peaks corresponding to the polysaccharides and the solvent (water). c Superimposition of the DOSY and 1H 1D spectra of BE-X (blue) and the BI-X (red). Differences in the molecular weight are observed (different diffusion coefficient). Moreover, no acetylation pattern around 2 ppm is observed for both xylans. The peaks at 1.85 ppm/− 9.03 LogD in BI-X and at 1.10 ppm/− 8.98 LogD in BE-X correspond to low molecular weight impurities. The x-axis represents chemical shift and the y-axis shows the translational diffusion coefficient