Isolation and Characterization of Hemicelluloses from Beet Pulp

Abstract

A xylan and xyloglucan were isolated from the 24% KOH extract of beet pulp. A methylation analysis and enzymic degradation studies on the polysaccharides showed that the former polysac-charide had a linear β-(1→4)-linked D-xylopyranosyl backbone with side chains, and the latter was built up of repeating-oligosaccharide units, XXXG, XXLG, XLXG, XXFG, XLLG and XLFG [where each (l→4)-β-linked D-glucosyl residue in the backbone is given a one-letter code accord-ing to its substituents: G, β-D-Glc; X, α-D-Xyl-(1→6)- β-D-Glc; L, β-D-Gal-(1→2)-α-Xyl-(1rarr;6)β-Glc; and F, α-L-Fuc-(1→2)-β-D-Gal-(1→2)-α-D-Xyl-(1→6)-β-D-Glc] in an approximate molar ratio of 44: 1: 3 : 25: 1: 26.