Structural features of arabinoxylans from bajra (pearl millet).

Structures of arabinoxylans (AX) from bajra, from a variety known to have characteristic quality in the making of roti, an unleavened flat bread, were elucidated by a combination of methylation analysis, (13)C NMR, FT-IR, etc. Arabinoxylans isolated from barium hydroxide-extracted polysaccharides and hemicellulose B had a backbone of xylose residues with beta-(1,4) linkages and were branched mainly through alpha-(1,3) linkages by arabinofuranosyl residues. Completely branched xylose residues were also present. The AX from bajra characteristically had large numbers of branches, and this may be one of the reasons for the crispiness of the rotis.