Structural characterisation of pentosans from hemicellulose B of wheat varieties with varying chapati-making quality

Wheat varieties, such as DWR-162 and GW-322 (good chapati-making quality), and MACS-2496 and HD-2189 (poor chapati-making quality), were used to study the structural features of pentosans. Structural features of the purified pentosans from hemicellulose B were elucidated by a combination of methods, such as methylation analysis, 1H NMR, FT-IR, periodate oxidation, Smith degradation and optical rotation measurements. Pentosans from hemicellulose B were mainly arabinoxylan type polysaccharides with xylan backbone in β-(1 → 4) linkages. Mono, and di-substituted xylosyl residues were present in these polysaccharides. Variations in structural features of pentosans could be responsible for the differences in chapati-making qualities of wheat.