Structural variations of arabinoxylans extracted from different wheat (Triticum aestivum) cultivars in relation to chapati-quality

Abstract

Wheat varieties, such as DWR-162, GW-322 (good chapati making quality) and MACS-2496, HD-2189 (poor chapati making quality) were used to study the structural features of arabinoxylans. Structural features of the purified arabinoxylans were elucidated by a combination of methods such as methylation analysis, 13C-NMR, FT-IR, periodate oxidation, Smith degradation and optical rotation measurements. The results indicated a xylan backbone in β-(1–4) linkage, which is substituted at O-3 or at O-2 and O-3. Completely branched xylosyl residues were also observed in these wheat arabinoxylans. The wheat varieties known for good chapati making quality (DWR-162 and GW-322) revealed arabinoxylans with higher degree of branching pattern compared to those of poor wheat varieties such as MACS-2496 and HD-2189. Variations in the structural characteristics of arabinoxylans such as degree of branching pattern coupled with ferulic acid contents are of interest in wheat varieties differing in chapati making quality.