Isolation and characterization of arabinoxylans from wheat bran and study of their contribution to wheat flour dough rheology.

The study was aimed to evaluate the yield and sugar composition of water-extractable (WE) and alkali extractable (AE) Hemi-A, Hemi-B and oligosaccharides (Oligo) fractions isolated from bran of four wheat varieties and their relationship with dough rheology. Wheat bran from all varieties were rich in protein content (12.45-16.97%). The yield of WE-Hemi-A, WE-Hemi-B and WE-Oligo were lower than the yield of AE-Hemi-A, AE-Hemi-B and AE-Oligo, for all varieties. Sugar composition of fractions determined by high-performance anion exchange chromatography with pulsed amperometric detector (HPAEC-PAD), showed sugars: rhamnose, galactose, glucose, galacturonic acid and glucuronic acid, in addition to the typical arabinoxylan containing arabinose and xylose are present in all wheat bran varieties. HD-3086 and HD-2947 wheat varieties which yielded a viscoelastic dough with high G' and G" values (indicative of good dough-making characteristics), had a higher percent of AE-Hemi-B and both WE-Oligo and AE-Oligo than C-306 and HS-490 wheat varieties.