, 1990). The non-covalent interactions involve intermolecular hydrogen bonding between unsubstituted regions and/or ionic forces between ionising substituents of AX chain (Fincher & Stone, 1986). While the gas retention ability of rye dough can be related to high viscosity of its aqueous phase (Hoseney, 1984 and Meuser and Suckow, 1986), the water economy in dough selleck chemicals llc and
bread is mainly controlled by absorbing properties of both starch and AX (Drews & Seibel, 1976). However, the AX water-binding potential may affect water availability for starch in the rye dough and bread, and thus its rate of retrogradation and bread staling (Gudmundsson, Eliasson, Bengtsson, & Åman, 1991). It has been shown that the oxidatively cross-linked AX usually exhibit an increased viscosity and water binding
capacity (Izydorczyk et al., 1990, Meuser and Suckow, 1986 and Vinkx et al., 1993). This may be explained by an increase in their asymmetric conformation, in which bridging structures such as di-ferulic acid, ferulic acid-tyrosine and ferulic acid-cysteine, reinforce gelation and swelling capacity. The AX water-binding ability, however, decreases upon addition of endo-(1 → 4)-β-d-xylanse (endoxylanase) that depolymerises their chains (Aulrich & Flachowsky, 2001). Nevertheless, a relatively small adjustment in AX macromolecular characteristics may cause significant changes in their physicochemical properties, Selleck Decitabine Dasatinib which influence the characteristics of wheat- and rye-based products (Cyran and Saulnier, 2012 and Redgwell et al., 2001). The physicochemical properties of AX, and subsequently, their functionality in wheat and rye flours and end-products are mostly dependent on
a polymer concentration, molecular size and proportion and spatial distribution of various β-d-xylopyranosyl residues over the backbone. Generally, they include the un-substituted and mono-substituted with single α-l-arabinofuranosyl residues mainly through O-3 and a little at O-2 as well as di-substituted residues through O-2,3 linkages ( Izydorczyk and Biliaderis, 1995 and Vinkx and Delcour, 1996). It is assumed that the distribution of the α-l-arabinofuranosyl residues along the xylan backbone, which alters an asymmetry of macromolecule, may have a greater importance in determining the AX properties than its substitution degree. Furthermore, the AX interactions with other cell wall components mediated through other minor side substituents, particularly feruloyl, α-d-glucuronopyranosyl and acetyl residues may contribute to modification of their physicochemical characteristics ( Fincher & Stone, 1986).