Water-soluble pentosans form very viscous solutions because of their much higher intrinsic viscosity compared to soluble proteins. A unique property of water-soluble pentosans is their ability to form gels in the presence of oxidizing agents. This process of oxidative gelation was monitored by Kundig et al. (1961b), who noted the disappearance of a peak at 320 nm in the UV spectrum of pentosans following the addition of oxidizing agents. The loss of this peak was attributed to involvement of ferulic acid in the gelation process. A mechanism was subsequently proposed by Neukom and Markwalder (1978) in which a dimer of ferulic acid formed a cross-linked between pentosans (Fig.5). Two active centers in ferulic
acid were thought to account for the increase in viscosity via cross-linking. One was the aromatic nucleus while the other was the activated double bond. Only the activated double bond in ferulic acid was involved in the gelation process. The formation of such cross-links through covalent binding of protein and polysaccharide chains could affect the rheology of
the dough. Kim and D′Appolonia (1977) suggested that pentosans decreased the rate of bread staling by decreasing the amount of starch components available for crystallization