ENHANCEMENT OF PROTEIN FOAM STABILITY BY FORMATION OF WHEAT ARABINOXYLAN-PROTEIN CROSS-LINKS

The foam stability properties of a defined mixed solution of Tween 20 and bovine serum albumin was evaluated as a function of arabinoxylan c oncentration. A marked increase in the foam stability was observed wit h low concentrations of arabinoxylan. Maximum improvement in the foam stability was obtained with 0.2-0.3 mg/mL of arabinoxylan. Enhancement of foam stability due to a combination of bulk viscosity changes and surface effects was identified. The relative contribution of arabinoxy lan to bulk viscosity and adsorbed layer structure was studied by exam ination of the properties of thin liquid films and the macroscopic air -water interface. Arabinoxylan reduced the rate of thin film drainage, increased the equilibrium thickness of the films, slowed the lateral diffusion of a fluorescent probe molecule located in the adsorbed laye r, and increased the surface elasticity. These data are congruent with arabinoxylan-mediated crosslinking of adsorbed protein. These observa tions may be of significance in gas retention during breadmaking. In a ddition, this naturally occurring polysaccharide offers potential for use in the control of protein foam stability.