Characteristic Change of Gliadin by β-lactoglobulin on the Dough Formation

Abstract

　We here investigated the mechanism underlying changes in baking quality when ω-gliadin is desorbed from gliadin aggregates due to the action of β-lactoglobulin (β-Lg). As a result of ω-gliadin desorption, gliadin became hardened and less sticky. In addition, the surface hydrophobicity of gliadin and the hydrophobic interactions between gliadin molecules increased as a result of ω-gliadin desorption. The intermolecular protein interactions in the dough were analyzed using a protein cross-linking experiment, and the results revealed that the intermolecular distances of α-, β-, and γ-gliadin decreased, thereby increasing their associative forces. These results revealed that ω-gliadin desorption led to an increase in the hydrophobic interactions among gliadin molecules, including increased hardening and decreased stickiness. Gliadin confers increased extensibility characteristics to the dough; therefore, these changes in gliadin properties would likely affect the extensibility of gluten degradation and degrade the baking quality of dough.