Crosslinking of wheat dough proteins by glucose oxidase and the resulting effects on bread and croissants

The crosslinking of wheat flour proteins results in significant improvements in the functional properties of baked products. In this research, the enzyme glucose oxidase was investigated for its crosslinking effect on the dough proteins of bread and croissants. The macroscopic effects resulting from the addition of glucose oxidase to the dough formulation were compared to changes seen at the molecular level in individual protein fractions. Treatment with glucose oxidase produced slight improvements in crumb properties but no increase in product volume. At the molecular level, crosslinking occurred mainly in the water-soluble (albumin and globulin) fraction and was demonstrated to involve both disulfide and non-disulfide linkages. The SDS-soluble and -insoluble glutenins, which make up much of the gluten network, were crosslinked to a much lesser extent, with mainly non-disulfide linkages. These findings corroborate our theories on the relationship of wheat protein crosslinking and functional properties. Specifically, we conclude that (i) crosslinking of albumin and globulin proteins enhances crumb properties and (ii) changes in croissant volume require crosslinking of the glutenin fraction of wheat proteins.