Impact of pyranose oxidase from Trametes multicolor, glucose oxidase from Aspergillus niger and hydrogen peroxide on protein agglomeration in wheat flour gluten-starch separation

The impact of pyranose oxidase (P2O), glucose oxidase (GO) and H2O2 on gluten agglomeration during wheat flour gluten-starch separation was studied. Analysis of gluten aggregate sizes in batter formed from wheat flour dough revealed that increasing levels of oxidising agents gradually decreased the tendency of gluten proteins to form large gluten aggregates. Low enzyme levels increased arabinoxylan (AX) and starch retention on the sieves, due to physical incorporation of AX and starch in the gluten aggregates. Higher enzyme levels increased retention of starch and AX on the smaller and larger sieves, respectively. Extensive oxidation leads to physical incorporation of AX and starch granules in the small gluten aggregates. AX is also crosslinked and hence more easily retained on the top sieves. Our results confirm that the size of gluten aggregates and the level of AX crosslinking and AX and starch incorporation in gluten proteins depend on the concentration of H2O2.