Impact of starch surface hydrophobicity on gluten aggregation behavior in dough-like model systems

Wheat flour dough can be viewed as a composite material in which gluten proteins form a continuous matrix, while starch granules act as dispersed filler particles. As the highest component in flour, starch was traditionally regarded as merely an inert filler within the gluten matrix. While, the impact of starch surface characteristics to gluten network formation has been largely overlooked. In this study, surface interactions between starch granules and gluten were investigated using a dough-like model systems which were developed with surface modified starch granules through heat treatment and gluten protein. Our results demonstrated that heat treatment induced structural rearrangements in starch molecules, weakening hydrogen bonding, ionic interactions, and hydrophobic associations between starch and proteins. As a consequence, the dough exhibited higher levels of free thiol groups, which inhibited the crosslinking and aggregation of gluten proteins. Moreover, the disruption of starch-gluten interactions altered the aggregation dynamics of gluten proteins during dough mixing, leading to a reduction in gluten macropolymer (GMP) content. These findings deepen the understanding of starch-protein interactions in dough processing and offer practical insights for improving preprocessing strategies in bread production.