Impact of wheat starch granule size on viscoelastic behaviors of noodle dough sheet and the underlying mechanism

Abstract

The contribution of starch to dough behaviors has been largely overshadowed by the role of gluten, receiving much less attention in comparison. The impact of wheat starch granule size on the viscoelastic behaviors of low-moisture noodle dough and its underlying mechanism were investigated. Dough with a high ratio of B-type starch granules (BS) had higher viscoelastic moduli (G″ and G′), percent stress relaxation (SR%), and smaller creep compliance (J max ), indicating higher viscoelasticity and strength. This might be related to the higher filling ability and water-binding capacity of B-type starch. Compared to large A-type starch granules (AS), small B-type granules would easily embed to form a more closely packed and uniform network structure. In addition, the differences in water distribution and hydration properties could affect the hydrophobicity of starch and the surface environments of the protein, thus influencing the polymer interactions in the doughs. The hydrogen bonds were the main con-covalent bonds in the low-moisture noodle dough. With increasing B-/A-type starch ratios, β-sheet and hydrogen bond contents significantly increased, while the GMP content showed a decrease, suggesting the enhanced hydrogen bond interaction in a high ratio of B-type starch dough could cooperate with intermolecular disulfide bonds to stabilize the network structure of gluten, improving the dough strength. These results demonstrated that the viscoelastic behaviors of dough sheets were related to the granule size distribution of wheat starch. Finally, a schematic model describing the mechanism of the influence of starch granule size on dough behaviors was built. • B-type wheat starch granules promoted uniform and compact gluten network formation. • Small B-type granules led to stronger hydrogen bond interaction in the noodle dough. • The enhanced interaction by hydrogen bonding could improve the dough strength. • Viscoelasticity of dough sheet increased with increasing B- to A-type starch ratios.