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

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′) and percent stress relaxation (SR%), and lower creep compliance (Jmax), 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 SDS-extractable protein content also increased, 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 sheet were closely 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.