Synergistic modification of wheat starch by freeze-thaw treatment and fucoidan: Insight into the gel properties, rheological behaviors, multiscale structure, and the application in hot-dry noodles.

The synergistic effects of freeze-thaw treatment (FT) and fucoidan (FC) on the physicochemical and structural properties of wheat starch (WS), alongside its application in hot-dry noodles, were investigated. The combined treatment significantly reduced the gel hardness and viscoelastic moduli of WS. Additionally, peak viscosity and swelling power decreased, whereas water absorption capacity increased. Microscopic observations revealed distinct alterations in the surface morphology of starch granules. Furthermore, the structural ordering of the starch was disrupted, as evidenced by significant declines in short-range and long-range molecular order. Specifically, the relative crystallinity was reduced from 12.37% to 7.41%. Upon application in hot-dry noodles, synergistically modified starch significantly enhanced the textural properties, resulting in superior hardness and springiness. These results demonstrated that the synergistic application of FT and FC effectively modulated the multiscale structure and functional characteristics of WS, providing a practical basis for developing clean-label modified starches with enhanced thermal stability.