**4. Conclusions**

Changes in the water migration and distribution, tissue microstructures, chemical interactions, protein spatial structure, and physical properties were studied. The addition of starch expanded and caused moisture migration, which was ascribed to the combination of free water and hydrophilic groups in starch. The competition between surimi and starch for water affected the chemical interactions and forces in surimi gel components, thereby indirectly resulting in changes in the microstructure and water holding properties of the gel matrix. For the direct cooking matrix, the porous surimi gel lost water when it was squeezed by starch, resulting in a reduction in pore size and immobile water inside. Moreover, starch was not conducive to the interactions of hydrophobic groups, whereas weak disulfide bonds were generated after adding starch. The enhancement of textural properties might be related to changes in protein structure. Subjected to the setting process, the matrix showed an ascendant trend in non-specific associations, ionic bonds, and hydrogen bonds, which was similar to non-setting gels. Setting-cooking gels with a compact structure were less affected by starch-swelling. However, adding excessive starch destroyed the integrity of SCG and decreased cohesiveness and resilience. Therefore, this study found that the addition of starch content had a better supporting effect on weak gels, which provided some insights for improving the quality of surimi-based products. Moreover, further studies are needed to improve the compatibility and active filling of starch in the two-step heating process.

**Author Contributions:** Conceptualization, X.J.; methodology, X.J. and N.X.; validation, N.X.; formal analysis, X.J., Q.C., and N.X.; investigation, X.J., Y.D., and Q.F.; resources, X.J., Q.C., and Y.D.; data curation, X.J. and Q.C.; writing—original draft, X.J.; writing—review and editing, Q.C., N.X., Y.D., and Q.F.; visualization, X.J.; supervision, W.S.; project administration, W.S.; funding acquisition, W.S. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the National Key R&D Program of China, grant number 2019YFD0902003.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Informed consent was obtained from all subjects involved in the study.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** The authors declare no conflict of interest.

#### **References**

