Ice crystal growth regulates the formation of anisotropic lamellar structure in vacuum-extruded surimi-based...

Surimi-based products typically exhibit a monotonous texture and lack juiciness due to their homogenized structure. This study proposes a vacuum-extrusion-freezing strategy to reconstruct anisotropic lamellar structures in surimi-based systems. The effects of freezing conditions and ice crystal growth on lamellar structure development were investigated using multiple visual and physicochemical analyses. Results indicated that ice crystal growth behavior plays an important role in regulating lamellar structure formation. Rapid freezing at -60 °C generated fine ice crystals and led to compact and less distinct lamellar structures, whereas slow freezing at -20 °C achieved a better balance among lamellar clarity, texture, and juiciness. During subsequent heating, the preformed ice crystal framework facilitated stable lamellar structure formation. Freeze-thaw cycles produced coarser ice crystals and looser lamellar structures. Lamellar structure formation regulated by ice crystal growth was accompanied by protein conformational changes, including α-helix to β-sheet transition, decreased intrinsic fluorescence, increased surface hydrophobicity, and reduced disulfide bond content. Overall, this work provides useful insights for texture regulation in surimi-based products.