NaCl-thermal synergy mediates structural transitions in hsian-tsao polysaccharide-myosin complexes to influence flavor-binding selectivity.

Hsian-tsao polysaccharide (HTP) with preferable gel-enhancing and bioactive properties improved surimi quality. This study elucidated how NaCl concentration (0.2-1.0 mol/L) and heating protocols (setting: 40 °C/30 min; two-step heating: 40 °C/30 min + 90 °C/20 min) modulated HTP-myosin complexation and its selective binding to off-flavors (1-octen-3-ol, hexanal, heptanal, nonanal). Associative phase separation occurred in HTP-myosin systems, while myosin transitioned from aggregation to dissolution with increasing NaCl concentration. Setting facilitated HTP-myosin complexation via electrostatic-hydrophobic interactions. HTP reduced myosin aggregation (26.24 % reduction in particle size at 0.6 mol/L NaCl) and increased sulfhydryl groups (17.02 % at 0.4 mol/L NaCl). The α-helix-to-β-sheet transitions reduced aldehyde-binding affinity but enhanced 1-octen-3-ol binding. Two-step heating promoted hydrophobic crosslinking, elevating turbidity and reducing flavor binding by 17.44 %-48.75 %. High NaCl (≥0.8 mol/L) induced electrostatic shielding, accelerating flavor release. PCA linked α-helix loss to alcohol release and β-sheet/sulfhydryl content to aldehyde retention, proposing NaCl-thermal strategies for surimi texture-flavor optimization.