Potential mechanisms of taste changes in surimi gels with typical cross-linking degrees during frozen storage: Based...

This study reveals a novel structure-flavor preservation mechanism in surimi gels during 90-day storage at -20 °C by coupling protein cross-linking degree with liquid nitrogen freezing strategy. Results showed that combining a high cross-linking degree (62.99%) with liquid nitrogen freezing (-80 °C) minimized ice crystal damage, preserved a dense gel network, and effectively retained umami compounds (carnosine, inosine monophosphate, adenosine monophosphate, guanosine monophosphate, aspartic acid, glutamic acid). Conversely, low cross-linking (29.66%) with conventional air freezing (-18 °C) promoted bitter compounds accumulation (inosine, hypoxanthine, branched-chain amino acids). The stability of protein secondary structures (α-helix, β-sheet, β-turn) and gauche-gauche-gauche was positively correlated with the retention of umami compounds, while increased random coil and trans-gauche-trans were associated with bitter compounds accumulation. Hydrogen bonding, ionic interactions, and non-specific binding contributed to umami preservation, whereas enhanced hydrophobic interactions facilitated bitterness development. These findings pave the way for developing frozen surimi products with stable taste profiles.