Mechanism Unraveling the Ice-Inhibition Differences of Inulin with Varied Polymerization Degrees and Its Cryoprotective Effects on Frozen Scallops

In this work, the ice-inhibiting effects and their underlying mechanisms of inulin with various chain lengths were elucidated through experimental measurements and molecular dynamics simulations. The results suggested that long-chain inulin (HP group) exhibited strong and stable ice-inhibiting effects, with a minimum %MGS (12.18%) and limited ice growth of 36.61% after 100 min of freezing. The extensive contact area of long-chain inulin with water molecules (higher Rg and solvent-accessible surface area (SASA) values) favored their hydrogen-bond formation, which further disrupted the original hydrogen-bonding network of water by transforming the hydrogen-bonding mode (DDAA–OH mode into the DA mode). The remarkable cryoprotective effects of the HP group on scallops were evidenced by no significant difference in mass loss, water-holding capacity (WHC), and structural stability of the myofibrillar protein with the commercial antifreeze group (p > 0.05). This study provides strong evidence to broaden the cryoprotection applications of inulin to improve the quality of frozen food.