Luo Wei, Yuan Chengzhi, Wu Jinhong, Liu Yongle, Wang Faxiang, Li Xianghong, Wang Shaoyun
School of Food and Bioengineering, Changsha University of Science & Technology, Changsha 410114, Hunan Province, China; College of Biological Science and Engineering, Fuzhou University, Fuzhou 350108, Fujian Province, China.
School of Food and Bioengineering, Changsha University of Science & Technology, Changsha 410114, Hunan Province, China.
Food Chem. 2023 Jul 15;414:135695. doi: 10.1016/j.foodchem.2023.135695. Epub 2023 Feb 15.
The membrane-separated silver carp hydrolysates (>10 k, 3-10 k and < 3 k) displayed abilities to mitigate oxidation and denaturation of myofibrillar protein and cryoprotective activities for frozen surimi. However, the mechanism of the membrane-separated fractions on ice crystal growth in the system is still unknown. Therefore, the cryoprotective activities (recrystallization inhibition, RI and thermal hysteresis activity, THA) of the fractions were investigated and the mechanism was explored by molecular dynamics (MD) simulation to predict the probable binding sites and model the possible interactions between the peptides and water/ice. The fractions < 3 k displayed remarkable RI activity, with significantly higher THA (0.60 ± 0.13 °C) and lower amount of ice nuclei (4.74 ± 0.53%) than that of fractions > 10 k and 3-10 k. The results of MD simulation certified that the main peptides in the fractions < 3 k interacted firmly with water molecules and inhibited growth of ice crystals with mechanism compatible with Kelvin effect. Hydrophilic and hydrophobic amino acid residues in the membrane-separated fractions offered synergistic effects on the inhibition of ice crystals.
经膜分离的鲢鱼水解产物（分子量>10k、3 - 10k和<3k）表现出减轻肌原纤维蛋白氧化和变性的能力以及对冷冻鱼糜的冷冻保护活性。然而，膜分离组分对体系中冰晶生长的作用机制仍不清楚。因此，研究了这些组分的冷冻保护活性（重结晶抑制，RI和热滞活性，THA），并通过分子动力学（MD）模拟探索其机制，以预测可能的结合位点并模拟肽与水/冰之间可能的相互作用。分子量<3k的组分表现出显著的RI活性，其THA（0.60±0.13°C）显著高于分子量>10k和3 - 10k的组分，且冰核数量（4.74±0.53%）更低。MD模拟结果证实，分子量<3k的组分中的主要肽与水分子牢固相互作用，并以与开尔文效应相容的机制抑制冰晶生长。膜分离组分中的亲水和疏水氨基酸残基对冰晶抑制具有协同作用。
