College of Food Science and Technology, Zhejiang University of Technology, Hangzhou, China; Zhejiang Key Laboratory of Green, Low-carbon and Efficient Development of Marine Fishery Resources, Hangzhou 310014, China; National R&D Branch Center for Pelagic Aquatic Products Processing (Hangzhou), Hangzhou, China; Collaborative Innovation Center of Seafood Deep Processing, Dalian Polytechnic University, Dalian 116034, China.
College of Food Science and Technology, Zhejiang University of Technology, Hangzhou, China; Zhejiang Key Laboratory of Green, Low-carbon and Efficient Development of Marine Fishery Resources, Hangzhou 310014, China; National R&D Branch Center for Pelagic Aquatic Products Processing (Hangzhou), Hangzhou, China.
Int J Biol Macromol. 2024 May;268(Pt 2):131941. doi: 10.1016/j.ijbiomac.2024.131941. Epub 2024 Apr 27.
The inherent functional fractions (gelation and ice-affinitive fractions) of gelatin enable it as a promising cryoprotectant alternative. However, the composition-antifreeze property relationships of gelatin remain to be investigated. In this study, the HW-PSG and LW-PSG fractions of gelatin from fish scales were obtained, according to the critical gelation conditions and ice-binding measurements, respectively. Thermal hysteresis (THA) value, associated with ice nucleation, of LW-PSG was higher than that of HW-PSG. Besides, the relatively low-sized ice crystals (210-550 μm) indicated that HW-PSG showed strong ice recrystallization inhibition (IRI) ability, compared to other groups. These results suggested that LW-PSG inhibited ice nucleation, while HW-PSG displayed the strong IRI ability. Furthermore, the antifreeze mechanisms were clarified through IRI measurements and molecular dynamics simulation. The minimum size of ice crystals was found for HW-PSG gels with dense microstructure, suggesting the HW-PSG retarded the growth of ice crystals by restricting the migration and phase transformation of water molecules. The hydrogen bond interactions between the ice crystal surface and ASN1294 and PRO1433 residues of LW-PSG, and hydrophobic interactions contributed to inhibiting the nucleation of ice crystals. This study provided some references to further enhance antifreeze performance of gelatin by modulating fragment composition.
明胶的固有功能片段（凝胶和冰亲和片段）使其成为有前途的抗冻保护剂替代品。然而，明胶的组成-抗冻特性关系仍有待研究。在这项研究中，根据临界凝胶化条件和冰结合测量，分别从鱼鳞中获得了明胶的 HW-PSG 和 LW-PSG 片段。与冰核形成相关的低温滞后（THA）值，LW-PSG 的值高于 HW-PSG。此外，相对较小尺寸的冰晶（210-550μm）表明，与其他组相比，HW-PSG 表现出强烈的冰晶重结晶抑制（IRI）能力。这些结果表明，LW-PSG 抑制了冰核的形成，而 HW-PSG 则表现出强烈的 IRI 能力。此外，通过 IRI 测量和分子动力学模拟阐明了抗冻机制。发现具有密集微观结构的 HW-PSG 凝胶中冰晶的最小尺寸最小，这表明 HW-PSG 通过限制水分子的迁移和相转变来延缓冰晶的生长。LW-PSG 中冰晶体表面与 ASN1294 和 PRO1433 残基之间的氢键相互作用以及疏水性相互作用有助于抑制冰晶体的成核。这项研究为通过调节片段组成进一步提高明胶的抗冻性能提供了一些参考。
