The influence of repeated freeze–thaw (F-T) treatments (0, 1, 3 and 5) on the functional and structural properties of myofibrillar protein (MP) from mirror carp (Cyprinus carpio L.) was investigated according to the changes in rheological properties, particle distribution, Zeta (ζ)-potential, molecular force, Fourier transform infrared (FTIR) spectra and sulfhydryl content. After F-T treatment with five cycles, a significant decrease in the storage modulus values (G'), loss modulus values (G"), ζ- potential, total sulfhydryl content and reactive sulfhydryl content of MP was observed (P < 0.05). The particle size increased within the third F-T cycles, but it decreased in the fifth F-T treatments (P < 0.05). The hydrogen bonds, hydrophobic interactions and disulfide bonds of protein were broken during multiple F-T treatments. In addition, as the F-T cycles increased, the α-helix and β-turn contents decreased (P < 0.05), and the β-sheet and random coil content increased (P < 0.05). Therefore, repeated F-T treatments damaged the structure of MP and reduced the functional properties of MP from mirror carp.

根据流变学性质的变化，研究了反复冻融（FT）处理（0、1、3和5）对镜鲤（Cyprinus carpio L.）肌原纤维蛋白（MP）功能和结构特性的影响、粒子分布、Zeta (ζ) 电位、分子力、傅里叶变换红外 (FTIR) 光谱和巯基含量。经过五个循环的FT处理后，观察到MP的储能模量值（G'）、损耗模量值（G"）、ζ-电位、总巯基含量和反应性巯基含量显着降低（P  < 0.05）。粒径在第三次 FT 循环内增加，但在第五次 FT 处理中减小（P < 0.05)。在多次 FT 处理期间，蛋白质的氢键、疏水相互作用和二硫键被破坏。此外，随着FT循环次数的增加，α-螺旋和β-转角含量降低（P  < 0.05），β-折叠和无规卷曲含量增加（P  < 0.05）。因此，反复FT处理破坏了镜鲤MP的结构，降低了镜鲤MP的功能特性。