鱼糜凝胶形成过程中物理化学变化

Changes in Chemical Forces and Protein Conformations during the Formation of Grass Carp Surimi Gels

采用化学法测定鱼糜凝胶形成过程中离子键、氢键、疏水相互作用和二硫键的变化,借助拉曼光谱仪分析草鱼鱼糜凝胶形成过程中鱼糜蛋白质构象的变化,进而研究化学作用力和蛋白质构象对鱼糜凝胶形成的影响。结果表明:在草鱼鱼糜凝胶的形成过程中,离子键、氢键显著减少,疏水相互作用、二硫键和非二硫共价键增加;α-螺旋结构部分转化为无规卷曲结构。疏水相互作用、二硫键及非二硫共价键是影响凝胶形成的主要作用力,α-螺旋和无规卷曲是草鱼鱼糜凝胶形成过程中维持鱼糜凝胶稳定结构的主要蛋白质构象。

Fresh water fish surimi products processing is one of the main directions of fisheries processing industry in China.Gelation is the most important factor that affects the quality of surimi products.So making the mechanism of gel formation clear is of great significance.In the present study,chemical methods were used to determine the changes in ion,disulfide and hydrogen bonds and hydrophobic interactions during the formation of grass carp （Ctenopharyngodon idellus） surimi gels and the technique used to analyze protein conformation changes was laser-Ramman spectroscopy.Furthermore,the effects of chemical forces and protein conformation on the formation of surimi gels were elucidated.The results illustrated that during surimi gel formation,ion bonds and hydrogen bonds decreased significantly.However,hydrophobic interactions,disulfide bonds and non-disulfinde covalent bonds increased markedly.The α-helix of protein conformation was change into turn and random coil structures in part.Based on these results,it can be concluded that hydrophobic interactions,disulfide bonds and non-disulfide covalent bonds are the main chemical forces affecting the formation of surimi gels from frozen grass carp and that α-helix and random coil structures are the main protein conformations keeping the structure of frozen grass carp surimi gels stable.