骨架蛋白降解对冰鲜草鱼质构的影响

Effect of Cytoskeletal Protein Degradation on Texture of Grass Carp(Ctenopharyngodon idella) during Ice Storage

利用免疫组化技术检测草鱼背肌白肉中骨架蛋白在冰藏条件下的变化,同时通过超微结构、剪切力、滴水损失率分析草鱼背肌组织精微结构和质构特性的变化,以期阐明草鱼骨架蛋白降解与鱼肉质构劣化之间的关系,从而为调控冰鲜淡水鱼品质提供理论依据。结果显示:冰藏21 d内伴肌球蛋白、伴肌动蛋白、抗肌营养不良蛋白分别降解了76.10%、78.21%、71.14%;冰藏14 d后草鱼肌纤维明暗带模糊,Z带、M带被破坏,肌纤维结构出现严重断裂松散现象。冰藏10 d内剪切力由81 N快速下降至32 N,滴水损失率由1.6%增加至7.8%;将骨架蛋白的灰度与剪切力及滴水损失率进行相关性分析发现,剪切力与伴肌球蛋白、抗肌营养不良蛋白的灰度呈极显著正相关(P<0.01);滴水损失率与伴肌球蛋白、抗肌营养不良蛋白的灰度值呈极显著负相关(P<0.01)。综上所述,骨架蛋白降解可能是草鱼在冰藏期间肌纤维结构破坏以及质构劣化的重要原因。

The aim of this work was to investigate the changes of cytoskeletal proteins in the dorsal muscle of grass carp(Ctenopharyngodon idella) during ice storage by immunohistochemistry,and to analyze the changes in the microstructure and textural properties by ultrastructural observation and measurement of shear force and drip loss.In addition,this study clarified the relationship between the degradation of cytoskeleton protein and the deterioration of fish texture,which will a provide theoretical foundation for the quality preservation of freshwater fish.The results showed that cytoskeleton proteins significantly degraded during ice storage.Titin,nebulin,and dystrophin degraded by 76.10%,78.21%,and 71.14%,respectively.The light and dark bands of grass carp muscle fibers were unclear after 14 days of ice storage.The Z-band and M-band were degraded.and the muscle fiber structure severely broke or became loose.Meanwhile,shear force rapidly decreased from 81 N to 32 N within 10 days of storage,while drop loss increased from 1.6% to 7.8%.Correlation analysis indicated a significantly positive correlation between shear force and the integrated option density(IOD) of titin and dystrophin(P<0.01).In contrast,a significantly negative correlation was observed between drip loss and the IOD of titin and dystrophin(P<0.01).The above results showed that the degradation of cytoskeletal proteins may be an important cause of the destruction of muscle fiber and textural deterioration of grass carp during ice storage.