超声辅助谷氨酰胺转氨酶对肌原纤维蛋白结构及凝胶性能的调控

Regulation of Ultrasound-Assisted Transglutaminase on Structure and Gel Properties of Myofibrillar Protein

以肌原纤维蛋白(myofibrillar protein,MP)为研究对象,借助圆二色谱、荧光光谱、电泳、流变、扫描电镜等方法分析超声辅助谷氨酰胺转氨酶(glutamine transaminase,TG)对MP的构象及凝胶性能的影响机制。结果表明:随着超声时间的延长,MP的α-螺旋含量、内源性色氨酸荧光强度和溶解度显著降低,蛋白交联聚集增加,导致弹性模量(G′)及凝胶硬度明显下降,但改善了凝胶的蒸煮损失率(降低34.8%)。TG和超声辅助TG处理使MP的溶解度降低,但凝胶形成能力及持水性明显提高。超声辅助TG处理使MP的α-螺旋含量明显增加,蒸煮损失降低达50.5%,形成了更加致密、均匀的凝胶三维网络结构。因此,100 W超声20 s辅助TG可以明显提高MP的质构特性和持水能力。

In this study,myofibrillar protein(MP)was used as the research object.The regulation mechanisms of ultrasound-assisted glutamine transaminase(TG)on the conformation and gel properties of MP were analyzed by circular dichroism,fluorescence spectroscopy,electrophoresis,rheology,and scanning electron microscopy.The results indicated that as the ultrasound time prolonged,theα-helix content,the fluorescence intensity and solubility of endogenous tryptophane of MP decreased significantly,and the crosslinking aggregation of the protein was aggravated,which further led to the decrease in the storage modulus(G′)and the hardness of gel.However,the cooking loss was improved(decreased by 34.8%).TG and ultrasound-assisted TG treatment reduced the solubility of MP but significantly improved the gel-forming ability and the water-holding capacity.Ultrasound-assisted TG treatment significantly increased theα-helix content of MP and reduced the cooking loss by 50.5%,which was favorable to the formation of a denser and more uniform three-dimensional gel network structure.In summary,ultrasound-assisted TG of 100 W for 20 s could significantly enhance the texture characteristics and water-holding capacity of MP.