超高压对带鱼鱼糜凝胶特性及其肌原纤维蛋白结构的影响

以带鱼鱼糜为原料,分别采用不同的超高压参数和热处理,分析鱼糜凝胶强度、白度、质构指标、微观结构以及肌原纤维蛋白含量和构象单元的变化,探究超高压处理对带鱼鱼糜凝胶特性及其肌原纤维蛋白结构的影响。结果表明:超高压诱导带鱼鱼糜凝胶网络结构形成,超高压诱导组质构特性、凝胶强度、白度均比对照组有所提高,扫描电子显微镜图显示350 MPa保压8 min后(350-8组)所形成的鱼糜凝胶网络结构与热诱导组接近;超高压处理后,鱼糜凝胶中的肌原纤维蛋白含量有所降低,经圆二色光谱测定,肌原纤维蛋白的两个负峰逐渐消失,其α-螺旋结构相对含量下降,无规卷曲和β-折叠的相对含量有不同程度上升,350-8组无规卷曲相对含量与热诱导组接近。综上,适宜的超高压处理条件(350 MPa保压8 min)显著影响带鱼鱼糜凝胶特性及其肌原纤维蛋白二级结构,促进凝胶网络形成,改善鱼糜凝胶品质。

Effect of Ultra-High Pressure on the Myofibrillar Protein Structure and Gel Properties of Hairtail Surimi

This study investigated the effect of ultra-high pressure (UHP) treatment on gel characteristics and myofibrillar protein structure in hairtail surimi. Changes in the gel strength, whiteness, texture properties and microstructure and the content and molecular conformation myofibrillar protein were measured after UHP treatment at different pressures for different times or heat treatment. The results showed that UHP could induce the formation of a network structure in surimi gel, and improve texture parameters, gel strength and whiteness compared to the control group. Scanning electron microscopy showed that the gel network structure of surimi treated with 350 MPa for 8 min (350-8 group) was close to that of the heat-induced group. UHP treatment reduced the content of myofibrillar protein in the surimi gel, and led to the gradual disappearance of the two negative grooves in the circular dichroism (CD) spectrum of myofibrillar protein. Meanwhile, the relative content of α-helix structure decreased, but the random coil and β-sheet contents increased to varying degrees. The random coil content of myofibrillar protein in the 350-8 group was close to that in the heat-induced group. Conclusion: Appropriate UHP treatment (at 350 MPa for 8 min) significantly affected the gel characteristics and the secondary structure of myofibrillar protein from surimi, promoted the formation of gel network and improved the quality of surimi gel.