为研究鲢鱼与金线鱼混合鱼糜的凝胶特性,本实验对混合鱼糜凝胶的凝胶强度、持水性、蒸煮损失、白度值、横向弛豫时间、微观结构和肌原纤维蛋白进行分析。结果表明:混合鱼糜的白度值较纯金线鱼鱼糜显著提高(P〈0.05),且鲢鱼鱼糜与金线鱼鱼糜质量比5∶1混合后的凝胶白度值高于纯鲢鱼鱼糜;此配比下的混合鱼糜凝胶性能最好,其中凝胶破断力、凹陷距离、凝胶强度和持水性较鲢鱼鱼糜分别提高了18.33%、27.29%、51.01%和5.65%,较金线鱼鱼糜分别提高了5.84%、19.50%、26.49%和3.45%;该配比下的混合鱼糜凝胶的蒸煮损失较鲢鱼鱼糜和金线鱼鱼糜分别降低了15.88%和7.48%。低场核磁共振分析显示鲢鱼鱼糜与金线鱼鱼糜质量比5∶1混合后的鱼糜凝胶的横向弛豫时间T22比鲢鱼鱼糜凝胶T22缩短了10.34 ms。通过扫描电镜观察发现鲢鱼鱼糜与金线鱼鱼糜质量比5∶1混合时可形成高度均匀、致密的空间凝胶网络结构。肌原纤维蛋白凝胶电泳图显示该配比下肌球蛋白重链(myosin heavy china,MHC)发生交联,大分子聚集体形成,进入凝胶中MHC更少,条带更细窄。
In order to explore gel properties of mixed surimi from silver carp surimi and Nemipterus virgatus at various ratios, the gel strength, water holding capacity, cooking loss rate, whiteness, transverse relaxation time, microstructure and myofibrillar protein of mixed surimi gels were analyzed in the present study. The results showed that the whiteness of mixed surimi was significantly promoted compared with the pure Nemipterus virgatus surimi gel(P 〈 0.05), and the whiteness of the mixed surimi gel from silver carp and Nemipterus virgatus with a ratio of 5:1 was improved compared with the pure silver carp surimi gel. At this ratio, gel properties of the mixed surimi gel were the best. The breaking force, deformation, gel strength and water holding capacity increased by 18.33%, 27.29%, 51.01% and 5.65%, respectively, compared with the pure silver carp surimi gel, and by 5.84%, 19.50%, 26.49% and 3.45%, respectively, compared with the pure Nemipterus virgatus surimi gel. In addition, cooking loss of the mixed surimi was lowered by 15.88% and 7.48% than that of silver carp surimi gel and Nemipterus virgatus surimi gel, respectively; the transverse relaxation time T22 of the mixed surimi gel was shorter by 10.34 ms in comparison with silver carp surimi gel. As observed under scanning electron microscope, microstructure of the mixed surimi gel from silver carp and Nemipterus virgatus with a ratio of 5:1 was highly uniform and dense. Sodium dodecyl sulfatepolyacrylamide gel electropheresis(SDS-PAGE) of myofibrillar protein indicated that the myosin heavy chain(MHC) cross-linked and formed large molecular weight aggregates so that less MHC entered the gel and the strip was more narrow.