海鲈鱼鱼糜冻藏过程中流变特性及凝胶结构的变化规律

为研究不同冻藏温度和冻藏时间对海鲈鱼鱼糜的流变特性和凝胶结构的影响,实验采用流变仪和显微镜对冻藏过程中的鱼糜进行分析观察。结果显示,海鲈鱼鱼糜的黏度随剪切速率增加而减小,存在剪切变稀现象;鱼糜的弹性模量(G′)和损耗模量(G″)随频率的增加而升高;鱼糜凝胶过程经历了三个阶段(不同冻藏温度和冻藏时间的鱼糜有所偏差):第一阶段在40℃之前,第二阶段出现在40~50℃,第三阶段在50℃之后,蛋白开始形成最终的凝胶;鱼糜随冻藏温度的升高和冻藏时间的延长,鱼糜的G′和G″减小,黏弹性下降,损耗角正切(tanδ)增大,流动性增加。鱼糜凝胶的微观结构显示,随冻藏温度升高和冻藏时间延长,纤维基质的损伤越大,形成的凝胶性能越差。本研究对海鲈鱼鱼糜的应用具有一定的借鉴意义。 

The changes of rheological properties and gel structures of sea bass surimi during frozen storage

The effect of different frozen temperatures and time on rheological properties and surimi gel structure were investigated by using rotational rheometer and microscopy. The results showed that the viscosity of sea bass surimi were significantly decreased with increasing shear rate. It was a shear-thinning phenomenon. The surimi elastic modulus(G′) and loss modulus(G″) were increased with increasing frequency. The gel process of surimi had three stages:the first stage appeared below 40 ℃,the second stage appeared between 40 ℃and 50 ℃,the third stage appeared over 50 ℃,and then the protein formed gel. The G′,G″ and viscoelastic of surimi were decreased with increasing frozen temperature and time,meanwhile the loss tangent(tanδ) and fluidity were increased. The gel microstructure revealed that the more matrix of fibers damaged,and the gel properties more weak with frozen temperature and frozen time extension. The results provided a certain reference for further widening the scope of the application of the sea bass surimi.