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.