Effects of Rigor Mortis and Salt Content on Gel Properties of Silver Carp (Hypophthalmichthys molitrix) Surimi

In order to study the effects of rigor mortis and salt content on the gel properties of surimi, surimi gels with sodium chloride contents of 1%, 2%, and 3% (m/m) were made from pre- and post-rigor silver carp (Hypophthalmichthys molitrix) muscle, and their texture characteristics, rheological properties, water distribution, microstructure, and intermolecular forces were measured and analyzed. The results showed that compared with the surimi gel made of post-rigor muscle and low salt content, the gel strength, resilience, cohesiveness, storage modulus (G’), loss modulus (G”), immobile water fraction, and water-holding capacity of the surimi gel made of pre-rigor muscle and high salt content increased, and the hardness and whiteness decreased. Scanning electron microscopy (SEM) images showed that compared with the surimi gel made of post-rigor muscle and low salt content, the surimi gel made of pre-rigor muscle and high salt content had a denser structure with smaller pores. In summary, the surimi gel made of pre-rigor muscle and high salt content has better quality characteristics in terms of texture characteristics and water-holding capacity than the post-rigor group and low salt content group.