Effects of Freezing Methods on the Properties and Structure of Myofibrillar Proteins from Crayfish (Procambarus clarkii)

In order to study the effect of freezing methods on the quality of crayfish, changes in the properties and structure of crayfish myofibrillar proteins (MPs) after air freezing (AF), immersion freezing (IF), static magnetic field-assisted immersion freezing (SMF), and liquid nitrogen freezing (LNF) were examined. Compared with AF, IF and LNF could enhance the absolute value of the zeta potential of crayfish MPs to different degrees, inhibit the decrease of total sulfhydryl content, and maintain the structural characteristics of the proteins enhancing their stability. SMF improved the stability of MPs more significantly than any other freezing treatment (P < 0.05), as evidenced by lower turbidity and particle size, higher absolute zeta potential and total sulfhydryl content, better maintained structural features, lower surface hydrophobicity, and greater retention of the myosin heavy chains. In conclusion, the quality of frozen crayfish is affected by different freezing media, and SMF can better stabilize the functional properties of crayfish MPs.