Quality enhancement of Pacific white shrimp (Litopenaeus vannamei) during frozen storage via static magnetic field-assisted freezing: insights into myofibrillar protein structure and functionality.

The effect of air freezing (AF-35), immersion freezing (IF-35), and static magnetic field-assisted freezing at -35 °C and - 25 °C (MF-35, MF-25) on the structure and functional properties of myofibrillar protein (MP) in Litopenaeus vannamei during frozen storage was investigated in this study. MF-35 exhibited higher reactive/total sulfhydryl groups and solubility (P < 0.05). This indicates superior inhibition of protein oxidation and aggregation, and it also preserved the highest α-helical content and fluorescence strength (P < 0.05), which demonstrates it effectively minimized disorder in secondary structure and unfolding of the tertiary structure. MF-35's emulsifying stability, rheological properties, and gel strength surpassed other treatments, demonstrating its effectiveness in mitigating MP emulsifying and gel properties degradation. IF-35 and MF-25 did not differ significantly in MP solubility, fluorescence intensity, or gel strength (P > 0.05). Overall, MF treatment delays MP degradation during frozen storage and also reduces energy use.