Changes in properties of myofibrillar protein and myofibrillar protein gel from freshwater fish after low-temperature and high-pressure collaborative treatment

This study investigated the effects of low-temperature and high-pressure collaborative and conventional air freezing (CAF) on myofibrillar protein (MP) characteristics from grass carp. Turbidity, solubility, and particle size analysis showed that the pressure shift freezing (PSF) treatment could inhibit the formation of large MP aggregates to a certain extent during freezing. Chemical interaction studies unveiled that PSF treatment not only mitigates damage to the inherent structure of MP during freezing but also enhances its crosslinking ability. Microstructure analysis revealed a densely woven fibrous protein network structure within the MP gel in the PSF group. MP gel with fiber shape network structure in the PSF group exhibited stronger water-holding capacity and mechanical properties compared to the CAF group having an incomplete protein network structure. This suggests that the combined application of low-temperature and high-pressure treatment holds promising potential for utilization in the surimi gel processing industry and aquatic products processing. Industrial relevance: The quality and safety of food are closely related to the commodity value of food. Combined low-temperature and high-pressure treatment can enhance the commodity value of low-value freshwater fish products and has potential in surimi gel new product development. This study provides theoretical guidance for high-pressure and low-temperature collaborative processing and industrial production of related aquatic products.