Effect of high pressure treatment on gel characteristics and gel formation mechanism of bighead carp (Aristichthys nobilis) surimi gels

This study investigated the effects of pressure treatment on the gel characteristics and gel formation mechanism of bighead carp surimi gels. Bighead carp surimi and isolated actomyosin were subjected to various pressures (100, 200, 300, 400, and 500 MPa) at 25°C for 30 min. Compared to traditional two-step heat-treated gels, gels treated at pressures above 300 MPa exhibited less hardness and chewiness but higher gel strength. The highest gel strength and springiness were observed at 500 MPa. Pressure-treated gels exhibited improved whiteness and water-holding capacity, while heat-treated gels were lighter (L*) and more yellow (b*). The increase in actomyosin turbidity with increasing pressure coincided with a decrease in protein solubility, suggesting the formation of protein aggregates. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) showed that high pressure treatment induced polymerization and degradation of myosin heavy chain. Scanning electron microscope (SEM) indicated that the pressure-treated gels exhibited more ordered protein networks. Practical applications As a new food processing technology, ultra-high pressure (UHP) technology can not only keep the original flavor of raw materials during processing, but also improve the quality of surimi gels. Actomyosin protein is a key protein in the process of high quality surimi gel. Studying the effect of ultra-high pressure on surimi gel and actomyosin proteins may provide theoretical support for the industrial production of surimi.