The influence of pressure-shift freezing based on the supercooling and pressure parameters on the freshwater surimi gel characteristics.

In this study, the phase transition curve of grass carp surimi gel in the ice I region was mapped and fitted. Additionally, the average adiabatic compressibility of surimi gel was calculated to be 2.7℃/100 MPa in the range of 0-320 MPa. Building upon this, the study further investigated the impact of pressure-shift freezing (PSF) treatment based on supercooling and pressure coupling on the gel strength, texture profile analysis (TPA), and water-holding capacity of surimi gel. Compared with the low level of supercooling (supercooling value > -15℃) treatment, the PSF treatment with a higher supercooling degree (supercooling value ≤ -15℃) could enhance the strength and water-holding capacity of surimi gel. The morphology and distribution of ice crystals suggested that the diameter and size distribution of ice crystals in the sample were dependent on the combination of pressure level and supercooling. The combination of precise control of supercooling and pressure parameters is beneficial in improving the mechanical properties and water-holding capacity of surimi gel. This is of great value for developing high-quality surimi gel products and also offers a new research thread in the realm of high-pressure freezing.