Quality Enhancement of Shrimp Surimi by Static Magnetic Field Treatment at 4 ºC

The aim of this study was to investigate the effect of static magnetic field (SMF) synergized with low temperature (4 °C) on the properties of shrimp gels and to reveal the underlying mechanisms through the biochemical properties, microstructural and rheological properties as well as the water distribution in the shrimp sols and gels. The experimental results showed that exposing shrimp sols to SMF for 16 h followed by heat treatment significantly improved the strength and hardness of the gels. This improvement was attributed to the fact that SMF treatment altered the water distribution in the sol, leading to a decrease in the T₂ relaxation time of the gel and the conversion of immobilized water to bound water. Furthermore, FTIR results indicated that the α-helix structure in the secondary structure of the proteins was transformed into β-sheet and random coiling under the influence of SMF. The gels treated with SMF for 16 h were observed to have the densest structure by microstructural measurements. However, continuous extension of the SMF treatment time negatively affected the gel quality. This study provides valuable insights for optimizing the preparation process of shrimp gels and may facilitate further application of magnetic field treatment techniques in food science.