Changes of protein secondary structures of pollock surimi gels under high-temperature (100 °C and 120 °C) treatment

Abstract

To produce instant surimi products, sterilization is essential. Previous studies found that the gel strength of surimi decreased significantly with treating temperature increasing from 100 °C to 120 °C, which affected the texture of the products. In this study, the changes of the secondary structures of surimi gels were studied to provide new train of thought for the improvement of the texture of high temperature treated surimi gels. Surimi gels from Alaska Pollock were obtained by heating and maintaining their central temperature at 100 °C and 120 °C for 10 min under a constant pressure (0.12 MPa). Infrared (IR) spectroscopy and Raman spectroscopy showed that the secondary structure of the surimi gels with high temperature (≥100 °C) treatment was mainly random coil and the random coil structure damaged with treating temperature increasing, which made the frames of the network structure become much more fragile and the holes become larger, leading to the destruction of the textural properties of the surimi gels.