Kinetics and mechanisms of thermal deterioration in silver carp (Hypophthalmichtys molitrix) surimi gel quality under high-temperature sterilization.

Background: The gelation properties of surimi gel under various high temperatures (115, 118, and 121 °C) and sterilization intensities (F values of 3-7 min) were systematically investigated. A kinetic model detailed quality changes during heat treatment through mathematical analysis, elucidating mechanisms for gel quality degradation.

Results: Increased sterilization intensity significantly reduced the quality characteristics of surimi gel. Compared to the gel without sterilization treatment, when the sterilization intensity was increased to 7 min, the gel strength of the groups treated at 115 °C, 118 °C, and 121 °C decreased by 68.35%, 51.4%, and 51.71%, respectively, and the water-holding capacity decreased by 24.87%, 16.85%, and 22.5%, respectively. The hardness, chewiness, and whiteness of the gel also significantly decreased, and the changes in these indicators all conformed to a first-order kinetic model. Activation energy of 291.52 kJ mol highlighted gel strength as the least heat-resistant. At equivalent sterilization intensities, 115 °C exhibited the poorest gel quality, followed by 121 °C, with 118 °C showing relatively better gel quality. Increased T and decreased PT suggested heightened water mobility and transition of immobilized water within the gel into free water. Protein degradation, weakened disulfide bonds and hydrophobic interaction, and protein conformation changes collectively led to a rough and incoherent gel network structure with large fissures, as verified by the results of scanning electron microscopy. Correlation analysis indicated potential for precise control over surimi gel quality by modulating physicochemical attributes.

Conclusion: The outcomes may be beneficial to improve the production and quality control of ready-to-eat surimi-based products. © 2024 Society of Chemical Industry.