Comparison of gel properties and biochemical characteristics of myofibrillar protein from bighead carp (Aristichthys nobilis) affected by frozen storage and a hydroxyl radical-generation oxidizing system

- A certain range in contents of disulfide crosslinks promotes gel hardness.
- Mild protein oxidation (−20 °C for 7 weeks or 0.1 mM H2O2) promoted gel properties.
- Freezing bighead carp for a certain period was a good source of gel products.

We wanted to clarify whether gel properties can be affected by in vivo or in vitro myofibrillar protein oxidation and, thus, to provide relevant information and a scientific foundation for the processing of gel products. To accomplish this, we measured the changes in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), total disulfide (SS) content, surface hydrophobicity (So-ANS), carbonyl content, and gel texture and water-holding capacity (WHC) of isolated myofibrillar protein from bighead carp fillets during frozen storage and under different H2O2 concentrations, which were used to represent in vivo and in vitro conditions, respectively. The results indicated that a certain range in content of disulfide crosslinks (0.91 mol/105 g protein) would promote gel hardness. Mild protein oxidation caused by a certain degree of frozen storage and hydroxyl radicals can promote gel texture and WHC. Based on those results, freezing bighead carp for a certain period can be used to produce gel products.