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

Abstract

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 (0.91mol/10⁵g 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.

Keywords: Bighead carp; Disulfide; Frozen storage; Gel texture; Hydroxyl radicals; WHC.