Quality Changes and Establishment of Predictive Models for Bighead Carp (Aristichthys nobilis) Fillets During Frozen Storage

The objectives of this study were to investigate quality changes of bighead carp fillets during frozen storage by measuring free fatty acids (FFA), salt extractable protein (SEP) content, Ca2+-ATPase activity, and total sulfhydryl (SH) content and to develop predictive models based on them. FFA increased with the extension of storage time. Meanwhile, SEP content, SH content, and Ca2+-ATPase activity all decreased during storage. A marked inhibition (p < 0.05) of FFA formation and SEP content, Ca2+-ATPase activity and SH content decrease was observed during storage of bighead carp fillets at −30 °C, compared to those stored at −10 and −20 °C. Additionally, the relative errors of models based on Ca2+-ATPase and SH were all below 10 %. Thus, the lower frozen temperature can inhibit quality damage effectively, and a reliable estimation of quality changes could be performed by models based on Ca2+-ATPase and SH.