Chitosan/polyvinyl alcohol-based active film maintain the quality of farmed sea bass (Lateolabrax maculatus) during refrigerated storage: Inhibit lipid oxidation and maintain myofibrillar proteins conformation

In this study, the effects of chitosan (CS)/polyvinyl alcohol (PVA)-based active film on lipid oxidation and myofibrillar proteins (MPs) oxidation and conformational changes in refrigerated (4 °C) sea bass ( Lateolabrax maculatus ) fillets were analyzed. The CS/PVA matrix combined with bacterial cellulose (BC) and 0.8 % (v/v) ginger essential oil (GEO), made the mixture form the film solution (CPB 0.8 ) by desiccation. Sea bass fillets coated with CS/PVA-based films were evaluated for lipid and protein oxidation at 3-day intervals. Ca 2+ -ATPase, total sulfhydryl, myofibril fragmentation index (MFI), and the secondary structure content were investigated to assess the oxidation degree and conformational changes in MPs. Malondialdehyde (MDA) and hydrogen peroxide (H 2 O 2 ) content were determined to evaluate the oxidation degree of sea bass fillets. Compared with other films, the results demonstrated that CPB 0.8 film could inhibit the oxidation and degradation of MPs after 18 days, which has the lowest MDA (86.44 nmol/g), Ca 2+ -ATPase (0.1567 U/mg), total sulfhydryl (53.7667 μmol/g), MFI (57.2). In addition, the conformational analysis of MPs showed that CPB 0.8 film could better maintain the secondary and tertiary structure of MPs, which effectively delay the destruction of protein conformation and maintain the microstructure of muscle fibers in fish. Therefore, CPB 0.8 film will be a hopeful strategy of keeping the quality of sea bass and have a long-term preservation effect.