Ultrasound-assisted chlorogenic acid-grafted chitosan soaking of sea bass (Lateolabrax japonicus) fillets to reduce protein oxidation and maintain gel properties

The perishability of aquatic products is a challenge for the processing of aquatic products, so it is better to choose suitable preservatives to prevent the degradation of proteins and the fission of their gel properties. Thus, this study investigated the effects of ultrasound-assisted chlorogenic acid grafted chitosan (GUA) soaking of sea bass (Lateolabrax japonicus) fillets on protein oxidation and gelation properties. The results showed that GUA could reduce the formation of protein carbonyls and maintain Ca²⁺-ATPase activity. Intrinsic fluorescence intensity (IFI) and SDS-PAGE results demonstrated that GUA stabilized the tertiary structure of protein and inhibited protein degradation. Interestingly, ultrasound attenuated the protein aggregation induced by the use of chitosan-grafted-chlorogenic acid (CS-g-CA), which has good particle size during storage. Meanwhile, GUA treatment endowed the gel with a dense network microstructure, increased water holding capacity (WHC), reduced water mobility, and improved MP gel color as well as textural properties.