Changes in quality characteristics based on protein oxidation and microbial action of ultra-high pressure-treated grass carp (Ctenopharyngodon idella) fillets during magnetic field storage.

• UHP treatment changed the quality and protein characteristics of fillets. • MF storage reduced the flora activity and water holding capacity of fillets. • UHP-MF delayed protein denaturation by inhibiting protein and lipid oxidation. • UHP-MF delayed quality deterioration by inhibiting flora activity and diversity. • UHP 300 -MF effectively extended the shelf life of fillets by at least 10 days. Ultra-high pressure (UHP) and magnetic field (MF) are emerging food preservation technologies, but the research on the effects of combined treatment (UHP-MF) on aquatic products quality is insufficient. Hence, we explored the effects of UHP-MF treatment on the protein properties, microbial action and quality characteristics of stored grass carp fillets. Results showed that 300 MPa UHP treatment combined with MF storage (UHP 300 -MF) delayed the protein oxidation of stored fillets by inhibiting the accumulation of protein radical and the formation of lipid pro-oxidation products, thus the quality (texture, color) deterioration caused by oxidation was deferred. Additionally, 16S rDNA bacteria flora analysis revealed that UHP 300 -MF treatment inhibited the flora activity and diversity of fillets, delayed the protein degradation and quality deterioration caused by microbial action. Overall, UHP 300 -MF treatment suppressed the lipid and protein oxidation as well as microbial action, retarded the quality deterioration, and prolonged the shelf life of stored fillets. [ABSTRACT FROM AUTHOR]