Thermal aggregation behavior of egg white protein and blue round scad (Decapterus maruadsi) myofibrillar protein

In the present study, egg white protein (EWP) and myofibrillar protein (MP) were mixed in different ratios (0/100, 10/90, 20/80, 30/70, 40/60, 50/50, 100/0 for EWP/MP) and subjected to unheated, preheated (40°C/30 min), two-step heated (40°C/30 min, 90°C/20 min), and one-step heated (90°C/20 min) treatments to study the thermal aggregation of the two proteins. Their aggregation behavior was characterized by turbidity, active sulfhydryl, degree of protein cross-linking, protein characteristic spectra, and microscopic morphology. The results indicated that for the mixed protein system composed of EWP and MP, the mixed protein aggregation volume was larger and regular at an EWP/MP of 30/70, when the degree of cross-linking was best. When the ratio of EWP/MP was 50/50, the aggregate-protein interaction was dominant, and the excess EWP acted as a barrier to cross-linking and wrapped around the surface of the aggregates to form larger aggregates. Comparing the two-step heated and one-step heated conditions, the former is superior. PRACTICAL APPLICATION: The combination of egg white protein and myofibrillar protein can provide a theoretical reference for the protein content in surimi products, and moderate addition has an enhancing effect on surimi protein cross-linking and promotes gel formation. Excessive addition will form aggregates outside the egg white protein wrapping phenomenon, and the quality of surimi gel products will be affected.