Texture and viscoelastic characteristics of silver carp (Hypophthalmichthys molitrix) surimi affected by combination of washing regimes and hydrogen peroxide

This study aimed to apply H₂O₂ at different concentrations in combination with mince:water (M:W) ratios and different washing cycles (WC) in order to produce surimi gel from silver carp without compromising its quality characteristics. Color, texture, microstructure and rheological properties of surimi gels were investigated. Water holding capacity, texture profile and gel strength, showed a greater dependency on number of washing cycles than the M:W ratios and percentage of H₂O₂ (p<0.05), i.e., higher washing cycles, firmer surimi gel. Accordingly, T2 (one WC, 2% H₂O₂, 1:3), T10 (two WC, 1% H₂O₂, 1:2) and T16 (three WC, 1% H₂O₂, 1:2) treatments resulted the most cohesive and resilient surimi compared to the rest (p<0.05), confirmed by SEM images. However, all treated fish mince samples with H₂O₂, resulted in a surimi gel with lower texture quality compared to the control surimi prepared by conventional washing process without H₂O₂ (p<0.05). A temperature sweep test was conducted based on the LVR stress and frequency values and the aforementioned surimi gels exhibited an obvious valley shape pattern at temperature range of 48-62°C. In the creep-recovery test, the Burgers model satisfactorily described the internal structure of the surimi gel samples as the lowest deformation belonged to the control samples followed by T2. However, after 300s strain, neither of surimi gels were fully recovered their original shape. Altogether, further studies are needed to clarify the effects of H₂O₂ in reduction of washing cycles, without significantly affecting the textural and rheological properties of resultant surimi gel.