Conformational changes in proteins recovered from jumbo squid (Dosidicus gigas) muscle through pH shift washing treatments

• pH shifting effect in jumbo squid proteins were evaluated.
• Protein acidic effect changes were favorable for functional–technological quality.
• Acidic conditions are an alternative technology for squid-based surimi production.

Conformational and thermal–rheological properties of acidic (APC) and neutral (NPC) protein concentrates were evaluated and compared to those of squid (Dosidicus gigas) muscle proteins (SM). Surface hydrophobicity, sulfhydryl status, secondary structure profile, differential scanning calorimetry and oscillatory dynamic rheology were used to evaluate the effect of treatments on protein properties. Acidic condition during the washing process (APC) promoted structural and conformational changes in the protein present in the concentrate produced. These changes were enhanced during the heat setting of the corresponding sol. Results demonstrate that washing squid muscle under the proposed acidic conditions is a feasible technological alternative for squid-based surimi production improving its yield and gel-forming ability.