Robustness of protein: Using pH shifting and low speed shearing to partially recover conformation and dispersibility of myosin from pale, soft, exudative (PSE)-like chicken breast

Abstract

An unresolved problem in the field of food protein is the poor dispersibility of pale, soft, exudative (PSE)-like meat protein. This study aimed to verify the structural and functional robustness of myosin. Two different models, namely, PSE-induced whole meat model and pH shifting plus temperature holding of protein solution model, were developed. A novel combination of pH shifting (from 5.6 to 7.0) and low speed shearing (400 rpm) treatment decreased myosin turbidity by 9.6% and 36.5%, respectively. After readjusting the pH to 7.0, z-average size decreased from 289.0 nm to 1563.6 nm–274.0 nm and 333.3 nm, respectively. The experimental groups exhibited excellent solubility like the normal group. Scanning electron microscopy revealed that large myosin clusters and aggregates decreased. The improvement in PSE myosin stability increased the absolute ζ-potential value from −13.1 mV to −15.5 mV under treatment. Raman analysis revealed that the increase in protein function was not only because of surface charge states induced by pH shifting but also because of conformation recovery as evidenced by the increase in α-helix content. Results indicated that pH shifting and proper low shearing could fulfill the robustness of myosin function by recovering conformation and improving solubility.