Molecular modifications of myofibrillar proteins in structural transitions induced by plasma-activated water rinsing:...

Plasma-activated water (PAW) was generated by cold plasma treatment for 2 to 10 min and used to rinse bighead carp mince replacing deionized water during surimi preparation. The effects of PAW rinsing on myofibrillar proteins (MP) were investigated across three structural states: native MP, salt solubilized MP (MP sols), and thermal MP gels. In native MP, PAW rinsing induced oxidative modifications, as shown by a 39.13 % increase in carbonyl content and a decrease in sulfhydryl groups (P < 0.05). Proteomic analysis revealed myosin heavy chain as the principal oxidation target (48.84 %), particularly in the C-terminal region, with mono-oxidized Lys and Arg residues. In MP sols, PAW increased surface hydrophobicity (27.14 %) and reduced sulfhydryl content, enhancing protein rigidity and gel stability. The reduction of sulfhydryl groups restricted chain flexibility but promoted tail-region aggregation, contributing to a stable gel network in MP gels. These findings demonstrate PAW's potential to improve surimi production.