“Cuckoo in the nest”: L-arginine promoted the migration of Na+ to ameliorate the gel quality of low salt fish balls

This study explored the influences of L-Arg in the ion migration and the quality of low-salt fish balls (L, 0.3 % NaCl). L-Arg significantly increased the weight gain and expansion rate of L by 18.33 % and 13.47 %. Water-holding capacity decreased from the internal to the external part of fish balls, consistent with the looser microstructure. Inductively coupled plasma-mass spectrometry (ICP-MS) revealed that L-Arg promoted Na + migration at setting ( P  < 0.05), decreased the internal concentration from 34.38 to 30.37 mg/L and increased the external one from 25.78 to 29.80 mg/L ( P  < 0.05). Conversely, Cl − concentration was decreased at setting and improved after the two-stage heating ( P  < 0.05), indicating the suppressed Cl − migration. The partial replacement of Na + by L-Arg facilitated the protein unfolding, formation of disulfide bonds and exposure of tryptophan residues. This study enriched the mechanisms of salt reduction and quality maintenance for surimi products regarding ion migration.