Strategy for Sodium-Salt Substitution in Meat Gel Products: Rheological and Gel Properties of Myosin as Affected by Ion Types and Concentrations

In order to reduce sodium chloride intake and related health risks, the effect of NaCl and KCl solutions on the myosin processing properties was investigated at different concentration (0.4, 0.8, 1.2, 1.6, and 2.0 m) to explore salt substitution strategy. Myosin solubility increased while turbidity reduced with increasing NaCl and KCl solution concentrations (P < 0.05). Compared with KCl, myosin exhibited greater solubility and lower turbidity in NaCl solutions of the same concentration. The gel hardness and water-holding capacity peaked at 1.2 m of NaCl or KCl (P < 0.05). As the concentration of NaCl and KCl increases, the microstructure of myosin gels changes from loose to compact and then to rough with the denser structure appears at 1.2 m for NaCl and 1.6 m for KCl. The α-helix and β-turn changed differently with the concentration and ionic species while β-sheet and random-coil did not alter with the concentration or ionic species (P > 0.05). The α-helix presented an overall downward trend as concentration of NaCl solutions increased while showed an opposite trend for KCl solutions. Myosin in 1.6 m NaCl or KCl solution could form a gel with fine porous structures and greater hardness and water-holding capacity, presenting an overall better gel characteristic than the other studied concentrations with no significant difference between the two ions. This study provides a basis for salt reduction in meat gel products.