Role of partial replacement of NaCl by KCl combined with other components on structure and gel properties of porcine myofibrillar protein

The effects of partial replacement of NaCl by KCl combined with other components on the structure and gel properties of porcine myofibrillar protein (MP) were investigated. Three salt substitute formulas were used: 100% NaCl (control, SF1), 70% NaCl +30% KCl (SF2), and 70% NaCl +20% KCl + 10% other components (SF3). The solubility, surface hydrophobicity, reactive sulfhydryl content, zeta potential, EAI and ESI of SF3 sample were significantly higher than those of SF1 sample (P < 0.05). SF3 reduced the α-helix content and increased the β-sheet content (P < 0.05). Low field nuclear magnetic resonance showed that T21 and T22 of SF3 sample were shorter than SF1 and SF2 samples (P < 0.05), implying that SF3 reduced the mobility of mobile water and free water. Additionally, SF3 had a better gel water holding capacity, gel strength, and gel microstructure. Overall, partial replacement of NaCl by KCl combined with other components improves the physicochemical and gel properties of MP.