Sodium replacement in the cod (Gadus morhua) muscle salting process

Cod fillets were salted in brines with different pHs (6.5 and 8.5) and saline compositions. Water-holding capacity, protein extractability, dry matter, ion content and hardness in muscle were assessed to determine the effect of replacing NaCl with varying combinations of KCl, CaCl2 and/or MgCl2. Discriminant and principal component analyses were performed to better understand the relationships between brine composition and functional properties of brined cod. Partial replacement of 50% NaCl with 50% KCl reduced penetration of Na+ into muscle, as did the addition of small amounts of CaCl2 (0.8%) and/or MgCl2 (0.4%) to pH 6.5 brines. The use of 0.4% MgCl2 at pH 6.5 negatively affected functional properties and further hindered salt penetration into the muscle. The use of KCl in pH 8.5 brines increased hardness, negatively affecting protein water-extractability. Moreover, the addition of divalent salts, at basic pHs, slightly decreased water-holding capacity.