Water uptake, drip losses and retention of free amino acids and minerals in cod (Gadus morhua) fillet immersed in NaCl or KCl

The aim of this work was to study differences in water uptake, drip losses and retention of low molecular components of cod fillets immersed in relatively weak NaCl or KCl solutions. Fillet pieces were excised from post rigor cod, immersed 12 h and stored 5 days at 4 °C, and further analysed for contents of chloride, minerals and free amino acids. A markedly increased water uptake was registered when concentration of immersion solution was raised from 342 to 513 mM. At chloride concentrations above 800 mg/100 g in cod fillet, both water uptake and drip losses reached a threshold in which increased swelling and reduction of drip loss were minimal. No significant difference was found between NaCl and KCl solutions with equal molar concentration with regard to water uptake, but fillet pieces immersed in 171 mM KCl had a significantly lower drip loss. Losses of free amino acids were up to 50%, but no difference was found among any of the immersion solutions.