Sodium Chloride (0.8 M) as a Better Protein Extractant for Fish Meat Quality Assessments

The extractability of proteins by NaCl, KCl, and LiCl as affected by different ionic strengths and pH was compared to determine the best protein extractant. The individual proteins in the extracts were identified by electro‐phoresis. The optimum ionic strength (IS) at pH 7.0 for the protein extractability (PE) of NaCl, KCl, and LiCl were 0.8, 0.9, and 1.0, respectively. The PE of NaCl and KCl declined as pH changed from 6.0 to 8.0, whereas an opposite effect was observed for the LiCl. The NaCl had the highest PE, followed by LiCl and KCl. The maximum number of proteins (15 bands) was found at the optimum IS of each salt. However, the resolution and clarity of the protein bands were better in the NaCl extracts.