1979 Volume 26 Issue 9 Pages 383-390
A new method for measuring salt and acetic acid content in mayonnaise was proposed, which is based on conductivity measurement in both water-ethanol and water-pyridine solvent systems. Between the specific conductance for a 300 times diluted solution of mayonnaise in the water-ethanol (67 vol%) solvent system and the salt content, a highly precise regression curve was obtained without the influence of coexistent acetic acid. The salt content estimated from regression curve agreed with that obtained from argentometry with an error of 0.02%. In the water-pyridine (10 vol%) solvent system, the found specific conductance of the 300 times diluted solution of mayonnaise agreed with the calculated value, i.e. the sum of the specific conductances which were determined separately in standard salt and acetic acid solutions. The acetic acid content can be calculated from the estimated salt content in the water-ethanol solvent system and the specific conductance of the 300 times diluted solution of mayonnaise measured in the water-pyridine solvent system by use of the two equations set up between the concentrations and the specific coductances of salt and acetic acid in the water-pyridine solvent system. The acetic acid content calculated by this method agreed with that obtained from alkalimetry with an error of 0.01%.
