Conductimetry: a rapid alternative technique for chlorides determination in cheese

Abstract

The correlation of two instrumental techniques for chlorides determination in Colombian cheese, Queso Molido Nariñense (a type of white cheese), was analyzed. Potentiometry of chloride precipitation is the standard technique to determined salt in cheese. Conductimetry is an alternative technique. Samples of Queso Molido Nariñense were made. In the processed cheeses the salt concentration (NaCl: 0.5 %, 0.8 %, 1.0 %, 2.0 %, 3.0 % and 6.0 %) was varied. Chlorides were determined by titration with silver nitrate in the potentiometric technique. In the conductimetric technique, each sample was analyzed by direct measuring its conductivity at room temperature. It was found that there is an adequate correlation between potentiometry and conductimetry. A maximum concentration of 2 % NaCl in cheese is equivalent to 2.9 S/cm for conductivity readings. Additionally, it was verified that the conductimetry constitutes an analytically reliable technique for the determination of chlorides in cheese, it is friendlier to the environment, cheaper and faster.

Keywords

• colombian cheese; white cheese; sodium chloride; potentiometry; conductimetry.