Inorganic indicators of the origin of edible salts marketed in Spain from a chemometric approach.

Twenty edible salts marketed in Spain were studied for content of inorganic constituents in order to identify one or more indicators of the origins of salts. In Spain the principal source of salt is seawater, either from the Mediterranean coast or from the Atlantic coast. In addition, some manufactured salts in the dietary category were also considered. Five "Atlantic," 12 "Mediterranean," and 3 dietary salts were analyzed for potassium, magnesium, calcium, strontium, manganese, zinc, and sulfate contents and for alkalinity. Salt samples were first dried for moisture determination. Metals were determined by inductively coupled plasma atomic emission spectrometry, sulfate was determined by turbidimetry, and alkalinity was determined by titration with hydrochloric acid. All the results were expressed as the means for triplicate experiments, as mg of analyte per kg of salt on a dry basis. From these results and by application of chemometric strategies (principal component analysis, variable-variable plots, and cluster analysis) it was found that the potassium content distinguishes sea salts from dietary salts very well, and the contents of strontium and manganese discriminate salts of Atlantic origin versus salts of Mediterranean origin. Dietary salts showed levels of potassium higher than the sea salts, and salts of Atlantic origin had greater strontium and manganese content values than salts of Mediterranean origin.