Comparison of a sodium-based and a chloride-based approach for the determination of sodium chloride content of processed foods in the Netherlands

Abstract This study reports and discusses the sodium content of a set of 1016 processed food samples collected in the Netherlands, which covered 10 food groups (cakes/pastries, chips/nuts, sauces, processed meat, conserves, snacks, ready-to-eat products, cheese, bread, and soups) and 100 food commodities. The food groups that showed highest sodium contents were processed meat (1030 mg Na 100 g −1 ), cheese (820 mg Na 100 g −1 ), and sauces (752 mg Na 100 g −1 ). Lowest sodium concentrations were determined in conserves (286 mg Na 100 g −1 ), cakes/pastries (322 mg Na 100 g −1 ), and soups (355 mg Na 100 g −1 ). In addition, two different approaches for the assessment of sodium chloride content in the same sample set have been compared for all 1016 samples: determination of sodium by flame emission spectroscopy and determination of chloride by potentiometric titration. The sodium chloride content was then calculated converting the sodium and chloride content into the corresponding salt (NaCl) content. For the NaCl contents determined by the two approaches, significant differences for seven out of the ten food groups were observed, and the sodium contents of nearly half of the commodities showed significantly different NaCl levels. At food group level, the NaCl contents calculated from sodium were significantly higher ( p