The use of iodised salt in the manufacturing of processed foods in South Africa: bread and bread premixes, margarine, and flavourants of salty snacks.

Salt is widely used by the food industry, but information on the use of iodised salt as an ingredient in the manufacturing of processed foods in South Africa is not available. The iodine content of salt used in the manufacturing of bread, margarine and salty snack flavourants was investigated in a cross-sectional descriptive study. Questionnaire information and salt sampled on 1 day per week for 5 consecutive weeks were obtained from 12 food manufacturers (eight bread and bread premix manufacturers, two margarine manufacturers and two salty snack flavourant manufacturers). The iodine concentration of salt samples was analysed using the potentiometric titration method. Eleven of the 12 manufacturers surveyed reported that they used non-iodised salt. The reported reasons for using non-iodised salt included properties of the final product, health reasons, and financial considerations. However, substantial amounts of iodine were found in the salt of one-third of these manufacturers (n = 4), ranging from a mean content of 39-69 ppm. Three of these four particular manufacturers distributed their products countrywide. This information serves as a strong indication that iodised salt does not necessarily cause the adverse affects that food manufacturers fear may affect their products. Although the amounts of iodine in the salt were variable, our results showed that an appreciable percentage of the food companies used iodised salt unknowingly in the manufacturing of frequently consumed processed foods, and this may have a considerable impact on the daily iodine intake of consumers.