Evaluating the stability of iodine in bottled mineral waters

•The stability of iodine concentrations in bottled mineral water is considered.•The tests were conducted for polyethylene (PE) bottles.•The concentration of iodide ions decreases with time. After 24 h, the value was lower by about 40%.

The paper presents the results of a study aimed at fortifying mineral waters with iodine ions. In the study, natural mineral water with low CO2 content was used, which had a high content of bioelements and minerals including calcium and magnesium and also included iodine concentrate and lemon flavour. Within the framework of the experiment, several water samples were prepared (1.5 L in volume each), which contained iodine concentrate (0.080 mg/L) and/or lemon flavour (0.5 mL). Additionally, analyses of control samples prepared using distilled water were carried out. In order to identify the changes in the composition of the analysed samples that were fortified with iodine, tests were performed immediately after the preparation of the samples and after 1 h, 4.5 h and 24 h. The results of the study showed a decrease in iodine content by 40% after 24 h. It was noted, however, that the decline in the content of iodides was 10% more rapid in samples of distilled water fortified with iodine than in samples of mineral water. Lemon flavour has a slight impact on the content of iodine determined, although these differences are in most cases statistically insignificant.