Stability of iodine content in potassium iodate iodized salt in Jilin Province / 中华地方病学杂志

ABSTRACT

Objective:To study the stability and influencing factors of potassium iodate iodized salt that can be sold in Jilin Province.Methods:In November 2020, 10 large supermarkets were randomly selected in Jilin Province, and two kinds of potassium iodate iodized salts were randomly selected in each supermarket, with five copies of each kind, a total of 100 samples of iodized salt, and the iodine content was determined by spectrophotometry (iodide-starch blue light method). Iodized salt samples were classified according to different salt species (mine salt, sea salt and lake salt) and different production processes (refined salt and non-refined salt). The salt was stored at room temperature, and the iodine content in the salt was measured at 0, 10 and 20 days after opening the packaging. The iodine content attenuation rates of different salt species and different production processes were compared.Results:The mine salt, sea salt and lake salt in iodized salt samples were 45, 45 and 10 portions, respectively. The iodine contents of the 0th day of storage [(19.89 ± 1.38), (20.62 ± 1.91), (19.78 ± 1.01) mg/kg] were compared, and the difference was not statistically significant ( F = 2.57, P = 0.093). On the 10th day, the iodine content of mine salt was lower than that of sea salt and lake salt, and the differences were statistically significant ( P < 0.05); on the 20th day, the iodine content of mine salt was lower than that of sea salt, and the difference was statistically significant ( P < 0.05). There was a significant difference in the iodine content of mine salt stored at 0, 10 and 20 days ( F = 90.62, P < 0.001). The iodine content of sea salt and lake salt on the 20th day was significantly lower than that on the 0th and 10th day, and the differences were statistically significant ( P < 0.05). The iodine content attenuation rates of mine salt, sea salt and lake salt on the 0 - 10 days was compared with that on the 10 - 20 days, and the differences were statistically significant ( Z = 2.24, 2.94, 2.80, P < 0.05). There was a significant difference in the iodine content attenuation rates of mine salt, sea salt and lake salt during the 0 - 10 days of storage ( Z = 24.05, P < 0.001), there was no statistically significant difference in the iodine content attenuation rates on 10 - 20 days ( Z = 5.86, P = 0.053). There was no significant difference in iodine content attenuation rates between refined salt and non-refined salt on 0 - 10, 10 - 20 days ( Z = 1.16, 0.28, P > 0.05). There was no statistical significant difference in the iodine content attenuation rates of refined salt and non-refined salt on the 0 - 10 days compared with those of 10 - 20 days ( Z = 0.76, 1.90, P > 0.05). Conclusions:Iodine loss occurs at 20 days after opening the packaging of iodized salt in Jilin Province. The attenuation of iodine content is less affected by salt species and production processes. It is recommended to eat iodized salt within 20 days after opening the packaging.