吉林省碘酸钾碘盐的稳定性分析

Stability of iodine content in potassium iodate iodized salt in Jilin Province

目的探讨吉林省销售的碘酸钾碘盐的稳定性及其影响因素。方法2020年11月在吉林省全省范围内以市(州)为单位,选择10所大型超市,每所大型超市选择2种碘酸钾碘盐,每种5份,共100份碘盐样品,采用分光光度法(碘-淀粉光度法)检测样品碘含量;将碘盐样品按不同盐种(井矿盐、海盐、湖盐)及不同生产工艺(精制盐、非精制盐)分类,开袋放于室温条件下储存,并分别于开袋后0、10、20 d测定盐碘含量,比较不同盐种、不同生产工艺碘含量衰减率。结果碘盐样品中井矿盐、海盐、湖盐分别为45、45、10份,存放第0天的碘含量[(19.89±1.38)、(20.62±1.91)、(19.78±1.01)mg/kg]比较,差异无统计学意义(F=2.57,P=0.093);第10天时,井矿盐的碘含量低于海盐、湖盐(P均<0.05);第20天时,井矿盐的碘含量低于海盐(P<0.05)。井矿盐存放第0、10、20天的碘含量比较,差异有统计学意义(F=90.62,P<0.001);海盐、湖盐存放第20天的碘含量均明显低于第0、10天,差异均有统计学意义(P均<0.05)。井矿盐、海盐、湖盐第0~10天碘含量衰减率与第10~20天比较,差异均有统计学意义(Z=2.24、2.94、2.80,P均<0.05)。井矿盐、海盐、湖盐存放第0~10天的碘含量衰减率比较,差异有统计学意义(Z=24.05,P<0.001);第10~20天不同盐种的碘含量衰减率比较,差异无统计学意义(Z=5.86,P=0.053)。碘盐存放第0~10、10~20天时,精制盐与非精制盐的碘含量衰减率比较,差异均无统计学意义(Z=1.16、0.28,P均>0.05);精制盐、非精制盐第0~10天碘含量衰减率与第10~20天比较,差异均无统计学意义(Z=0.76、1.90,P均>0.05)。结论吉林省销售的碘盐包装开封20 d后发生碘损失,其碘含量的衰减受盐种、生产工艺的影响较小。建议食碘盐在打开包装后20 d内食用。

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.