加碘盐生产过程中碘含量不稳定的探讨

从生产环节控制的角度,对加碘盐中碘含量不稳定现象产生的原因进行了分析,提出了在生产过程中消除碘含量不稳定现象的方法和措施。     

含乙二胺四乙酸铁钠碘盐中碘含量的测定

介绍一种对含乙二胺四乙酸铁钠碘盐中碘含量的测定方法。通过实验证明，该方法操作简单，准确可行。     

食用加碘绿标盐结块原因分析与措施

食用加碘绿标盐2012年投放市场以来，因产品存在着不同程度的结块，影响产品的分装和市场销售，制盐生产企业为此进行不懈的调试，但收效甚微。井神盐化公司二分公司是国家食盐生产定点企业，满足人民生活需要是生产第一要务，通过一系列的生产和过程控制调试，绿标盐结块现象明显好转，既满足市场需要，又提高企业经济效益。     

Adding an oxidant increases the stability of iodine in iodized salt

It has been shown that moisture plays a critical role in the stability of iodine and that reducing agents in iodized salt reduce the stability of iodine. We question whether this is valid in all cases, and have found that the reducing agent may play a more important role than moisture in decreasing the stability of iodine. We reviewed current methods to enhance iodine retention in iodized salt, and propose methods to produce stable iodized salt and to analyze its stability. Our experiments showed that when reducing impurities are removed, iodine remains stable in iodized salt, even when the salt is "wet." We suggest that the stability of iodine in iodized salt can be improved by oxidizing iodized salt with sodium hypochloride, and that the iodine content of iodized salt, after heating at 120 degrees C for one hour, can be used to reflect the quality of iodized salt. We have demonstrated that reducing agents play a critical role in the stability of iodine in iodized salt. We have shown a method of purifying salt by removing reducing materials, which can be used to produce iodized salt with sufficient stability at lower cost. We also propose an analytical method to determine the stability of iodine in iodized salt. These methods could be further developed to achieve better accuracy, precision, and reliability and be applied to a greater variety of iodized salts.     

微分脉冲伏安法测定加碘盐中碘酸根离子

报道了运用微分脉冲伏安法测定食盐中碘酸根含量的方法。在1.0mol/LNaCl,pH=12的介质中,当脉冲振幅为70mV,脉冲周期为0.2s时,碘酸根离子在微分脉冲伏安图上出现一个灵敏的微分脉冲伏安峰,峰电位为-1.30V(vs.Ag/AgCl),峰电流与碘酸根离子浓度在2.0×10-7～1.0×10-5mol/L范围内成良好的线性关系,相关系数为0.9995,方法检出限为1.0×10-7mol/L。方法已用于加碘食盐中碘酸根含量的测定,平均回收率为100.7%。循环伏安(CV)测试表明,碘酸根在汞膜电极上电化学反应是不可逆过程。     

碘盐直销模式的实践与思考

随着盐业体制改革的逐渐明朗化,各盐业公司如何应对成为研究方向。本文以盐城地区为例,介绍了碘盐直销模式,从管理到考核,提出了整合资源、抓大放小、打造品牌、区域代理等经营管理方法。     

精制食盐及加碘精制食盐营养健康效应的对比实验评价

目的采用小鼠模型及损益指数及总积分(benefit damage index-general score, BDI-GS)系统对比评价市售精制食盐及加碘食盐的营养健康效应,揭示其过度摄取的健康危害。方法生长期雄性ICR实验小鼠分为7组,分别是玉米空白对照组,0.5%、1.0%、1.5%精制食盐及0.5%、1.0%、1.5%加碘盐实验组,每组各8只小鼠。总计喂养10d,隔日称取体质量1次。第10d取血分离血清,处死小鼠并解剖。准确称取心、肺、胸腺、脾、肝脏、胰腺、双肾、性腺及股骨质量;血清测定常规血生化指标,并进行统计学分析。结果精制食盐组小鼠胰腺的营养及健康指标BDI均小于等于0.90。加碘食盐小鼠之胰腺营养健康损害更严重,个别剂量BDI甚至低至0.67,并且统计学与空白对照组存在显著性差异(P0.05)。加碘食盐对性腺营养健康存在较重损害,各剂量组BDI均明显低于1.0。结论精制食盐过度摄取对人体营养健康会造成不利影响,加碘食盐存在一定健康问题。     

Iodine nutrition: iodine content of iodized salt in the United States

Adequacy of iodine nutrition in the United States has lately been of concern. A major source of dietary iodine for the U.S. population is iodized salt. The U.S. Food and Drug Administration (USFDA) recommends 60-100 mg Kl/kg salt, equivalent to 46-76 mg l/kg salt. All U.S. iodized salt contains 45 mg l/kg according to labels. We collected samples of table salt from freshly opened containers from U.S. volunteers. A sample was sent to us when the can was first purchased. Subsets of volunteers sent further samples when the salt container became half-empty through normal use and a further final sample when the container was nearly finished. We also looked at iodine distribution homogeneity within individual containers, loss of iodine from salt upon exposure to humidity and sunlight, and upon short-term heating (dry and in solution) as may be encountered in cooking. Measurements were made in 0.01% w/v salt solutions by induction coupled plasma-mass spectrometry with 72Ge as an internal standard. The median and mean (+/-sd) I content in freshly opened top-of-the-can salt samples was 44.1 and 47.5 +/- 18.5 mg/kg (n=88, range 12.7-129 mg l/kg) and geometric mean and standard deviation of 44.70 and 1.41. Forty-seven of 88 samples fell below the USFDA recommended I content while 6 exceeded it. The homogeneity in a single can of salt varied greatly: in 5 samples taken from the same container from different depths, the iodine content varied by as little as 1.2x (8.3% coefficient of variance (CV)) to as much as 3.3x (49.3% CV) from one container/brand to another. Iodine is significantly lost upon high humidity storage but light or dry heat has little effect. There is much recent literature on iodine sufficiency and uptake inhibitors; there is also much misinformation and disinformation. We review the relevant literature and discuss our results with reference to the United States.     

Difference in goiter rates between regular and occasional users of iodized salt in Mongolia

In Mongolia many households use iodized salt only occasionally. We investigated whether the occasional use of iodized salt had an impact on the reduction of goiter size. We examined 685 children (8-11 years old) in five groups of households that (1) used iodized salt regularly, (2) used more than 10 kg of iodized salt annually, (3) used 6 to 10 kg annually, (4) used less than 6 kg annually, (5) and regularly used noniodized salt. The prevalence of goiter as determined by ultrasound in these five groups was 31.1%, 30.3%, 40.6%, 52.1%, 56.6%, respectively. There was no difference between goiter rates among the first three groups, but these groups had significantly lower rates than the last two groups. We concluded that annual use of more than 6 kg of iodized salt, preferably more than 10 kg, by a household had a beneficial effect on the rate of goiter. In addition, the possibility was suggested that households that consumed only iodized salt consumed less salt than other households.     

连云港市生产批发环节碘盐监测结果分析

通过对连云港市2002～2005年生产批发环节碘盐监测结果的分析，找出盐碘含量的均数分布和标准差分布特征及变化情况，为提高碘盐质量提供科学的参考依据。     

Study on the stability of potassium iodide of the iodized salt]

The stability of potassium iodide in iodized salt has been studied with respect to the purity of the salt used as raw material. It has been found that the iodized salt prepared from high purity salt and preserved under proper conditions (protection from light, humidity and high temperatures) keeps, for several months, the most of the initially added potassium iodide, without any addition of stabilizers, except for a small bicarbonate.     

Stability of iodine in iodized fresh and aged salt exposed to simulated market conditions

BACKGROUND: The salt iodization law of the Philippines required that iodized salt sold at retail not be exposed to direct sunlight, high temperature and relative humidity, and contamination with moisture and dust from the environment. However, because the majority of local consumers buy salt displayed in open heaps, it was suggested that iodized salt should be sold in the same manner for greater accessibility and availability. Objective. We aimed to provide evidence on the stability of iodine in local aged and fresh salt iodized at 100 ppm iodine and exposed to various market and storage conditions. METHODS: Samples of salt in open heaps and repacked salt were exposed for 4 weeks, and salt packed in woven polypropylene bags was stored for 6 months. The iodine content of the salt was determined by the iodometric titration method, and the moisture content was determined by the oven-drying method. RESULTS: For all types of exposed salt, iodine levels were above 60 ppm after the end of the study (4 weeks). Within each salt type, losses were greater for open-heap salt than for repacked salt. The greatest drop in moisture content occurred in the first week for most types of salt and exposure combinations. Moisture content was linearly correlated with iodine content. Iodine levels in stored salt remained above 60 ppm even after 6 months. CONCLUSIONS: Iodized salt is able to retain iodine above the recommended levels despite exposure to an open environment and use of ordinary packaging materials while being sold at retail and kept in storage.     

Investigation of iodine bioavailability from chicken eggs versus iodized kitchen salt with in vitro method

The goal of the presented studies was to investigate speciation and bioavailability of iodine from chicken eggs versus iodized kitchen salt with an in vitro method. Determination of iodine total content in chicken eggs and iodized kitchen salt was carried out by inductively coupled plasma mass spectrometry (ICP MS). The majority of iodine was accumulated in the yolk—the concentration was even 37 times higher than in white. Chicken eggs were treated with buffer (Tris HCl pH = 7.5) and enzymatic extraction media and analyzed by size exclusion chromatography hyphenated with inductively coupled plasma mass spectrometry (SEC ICP MS). The enzymatic extraction being an in vitro bioavailability assessment method was based on two-stage digestion model simulating gastric (pepsin digestion) and intestinal (pancreatin digestion) juices. Speciation analyses along with bioavailability studies presented iodide as the major form in chicken eggs. The bioavailability was established as 33% from white and 10% from yolk and decreased with longer time of boiling. It allows to suggest that the majority of iodine remains in forms bound to non-digestible coagulated and water-insoluble proteins.     

烹饪调味过程对加碘盐补碘效率的影响

本文在常规烹饪盐咸味的调味过程中,分别用斯柯维法、P*S蓝光度法测定食物盐咸味的调味效果及加碘盐的碘损失情况,分析烹饪调味过程对加碘盐补碘效率的影响。     

Iodine stability in iodized salt dual fortified with microencapsulated ferrous fumarate made by an extrusion-based encapsulation process

The development of a novel, extrusion-based process for making microencapsulated ferrous fumarate for salt double fortification has been reported earlier. This paper focuses on the results of a one-year storage test, specifically the stability of both iodine and ferrous iron in the double fortified salt (DFS) samples prepared using optimal formulations of the iron premix. The study was devised to test the effectiveness of the encapsulation system in the prevention of interaction between ferrous fumarate and iodine, and preservation of the iodine in iodized salt. The results confirmed that direct iodine–iron interaction occurred in the DFS samples when the iron compound was added without proper coating. However, when an appropriately encapsulated iron premix was used, the interaction could be completely prevented. The extrusion-based process has proven to be an effective approach to producing a stable, bioavailable iron premix, suitable for incorporation into iodized salt for combating iodine and iron deficiencies.     

2004～2013年湖南省加碘食盐碘含量检测结果与分析

检测湖南省加碘食盐碘含量,为碘缺乏病的消除及防治提供科学决策依据。根据GB/T 8618—2001《制盐工业主要产品取样方法》取样和《食盐卫生标准》检测,2004~2013年每年每个季度在全省14个地级市各大型超市抽取不同品种的加碘食用盐样品。结果表明:2004~2013年共抽取和检测加碘食用盐样品1 680份,加碘食盐碘含量平均值为27.31~33.98 mg/kg,加碘食盐中碘含量中位数为27.58~33.70 mg/kg,符合GB 5461—2000和GB 26878—2011中关于碘含量的规定。加碘食盐中碘含量合格率为95.55%~100%,且呈稳步提高趋势。     

Formation of iodoacetic acids during cooking: Interaction of iodized table salt with chlorinated drinking water

Iodoacetic and chloroiodoacetic acids were formed when municipal chlorinated tap water was allowed to react with iodized (with potassium iodide) table salt or with potassium iodide itself. Iodoacetic acid was recently shown to be a potent cytotoxic and genotoxic agent. For analysis, samples were extracted with t-amyl methyl ether and converted to the corresponding methyl esters using methanol and sulfuric acid. The concentration of iodoacetic acid was determined by gas chromatography-mass spectrometry (GC-MS) using an authentic standard. The identities of iodoacetic and chloroiodoacetic acids were further confirmed by gas chromatography-high-resolution mass spectrometry (GC-HRMS). Certain influences of sodium hypochlorite and humic acid as well as the concentration of potassium iodide on the yields of these acids were investigated. The concentration of iodoacetic acid in tap water samples boiled with 2 g l^-1 of iodized table salt was found to be in the 1.5 µg l^-1 range, whilst the concentration of chloroiodoacetic acid was estimated to be three to five times lower.