Diosady L L, Alberti J O, Ramcharan K, Mannar M G Venkatesh
University of Toronto, Department of Chemical Engineering and Applied Chemistry, Toronto, Ontario, Canada.
Food Nutr Bull. 2002 Jun;23(2):196-207. doi: 10.1177/156482650202300209.
Deficiencies in small quantities of micronutrients, especially iodine and iron, severely affect more than a third of the world's population, resulting in serious public health consequences, especially for women and young children. Salt is an ideal carrier of micronutrients. The double fortification of salt with both iodine and iron is an attractive approach to the reduction of both anemia and iodine-deficiency disorders. Because iodine is unstable under the storage conditions found during the manufacturing, distribution, and sale of salt in most developing countries, the effects of packaging materials and environmental conditions on the stability of salt double-fortified with iron and iodine were investigated. Salt was double-fortified with potassium iodide or potassium iodate and with ferrous sulfate or ferrous fumarate. The effects of stabilizers on the stability of iodine and iron were followed by storing the salt under three conditions that represent the extremes of normal distribution and sale for salt in developing countries: room temperature (25 degrees C) with 50%-70% relative humidity, 40 degrees C with 60% relative humidity, and 40 degrees C with 100% relative humidity. The effects of stabilizers, such as sodium hexametaphosphate (SHMP), calcium carbonate, calcium silicate, and dextrose were investigated. None of the combinations of iron and iodine compounds was stable at elevated temperatures. Essentially all of the iodine was lost over a period of six months. SHMP effectively slowed down the iodine loss, whereas magnesium chloride, a typical hygroscopic impurity, greatly accelerated this process. Calcium carbonate did not have a sparing effect on iodine, despite contrary indications in the literature. Ferrous sulfate-fortified salts generally turned yellow and developed an unpleasant rusty flavor. Salt fortified with ferrous fumarate and potassium, iodide was reasonably stable and maintained its organoleptic properties, making it more likely to be acceptable to consumers. We confirmed that application of the iodine compounds as solutions resulted in a more even distribution of the iodine throughout the sample. The effect of the packaging materials was overshadowed by the other variables. None of the packaging materials was clearly better than any other. This may have been due to the fact that the polymer bags were not heat sealed, and thus some moisture penetration was possible. The results indicate that with careful control of processing, packaging, and storage conditions, a double-fortified salt could be stabilized for the six-month period required for distribution and consumption. Unfortunately, the processing and storage required are difficult to attain under typical conditions in developing countries.
微量营养素的少量缺乏，尤其是碘和铁的缺乏，严重影响着世界超过三分之一的人口，导致严重的公共卫生后果，对妇女和儿童尤为如此。盐是微量营养素的理想载体。碘和铁对盐进行双重强化是减少贫血和碘缺乏症的一种有吸引力的方法。由于在大多数发展中国家盐的生产、分销和销售过程中的储存条件下碘不稳定，因此研究了包装材料和环境条件对碘铁双重强化盐稳定性的影响。盐用碘化钾或碘酸钾以及硫酸亚铁或富马酸亚铁进行双重强化。通过将盐储存在代表发展中国家盐正常分销和销售极端情况的三种条件下，来跟踪稳定剂对碘和铁稳定性的影响：室温（25摄氏度）、相对湿度50%-70%；40摄氏度、相对湿度60%；40摄氏度、相对湿度100%。研究了六偏磷酸钠（SHMP）、碳酸钙、硅酸钙和葡萄糖等稳定剂的影响。在高温下，铁和碘化合物的任何组合都不稳定。基本上所有的碘在六个月内都会损失。SHMP有效地减缓了碘的损失，而典型的吸湿杂质氯化镁则大大加速了这一过程。尽管文献中有相反的说法，但碳酸钙对碘没有保护作用。硫酸亚铁强化盐通常会变黄并产生难闻的铁锈味。用富马酸亚铁和碘化钾强化的盐相当稳定，并保持其感官特性，使其更有可能被消费者接受。我们证实，以溶液形式应用碘化合物会使碘在整个样品中分布更均匀。包装材料的影响被其他变量所掩盖。没有一种包装材料明显优于其他材料。这可能是因为塑料袋没有热封，因此可能有一些水分渗透。结果表明，通过仔细控制加工、包装和储存条件，双重强化盐可以在分销和消费所需的六个月内保持稳定。不幸的是，在发展中国家的典型条件下，所需的加工和储存难以实现。
