Data from several efficacy studies and a long-term effectiveness study have encouraged the governments to adopt a policy of providing double-fortified salt (DFS) in the Mid-Day Meal (MDM) programs in government schools across India. These envisaged food security events are likely to boost the manufacturing of DFS in a big way. Thus, it becomes pertinent to come up with a robust monitoring system involving community and field workers for quality checks. It is imperative to equip these field workers with simple testing kits (STKs) capable of qualitative detection of iron and iodine in DFS. As the consumer acceptance of foods is based on several factors including sensory characteristics, performance, convenience, cost, nutrition, and product image, a variety of iron compounds are in use for fortification. However, it becomes challenging to provide a kit that can overcome the chemical masking of iodine detection by iron compounds.
We aimed at (1) the development of a field-friendly STK for quick qualitative assessment of iodine and various forms of iron present in DFS, (2) to check its validity under field conditions.
We put in place reagents combined using known chemical reactions and balanced use of oxidants to overcome the problems of encapsulation and to maximize the use, by enabling reagent combination to react with all forms of iron.
The kit reagents successfully detect iodine as well as three commonly used iron fortificants in DFS. Published field trials confirmed the specificity and sensitivity of the developed kit. The simplicity and use of the kit by a field worker can be seen in the enclosed video.
The combination of improvised kit reagents allows early detection of iron and iodine in DFS. Iron is detected in a variety of iron-containing fortifications. The provision of diluted H2O2 ensures the presence of oxygen-free radicals that enhances iodine release captured by concentrated KI making iodine detection an easy task.