Microencapsulation for iodine stability in salt fortified with ferrous fumarate and potassium iodide

Fortification of salt with both iodine and iron is an attractive approach to simultaneous reduction of anemia and iodine deficiency disorders (IDD), which affect some 2 billion people in the developing world. Unfortunately iodine is unstable under storage conditions found in most developing countries. Its disappearance is accelerated by iron compounds as well as impurities found in most salts in these markets. Potassium iodide and potassium iodate were encapsulated in modified starches, gelatin, sodium hexametaphosphate and purified sodium chloride by spray drying and fluidized bed drying to produce microcapsules containing 0.3 to 2% iodine. Salt mixed with ferrous furnarate or ferrous sulphate, and encapsulated iodine was then stored at high temperature and high humidity. The most stable combination, containing 50 mg iodine and 1000 mg iron per kg salt, retained more than 75% of the added iodine for a year at 40 degreesC, 100% RH. Double-fortified salt prepared using this approach has been successfully tested in large-scale field trials. The results will be published after completion of data analysis. (C) 2002 Elsevier Science Ltd. All rights reserved.