Effects of Potassium Iodate Application on the Biomass and Iodine concentration of Selected Indigenous Nigerian Vegetables

Abstract

Iodine is a trace element in soil and water that is involved in some important metabolic functions in human development. In many areas of the world, the surface soil becomes progressively poorer in iodide through accelerated deforestation, flooding and soil erosion. Hence, the food grown in iodine deficient regions can never provide enough iodine for the people and livestock living there. This study was aimed at increasing the level of iodine in commonly consumed vegetables by iodination of irrigation water with potassium iodate. The results obtained showed that, the increase in iodine concentration in fluted pumpkin ranged from 89.02 ± 0.31 to 140.36 ± 1.08 ìg/100 g in week 4 and 102.86 ± 0.60 to 115.89 ± 0.05 ìg/100g in week 6. The increase in iodine concentration in the vegetable marrows ranged from 60.879 ± 0.32 to 76.786 ± 0.16 ìg/100 g in week 4 and 62.078 ± 0.09 to 107.679 ± 0.24 ìg/100 g in week 6. The increase in iodine concentration in water leaf ranged from 61.59 ± 0.24 to 73.41 ± 0.83 ìg/100 g in week 4 and 62.06 ± 0.09 to 96.25 ± 0.025 ìg/100 g in week 6. From the results, the vegetables treated with 40 ìg/l potassium iodate showed the highest iodine level in week 4. These results from this iodine biofortification studies, suggest that the iodine added to the soil increased iodine uptake by the vegetables. Suggesting that iodination of irrigation water is an advantageous and cost-effective method of supplying iodine, since it requires simple technology.

Key words: Fortification, iodine deficiency disorders, iodination, irrigation, potassium iodate.