Iodine Accumulation and Distribution in Carrots (Daucus carota L.)

Iodine is a critical trace element necessary for human and animal health owing to its role in thyroid hormone synthesis. Despite its importance, iodine deficiency remains a global health concern. Traditional methods to address this issue, such as salt iodization, face challenges like iodine loss during storage and cooking. The biofortification of plants, particularly carrots, offers a promising alternative. This study investigates iodine accumulation and distribution in carrots biofortified with potassium iodide (KI) and potassium iodate (KIO3) using single extraction at elevated temperatures with tetramethylammonium hydroxide followed by iodine determination by ICP-MS. Results show that iodine biofortification significantly increases the iodine content of various parts of the carrot, especially the leaves and the root peels. Carrots treated with iodate accumulate 2.7 times more iodine than those treated with iodide. The leaves exhibit the highest iodine content, particularly in iodate-treated plants, where levels can be over 24 times higher than those of control carrots. Root peel and roots also accumulate substantial amounts of iodine, with the iodate treatment resulting in 5.42 mg·kg−1 and 3.75 mg·kg−1 dry weight, respectively. The potential application of biofortified carrots can help meet human dietary iodine requirements; additionally, iodine-rich carrot leaves as livestock feed offer a sustainable approach to increasing the iodine intake in animals.