Enhancing iodine delivery through sourdough wheat bread: influence of biofortified flour and iodized salt on iodine concentration and bioaccessibility

Official URL: https://dx.doi.org/10.1016/j.foodchem.2025.147232

Iodine deficiency remains a critical health concern, particularly in populations with limited access to iodized salt or shifting dietary patterns. This study assessed the impact of iodine-biofortified wheat flour (IBF), alone or combined with iodized salt (IS), on iodine content and bioaccessibility in sourdough bread. In vitro digestion showed that IBF increased iodine content to 158 μg/kg, and to 340 μg/kg with IS, compared to 1.63 μg/kg in control bread. This corresponds to an estimated intake of 68 μg/day. The IBF + IS formulation demonstrated the highest iodine bioaccessibility (224 μg/kg; 65 %). Interestingly, while iodine-fortified breads showed reduced values for selenium, potassium, and calcium, breads made with plain salt exhibited higher bioaccessibility for these minerals. These findings confirm the efficacy of IBF in enhancing iodine intake and its potential as an alternative or complement to salt iodization. They also indicate the importance of fortification approaches, considering the broader nutritional matrix over individual nutrients.