Iodine biofortification of four microgreens species and its implications for mineral composition and potential contribution to the recommended dietary intake of iodine

The World Health Organization has identified iodine deficiency as one of the nutritional problems that affect more than a third of the world's population. About 60% of the world's population suffers from ‘hidden hunger’ with subtle and nonspecific health effects, regardless of social and economic status. The agronomic biofortification of leafy vegetables with iodine could increase the uptake of this crucial element. The current study constitutes the first report of results on the agronomic biofortification with iodine of four different species of microgreens (tatsoi, coriander, green basil, and purple basil). Biofortification was applied through the nutrient solution, using two doses of I (4 and 8 µM) plus an untreated control. Iodine supplementation across species had no effect on the dry matter content, color parameters, and nitrate levels of harvested microgreens. However, the 8 µM dose of iodine increased tissue iodine concentration by 226.52% (on average), with the highest values obtained from tatsoi (15.03 µg g − 1 fw). Taking into account the iodine recommended dietary allowance (RDA), consuming one serving of tatsoi biofortified with 8 µM I solution would cover 100.19% and 37.57% of daily requirement for adults and children, respectively. Our results demonstrated significant differences in the response of the four species to biofortification with iodine, highlighting the significant potential of select microgreens species for contributing to the combating of hidden hunger as an efficient and sustainable dietary resource.