Zinc biofortification and light intensity independently modulate zinc bioaccessibility, minerals, phytochemicals, and yield components of pea and radish microgreens

Over 17% of the global population is at risk of zinc (Zn) deficiency. Agronomic Zn-biofortification of nutrient-dense crops like microgreens, characterized by rapid growth and low phytic acid content, can contribute to addressing Zn-deficiency. However, limited research exists on how light intensity and Zn fertigation interact to influence Zn accumulation, bioaccessibility, and the nutritional profile of microgreens. To this purpose, a study was conducted to evaluate the effects of Zn (0, 5, 10, 15 mg/L) and light intensity (100, 200, 300, 400 µmol/m 2 /s) levels on Zn accumulation and bioaccessibility, yield, and nutrient profile of pea and radish microgreens. Increasing Zn level enhanced Zn content and bioaccessible-Zn in both species. A 15 mg/L Zn-application resulted in a 4-fold and 17-fold increase in bioaccessible-Zn in pea and radish microgreens, respectively, with minimal impact on biomass. Although Zn-enrichment reduced the content of other essential nutrients like iron (Fe), it also decreased undesirable antinutrients like nitrate. Light intensity did not affect Zn accumulation but increased phytochemical content, including total phenols, flavonoids, and antioxidant activity. These findings suggest that agronomic biofortification via Zn fertigation effectively enhances Zn content and bioaccessibility in microgreens. Additionally, modulating light intensity can improve phytochemical content, producing Zn-enriched and nutrient-dense functional microgreens.