Chitosan-Selenate Complex Improves Bioactive Profile and Antioxidant Response in Wheat Sprouts (Triticum aestivum L.)

Abstract

Selenium (Se) deficiency is a global health problem affecting more than 500 million people; crop biofortification is a sustainable strategy for its mitigation. This study investigated the effect of the application of selenate nanoparticles (SeO42−) and the combination of selenate (SeO42−) and chitosan (CS) (forming a SeO42−-CS complex) on the antioxidant profile, growth, biomass, bioactive compounds, enzymes, and Se accumulation of wheat (Triticum spp.) sprouts. Fourteen treatments were applied using a factorial design combining seven concentrations and two formulations: SeO42− and SeO42−-CS. It was identified that chitosan increased Se uptake efficiency by 30% versus conventional selenate. The optimal dose for biomass was 0.15 mg L−1 of SeO42−-CS (+40% vs. control), while 0.25 mg L−1 maximized bioactive compounds (phenolics (25%) and flavonoids (21%)) as well as antioxidant capacity (26%) and enzymatic activity (SOD: 37%; POD: 41%). In addition, CS reduced Se phytotoxicity at doses ≥1.50 mg L−1, evidencing its dual role as a delivery vehicle and cell protector. These findings demonstrate that the SeO42−-CS hybrid system is a technologically viable and efficient alternative to traditional selenate for the production of biofortified sprouts. This strategy shows high potential for scaling up in the functional food industry and for application in agricultural regions with selenium-deficient soils.