Effects of Cerium and Titanium Oxide Nanoparticles in Soil on the Nutrient Composition of Barley ( Hordeum vulgare L.) Kernels

The implications of metal nanoparticles (MeNPs) are still unknown for many food crops. The purpose of this study was to evaluate the effects of cerium oxide ( n CeO 2 ) and titanium oxide ( n TiO 2 ) nanoparticles in soil at 0, 500 and 1000 mg·kg −1 on the nutritional parameters of barley ( Hordeum vulgare L.) kernels. Mineral nutrients, amylose, β-glucans, amino acid and crude protein (CP) concentrations were measured in kernels. Whole flour samples were analyzed by ICP-AES/MS, HPLC and Elemental CHNS Analyzer. Results showed that Ce and Ti accumulation under MeNPs treatments did not differ from the control treatment. However, n CeO 2 and n TiO 2 had an impact on composition and nutritional quality of barley kernels in contrasting ways. Both MeNPs left β-glucans unaffected but reduced amylose content by approximately 21%. Most amino acids and CP increased. Among amino acids, lysine followed by proline saw the largest increase (51% and 37%, respectively). Potassium and S were both negatively impacted by MeNPs, while B was only affected by 500 mg n CeO 2 ·kg −1 . On the contrary Zn and Mn concentrations were improved by 500 mg n TiO 2 ·kg −1 , and Ca by both n TiO 2 treatments. Generally, our findings demonstrated that kernels are negatively affected by n CeO 2 while n TiO 2 can potentially have beneficial effects. However, both MeNPs have the potential to negatively impact malt and feed production.