Enhancing durum wheat (Triticum turgidum ssp. durum L.) grain quality and safety: the role of organic foliar fertilization and selenium biofortification in mediterranean farming systems

Mediterranean durum wheat systems face dual challenges: declining grain quality due to climate-driven abiotic stresses and increasing demand for nutrient-rich, safe food. This study aims to evaluate whether integrating organic foliar fertilization and selenium (Se) biofortification can enhance nutritional quality, technological traits, and food safety of durum wheat ( Triticum turgidum ssp. durum L.) under Mediterranean climate conditions. A two-year field experiment (2018–2019) was conducted using modern (“Marco Aurelio”, “Nadif”) and old (“Cappelli”, “old Saragolla”) cultivars, foliar applications of organic nitrogen (N), sulfur (S), combined N + S, and Selenium (Se) biofortification, arranged in a split-plot design with three replicates. Analyses focused on gluten protein polymerization and aggregation potential, grain concentrations of N, S, Se, Fe, and Zn, and the profile of major and emerging mycotoxins. Water stress significantly reduced the formation of large aggregates in older cultivar “Cappelli” by 34%, while the modern “Marco Aurelio” maintained a high aggregation capacity, linked to improved technological and nutritional quality over the years. In the wetter year, organic S foliar fertilization significantly increased the protein polymerization by 11% and gluten index by 14% with respect to the control. Biofortification with Se simultaneously and significantly improved grain Se, and Fe and Zn concentration under water-limited conditions, and significantly reduced deoxynivalenol (29%), moniliformin (33%) and enniatins (58%). Thus, the combination of foliar organic S, biofortification with Se, and resilient modern cultivar offers a practical strategy to co-improve the nutritional and technological value and food safety of durum wheat growing under rainfed Mediterranean condition.