Advances in Cold-Plasma Technology for Legume Seeds: Mechanisms, Nutritional Quality Improvement, Food Safety and Sustainable Agriculture

Abstract

Cold plasma (CP), a nonthermal ionised gas rich in reactive oxygen and nitrogen species (RONS), has emerged as a sustainable technology for enhancing legume production and quality. This review summarises current advances in CP applications in legumes, focusing on seed germination, seedling vigour, nutrient enhancement, antinutrient reduction, technofunctional modification and microbial decontamination. Optimised CP treatments significantly improve germination performance, nutrient digestibility and bioavailability while reducing antinutritional compounds such as phytic acid and trypsin inhibitors. CP also effectively inactivates bacterial and fungal contaminants without compromising seed quality. Beyond these established applications, the review highlights emerging research areas, including CP-mediated abiotic-stress priming for improved drought, salinity and chilling tolerance through modulation of antioxidant defenses and stress-responsive pathways. Recent evidence on enhanced legume–Rhizobium symbiosis and biological nitrogen fixation is discussed, emphasising improvements in nodulation and nitrogenase activity. Furthermore, CP-induced alterations in seed microbiomes, including suppression of pathogens and promotion of beneficial microbes, are examined. The potential of plasma-activated water (PAW) for producing safer, nutritionally enriched and uniformly sprouted legumes is also explored. Finally, challenges related to treatment standardisation, safety assessment, process scale-up and regulatory acceptance are addressed. Overall, CP represents a multifunctional and environmentally friendly approach for sustainable legume production and quality enhancement.