Comparative analysis of synthetic and organic chitosan nanoparticles as seed primers on germinated soybeans

Abstract

The present study investigated the effect of synthetic and organic chitosan nanoparticles (CNPs) at different concentrations (20–100 ppm) on soybean germination performance, bioactive components, and antioxidant potential. Germination parameters including radical length, seedling weight, and germination percentage were significantly influenced by nanoparticle treatments. Compared with control (T), both synthetic and organic CNPs enhanced radical length and germination rate, with the highest improvements observed at 100 ppm (T5 and T50). Organic CNPs consistently showed slightly superior performance in stimulating seed vigor compared to synthetic counterparts. Analysis of bioactive components revealed that CNP application significantly elevated total phenolic content (TPC), flavonoids, and flavanols in germinated soybeans. At 60 ppm, organic CNPs (T30) recorded the highest levels of flavonoids (2.25 mg catechin/100 g) and flavanols (0.30 mg catechin/100 g), highlighting the role of chitosan in inducing secondary metabolite synthesis. These findings are consistent with previous reports that nanoparticles act as elicitors, activating phenolic and flavonoid biosynthesis pathways. Antioxidant activity, measured as radical scavenging capacity, increased in a concentration-dependent manner. The control (45.34%) was significantly lower than treated samples, with the maximum activity observed at 100 ppm organic CNPs (86.3%). The higher antioxidant potential corresponds with elevated phenolic and flavonoid content, suggesting that CNPs enhance reactive oxygen species (ROS) scavenging systems. In a nutshell, the study demonstrated that CNPs, particularly organic variants at 100 ppm, effectively improve germination, bioactive compounds, and antioxidant activity in soybeans. These results highlighted the potential of CNPs as sustainable, eco-friendly biostimulants to enhance crop quality and functional value.