Biosynthesis of Magnetite Nanoparticles and its Impact on Productivity and Biochemical Components of Chili Pepper Under Saline Conditions

Abstract

This study aims to green-synthesize magnetite nanoparticles (Fe₃O₄-NPs) using chili pepper aqueous extract, as well as chemically prepare and confirm the synthesis utilizing specialized equipment analysis. Furthermore, an investigation of the impact of chili pepper aqueous extract and magnetite nanoparticles green and chemical synthesis on the growth, yield, antioxidant activity, and active ingredients of chili pepper (Omega F1 cultivar) under salinity stress conditions was performed. The size of the formed magnetite nanoparticles in green synthesis ranged from 30.43 to 45.4 nm. However, chemically prepared magnetite nanoparticles were 10 ± 26 nm. From the results, the exogenous application of magnetite NPs alleviated the adverse effect of salinity on chili pepper plants and improved growth, fruit physical properties, and yield, photosynthetic pigments, antioxidant enzymes activity, superoxide dismutase (SOD), peroxidase (POD), and antioxidant capacity (DPPH scavenging). Plants treated with green-synthesized magnetite NPs had the greatest effect on these parameters when compared to other treatments. The main capsaicinoids found in chili peppers are capsaicin and dihydrocapsaicin. The highest levels of capsaicin and dihydrocapsaicin were found when plants were treated with green-synthesized magnetite nanoparticles at 10 ppm. The Scoville heat unit (SHU) was calculated for the overall flavor of chili pepper, and a high SHU was linked to higher capsaicinoid levels. The GC/MS analysis confirmed the existence of 32 active compounds, with the major bioactive molecules being N-acetyl aspartyl glutamic acid; (S(Fe), S(Fe’)) Bis[à[(2 S,4 S) 4 (Methoxymethyl) 1,3dioxan2yl]ferrocenyl] Ketone; 5-[4-(Dipropylamino) phenyl]-10,20-diphenyl-15-propylporphyrin; Dodecachloroperylene; 3,3’’’,5,5’’’-Tetrachloro-4,4’’,4’’’,6’-tetramethoxy2’,2’’-dinitromquaterphenyl; and m-Bis (3,4-diamino-2,5-diphenyl-6-pyridino) benzene.