Dual-Function Metal–Phenolic Network-Capped Starch Nanoparticles for Postharvest Pesticide Removal and Produce Preservation

Pesticide residues and postharvest losses threaten produce safety and quality, necessitating innovative and effective solutions. Herein, we developed a dual-action postharvest wash based on metal-phenolic network-capped starch nanoparticles (FTN@SNPs) to reduce surface pesticide residues while helping maintain produce quality during storage. FTN@SNPs were prepared by coordinating tannic acid (TA) with Fe³⁺ to form a metal-phenolic network (MPN) and capping the MPN onto starch nanoparticles. Wash performance was evaluated using SNPs concentrations of 0.5-1.25 wt % and varying FTN loadings, and the best performance was obtained at 1.0 wt % SNPs with 0.25 mM FTN. Comprehensive evaluations on fresh produce demonstrated that the FTN@SNP wash significantly reduced a range of surface pesticide residues, achieving over 86% removal of thiabendazole as quantified by surface-enhanced Raman spectroscopy. The optimized formulation further achieved 93.51% and 89.03% removal of acetamiprid and imidacloprid, respectively, outperforming conventional wash solutions. Molecular dynamics simulations supported high pesticide-MPN affinity with binding energies of -32.40 kcal/mol (acetamiprid), -24.45 kcal/mol (imidacloprid), and -20.98 kcal/mol (thiabendazole), consistent with interactions dominated by π-π stacking, hydrogen bonding, and van der Waals forces. In addition, the wash solution helped maintain postharvest quality of both whole and fresh-cut produce over 15 days of storage, as reflected in the visual appearance, weight loss, titratable acidity, and total soluble solids. This dual-action approach highlights the potential of the FTN@SNPs wash as a sustainable, biodegradable, and scalable strategy to improve food safety and minimize postharvest losses across the fresh produce supply chain.