Self-assembled natamycin-loaded kafirin nanoparticles: Preparation, characterization and application in truss tomato preservation.

Natamycin-loaded kafirin nanoparticles (Nata-Kaf NPs) were prepared via an antisolvent self-assembly strategy, the encapsulation of natamycin was confirmed by FTIR, XRD, CD, and TGA, while morphology and size distribution were characterized by SEM and dynamic light scattering (DLS). Under the selected formulation conditions, nanoparticles with high encapsulation efficiency (77.28%) were prepared, featuring controlled size (199.33 nm), narrow distribution (PDI 0.13), and sufficient surface charge (ζ-potential -38.53 mV). In an 8-day truss tomato preservation test, the nanoparticles effectively inhibited fungal growth on calyx; on day 8, disease incidence decreased by 77.18% and 85.63% at effective natamycin concentrations of 0.3 and 0.6 mg/mL, respectively. Moreover, quality deterioration was alleviated, as indicated by lower weight loss, delayed firmness decline, and higher contents of total soluble solids, vitamin C, total phenolics and flavonoids. Overall, Nata-Kaf NPs demonstrated the potential for further development as an eco-friendly delivery system for postharvest preservation of truss tomato.