Fabrication and characterization of methyl jasmonate-loaded Zein–Pullulan nanoparticle coatings for Suppressing light-induced greening in potato tubers

Methyl jasmonate (MeJA), a signaling molecule, plays a crucial role in regulating chlorophyll (Chl) metabolism in fruits and vegetables after harvest. However, its poor water solubility and volatile characteristics restrict its practical application. In this study, MeJA loaded into zein–pullulan composite nanoparticles (MeJA/Z–P NPs) were prepared through antisolvent precipitation. Their physicochemical properties were then investigated, and their inhibitory effects on the greening of potato during storage were explored. Results showed that the optimized MeJA/Z–P NPs (zein: pullulan = 20:1; 10 mmol/L MeJA) had an average particle size of 200.00 ± 0.92 nm, a zeta potential of 35.76 ± 0.15 mV, and an encapsulation efficiency of 90.05 %. Structural analyses confirmed that the interactions among the components of the composite nanoparticles were maintained by hydrogen bonds and hydrophobic interactions. MeJA/Z–P NPs exhibited excellent sustained release properties over a 20-day storage period. Additionally, MeJA/Z–P NPs coating treatment significantly inhibited greening during potato storage. After 60 days of storage, the chl content of MeJA/Z–P NPs potatoes had reduced by 27.85 %, 11.34 %, and 8.45 % compared with those of the control, Z–P NPs, and MeJA potatoes, respectively. Thus, MeJA/Z–P NPs coating treatment is an effective strategy for inhibiting greening during potato tuber storage. • Zein-pullulan nanoparticles were fabricated to deliver methyl jasmonate. • The composite nanoparticles exhibited excellent physical stability. • Sustained release of methyl jasmonate from composite nanoparticles over 30 days. • Composite nanoparticles as coatings can effectively inhibit potato greening.