Curcumin-loaded Pickering emulsion enhanced the sustained-release performance for chitosan coating and improved the postharvest quality of plum fruits (Prunus salicina).

Curcumin is a promising natural preservative, but its poor solubility and susceptibility to photo-oxidation limit its application in active coatings. This study developed a cellulose nanofiber-stabilized curcumin Pickering emulsion incorporated into chitosan for postharvest plum preservation. The Pickering emulsion prepared at a water-to-oil ratio of 40:10 (w/w) exhibited uniform droplet distribution and good electrostatic stability. Its incorporation enhanced the mechanical performance and water resistance of PE/CS coating films, while FTIR and XRD analyses indicated hydrogen-bonding interactions within the composite matrix. Notably, PE/CS coating films showed sustained curcumin release in 50% ethanol, reaching 65% after 96 h. This controlled-release behavior was associated with enhanced antimicrobial and antioxidant activities, as reflected by inhibition zones above 10 mm and DPPH/ABTS+ scavenging rates exceeding 98%. PE/CS coating effectively delayed flesh browning, water loss, and firmness decline in plums, providing a Pickering emulsion-based strategy for active fruit preservation.