Pullulan-based coatings carrying biocontrol yeast mixed with NaCl to control citrus postharvest disease decays

The decline in postharvest citrus quality due to fungal infections necessitates innovative packaging solutions. This study presents a pullulan-based edible film (PBYFs) with biocontrol yeasts, designed to dissolve in both liquid and soil. This film is capable of enveloping entire citrus fruits, effectively managing postharvest diseases, and extending their shelf life. The formulation of PBYFs includes NaCl 0.1 M, Kloeckera apiculata 34-9 at 1.0 × 10⁷ CFU mL^-1, pullulan 3 % w/v, SA 0.5 % w/v, and glycerin 1 % w/v. Our experiments, conducted on eight citrus varieties, demonstrated that PBYFs significantly reduced the occurrence of green and blue molds, sour rot, and anthracnose in vivo. Moreover, PBYFs-coated fruits exhibited an extended shelf life without compromising the quality parameters such as weight loss, TSS (total soluble solids), TA (titratable acidity), VC (vitamin C), or the accumulation of off-flavor volatiles. This research presents a promising approach for creating scalable, cost-effective, and environmentally sustainable biodegradable antifungal packaging systems for citrus fruits.