Production of plasma activated-water and clay/nanocomposite low density polyethylene film and application in post-harvest preservation of citrus fruit

This study explores the combined use of plasma-activated water (PAW) washing and clay nanocomposite polyethylene (NCPs-PE) films to enhance the postharvest preservation of sweet lemons over five months under ambient storage. Structural analyses (FTIR, XRD, SEM, AFM and, EDS) confirmed successful incorporation of clay nanoparticles into the PE matrix, resulting in intercalated nanocomposite structures, homogeneous surface morphology, and good filler-polymer compatibility. The NCPs-PE films exhibited higher moisture content (MC), water vapor permeability (WVP) than pure PE, while water vapor transmission rate (WVTR) remained unchanged at p < .05. The films demonstrated superior antifungal activity against Penicillium digitatum (inhibition zone = 30 mm) and reduced decay rates compared to neat PE. Fruits packed with NCPs-PE showed the lowest decay rate (33%), while PAW washing combined with PE packaging resulted in minimal weight loss (3.18 ± 0.26 g) and optimal firmness (1.92 ± 0.02 N). Overall, the synergistic effect of nanocomposite packaging and PAW treatment effectively limited microbial growth, maintained fruit quality, and extended shelf life, indicating the potential for sustainable citrus preservation, though further optimization is needed for commercial application.