Supercritical impregnation of pomegranate biomass as active packaging

This study explores the effect of supercritical solvent impregnation (SSI) time (1, 3 and 5 h; 300 bar and 60°C) of pomegranate peel extract on the physical and functional properties of low‐density polyethylene (LDPE) films. The results indicate that SSI significantly increased both film thickness and mass. Impregnation time of 1 h maximised impregnation yield (mass gain 5.55 mg and impregnation yield 2.13%), increased film thickness to 102.0 μm and improved the light barrier properties as compared to the control film. Film opacity increased from 2.37 to 2.88 AU mm −1 (1 h) and to 3.39 AU mm −1 (5 h). Surface roughness also increased with impregnation time. The Fourier transform infrared spectra corroborated the presence of oxygenated phenolics in impregnated films. The highest total phenolic content (0.037 mg GAE g −1 film) was observed at 1 h, consistent with the results of DPPH and ABTS radical scavenging activities. SSI provided these improvements through a short, solvent‐free and low‐temperature process, which eliminates the need for toxic organic solvents, avoids high‐energy solvent evaporation steps and achieves functionalisation within 1 h compared with multi‐hour or multi‐step conventional methods. Overall, the results demonstrate that SSI is an energy‐efficient sustainable technique for producing active LDPE films with antioxidant properties.