Physicochemical and Mechanical Characterization of HDPE and LDPE Films Used in the Postharvest Packaging of Banana (Musa paradisiaca)

The postharvest preservation of banana (Musa paradisiaca) is essential to maintain fruit quality, reduce losses, and ensure consumer acceptability during storage and dis-tribution. Packaging films play a critical role in protecting fruit from mechanical damage and environmental stress while extending shelf life. This study compared the physico-chemical and mechanical properties of two widely used polyethylene films—high-density polyethylene (HDPE) and low-density polyethylene (LDPE)—under simulated post-harvest conditions. Films were characterized by Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), and Flame Atomic Absorption Spectroscopy (AAS) for trace element detection. Structural integrity was assessed by macro- and microphotography, while tensile tests quantified mechanical performance. Results showed that HDPE presented higher melting stability, crystallinity, and tensile strength, with detectable zinc content (0.82–0.94 mg/100 g), whereas LDPE was zinc-free but exhibited greater flexibility. Both materials retained their polyethylene chemical fingerprint without oxidative degradation, although LDPE displayed more pronounced surface deterioration after weathering (288, 864, and 1440 h). These findings highlight HDPE’s superior stability and safety for banana export pack-aging, while emphasizing the importance of monitoring potential trace element migra-tion to ensure compliance with food-contact regulations and sustainability in tropical fruit supply chains.