Effect of pistachio hull extract incorporation on the physical, mechanical, thermal, antifungal, and antioxidant properties of low-density polyethylene film for active packaging

Utilizing agro-industrial waste in active packaging can simultaneously address environmental concerns and promote public health by delivering bioactive compounds. In this study, low-density polyethylene (LDPE) films incorporating pistachio ( Pistacia vera L .) hull extract (PHE) were fabricated via extrusion at concentrations of 0.5, 1, 2, 4, and 8 wt.%. Among the formulations, the film containing 2 wt.% PHE demonstrated a sustained release of active compounds, resulting in significant antifungal and antioxidant activities. Therefore, detailed structural, thermal, and mechanical characterizations focused on this formulation. SEM revealed a heterogeneous distribution of PHE aggregates within the film. FTIR and XRD analyses confirmed the presence of PHE and an increase in crystallinity. DSC and TGA demonstrated improved thermal stability. However, incorporating PHE significantly reduced tensile strength and elongation at break (P < 0.05), while increasing water vapor transmission rate and oxygen permeability. These results suggest that PHE can function as an effective natural additive to develop bioactive LDPE-based packaging materials.