Efficient biomass antibacterial film with plant essential oil components for fruit packaging and preservation

Abstract

High-performance biomass-based films incorporating plant essential oils as antibacterial agents have attracted significant research interest. However, the inherent complexity and high volatility of plant essential oils limit their practical applications. In this work, a method was proposed to isolate efficient antibacterial components from Ledum palustre L. essential oil (LPEO) using molecular distillation technology. These components were then integrated into a sodium alginate/pectin-based biomass matrix as a sustained-release carrier to prepare a series of composite films (LPEF). The physicochemical properties of the films were systematically characterized and analyzed. The results show that as the essential oil content increases, the surface roughness of LPEF films decreases, resulting in reduced moisture permeability and an increased contact angle. Due to the plasticizer-like effect of the essential oil, the film toughness improves, with its fracture stress and tensile strength increasing to 3.02 N and 6.37 MPa. The LPEF-50 film achieved an essential oil release rate of 21.9% within the first 2 h, followed by a gradual release, thereby maintaining antibacterial functionality while enabling material reusability. Furthermore, green grapes packaged with this film could be preserved for 7 d under conditions of 25 °C and 40% relative humidity. This work provides a novel strategy for identifying and utilizing functional antibacterial components from plant essential oils.