Effects of ultraviolet‐C irradiation on the physicochemical properties of polysaccharide films prepared from the stalk base of oyster mushrooms (Pleurotus ostreatus)

OMP films containing CTLE were prepared from underutilized oyster mushroom stalk base. UV‐C irradiation enhanced the physical properties of the films without affecting antioxidant and antimicrobial activities. The developed films can be applied as a food packaging material. Summary The effects of ultraviolet (UV)‐C irradiation on the physicochemical properties of oyster mushroom polysaccharide (OMP) films were investigated. The prepared OMP films were subjected to UV‐C treatment (5.4 kJ m−2). UV‐C irradiation increased the tensile strength and decreased the water vapour permeability of the OMP films. In addition, the incorporation of 1.0% Cudrania tricuspidata leaf extract (CTLE) enhanced the antioxidant activity as well as antimicrobial activity of OMP films; however, UV‐C treatment did not affect the activities of films containing CTLE. Furthermore, UV‐C‐irradiated films had higher contact angles than non‐irradiated films, indicating increased surface hydrophobicity. Microstructural imaging revealed that UV‐C treatment caused the surface of treated films to be smoother than that of untreated films owing to surface degradation. These results indicated that UV‐C irradiation can be used for OMP films to improve film properties that are associated with application of films as food packaging material.