Preparation of pullulan-shellac edible films with improved water-resistance and UV barrier properties for Chinese cherries preservation

In order to improve the water-resistance and ultraviolet (UV) barrier properties of pullulan (PL) film, edible composite films were prepared by solution casting based on PL and shellac (SH). The physical properties, thermal stability, mechanical properties, water vapor permeability and UV barrier of the composite films were characterized. The analysis of the functional properties revealed that the composite films had good compatibility, water-resistance (33.50˚–60.15˚), and strong UV-blocking properties (84.60%–0.00%). The addition of SH improved the water-resistance and mechanical properties of the films, but the thermal stability was slightly reduced. These films can be used as an edible coating on Chinese cherries. According to the characteristics of weight loss, decay incidence and other indicators of cherries, the PL-SH composite films can keep Chinese cherries fresh at room temperature at least for 7 days. Therefore, PL-SH composite films may be an environmentally friendly packaging material with application prospects in the fruit preservation industry.