Construction and functional assessment of zein thin film incorporating spindle-like ZnO crystals

The use of plastics has rapidly progressed during recent years in food packaging, which can be attributed to technological innovations in the synthesis of plastics and lower costs. However, the massive accumulation of plastic waste is often accompanied with their excessive consumption because of their poor degradability. Consequently, interest in the native materials is growing. It is noted that zein is a corn protein, has good compatibility and has been widely applied in the food industry. However, microbial contamination is a huge detriment to its long-term applications. This study aims to identify a method, which can provide antibacterial activity to a zein thin film. Monodispersed and spindle-like ZnO crystals made of nanocrystals were synthesized and added into zein thin films. EDX mapping confirmed the homogeneous distribution of ZnO in films. The antibacterial activities have been approved and showed great stability. In summary, the potential of zein thin films incorporating ZnO crystals as a functional packaging film has been demonstrated.