Preparation and Characterization of Poly(vinyl alcohol)/Tannin Blend Film for Active Food Packaging

The challenge for the food industry is to maintain or improve the quality of food products throughout the entire process of transportation, storage and consumption of foods. Hence, smart packaging technologies are actively studied in the food packaging industry. For instance, biomaterial-based food packaging technologies have been attempted in recent years owing to the abundance, biocompatibility, biodegradability, and non-toxicity of biopolymers. In this study, an active packaging film that can extend the shelf life of food was developed by blending tannic acid (TA), a natural polyphenolic compound with antioxidant and antibacterial activities, with poly(vinyl alcohol) (PVA), which is eco-friendly and has an excellent film-forming ability. The blend film was prepared via a simple solution-casting method, and its antioxidant and antibacterial properties, which can delay food spoilage, were evaluated. In addition, the anti-spoilage ability was evaluated in terms of browning and weight loss by packaging bananas, which are easily discolored during storage. Therefore, the PVA/TA blend film was found to extend the storage period of food.