Intelligent colorimetric indicator film based on bacterial cellulose and pelargonidin dye to indicate the freshness of tilapia fillets

This work aimed to develop an intelligent packaging film based on bacterial cellulose (BC) and pelargonidin (Pg) for tilapia fillets freshness. The color of Pg solution and Pg-BC films changed from red to blue within pH3−pH10. The introduction of Pg reduced the light transmittance and improved the mechanical properties of the film. FTIR results showed that BC and Pg formed intermolecular interactions. The diffraction peak intensity of Pg-BC film decreased during storage. The cross section and surface of Pg-BC film were damaged during storage by SEM. The Pg-BC film had a great color difference from red to colorless when employed to monitor the freshness of fillets stored at 4 °C and 25 °C, which was consistent with the change of TVB-N and sensory scores of fish. Therefore, the Pg-BC film can be used as intelligent packaging film to monitor and visualize the freshness of fish during storage.