Preparation, Characterization and Application of Polymethoxy Flavone-Anthocyanin-Chitosan Composite Membrane in Pork Freshness Indication

This study was carried out in order to develop a composite film that serves the dual function of acting as an intelligent indicator for meat freshness and preserving meat using chitosan (CS) as the film-forming substrate, glycerin as the plasticizer, polymethoxy flavones (PMFs) as the bacteriostatic agent and anthocyanin (AC) as the color developing agent. The effects of AC and PMFs on the mechanical, barrier, permeability, indicator and preservative properties of the composite film were investigated. The results showed that the composite film extended the shelf life of pork to 7 d at 4 ℃, this effect being more pronounced than that of blank group without film coating, control groups coated with polyethylene film and CS film. The composite film exhibited blue gray, light brown red and dark brown red colors for fresh, second fresh and spoiled meat respectively, and can enable real-time and non-destructive indication of pork freshness.