Gellan gum-based functional films integrated with bacterial cellulose and nano-TiO2/CuO improve the shelf life of fresh-cut pepper

Active food packaging materials often possess barrier, hydrophobic and antioxidant properties, which are essential for maintaining food quality and safety. In this study, low acyl gellan gum (LAGG) and high acyl gellan gum (HAGG)-bacterial cellulose (BC) composite films (LAGG-BC and HAGG-BC) were respectively prepared by incorporating BC into LAGG and HAGG. The results showed that the mechanical, barrier properties and stability of the composite films were significantly improved after incorporating with BC. However, LAGG-BC film possessed higher mechanical, hydrophobicity, barrier properties and stability than HAGG-BC film. The structural characterization results indicated that BC and LAGG showed good compatibility and intermolecular interactions, and the formed film was smooth and flat. Furthermore, the added nano-TiO2/CuO further lowered its transparency and enhanced the UV-barrier, antioxidant activity and flexibility. The application experiments proved that LAGG-BC/T-0.4 %CuO film effectively inhibited the softening, reddening, browning and rotting of fresh-cut peppers during storage, and also provided excellent anti-fogging, bending and thermal reversibility properties. Thus, LAGG-BC/T-0.4 %CuO film could be used as a packaging material for fruits and vegetables preservation.