Modification of microporous bionanocomposite films with visible light-activated photocatalytic antimicrobial TNT-CuO nanoparticles for active fruit packaging.

Active packaging technologies are evolving to enhance the preservation of fresh produce by fighting against microbial contamination and controlling internal packaging atmospheres. This study introduced an active fruit packaging called MT film, created by modifying a microporous polyvinyl alcohol/chitosan/cellulose nanocrystal bionanocomposite film with CuO-doped titania nanotubes. The MT film, with an average micropore size of 2.4 μm, displayed excellent mechanical properties and hydrophobicity due to its crosslinked structure. When exposed to visible light, the MT film could produce reactive oxygen species, effectively inhibiting the growth of Staphylococcus aureus and Escherichia coli O157:H7. Moreover, experiments on blueberry preservation demonstrated that the MT film could remove excess CO and maintain a higher O level. Under visible light, this film significantly reduced total viable count (4.6 ± 0.2 log CFU/g) and mold colony count (2.6 ± 0.1 log CFU/g), with Bacillus and Ascochyta being the primary inhibited genera. These findings highlight the potential of MT film in utilizing visible light to prevent microbial growth on blueberries and regulating the gas exchange of food packaging. MT film holds promise as an active packaging solution to improve the quality and shelf life of fresh produce while reducing food losses in the supply chain.