Preparation of chitosan photodynamic antibacterial film loaded with VK complex in the preservation of chilled mutton.

To effectively utilize the photodynamic antibacterial ability of vitamin K (VK), by solving the photothermal instability of VK, it was combined with natural polymers to apply the preservation of chilled mutton. We encapsulated VK in the (2-Hydroxypropyl)-β-cyclodextrin (HP-β-CD) to construct VK-HP-β-CD complex and then introduced the complex to chitosan (CS) and polyvinyl alcohol (PVA) to fabricate an antibacterial film (CS/PVA-VK-HP-β-CD film). Through the packaging performance test of the film, the content of VK-HP-β-CD was an important factor determining the properties of film including tensile strength, elongation at break, water vapor permeability, water content and water contact angle. Meanwhile, CS/PVA-VK-HP-β-CD films could continuously release ROS under light and suspended in dark, thus realizing >99 % antibacterial rate for Escherichia coli and Staphylococcus aureus. In the application experiment of chilled mutton, CS/PVA-VK-1-HP-β-CD film could significantly inhibit the increase of total viable count (TVC), pH value (pH) and total volatile base nitrogen (TVB-N) of chilled mutton, and extended its shelf life for at least 12 days. These results indicated that the CS/PVA film with the VK-HP-β-CD complex might have promising potential as an antibacterial material for packaging and preserving food.