Photothermal mediated bionanocomposite films with pasteurization-like activity for tangerine preservation

Herein, we propose a composite packaging film with pasteurization-like activity by doping the MnO_x/MoO_x into chitosan film (CMM). The prepared CMM films exhibited excellent photothermal activity, which was inherited from the material. Under near infrared (NIR) irradiation, CMM films showed pasteurization-like activity due to the photothermal performance, in which CMM_0.1 was able to kill 99.15 % of E. coli and 99.39 % of S. aureus. CMM_0.1 film also showed good light transmittance (T₆₆₀ = 69.2 %), tensile strength (TS = 41.4 MPa) and UV-light/water vapor/ oxygen barrier ability. Less than 4.28 % of hemolysis rate and more than 92.89 % of cell survival rate after being treated with MnO_x/MoO_x demonstrated the biosafety of the CMM films. The shelf life of tangerines treated with CMM_0.1 + NIR can be extended from 9 days to 21 days, in which the nutrients can be retained well during storage. Our work provides a new perspective on the combination of pasteurization and packaging technology.