Selective gas-permeation films with nanoMOFs as gas “Switches” for mango preservation

Abstract

The storage atmosphere of low O2 and high CO2 concentration can regulate plant cell respiration and microbial growth, which plays a crucial role in food preservation. However, traditional modified atmosphere packaging (MAP) cannot accurately control gas penetration. In this study, a novel strategy for accurately controlling the selective CO2/O2 permeation is developed by using nanoMOFs with different pore structures as gas “switches”. Combined with experimental data and molecular simulation results show that the selective CO2/O2 permeations of nanoMOFs/carboxymethylcellulose(CMC)/Zein are successfully controlled from 2.87 ± 0.12 to 8.65 ± 1.63 owing to the synergistic effect of nanoMOFs with different pore structures and the different affinity between nanoMOFs and molecules of CO2 and O2. In which, 1.6 % HKUST-1/CMC/Zein has the best CO2/O2 selectivity of 8.65 ± 1.63. Furthermore, the 1.6 % HKUST-1/CMC/Zein with excellent antibacterial activity and selective CO2/O2 permeation can maintain the appearance and freshness of mango for at least 7 days compared with other packaging films. Therefore, we have developed a new type of gas “switches” for MAP to accurately control the selective permeation of gases at the molecular level, which will expand the application of MAP in food preservation field.