Humidity-regulating antibacterial trilayer Janus membrane of polyacrylonitrile/gelatin-potato starch/polycaprolactone-cinnamon essential oil for cherry tomato preservation

Antibacterial packaging is widely used for food preservation by inhibiting microbial growth. However, elevated moisture can promote microbial spoilage, posing a challenge in creating packaging systems that combine bioactive properties with moisture regulation. Herein, a trilayer Janus membrane is developed using a layer-by-layer electrospinning technique for cherry tomato preservation, which comprises a superhydrophilic polyacrylonitrile (PAN) outer layer, a hygroscopic gelatin-potato starch (GA-PS) intermediate layer, and a bioactive hydrophobic polycaprolactone-cinnamon essential oil (PCL-CEO) layer. Its asymmetric wettability gradient and hierarchical structure facilitate efficient directional water transport (DWT), achieving a water evaporation rate of 0.41 g h −1 and reducing the relative humidity (RH) within the package from 75 % to 40 % (with surrounding RH of 75 %) without external energy input. The controlled release of CEO through Fickian diffusion maintains strong antibacterial and antioxidant activities inside the package. Combining humidity regulation with bioactive properties, the PAN/GA-PS/PCL-CEO membrane can extend the shelf-life of cherry tomato from 6 days to 18 days at 25 °C compared to polyethylene plastic wrap.