Multilayer packaging with CO2/O2-selective gas regulation and humidity-responsive release of cinnamon essential oil for cherry tomato preservation.

Fresh produce preservation remains a major challenge due to nutrient loss and microbial spoilage. Here, we reported a biobased paper window that combined gas regulation with humidity-responsive antimicrobial release of cinnamon essential oil (CEO) to address these challenges. The bifunctional paper window exhibited appropriate gas permeability and CO2/O2 selectivity (2.1-6.0). Molecular dynamics simulations revealed the mechanism of selectivity, showing a 16.9-fold stronger CO2 adsorption than O2 at 100 kPa. Furthermore, humidity generated from produce respiration and transpiration triggered sustained CEO release for >21 days. Validated on cherry tomatoes, the bifunctional paper window extended shelf life from 12 to 20 days at 23 ± 3 °C while maintaining total soluble solids at 8.2%, titratable acidity at 0.56%, and firmness at 7.33 N, and remained free from mold growth throughout storage. This bifunctional paper window offers an efficient and sustainable strategy for reducing fresh produce losses.