Gas-permeation controllable gelatin-based films with plant pore-like polyethyleneimine-modified porous chitosan microspheres for fruit preservation

Modified Atmosphere Packaging (MAP) technology holds significant potential for preserving fruits and vegetables. In this study, we explored a novel MAP gas regulation technology that regulates selective gas permeation and achieves gas equilibrium within the package. Inspired by natural leaf stomata that regulate plant respiration, we fabricated polyethyleneimine-modified porous chitosan microspheres (PEI-PCM) that mimic the function of stomatal ‘switches’ in order to enhance respiratory regulation. And PEI-PCM were introduced into the gelatin-tannic acid (GT) film to construct a biomimetic porous chitosan microsphere-composite gelatin-based film (GT@PEI-PCM, GTPP) for the preservation of perishable fruits (litchi and waxberry). GTPP film can control and regulate gas exchange driven by CO 2 concentration levels, achieving atmospheric equilibrium within 24 h and preventing oxidative damage to fruits. In addition, GTPP films demonstrated excellent tensile strength as well as water resistance, antibacterial, and antioxidant properties. The incorporation of modified microspheres could regulate the gas permeability and selectivity (CO 2 /O 2 : 0.79–2.53) of the gelatin-based films, which successfully prolonged the freshness of litchis and waxberries. Overall, this innovative gas permeation control strategy provides a novel concept for improving MAP technology.