Eco-Friendly packaging film with integrated functions of High-Efficiency radiation cooling and Sustained-Release antimicrobial activity

The storage temperature and microbial contamination typically have significant impact on the deterioration rate and postharvest lifespan of fresh food.To meet the critical requirements of fresh food packaging, a hybrid functional packaging coating is developed by combing tannic acid (TA) as a binder, chitin nanofibers (CNF) as a crosslinker, and acidified halloysite nanotubes containing Apigenin (CA@e-HNTs) as an antimicrobial/cooling agent. The functional coating was sprayed on a poly(butylene adipate-co-terephthalate) (PBAT) substrate, integrating both radiative cooling capabilities and sustained antimicrobial properties. The hybrid film achieved subambient cooling through a high solar reflectance (90.5 %) and high mid-infrared emittance (94.0 %), resulting in a temperature of 6.2 ℃ below ambient under intense sunlight. When used for fresh food packaging, the hybrid functional film outperformed other commercially available food packaging materials in maintaining the quality of Agaricus bisporus and extending the storage time of fresh strawberries to 9 days. Moreover, the film exhibited excellent antibacterial and antioxidant properties. This zero-energy cooling technology with sustained antimicrobial characteristics has enormous potential for application in the preservation of fresh food, offering a more sustainable way to extend the shelf life of fresh produce and reduce food waste.