Multifunctional film based on gelatin with titanium dioxide and thymol@B-cyclodextrins for fresh-keeping packaging

Microbial infection and ethylene accumulation can cause spoilage of fresh fruit and vegetables during post-harvest storage. Here, gelatin film incorporated with titanium dioxide (TiO2) nanoparticles and thymol-loaded B-cyclodextrin (THY@B-CD) was prepared by the solution casting method for scavenging ethylene and inhibit-ing microbial growth. The scanning electron microscope and ethylene scavenging experiment showed that 1% TiO2 nanoparticles did not agglomerate in the gelatin film and achieved 23.1% ethylene degradation efficiency under UV light. Loading rate and thymol release behaviors indicated that thymol encapsulated in the B-CD carrier could be effectively loaded into gelatin film and avoid rapid volatilization. More importantly, TiO2 and thymol exhibited synergistic antimicrobial properties under UV light, achieving a 100% inhibition rate against Escher-ichia coli, Staphylococcus aureus, and Rhizopus stolonifer. In addition, the THY@B-CD/TiO2/Gel film had good tensile strength, water solubility, and biocompatibility. And they could significantly extend the shelf life of strawberries and tomatoes. Hence, this active packaging film system provided an effective postharvest strategy for delaying ripening and avoiding microbial contamination.