A network of halloysite nanotubes—small, hollow cylinders—incorporated into a polyethylene film kept oxygen from entering and water and other gases from leaving. The tubes also absorbed ethylene, the chemical that causes ripening, keeping it from building up around the tomatoes. Finally, carvacrol, a natural antibacterial oil found in thyme and oregano, was coated on the inner surface of the film to kill microbes. Tomatoes in this film stayed fresh for 10 days, while the control tomatoes rotted after just six days.
“Food packaging that is capable of interacting with food can contribute to safety and prevent economic losses from spoilage,” says lead author Hayriye Unal, of Sabanci University. “Specialized films that can preserve a wide array of foods are highly sought after.”