Researchers have developed a packaging film made from clay nanotubules that can keep food fresh for longer.
According to the United Nations Food and Agriculture Organization, consumers in rich countries waste roughly 220 million tonnes of food each year – almost as much as the entire net food production of sub-Saharan Africa. However, if food could stay fresh longer, consumers might waste less.
Although we have seen packaging film that can delay bacterial contamination or that reduced waste by allowing food to continue growing at home, researchers have had difficulty in developing an antimicrobial packaging that can also prevent the build-up of ethylene – the chemical that causes ripening. Now researchers from the Nanotechnology Research and Application Center at Sabanci University in Istanbul, led by Dr. Hayriye Ünal, have developed a new packaging film made from nanotubules, that may provide a solution. The researchers incorporated clay halloysite nanotubes – small, hollow cylinders derived from clay, into a polyethylene film. The clay nanotubes absorb ethylene and prevent oxygen from entering the film, while stopping water vapor and other gases from escaping. To kill microbes, the researchers loaded the hollow nanotubes with carvacrol – an antibacterial essential oil found in thyme and oregano.
During trials, tomatoes, bananas and chicken showed less bacterial growth and better preservation that control foods wrapped in plain polyethylene film. However, moving the film from the lab to the retail shelves will require some additional work, according to Ünal. Her team will now need to test the new film to make sure it is safe and nontoxic. What other uses might there be for a packaging film that prevents spoilage?