A new ‘smart pack’ keeps food fresher for longer by slowly releasing antimicrobials to kill E. coli and Salmonella

Researchers from Harvard and the Nanyang Technological University developed a waterproof transparent package. The new packaging material can serve as an environmentally friendly alternative to petroleum-based polymers, which can have a significant adverse environmental impact. The smart release of antimicrobials occurs when bacteria or high humidity is present. It provides protection only when needed, thus minimizing the use of chemicals and preserving the natural composition of packaged foods. The package demonstrated superior antimicrobial qualities in combating various food-related bacteria and fungi. The smart packaging material is made via electrospinning, in which charged threads of polymer solution are drawn out into fibers. The main ingredient for the material is a type of corn protein called 'zein' — a waste by-product in the production of ethanol from corn starch or oils. The researchers added the plant starch cellulose and acetic acid. The team infused these with a cocktail of natural antimicrobial compounds derived from plants, including thyme oil and citric acid. In laboratory tests, the team was able to show that the antimicrobials are released in minuscule amounts from the fibers in the packaging material when exposed to either a rise in humidity or certain enzymes released by harmful bacteria. @ https://www.dailymail.co.uk/sciencetech/article-10355721/amp/Tech-Smart-pack-keeps-food-fresh-longer-releasing-antimicrobials-kill-harmful-bugs.html