Two chemistry professors at the University of Rhode Island and a food safety company may have found a way for packaging to alert consumers that the product inside may be spoiled.
SIRA Technologies created barcodes for use on refrigerated food products that will incorporate an ink that is invisible. That is, until conditions change.
If a package of meat was exposed to warm temperatures for example, the ink will turn red and the barcode will be rendered incapable of transmitting data when scanned.
The University professors developed the polymer that is added to the barcode ink to make it change colour. They began studying thermochromic pigments – those that change colour at certain temperatures – a decade ago.
It wasn’t until they modified their discovery into an irreversible polymer – one that does not revert to its original colour after changing – that SIRA Technologies took notice.
The researchers say that other thermochromic indicators are commercially available, but that they are expensive and lack the archival feature required by regulatory agencies to track and trace products on a global scale.
They also rely on human examination to judge whether the product has been rendered unsafe for consumption.
The ink is now trademarked and patented as The Food Sentinel System.