University of Rhode Island chemistry professors Brett Lucht and Bill Euler discovered that a certain color pigment mixed with ink would change when temperatures got too hot.
The two professors patented the pigment because they found that the ink would change colors when exposed to certain temperatures. So if a product like packaged meat is exposed to warm temperature, the bar code would change colors letting the consumer know that product might be questionable.
Professor Lucht says, "We had to design the pigment so that not only would it change colors irreversibly at 40 degrees Fahrenheit, or refrigerator temperatures, but that it would do so over a period of time after being removed from the refrigerator".
When the packaged meat product is handled at the proper temperature, the bar code will look normal. However, Lucht says, if it hasn't been handled properly, "These two bars change and this makes the bottom bar code not readable any longer, and the top bar code becomes readable, so when you scan this at the checkout counter, instead what it comes up with is: error, bad product".
URI holds the patents, and now has an exclusive licensing agreement with a company that specializes in food safety products called "Sira Technologies". Marketing is already underway, so we should be seeing more about this, commercially, very soon.