Scientists from the University of New South Wales, Australia, have devised a plan that claims seniors can someday predict a food’s level of freshness. The team came up with three deciding colors consisting of blue (fresh), purple (need to eat soon), and red (bad). Each sensor is made of a film-like substance that will counteract the food’s chemicals to determine its exact freshness. Similarly, a team of researchers in the UK devised their sensors that utilize smartphones which, once the bar code is scanned, will determine the food’s freshness. In addition, using this technique can do good when preserving a food’s exact expiration date.

Source Here: https://www.techtimes.com/articles/267580/20211105/food-sensors-can-tell-if-food-is-fresh-or-not.htm