To make the work simpler, MIT trained a machine learning system to recognize the difference between pure and impure materials and provide a verdict.

RFIQ isn't ready for the grocery store yet. There's a wide variety of containers and other packaging out there, and the scientists want to produce technology sufficiently generalized that it could work with everything from a pickle jar to a package of bacon. The appeal is obvious if it a more universal technology becomes available, though. You'd know whether or not to toss out that old foodstuff without having to sniff or taste it, and grocery stores would be more likely to pull contaminated products before they reach customers.