FOODS - Knowing whether food has spoiled without even opening the container

A color-coded smart tag could tell consumers whether milk has turned sour or green beans have spoiled without opening the containers, say researchers. The tag, appearing on the packaging, also could be used to determine if medications and other perishable products were still active or fresh ...

http://www.sciencedaily.com/releases/2014/03/140317170638.ht