Stop Smelling Sour Milk! New Tags Tell You When Food Has Gone Bad

1 comments



Imagine not having to rely on the often faulty sniff test to determine when it’s time to pour milk down the sink. Itty-bitty gel-like tags, created by Chinese researchers, promise to turn colors when food goes bad. The tags contain metallic nanorods that morph color over time — red denotes fresh food, green indicates spoiled food. The non-toxic tags are cheap to produce (about a fifth of a penny per tag) and pose no known safety concerns, the researchers say.

Initial research focused on milk was presented at a meeting of the American Chemical Society — the tags were able to detect E. coli growth — but researchers say this technology could be applicable to other perishable food items and even medicine. Lead researcher Chao Zhang says the tags are programmed to detect ambient-temperature deterioration. So, despite the cold temperature of a refrigerated milk carton, the tag could detect if manufacturers and grocery-store employees exposed it to higher temps during packing, shipping, and/or stocking. It's these fluctuations that can lead to the overgrowth of bacteria and, ultimately, spoilage.

These tiny tags could make a huge impact on unnecessary food waste. A survey from the Food Marketing Institute found a whopping nine out of 10 Americans needlessly throw away food before it’s technically unsafe because they abide by stamped “sell by,” “use by,” and “best before” dates. With perishable items often carrying hefty price tags compared to processed foods with months-long shelf lives, we wonder if these tags could eventually help families facing food insecurity put more fresh food on the dinner table. But, it’s unclear if and when we’ll see the smart tags latched onto food items at a store near you. Zhang says the next step in commercializing them is selling manufacturers on the usefulness and accuracy of the technology. (CBS News)