Smart food labels can tell you when a product goes off

 Smart labels that detect when food has gone off have been invented by scientists in the US and could soon be adopted by supermarkets.

Researchers at Clarkson University have developed the new technology, which could transform the way supermarket food is sold and eaten.

Tiny sensors contain “redox active” particles which change colour when they come into contact with a wide range of chemicals and toxins in food.

When they interact with the substances, their appearance changes and the intensity of the change reveals how unsafe the food is.

One prototype label can spot ochratoxin A, a fungal toxin commonly found in cereals and coffee.

Scientists are also working on sensors which can detect salmonella and e-coli.

Professor Silvana Andreescu, of Clarkson University in New York, said: “My lab has built a versatile sensing platform that incorporates all the needed reagents for detection in a piece of paper.”