Health: Colour warning for food freshness

New stick-on freshness testers could help cut rising rates of food poisoning. The revolutionary sticky labels change colour as goods reach their sell-by date and if storage conditions drop below ideal temperatures.

Store chiefs say the labels help them monitor food freshness while the goods are in transit and help cooks keep tabs on whether the food is safe to eat. The labels are made up of a green ring on a yellow background; the centre circle is printed with heat-sensitive ink which changes from yellow to dark green over time and with rises in temperature. By the time the centre circle becomes darker than the surrounding green ring the product should have been eaten. Tesco is trying out the labels behind the scenes and Sainsbury's has introduced them on some meats and on Rogan Josh ready meals. Both stores plan to expand the range if it proves popular with customers.