NEWS: Low cost dynamic food spoilage sensor on the shelf in ‘three years’


Academics at Imperial College London, have developed low-cost, smartphone-linked, eco-friendly spoilage sensors for meat and fish packaging.These sensors are cheap enough that the developers hope supermarkets could be using them within three years,according to Dr Firat Güder, head of the college’s Department of Bioengineering.

Studies show one in three UK consumers throw away food solely because it reaches the use-by date, but 60% (4.2million tonnes) of the £12.5 billion-value of food thrown away each year is safe to eat.

These new laboratory prototype sensors cost two US cents each to make, says the development team. Known as ‘paper-based electrical gas sensors’ (PEGS), they detect spoilage gases like ammonia and trimethylamine in meat and fish products.

The sensor data can be read by smartphones, so that people can hold their phone up to the packaging to see whether the food is safe to eat. PEGS are made of carbon electrodes printed on to readily available cellulose paper.

Dr Güder explains that the materials are biodegradable and non toxic, so they don’t harm the environment and are safe to use in food packaging. The sensors are combined with Near Field Communication (NFC)’ tags – that can be read by nearby mobile devices.

During laboratory testing on packaged fish and chicken, PEGS picked up trace amounts of spoilage gases quickly and more accurately than existing sensors, at a fraction of the cost.The researchers say the sensors could also eventually replace the ‘use-by’ date – which is a far less reliable indicator of freshness and edibility.

Dr Güder said: “Although they’re designed to keep us safe, use-by dates can lead to edible food being thrown away. In fact, use-by dates are not completely reliable in terms of safety, as people often get sick from food borne diseases due to poor storage, even when an item is within its use-by date.”

Once on the market, these sensors could help retailers identify how fresh their meat and fish products are and dynamically price them accordingly. This could lead to more sophisticated dynamic pricing as food begins to turn, but is still safe to eat, but sells at a discount. Or it can offer the opportunity to sell the freshest products at full price as they arrive at the store.