Science Reporting

Food sensors will replace expiry dates in the future

In the not too distant future, sensors that precisely detect the degree of freshness of foods could replace the expiration dates on food products. Such a technology would cut sharply the enormous food waste that occurs in the world, naturally to a greater extent in the industrialized world.

Many consumers, in fact, throw perfectly healthy or not at all dangerous food in the trash just because the expiry date has been reached but a calculation reveals that 60% of the food that is thrown away in the UK alone, for example, is safe to eat. A new research group based at Imperial College London is therefore developing new sensors, incorporated into the packaging of food products themselves, at minimal cost (at the moment the cost is two cents each) that are able to detect even the smallest traces of gas that can develop from deteriorating food.

These gases can be, for example, ammonia and trimethylamine in products such as meat and fish. These paper-based electrical gas sensors (PEGs) can then be easily elected by a smartphone by simply passing the device on the packaging. Researchers have created these sensors by printing carbon electrodes on cellulose paper, making them biodegradable and non-toxic materials that are perfectly safe for food packaging.

These sensors boast small NFC microchips that can also be chosen by common mobile devices. Compared to other similar sensors already in existence, the PEGs have, during the test phases, detected small traces of gas to a better and more precise extent, according to the researchers. In addition, these new sensors work effectively even at the highest humidity levels, environmental conditions where most of them fail.