In order to help discover spoilage(变质)and reduce food waste for supermarkets and consumers, researchers have developed new low-cost, smart phone-linked, eco-friendly spoilage sensors for meat and fish packaging.
One in three UK consumers throw away food just because it reaches the use-by date(保存期),but 60% (4.2 million tonnes) of the £12.5 billion-worth of food we throw away each year is safe to eat.
The researchers, whose findings were published in ACS Sensors, say the sensors could also eventually replace the use-by date-a widely used indicator of being fresh and eatable.
The sensors cost two US cents each to make. Known as "paper-based electrical gas sensors(PEGS)", they detect spoilage gases like ammonia (a poisonous gas with a strong unpleasant smell) in meat and fish products. The information provided by the electronic nose is received by a smart phone, and then you can know whether the food is fresh and safe to eat.
The Imperial College London researchers who developed PEGS made the sensors by printing carbon electrodes(电极)onto a special type of paper. The materials are eco-friendly and harmless, so they don't damage the environment and are safe to use in food packaging. The sensors, combined with a tiny electronic system, then inform nearby mobile devices, which identify and understand the data about spoilage gases.
Lead author Dr Firat Guder, of Imperial's Department of Bioengineering, said"Although they're designed to keep us safe, use-by dates can lead to eatable food being thrown away. They don't always reflect its actual freshness. In fact, people often get sick from foodborne diseases due to poor storage, even when an item is within its use-by date. These sensors are cheap enough so we hope to see supermarkets using them within three years. Our goal is to use PEGS in food packaging to reduce unnecessary food waste."
The authors hope that PEGS could have applications beyond food processing, like sensing chemicals in agriculture, air quality, and detecting disease markers in breath like those involved in kidney disease.