Thursday, 13 Jun 2019 11:23 GMT

Printed paper sensors could reduce food waste

Academics at Imperial College London have developed a low-cost, smartphone-linked and eco-friendly packaging solution for identifying out-of-date meat and fish.

Researchers say that their new sensors for food packaging could help to detect spoilage and reduce food waste. The paper-based electrical gas sensors, or PEGS, detect spoilage gasses like ammonia and trimethylamine in meat and fish products.

Data from the sensor can be read by smartphones so that people can check with their phone whether the food is safe to eat.

PEGS were created by printing carbon electrodes onto readily available cellulose paper and combined with NFC (near-field communication) tags that can be read by mobile devices when in close proximity.

Lab tests found that the sensors could detect trace amounts of spoilage gases in packaged fish and chicken much quicker than existing sensors, and at a fraction of the price. Researchers say the sensors cost two U.S cents to make.

The sensors are made of carbon electrodes printed onto cellulose paper.

Photo: Imperial College London

Lead author Dr Güder of Imperial College London’s Department of Bioengineering, comments: “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 foodborne diseases due to poor storage, even when an item is within its use-by.

“Citizens want to be confident that their food is safe to eat, and to avoid throwing food away unnecessarily because they aren’t able to judge its safety. These sensors are cheap enough that we hope supermarkets could use them within three years.

“Our vision is to use PEGS in food packaging to reduce unnecessary food waste and the resulting plastic pollution.”

… it’s time to embrace technology that could more accurately detect food edibility and reduce food waste and plastic pollution

First author of the study, Giandrin Barandun, adds: “Use-by dates estimate when a perishable product might no longer be edible, but they don’t always reflect its actual freshness.

“Although the food industry – and consumers – are understandably cautious about shelf life, it’s time to embrace technology that could more accurately detect food edibility and reduce food waste and plastic pollution.”

The research team used ballpoint pens and robotic cutters to create the sensors and hope that the PEGS will one day be mass produced.

Dr Güder adds: “We believe our very simple technique could easily be scaled up to produce PEGS on a mass scale by using existing high-volume printing methods such as screen printing and roll-to-roll printing.”

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