Home Invention Food freshness sensors could replace ‘use-by’ dates to cut food waste

Food freshness sensors could replace ‘use-by’ dates to cut food waste

Imperial academics have developed low-cost, smartphone-linked, eco-friendly spoilage sensors for meat and fish packaging.

Food waste is a major global problem with substantial economic and environmental consequences. 30% of all food produced for human consumption (∼1.3 billion tons) is thrown away each year. Although this number arises from various inefficiencies throughout the entire supply chain, food waste by consumers is a major contributor.

One in three UK consumers throw away food solely because it reaches the use-by date, but sixty percent (4.2million tonnes) of the £12.5 billion-worth of food we throw away each year is safe to eat.

This problem could be solved, thanks to a new sensor developed by Imperial Academics. Scientists have developed low-cost, smartphone-linked, eco-friendly spoilage sensors for meat and fish packaging.

Dubbed as ‘paper-based electrical gas sensors’ (PEGS), the sensor could detect spoilage gases like ammonia and trimethylamine in meat and fish products.

PEGS are made of carbon electrodes printed onto readily available cellulose paper.
PEGS are made of carbon electrodes printed onto readily available cellulose paper.

The materials used for the sensors are biodegradable, non-toxic and eco- friendly. Combined with NFC tags, the sensor can be read by nearby mobile devices.

When tested, the sensor precisely detected amounts of spoilage gases quickly than existing sensors.

Scientists noted, “the sensors could also eventually replace the ‘use-by’ date – a less reliable indicator of freshness and edibility. Lower costs for retailers may also eventually lower the cost of food for consumers.”

Dr Firat Güder’s team at Imperial’s Department of Bioengineering 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 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.”

The first author of the study Giandrin Barandun, also from Imperial’s Department of Bioengineering, said: “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.”

Because PEGS work on high-value items like meat and fish, they could save money for shops and their customers, by reducing waste and by enabling shops to use targeted price reduction for specific items based on PEGS rather than use-by dates.

The authors hope that PEGS could have applications beyond food processing, like sensing chemicals in agriculture, air quality, and detecting disease markers in a breath like those involved in kidney disease. However, before they can be applied beyond their current use, the researchers will address how sensitive PEGS are to lower humidity.

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