Amsterdam, Feb 28 (IANS): Millions of tonnes of food are dumped into the waste bin each year, as the "best before" date on the package has passed. Much of what is dumped might still be safe to eat. A new device could aid that eat-or-throw decision.

Researchers at Eindhoven University of Technology, (The Netherlands), Universita di Catania (Italy), CEA-Liten (France) and STMicroelectronics, one of the world's largest semiconductor companies, have invented a circuit that makes testing of food products possible through a plastic analog-digital converter.

Consumers and businesses in developed countries throw away around 100 kg of food per person per year, mainly because the "best before" date on the packaging has passed. Such wastage is bad not only for consumers' budgets, but also for the environment, an Eindhoven statement said.

Much of the wastage occurs because there is difficulty in estimating how long food will stay usable. To minimise the risk of selling spoiled food, producers show a relatively short shelf-life on the package.

The plastic sensor circuits, costing less than one euro cent, could help solve the phenomenal waste problem. These ultra-low-cost plastic circuits have numerous potential uses, including in pharmaceuticals.

To fight food waste, producers could include an electronic sensor circuit in their packaging to monitor the acidity level of the food, for example.

The sensor circuit could be read with a scanner or with a mobile phone to show the freshness of steak, or even whether frozen food was earlier defrosted.

Said researcher Eugenio Cantatore of Eindhoven University of Technology: "In principle, such testing is already possible, using the standard silicon ICs (integrated chips). The only problem is they're too expensive. They easily cost ten cents. And that cost is too much for a one-euro bag of crisps."

"We're now developing electronic devices that are made from plastic rather than silicon. The advantage is you can easily include these plastic sensors in plastic packaging."

The plastic semiconductor can even be printed on all kinds of flexible surfaces, which makes it cheaper to use.

The invention was presented last week at the International Solid-State Circuits Conference in San Francisco, US.