Smart label can indicate product freshness, says developers

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By Jane Byrne, 11-Feb-2009

A ‘smart’ barcode for food packaging can inform consumers and retailers whether refrigerated food products such as chicken, milk and beef are no longer fresh, says the development team.

Smart packaging including freshness and time-temperature indicators (TTIs) for use in supply chains for foods that are highly temperature sensitive is a growing trend.

The University of Rhode Island (URI) said the system was developed by a partnership of two URI chemistry professors and the food safety company, SIRA Technologies.

Invisible ink

According to the development team, the barcode label is based on the employment of an ink that is nearly invisible, but which turns red when the food is contaminated, with the change in colour on the barcode preventing the product from being scanned at the checkout counter.

The labelling thus establishes an irreversible, untamperable, archived signal in any applicable database, claims the team.

Project history

URI researchers, Brett Lucht and William Euler, explained that they began studying thermochromic pigments, those that change colour at certain temperatures, a decade ago when a cookware company sought a polymer that could be added to its products to make them change colour when they were too hot to touch.

They added that they later modified their discovery into an irreversible polymer – one that does not revert to its original colour after changing - and this appealed to SIRA Technologies in terms of its potential for food safety.


While there are other thermochromic indicators on the market, said Lucht, they are expensive and they lack the archival feature required by regulatory agencies to track and trace products on a global scale.

He said that this new colour changing barcode is cost effective at four cents per label.

Intelligent packaging drivers

Smart packaging, in particular electronic labelling, will provide added value packaging to enable food and drink companies enhance their existing brands with multiple promotion, safety, security and entertainment features, claims consultancy IDTechex.

The company predicts that e-labels and associated e-packaging will become a new growth market, with strong demand for electronic labels that present information more clearly.

Peter Harrop, IDTechex chairman, said that printed electronics are also emerging that will engage more of the human senses: “Future labels will be able to sense when a consumer is near and emit an aroma such as coffee to encourage them to purchase the product.”

He added that the next generation printed electronics will also include reusable, reconfigurable and programmable labels, some of which are responsive and interactive such as moving colour pictures.

Mass usage needed

However, Harrop notes that e-labels will only succeed if economy of scale is achieved by defining standard products acceptable across many applications and industries and if most people can use them, from children to the sick and elderly: “Otherwise the price of the e-labels will be too high for mass usage.”

IDTechex is carrying out research into this new technology in order to establish common needs across industries, gain economy of scale and make the products affordable, he added.



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