Top Editors ... Intelligent and active packaging

Title: Intelligent and active packaging
Date: 29/07/2008
Autor: Claire Rowan

Awide array of packs and labels can be considered as smart packaging today as advances are made in all areas of active and intelligent packaging technology and materials, which bring additional benefits – over and above standard protection and presentation of products – to both consumers and manufacturers.
In the USA, demand for smart packaging is projected to climb by 13% annually to 2011 to reach US$1.1 billion, according to research by the Freedonia Group. The growth will be fuelled by the development of new products with improved performance as well as lower cost, which is one of the main obstacles to smart packaging development.
Significant growth – of more than 30% - is expected in the area of intelligent packaging due to the emergence of lower cost timetemperature indicator labels.
OnVu time temperature indicators (TTI), developed by Ciba Specialty Chemicals and FreshPoint (FBI June 06) using novel ink technology are now being used by Jeronimo Martins, a subsidiary of Ahold, in Portugal for its own label salads and poultry products, and a German manufacturer. UV light is targeted at the pack to activate the OnVu device, which can be supplied as an integral part of a carton or applied to packs as a separate label using conventional technology. The UV light calibrates the OnVu device according to the shelf life and optimum storage conditions of the product to be monitored, turning the device blue on activation. From that moment on, the clock begins to tick and the OnVu’s temperaturesensitive blue colour material begins to fade depending on the time lapsed and temperature experienced by the product.
“The first OnVu TTIs, designed for meat, fish and convenience products with a shelf life of 5 to 6 days at 5°C, have attracted great interest and are currently being field-tested under hands-on conditions,” said Hermann Angerer, global head of Ciba’s Coating Effects Segment. “The new generation of TTIs now allows us to offer freshness monitoring for products with a shelf life of one week or more, for example processed meat such as sausage, dairy products, ready meals and other convenience foods.”
The OnVu technology has also been extended for use throughout the supply chain with the introduction of OnVu Logistics, which allows producers and retailers to check at a glance whether perishable goods have been stored and transported correctly.
As the goods are packed, the OnVu Logistics indicator label is applied to the outer box and activated by UV light. A filter is then placed over the label to protect it from deliberate or accidental reactivation.
An intelligent label that relies on a proprietary patented microbial technology to indicate a product’s freshness has been introduced by Cryolog following extensive research and development in France. The eO is an intelligent label, which is attached to the pack in much the same way as the OnVu. It changes colour when the product is no longer fit for consumption either due to it reaching its Use By date or due to a critical accumulation of ‘ruptures’ in the cold chain, eg breaks in required temperature parameters, and is based on novel predictive microbiology and
mathematical modelling techniques. The eO label contains food grade micro-organisms, which are selected in order to match the characteristics and conditions of the foodstuff being monitored. In France, eO labels were adopted for the first time last year by the retailers Leclerc and Monoprix for sandwiches, convenience meals, and meat and poultry products; and are currently on test at Edika in Germany.
Further development of the system includes the Echo-tag temperature sensor that calculates the freshness of products in transit and transmits the information via RFID, in real time. Information is recorded into the Echo-tag and can be read remotely, with a reader scanning 25 tags per minute; or visually by use of a light on the tag itself that gives an ‘OK/check/reject’ indication of quality.

Another system that has been used to track shelf life is Timestrip technology, which has recently been improved to allow the distinctive Timestrip smart labels to be applied to standard labels and packaging.
The ‘blister button’, which is used to activate the device, can now be situated on the back or the front of the smart label. If the ‘blister button’ is situated at the front of the smart label, the reverse is left completely flat leaving it free to be stuck to standard labels and packs.
Once activated, Timestrip measures the elapsed time of the product during its life cycle – in minutes, hours, days or months, as required. A food grade liquid travels across the label at a consistent rate, giving a clear indication of the amount of time that has passed since the label was first applied or the product opened – depending on the application.

“Timestrips can now be more readily accepted into production lines and the development means we are moving forward on other packaging innovations, such as integrating labels into the lids of tubs and jars,” said Rueben Isbitsky, CEO, Timestrip.

Active Packaging
Another area of development is active packaging that can actively reduce the levels of oxygen or even reduce the microbial count within the pack.
Oxygen scavenging pads, such as Mitsubishi Gas Chemical’s Ageless device or Multisorb’s FreshPax CR (see FBI February 08 Clean Labelling) are already making inroads into the market, and oxygen absorbers can also be incorporated into the packaging itself.
Wipak Walsrode in Germany introduced its active Combitherm oxygen absorbing film a few years ago and has seen slow commercial take-up in countries such as the UK, The Netherlands, Spain, Germany and Denmark.
Besides a classic EVOH barrier layer, the Combitherm film contains an oxygen absorbing substance sandwiched between the film layers (so there is no direct food contact), which interacts specifically with oxygen, binding it irreversibly within the film layers.

“The Combitherm system is triggered by moisture (it is activated by a relative humidity of 70%),” said Reinhard Ruhland, director application services, Wipak, “We have done extensive trials with companies, and the technology is particularly valuable for sliced ham, sausages and processed meat applications where using Combitherm can prolong the shelf life of the product for as much as one year. As a result of the extension to the shelf life it can take a year to complete a shelf life test.”
Wipak is also conducting preliminary research into the use of antimicrobials that would operate in a similar way to its oxygen absorbing technology to surpress antimicrobial growth in-pack. According to a recent report from Intertech Pira entitled The Future of Global Markets for Antimicrobials in Plastics, the use of antimicrobials in packaging is a growing trend across a range of consumer products.
The Report highlights the recent work at Clemson University, USA, that has studied the favourable use of nisin to coat food packages including plastic wrap packaging for hot dogs.
Other research looks at the use of additives that produce an antimicrobial such as chlorine dioxide under different relative humidity or UV light conditions. According to Intertech Pira, the benefit of such systems is that the antimicrobials can be used to protect any product within the pack rather than just the product that comes into contact with a protective coating. The additives are currently incorporated in a sachet inside the package, although they can also be compounded into the packaging polymer.
Yet, despite their potential, such antimicrobial applications are facing a difficult legislative environment, which varies from one EU member state to another and is likely to hamper their progress in the short term.
A new integral liquid ‘absorber’ that meets all current safety and migration legislation has been introduced by Faerch Plast for use with flowpacked, top sealed or overwrapped trays to ensure the optimal appearance of the finished product without the need for a separate ‘absorber’ pad. A tray with a base area of 225cm2 can trap and retain approximately 15ml of fluid from meat or poultry products. The surface tension traps the liquid in the recesses in the bottom of the tray and prevents unsightly products on the shelf.