Active and Intelligent Packaging: The Saga Continues

From Campden & Chorleywood Food Research Association Group in the United Kingdom (www.Campden.co.uk) comes another update in the crescendo of active and intelligent packaging. Those who attended the organization’s Fall 2002 biannual event were educated and titillated with glimpses of progress and a potential future.

Aside from my after-dinner keynote address, an array of 20 or so experts overwhelmed a largely European audience with facts, data, conclusions, speculations, and dreams.

Antimicrobial Package Materials
Joe Hotchkiss of Cornell University presented an overview of antimicrobial package materials intended to inhibit, reduce, stop growth of, or inactivate microorganisms in packaged foods. Antimicrobial package materials may be classified as migrating, adsorptive, regenerating, and non-migrating.

Migrating compounds have been discussed, tested, and written about, but how might compounds that do not move from the package material to the food function? Obviously, non-migrating compounds would be long acting, not affect the food itself, and be less subject to regulatory concerns.

Hotchkiss described formation of surface-modified chitosan-grafted polyester, quaternary ammonium polymer salts covalently attached, and peptides as capable of antimicrobial activity in liquids in contact, especially those undergoing forced convection during normal distribution. The peptides have been immobilized on plastic polymer surfaces to produce antimicrobial activity on the contacted food. Up to a 3-log kill of pathogens such as Escherichia coli O157:H7 has been reported.

Regeneratable antimicrobial polymers may oxidize to the form P–C=O attached to hydrantoin that reacts with chlorine to form chloramines to release (antimicrobial) chlorine over time in a reversible reaction. The surface would be cleaned with a chlorine solution to regenerate the antimicrobial system in the polymer.

Active Packaging Technologies
Andrew Scully of Food Science Australia, West Ryde, N.S.W., suggested some fascinating active packaging technologies being studied in that faraway region: sulfur dioxide release, ethylene scavenging, and visible tamper evidence, all in addition to an update on the ever-popular on-demand ZerO₂ oxygen scavenging technology entering the market.

• SO₂ Release. Although not applauded by regulatory authorities because of its allergic reactivity, SO₂ is an effective antimycotic desired by grape-growing and marketing interests to prolong shelf life. SO₂ gas may be released from a new fiberboard package material structure containing an organic acid plus a calcium sulfite layer. In the presence of water vapor, SO₂ is formed on a continuous basis.

• Ethylene Scavenging. Traditional potassium permanganate absorbed on carriers in pouches has been applied for years to fresh produce pallets to remove excess respiratory and environmental ethylene to extend shelf life. The Australian group has incorporated ethylene-specific tetrazine compounds. Within hours, ethylene is effectively removed from the headspaces.

• Tamper Evidence. The Australian group has developed a technology for flexible packaging that causes a major large-diameter physical color change on the surface—with even a pin prick. The highlighted visibility is claimed to alert consumers to overt or accidental damage that may have compromised package integrity.

Radio Frequency Identification
Colin Bravington of Omron Electronics Ltd., London, U.K., discussed the emerging field of radiofrequency identification (RFID) and its potential for food and its packaging. The future of intelligent packaging, he asserted, lies with the silicon chip and computer technology—the RFID tag. Incorporating an RFID tag into the body of a package or on its label creates a “truly intelligent” package.

The RFID tag provides a mobile database moving with the product and carrying potentially all details needed about the product and its history. The availability of the tag and its database opens up a new vista of opportunities for all participants in the extended supply chain from raw material supplier to the consumer. It also provides a positive means of knowing where the product is, has been, and potentially where it is going. Traceability becomes an inherent benefit of the RFID tag.

• Active vs Passive RFID. Applications to date have been based on active tag technology, in which the tags are self-powering. In recent years, there has been an explosion of development work on a lower-cost passive RFID technology. In these cases, the tags are powered by the same radio frequency that is used as the means of communication with the tag. Today, the greatest developments are taking place in the field of low-cost disposable tags, with the ability to tag all items individually and at a competitive cost.

Passive RFID technology consists of a combination of an RFID tag, a read/write antenna, and a computer system that can manage the data that are written to or read from the tag. This computer system can be a handheld PDA, a link to a network or the Internet, or a control system. In general, the RFID tag consists of a silicon chip mounted on a film and linked to a small circuit that forms the tags’ local antenna.

The read/write antenna can occur in many different formats. In manufacturing, it may be a small electronic device mounted on a production line; in a warehouse, it may be vehicle-mounted or a plug-in option on a PDA. It could also be a portal-style reader, where the packaged item is sensed as it passes through. These portal antennas may also be used at the entry and exit bays of a distribution facility. In retail, the antenna may be in the form of a gateway.

When an RFID tag is present in the radio frequency field created by the antenna, the tag chip is switched on, so that data can flow between the tag and the antenna. The data controller may simply read specific data from the tag or update the data stored on the tag. Through the connection to the system, the data can be used for management purposes.

RFID tags can be used at different frequencies, each with its own advantages in terms of interference, sensing distance, and effectiveness in various environments. In North America, the 868/900 MHz frequency range appears to be preferred.

• Standards. Standards are important for universal use of RFID tags. The expectation is that any tagged item will be read by whoever’s equipment is installed at the many locations it may pass through during its passage through the supply chain. A tag meeting a standard can be read anywhere in the world by an antenna/controller system that also meets this standard.

• Displacement of Bar Codes. Bar codes can be used to drive a computer-based database, but this may not be sufficiently reliable, given the problems that have been experienced with bar codes on food packages. The RFID tag has significant advantage over these alternatives in traceability. As a mobile database accompanying the product, it can be read without requiring line of sight; bulk reading is possible on pallets; and it can be readily updated if required. But by far the greatest advantage for traceability is that the database can be read from the tag locally without requiring reference to a remote database. The exclusion of the retailer-to-consumer stage at present supports the use of RFID tags for case or returnable crate tagging in the rest of the supply chain because individual item tagging would not be required to meet the needs of traceability.

• Process Applications. Tagging of items in a processing/packaging operation provides the basic traceability that supports the foundations of manufacturing implementation systems, delivering to management the information to control and understand operations in detail.

From the moment that products have been manufactured, RFID tags will enable information to be encoded directly onto containers that will transport the products through the supply chain. This information can include product identification codes and special instructions. The automated bulk reading of RFID tags using RFID portal readers can then enable fast and accurate inventory management within the entire distribution system.

• Retail Applications. Modern retailers require accurate product data, especially if the products are fast moving, high value, or have a short shelf life. RFID portal readers enable fast, accurate, and efficient automatic bulk reading of products or containers. This enables warehouse staff to speed the receiving process by eliminating manual checking of deliveries, and also provides improved stock management by ensuring that products with a short shelf life are taken to the retail sales environment in the correct order. Ultimately it could be anticipated that individual-item intelligent packaging could extend these advantages into the retail space. Consumers may first see the benefits at the retail checkout. There, the multiple auto scan gate can read all the products selected in the store, verify the payment details from the customer, and produce a receipt.

• In-Home Applications. Internet-linked refrigerators and freezers can allow the user to record what is in the appliance and to reorder online each time a product is consumed. In the future, these appliances can be fitted with RFID antennas that will read the contents of the refrigerator and freezer and the use-by dates. The integral computer system (or possibly a home networked computer) will be able to construct a weekly shopping list based on the contents of the appliance, recommend tonight’s recipe, and advise when something should be used quickly or thrown away.

When the consumer has removed the meal or fresh soup from the refrigerator and placed it in the microwave oven of the future, it will read the cooking instructions on the tag and automatically set the cooking power to ensure that the meat is cooked correctly and for the right length of time to ensure safe consumption.

• Supply Chain Applications. Management of the supply chain is an increasingly important function for major retailers. The ability to speed or delay the shipment of goods from the manufacturer to the retailer has become an essential operational function in efficiently matching supply and demand. To achieve this function, good-quality and accurate data acquisition is required, without increasing costs or processing time within the distribution process. An RFID system can significantly improve data acquisition by providing efficient automatic bulk identification of products or containers at strategic points throughout the supply chain.

Distribution centers are busy environments that can benefit from automated processes. RFID portal readers enable the accurate and efficient automatic bulk reading of products or containers, in both the receiving and shipping areas. These benefits include improved unloading and loading times of transportation vehicles, the elimination of time-consuming manual scanning associated with other identification systems such as bar codes, and the flexibility of being able to automatically update or change vital information contained within the RFID tags.

RFID tag prices will continue to fall as they have done over the past few years. Costs have not fallen as quickly as had been anticipated, but this may be due to the slower take-up of RFID tag technology by retailers and the supply chain rather than to the technology’s not developing quickly enough. The fact is that RFID tag price has a major influence on the potential to really deliver item-level intelligent packaging.

The most significant feature and maybe most awe-inspiring future will be active shelf antennas in retail supermarkets. These will be able to collect data about the consumer’s behavior when selecting a product—and enable the marketer to use it.

• An Incredible Future. What an incredible future intelligent packaging is forging! Will Big Brother be watching us? Will food industry professionals use the data to enhance customer service? Whatever happens, will happen on packaging.

by AARON L. BRODY
Contributing Editor
President and CEO, Packaging/Brody, Inc.
Duluth, Ga.