Active Packaging Solution: Where the Action Is

Hormel’s Party Tray has pre-cut meats and cheeses, which rapidly lose color or fade in the presence of oxygen. They’re kept fresh in pouches incorporating Cryovac’s Freshness Plus oxygen scavenging film.

The trends toward natural and organic foods and products featuring heart-healthy but oxygen-sensitive unsaturated fats have combined to fuel development of active packaging solutions in flexible and rigid formats.

Active packaging interacts chemically with the food inside the package to safeguard against product degradation from exposure to oxygen and/or moisture. By using active packaging, processors can increase shelf life, protect flavor profiles and maintain the food’s appearance and texture — all without adding preservatives to the product formulation.

“We’re trying to offer the processors another option for protecting their products by putting more of the burden on the package,” says Scott Beckwith, manager of new business development with Sealed Air’s Cryovac Food Packaging (www.sealedair.com), Duncan, S.C. The goal is packaging that provides protection throughout the life of the product.

A family of active packaging materials called Cryovac Freshness Plus, which were designed to maximize freshness, flavor and product appearance, act to prevent mold growth and preserve food color.

This family of flexible packaging materials includes an oxygen scavenging film, an active barrier film that binds oxygen inside the packaging material and an odor scavenging film. The materials can be used for pouches and lidding.

Product applications for the oxygen scavenging film include products packed using modified atmosphere packaging. Applications include fresh pasta and processed meats. Cryovac currently is testing this film on bakery products.

Hormel Foods Corp. (www.hormel.com), Austin, Minn., uses Freshness Plus Oxygen Scavenging film to package pepperoni and hard salami in pouches that are packed with other products into a rigid plastic package and merchandised as the Hormel Party Tray. Both types of meat rapidly lose color or fade in the presence of oxygen, and the active packaging protects against this undesirable effect.

The oxygen scavenging film can be used to extend shelf life, as well — sometimes significantly. Shelf life for Nestlé’s Buitoni fresh pasta was extended by almost 50 percent using Freshness Plus oxygen scavenging film lidding on the pasta trays.

For its active barrier films, which have not yet been commercialized, Cryovac uses the same polymeric oxygen scavenging technology but incorporates it into the barrier portion of a multilayer film. The films are compatible with vacuum packaging and suitable for products with little head space.

With many standard passive-barrier films, “Oxygen can migrate through them over time. By incorporating the oxygen scavenging capability, our active barrier films provide an improvement over the passive barrier,” Beckwith explains.

Applications for the active barrier films include processed meats as well as products containing the unsaturated fats used in health-oriented products. Because unsaturated fats are more oxygen-sensitive than saturated fats, heavy-duty protection against oxidative degradation is essential.

An additional benefit of active packaging for products containing unsaturated fats is the ability to eliminate antioxidants from the product formulation without endangering shelf life or flavor. Fewer ingredients in the product translate into a shorter ingredients list, or a cleaner label.

Regarding the active barrier films, “We’re really trying to tailor them to less processed, natural, organic, cleaner-label products,” as well as heart-healthy and trans fat-free foods, Beckwith says.

For meat products, Cryovac’s odor scavenging film provides the key benefit of protecting the aroma profile. This film scavenges the small volatiles produced as food ages — volatiles that generate confined or off odors. The film essentially pulls the odors out of the package to extend product freshness. All applications for this film have been meats; processed meats are commercially available in the packaging, and fresh meats are being tested.

Built-in activity

Incorporating active chemistries into package materials and structures has been a research focus for the packaging industry for years, but it appears to be picking up steam. Bob Sabdo, business development leader for food & beverage packaging at Multisorb Technologies (www.multisorb.com), Buffalo, N.Y., describes it as the “the trend toward building the active packaging technology right into the structure, whether you fit it into a component so it’s restricted in its movement or actually built into a film or into a resin for a bottle wall.”

This contrasts with the conventional approach of dropping an oxygen scavenging sachet into the package with the product. Eliminating that extra piece eliminates consumer questions about the sachets as well as a step on the packaging line.

Cryovac’s Freshness Plus is a family of active packaging materials designed to maximize freshness, flavor and product appearance. They include an oxygen scavenging film, an active barrier film that binds oxygen inside the packaging material and an odor scavenging film. The materials can be used for pouches and lidding.

Multisorb’s FreshBlend system incorporates iron-based oxygen scavenging technology into polyester resin. The resin is compounded specifically for each application, and it can be used in molded, sheeted, thermoformed or film packaging applications.

In some cases, the oxygen scavenging resin makes it possible to replace a multilayer structure with monolayer packaging, which delivers the benefit of lower materials costs and easier recyclability. The resin also could enable use of thinner gauge materials or be used to replace passive-barrier materials.

FreshBlend materials have a relatively high reactivity with permeating oxygen, which provides protection against oxidative degradation and extends product shelf life. The materials can be customized to meet individual product demands depending on packaging format and product preservation requirements.

Another approach, the FreshCard oxygen absorbing card from Multisorb, offers a different way to merge active packaging functionality with package structure. The FreshCard is a flat multilayer card enclosing an oxygen absorbing component. By controlling oxidative chemical reactions, the FreshCard lets food products retain their natural color, flavor, and nutrients while foiling growth of organisms that cause spoilage.

The card may be slipped into a package as a discrete (and discreet) item — or it can double as a supportive structural element of the package. For additional functionality, the card may be printed with a coupon, promotional information, recipes or cooking instructions.

According to the Multisorb, the card reduces and maintains oxygen levels inside food packages to less than 0.01 percent. Yet the card does not provoke the same consumer concerns about safety, because it looks like a standard packaging component or insert.

“The consumer would probably not even know the FreshCard is active packaging unless ‘Do Not Consume’ was printed on the package,” Sabdo says.