Is Something Fishy About Packaging?

An unexpectedly large number of seafood experts from around the world gathered at the National Fisheries Institute’s conference on Technical Innovations in Seafood Products and Processing, held in Orlando, Fla., on February 11–14.

Jammed into a space reminiscent of a fish pen, these professionals from industry, government, and academia, as well as suppliers and consultants, orated, droned, spoke, and pointed to special sites on their presentation visuals. Each suggested that his or her topic was the focus of a revolution in seafood production, harvesting, preservation, spoilage indication, quality measurement, or even consumption. A few dared to touch on packaging as a vehicle to enhance the uninspiring state of fish eating in the United States.

Sorting out the innovation from the facts and near-facts was a daunting task, especially those relatively few in the realm of packaging—so critical to the delivery of seafood products to consumers—but here is a brief discussion of the packaging-related presentations:
• Antimicrobial Compounds. Several discussions addressed antimicrobial compounds that recently surfaced as processing aids that might be incorporated into package structures to convert them into active packaging: chlorine dioxide, silver salts, bacteriocins, ozone, and natural spices such as rosemary and its derivatives.

• Spoilage Indicators. Cox Technologies, Belmont, N.C., a source of temperature loggers and of color-changing time–temperature integrators to be affixed to package surfaces, has been testing spoilage indicators called FreshTag™, which are currently in the form of rapid detection kits that measure and signal the presence of decomposition volatile bases such as ammonia, trimethylamine, and dimethylamine. The company has been working on devices that might be affixed to package surfaces to measure and portray internal content spoilage. To date, results have been promising, but not yet commercial, for shrimp, scallops, and coldwater fresh fish, but not for fatty fish such as salmon or tuna.

Related is Toxin Alert™, a spoilage indicator being developed by a Canadian company of that name in Mississauga, Ont., Canada. The principle is that antibodies specific to pathogenic microorganisms react to produce a colorimetric or fluorometric response. Primary antibodies are encapsulated on the interior surface of the packaging material, and colored secondary antibodies are overlaid on the capsule interior. The entire antibody structure is flexographically printed on the base plastic film within a microbiologically porous material constituting the surface facing the food in the package. The spoilage or pathogenic microorganism passes through the porous material into the capsule and binds to the secondary antibody. The secondary antibody binds to the primary antibody and signals by the presence of color any adverse microbiological problem. The system depends on liquid from the interior containing a relatively high microbiological count in contact with the print surface. The system is real time, meaning that no sampling or waiting is required.

• Time–Temperature Integrators. Modified-atmosphere packaging and its subcategory, reduced-oxygen packaging, have been demonstrated to better retain seafood quality and retard spoilage than conventional refrigeration. Unfortunately, under reduced oxygen conditions, anaerobic clostridia are capable of growth and even toxin production without signaling spoilage, although some recent data tend to refute this allegation. Even regulatory officials have recently permitted commercial reduced-oxygen packaging of seafood under tight controls. Among these controls might be the inclusion of time–temperature integrators that signal abuse on package surfaces.

The University of Florida’s Steven Otwell and other faculty and graduate students evaluated the Vitsab® time–temperature integrator for use in modified-atmosphere packaging of seafood. Results demonstrated that the color change from enzyme-based Vitsab labels correlates to spoilage of packaged salmon and other fish. The labels change color before the toxin formation. Furthermore, the Vitsab indicator reflects the experience of the contents within the package.

• Incidence of Anaerobic Pathogens in Seafood. Otwell stated that the incidence of Clostridium botulinum type E was measured as much lower in nature than suggested in prior studies that had presented very bleak microbiological scenarios for reduced-oxygen packaging of seafood.

• Preferred Quality. Another of Otwell’s propositions is that seafood and other food quality could be described by the term “preferred quality.” Rather than use metrics of “shelf life,” hedonic score or “absence of spoilage,” the new term reflects consumer preference for the product over alternative product conditions. It is fascinating to regard consumers as being capable of judging the quality of the foods they are purchasing and eating. And the concept would be applicable to all foods, including prepared and precooked.

• Oxygen Scavengers. Ciba Specialty Chemicals, Tarrytown, N.Y., recently acquired some of the oxygen-scavenging assets of BP Amoco Chemicals and is marketing them under the ShelfPlus™ trade name. Ciba’s offerings are the ferrous iron–based materials intended for incorporation into plastic package structures. Removal of oxygen from package interiors improves shelf life by sub-optimizing the environment for aerobic microbiological growth and for adverse oxidative reactions such as rancidity. Ferrous iron–based oxygen scavengers rely on the presence of moisture for activation, with a water activity of 0.7 required, and 0.85–0.9 being preferred. Obviously, for optimum performance, oxygen should be removed from the product and package interior, and the package should be an oxygen-barrier structure.

Ciba also announced the commercial development of transparent ultraviolet radiation filters for incorporation into plastic package materials and of new anti-fog agents to foster the transparency of films on which moisture can condense.

• Edible Films. A representative from the University of Georgia’s Marine Extension Station provided a very detailed description of most of the world’s edible films in recorded history. The corn protein zein is used commercially on the surface of raisins to retard moisture transfer into dry cereals they are blended with, and on gummy bears and licorice. One major quick-service restaurant chain has been using a pectin/calcium/breading coating on its French-fried potatoes to reduce oil uptake and to enhance the mouthfeel of the finished product. Methyl cellulose and hydroxypropyl cellulose reduce uptake of fat in frying, so important to the preparation of many seafood products. Alginates reduce moisture loss from fish, and palmitates reduce moisture loss from frozen fish. Other edible films demonstrated to reduce moisture transfer, especially out of frozen fish, include whey protein isolates, coconut oil, and acetylated mono-and diglycerides.

• Thermally Processed Seafoods. Despite the recent introduction of tuna in retort pouches, relatively little attention was paid to ambient-temperature shelf-stable or pasteurized extended-refrigerated-shelf-life seafoods. From Scotland came an intriguing technology called VaporVac™ in which a seafood product such as soup is pasteurized, hot filled into plastic cans, hermetically sealed, and chilled in ice and water prior to refrigerated distribution of up to 90 days. The plastic can has a metal closure and snap overcap reclosure, and is claimed to be microwavable.

The technology is a minimal process, not unlike many in the contemporary chilled distribution marketplace, such as standup flexible pouches of soups and sauces and multilayer barrier plastic trays with flexible lidding. An interesting feature is the use of transparent plastic cans not too different from those used for pasteurized oysters in the U.S. Obviously, one issue is the potential for anaerobic pathogenic microbiological growth, since aerobic spoilage microorganisms have been destroyed. That concern was in part addressed by the findings from the University of Florida discussed above, but their data still suggest great caution in applying this or any other analogous technology on a commercial scale.

Seafood consumption has not been increasing in the U.S. for decades. Seafood sourcing has been gradually shifting from harvesting the depleted stocks in the natural waters to farming shrimp, salmon, and many other species. Frozen seafood has not represented a growth category. Ionizing radiation is being seriously considered as a means to increase microbiological safety and to enhance chilled distribution of both raw and prepared fish.

Any true increments in seafood consumption will be driven, however, by adding value to the raw material. Value is not merely in gutting, trimming, and cleaning but in striving for ready-to-eat or ready-to-heat-and-eat with all of the accompaniments of sauces and toppings. And these innovations will have to be supported by packaging that incorporates convenience, just as is offered by many minimally processed prepared foods.

The conference (which included an excellent forum on the technology of food irradiation) brushed some of the core value-added propositions. Attention to the historical problems of spoilage and its rapid measurement throughout the event did not, however, focus on the imperative to address the reasons and solutions to increase seafood consumption—it is just no fun to handle and prepare seafood. Sushi in Bento boxes is one of the many imaginative offerings from Japan, where seafood is a major food and much easier on the eye, nose, hand, and palate than frozen blocks of fillets packaged in waxed-paper-wrapped, solid bleached paperboard cartons and requiring odoriferous preparation.

Processors/packagers must leap over raw fish when assessing how to deliver seafood to real live consumers. That might be the theme for the organizers of their next seafood technical innovations event.

PRODUCTS & LITERATURE
Aseptically Packaged Soy Beverages are being marketed in single-serve packages by Oregon Chai and the Hain Celestial Group. Tea lattes, in Original Chai and Kashmir Green Tea flavors are made of tea and spices plus soy, instead of espresso. Positioned somewhere between a breakfast beverage and a health drink, the ready-to-drink products require a package that protects the flavor of the beverage and provides a branding tool. Soy ingredients require extra protection in beverages.

The 330-mL packages’ unique shape and metallic surface are used to differentiate the soy latte on the shelf.

The Hain Celestial Group also used aseptic packages for its single-serve Westsoy Singles™ line of soy-and-rice-based fruit beverage products and tea-based Westsoy Chai products. The wedge-shaped package is made from paper fiber, and measures 5.25 in tall, 3 in wide at the top, and 2 in wide at the bottom. It is made from roll-fed stock, and is packaged at the rate of about 6,000/hr.

Oregon Chai uses the Tetra Prisma Aseptic package, and Hain Celestial uses the Tetra Wedge 200S aseptic package with a Tubex straw applicator. The aseptically packaged beverages can be distributed at ambient temperatures and sold from a refrigerated display if desired. No preservatives are used in the beverage, so aseptic packaging is essential.

For information about these and other packaging products, contact Tetra Pak Americas Inc., 1100 Peachtree St., Atlanta, GA 30309 (phone 404-815-3400, fax 404-815-3399, www.tetrapak.com—or circle 315.

by AARON L. BRODY
Contributing Editor