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Plastics powering packaging innovation as 'smart' containers protect and cook.

Plastics Powering Packaging Innovation As `Smart' Containers Protect and Cook

Microwave oven requirements are molding the shape of things to come. But wait just a minute, warns FDA, material migration into food may pose safety problems. Chill packs are also setting off nervous regulatory alarms.

Food packaging has come a long way in the past half-decade. Much more than a protective barrier, today's sophisticated packages do double service as actual cooking containers. Indeed, "high tech" is very much the theme as the lack of standardization in microwave ovens requires "smarter" and "smarter" containers.

"The trend is to make the product consumer-friendly with packages that are easier to open and use, recloseable, or packaged in single-serve portions," said Clay Smith, director of sales for Du Pont Company's packaged goods products division.

"We find that many of the products we've had available for major or minor industrial applications can solve problems for packaged goods marketers -- like an unrippable film for ice cream packages," he added.

Plastics have been in the forefront of the Wilmington, Del., U.S.A.-based outfit's research efforts. Du Pont is currently developing plastic packaging designed to permit different foods to cook at varying rates within a single container. The goal is to perfect a dinner tray system in which compartmentalized meat, vegetables and desserts are reconstituted separately and unequally.

Also on the drawing board, reportedly, is a breatheable microwave package that facilitates the safe escape of steam, thus reducing the danger of finger burns.

Enter Gemini

In Great Britain, the news from Metal Box is also about plastics. Its recently introduced Gemini system -- designed particularly with ice cream, fruit and vegetable containment in mind -- features 11 square and rectangular profiles. Cross sections can range from 80mm to 185mm, available at any height between 30mm and 90mm. Volume may vary from 85ml to two liters.

"Its fill can be adjusted to whatever is desired," advised Gerry Brunskill, general manager of the Worcester company's food packaging division. "And because we can adjust the base without affecting either the lid fit or the denest, Gemini and standard pots run on the same filling line.

Accurately pressure-formed plastics are used for high speed filling and precise lid fitting, Brunskill further explained. They can be made of polystyrene, ABS, PVC or even higher barrier polypropylene for aseptic packaging. Both snap-on lids and overcaps for foil seals are available.

Pre-cut blanks are printed in up to five colors and overvarnished to provide maximum protection. Finishes include foil and plastic coatings.

Meanwhile, Metal Box continues to aggressively market its Diotray high speed lidders and Diotray II erector hot air forming systems for dual-ovenable trays. Among the major frozen food brands incorporating diotrays in their lineups are Swanson Gourmet of Canada, PictSweet Express in the United States, and Rusttikale Kuche in West Germany.

Formed from plastic coated board blanks, diotrays are designed to contain both solid and liquid reheat-and-serve products. A combined inner food tray and printed outer carton simplifies the packaging process and thus reduces costs. The choice of inner materials includes polyester and other heat-seal plastic-coated boards.

MicroReady Indicator

Although in the retail market-place for a few years now, a "smart" packaging accessory worth noting again (see QFFI, April 1988, page 89, for detailed story) is ConAgra's MicroReady Indicator. Affixed to the lids of Armour Dinner Classics and Dinner Classic Lite products, the litmus strip-like material turns from white to blue when the package's food contents have been properly prepared for eating.

"The challenge is to get people to be more confident in using microwave ovens and to use them more frequently," said Scott Rahn, president of the company's Ballwin, Mo., USA-based consumer frozen foods division. "But one problem is that people overcook foods. We can't put directions on the back of every box for every oven. MicroReady Indicators take the worry out of cooking it."

But it has not been only the frozen food sector that has witnessed recent packaging advances. The controlled/modified atmosphere packaging (CAP/MAP) segment, long a factor in Europe, has been gaining momentum in North America. Almost 21 billion pounds of perishable food was industrially vacuum-packed this way in the U.S. last year, according to Schotland Business Research Inc., Princeton, N.J. Add to that an additional 1 billion pounds of product moved through an estimated 700 million packages at the retail store level, and the size of the market becomes apparent.

New controlled atmosphere packaging from Hercules, Inc., claims to double or triple the shelf life for fresh fruits and vegetables. Its trademarked Heart of the Fresh Hold system features a permeable membrane made from polymer-modified polypropylene. The printable, pressure-sensitive film, which doubles as a label, is adhered over lid holes. The microporus strip works by regulating the escape of water vapor and carbon dioxide from the package, and controlling permeation of oxygen into the container. The result is suppressed ripening of the contents as the evolution of ethylene is interrupted.

Test marketing of broccoli florets packaged in half-pound containers has been going on at Ukrop's, a small chain of supermarkets in Virginia. Shelf life extension is said to have been boosted from seven days to 17 days.

Custom membranes can reportedly be developed to house a broad array of vegetables and fruits. With an estimated 6 billion pounds of produce lost to waste and spoilage in the U.S. each year, Hercules sees a bright future for its packaging system.

Safety Concerns

But all is not well in the CAP world, as a moratorium on vacuum-packing fish remains in place in the U.S. And doubts about the wisdom of over-wrapping so-called fresh fish in supermarkets were voiced by Russ Byerly of the New England Shrimp Co. at this spring's Boston Seafood Show:

"I have some concerns about its safety because in the absence of oxygen, anaerobic pathogenic bacteria can grow. And deadly toxins kill... Too many people use wrapping techniques to extend the shelf life of an already bad piece of fish."

The consensus among many packaging people attending the National Food Processors Association convention in Anaheim, Calif., was that sooner or later the Food and Drug Administration (FDA) and U.S. Department of Agriculture will seriously begin monitoring CAP and MAP products. And Patricia Schwartz, acting director of the FDA's division of food chemistry and technology, confirmed their suspicions. But she had other worries too -- namely:

* Multi-layer plastics are raising the issue of migration of packaging materials into food. This is especially bothersome to Washington as the boom in microwave oven-compatible packaging generally results in the replacing of metal or foil with plastics.

* Susceptors. "While they come in many forms," said Schwartz, "in essence the metalized film laminate acts as a mini-frying pan inside a microwave. The migration of some susceptor components can be substantial. So we can't say that use of them is safe."

* As for metalized PET trays, FDA lab results have revealed unsettling component breakdown problems.

* Garbage. The fact that increased food packaging is adding to the nation's trash disposal crisis -- Americans throw away some three pounds of refuse per capita each day -- has also attracted the regulatory agency's attention, but that is a matter QFFI will address in detail in a future issue.

The FDA officer also noted that the increasing interest in chilled food packaging has her very concerned about the danger of foodborne microorganisms. The sous vide vacuum cooking process, she said, "could constitute an unnecessary threat to consumer safety." (See related story in QFFI, April 1989, page 93.)

The refrigerated food industry uses gas-flushing technology to extend shelf life by inhibiting the growth of spoilage bacteria. The technique facilitates certain conditions which are hostile to undesirable microorganisms. Intrinsic factors such as temperature, relative humidity and gaseous composition of environment are manipulated as much as possible in this regard.

Ideally, packers attempt to keep their products as close to or slightly above 32 [degrees] F, a temperature at which bacteria counts double every 20 hours. At 50 [degrees] F they double ever three hours.

"Food will spoil about four times as fast at 41 [degrees] F than it will at 32 [degrees] F," advised Cynthia Wilbrandt of Liquid Carbonic, Chicago, Ill. "Therefore, care must be taken that refrigerated products have a low microbial count to begin with. Otherwise minor temperature abuse can result in spoilage, or worse, a health hazard."

The U.S. chilled foods industry is still in a learning phase. "Only in the past year have I realized that we don't have oxygen under control," admitted Dick Perdue of Cryovac, a Duncan, S.C., U.S.A. manufacturer of shrink film. He pointed to Mitsubishi of Japan as a company that is on the cutting edge of MAP technology.

"Their oxygen absorbers make it possible to avoid the interjection of chemicals," said Perdue. "They're used in vacuum packaging to keep food very fresh."

The Cryovac veteran of 37 years explained that active absorbers go a long way in inhibiting mold growth, yielding a shelf life of up to three months for many products.

"They can be used with frozen foods too," he added, "especially frozen fried chicken and fish. How often do you get such products and find them to be rancid?"

So, the global competition for the non-frozen extended shelf life packaging market is heating up. And in this era of heightened consumer attention on food safety, one can expect the FDA and other like national groups to respond by broadening their scrutiny of such packaging systems.

Webber Shrink-Wrapped Ribs Defy Conventional Wisdom

Webber Farms, Inc., Cynthiana, Ky., U.S.A., found it could save 25 cents a unit by switching from vacuum packaging to shrink-wrapping for its frozen barbecued ribs for the institutional market.

The firm is using equipment from Norco Packaging Machinery, Inc., Fort Wayne, Ind., to apply polyetheylene shrink wrap to its products. Top and bottom webs are cut automatically and joined at the leading and trailing edges of each package. Top and bottom surfaces are then held smoothly against the product while shrink action is directed toward the sides, sealing the unit and compressing excess film along the sides while leaving the top and bottom clear for product visibility and graphics undistorted by stretching or shrinking.

The system allows the use of pre-printed film and hot-stamping with good registration; a side trim/seal option is available to remove excess film. Webber offered an unusual challenge in that it applies barbecue sauce to its ribs before packaging, but Norco's approach solved that problem too.

BWI Acquires Holmatic Inc. To Complement Fords Systems

Barry Wehmiller International, Inc. (BWI), a British firm specializing in the packaging machinery business, has acquired Holmatic, Inc., Norcross, Ga., U.S.A

BWI already owned Fords Packaging Systems, Bedford, England, and the two companies both serve the food and dairy industries.

For Holmatic, it's tamper-evident membrane sealing equipment for pre-formed containers, as well as filling, sealing and lidding equipment. For Fords, it's rotary cup fillers, high-speed foil closure presses and sealers.

PHOTO : The combined plastics and board pack Gemini system from Metal Box boasts flexibility in

PHOTO : packaging foods ranging from ice cream to fruits and vegetables.

PHOTO : Norco machinery and polyethylene shrink-wrap add up to packaging savings for Webber Farms.
COPYRIGHT 1989 E.W. Williams Publications, Inc.
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Copyright 1989 Gale, Cengage Learning. All rights reserved.

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Title Annotation:includes related article on food packaging
Publication:Quick Frozen Foods International
Date:Oct 1, 1989
Previous Article:Japanese FF consumption advances 8.1%; frozen vegetable imports surge again.
Next Article:Campbell to close four U.S. factories in efficiency, competitiveness move.

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