We Americans like our milk chilled, our ice cream frozen and our yogurt cold. Dairy products belong in the refrigerator. Period. That’s what we know and we’re used to. That’s how we like it.

Realizing consumer preferences, most U.S. retailers sell aseptic milk in the dairy case, even though refrigeration is unnecessary.  

But in other parts of the world, consumers with small iceboxes chug their milk from a rectangular drink box kept in the pantry. And places with poor refrigeration or contaminated water sources rely on aseptically packaged milk for nourishment.

Needless to say, the U.S. road to aseptic packaging is wide open. There’s lots of room to pass and move ahead. American consumers need to be educated and warm up to the fact that milk out of a drink box can be just as good and tasty as milk from a frosty single serve or chilly gallon.

Industry insiders say schools are the next best hope for aseptic dairy packaging in the United States. And, sadly, bioterrorism and Hurricane Katrina may have given consumers even more compelling reasons to purchase aseptically packaged food and beverages.

Like drying fruit, salting meat or canning vegetables to keep them from going bad, aseptic packaging is a way to preserve food. Aseptic packaging involves filling a sterilized package with a sterile food under a confined hygienic environment, as defined by the Washington, D.C.-based Aseptic Packaging Council (APC). Shelf stability is achieved without preservatives or refrigeration.

The multi-layer, high-performance aseptic package — commonly known as a “drink box” — combines the best attributes of paper, plastic and aluminum, locks out light and air, seals in nutrients and flavor and allows contents to remain at room temperature for months, the APC explains on its Web site. Aseptic packaging is consumer friendly because it’s shatterproof, tamper evident and offers safety, nutrition and ease of handling, the association says.

Because aseptic packaging can deliver whole milk and 100-percent juices to areas with little or no refrigeration, disaster agencies like the American Red Cross routinely request the drink box, the APC says. Vulnerable populations in less-developed countries rely on drink boxes to fight hunger and malnutrition.

Aseptically packaged milk is vital in places where water supplies are inadequate or contaminated, whether that place is a Third World country or the hurricane-ravaged U.S. Gulf Coast. With sources of potable water impaired, powdered milk is unusable in these circumstances, leaving the drink box the only source of milk for children and pregnant women.

In the United States, aseptically packaged milk and juice concentrates are a staple of the federally sponsored Women, Infants and Children program aimed at improving nutrition among poor and homeless families.  

The Chicago-based Institute of Food Technologists (IFT) named aseptic processing and packaging technology the most significant food science innovation of the last 50 years.

“Compared with traditional canning techniques, the aseptic process allows a substantial reduction in the time and temperature necessary for sterilization,” IFT says on its home page. “That, in turn, increases nutrient retention and flavor while ensuring safety.”  

The drink box is one of the best examples of minimal packaging, according to the APC. It uses less energy to manufacture, fill, ship and store than almost any other package. The aseptic package won the Presidential Award for Sustainable Development in 1996, an environmental award.

Packaging experts cite aseptic packaging as environmentally responsible because it uses fewer materials, is lightweight and energy efficient and easy to recycle, says the APC.

Box-shaped aseptic packages contain six layers in a laminate of three materials: 70 percent high-quality paperboard; 24 percent polyethylene; and 6 percent aluminum. Paper provides stiffness, strength and the efficient brick shape to the package; polyethylene on the innermost layer forms the seals that make the package liquid-tight and a protective coating on the exterior keeps the package dry; and an ultra-thin aluminum layer forms a barrier against light and oxygen, eliminating the need for refrigeration and prevents spoilage without preservatives.

Aseptic packaging was introduced to the United States in the early 1980s. Products once considered perishable could be distributed and stored without refrigeration for at least six months. The key to achieving room-temperature shelf stability is by filling a sterilized package with a sterile food product within the confines of a hygienic environment. Most other package types and systems use preservatives or refrigeration to achieve a long shelf life.

Aseptically processed liquid foods and beverages are sterilized outside the package using an ultra-high-temperature (UHT) process that rapidly heats and cools the product before filling. Processing equipment allows the time — 3 to 15 seconds — and temperature — 195 to 285 degrees F — to be tailored to place the least amount of thermal stress on the product while ensuring safety.

The flash-heating-and-cooling aseptic process reduces the energy use and nutrient loss found in conventional sterilization. Aseptically packaged products retain more nutritional value and exhibit more natural texture, color and taste, the APC says.

Aseptic packaging is popular in Canada, Europe and Asia, where milk can also be found in aseptic pouches, notes Andrew Mykytiuk, editor in chief of Flexible Packaging magazine.  

A discussion about aseptic packaging would not be complete without Tetra Pak, the Swedish company founded in 1951 that pioneered the technology in the 1960s. Tetra Pak was founded to develop and commercialize tetrahedron-shaped packages for fresh milk and other dairy products.

Its aseptic process is based on the assurance that both food and packaging materials are bacteria-free at the moment the food is packaged, the company explains on its Web site. Not only are the food and packaging materials commercially sterile, but so are the machinery and the environment.

Roll-fed packaging material is sterilized and shaped into a tube, which is filled with product. Packages are shaped and sealed below the surface of the liquid to lock out air space in the package. During the aseptic packaging process, the product passes from UHT treatment in a closed system to the packaging machine, where it is packed under aseptic conditions in a sterile packaging material that keeps out light and air. Packaging material is sterilized in a heated hydrogen peroxide bath. Residue is removed by pressure rollers or hot air, leaving the packaging material dry and sterile.

Tetra Pak’s parent company is Switzerland-based Tetra Laval. Tetra Pak, with headquarters in Switzerland and Vernon Hills, Ill., is a sister company to Sidel Inc. of Norcross, Ga., and Octeville Sur Mer, France; and De Laval of Sweden. Sidel builds machinery for aseptic packaging of plastic bottles, with a focus on high-speed rotary machines.

Christopher Hoemeke, North American product manager for business development at Sidel, points to growth in aseptic processing and packaging in the United States. “It used to be that 20 percent of all inquiries came from the United States, and now 90 percent of inquiries are from the United States,” he says.

Aseptic packaging is the next big thing in the dairy industry, Hoemeke says, noting that schools districts across the country are the next battleground. As carbonated soft drinks are shut out of cafeterias, schools are seeking alternatives to cold milk storage.

Because aseptic packaging doesn’t require refrigeration, it’s the perfect alternative, Hoemeke says. He points to the new Quaker Milk Chillers as a good example of aseptic packaging in a plastic bottle.

“The market dynamics have to shift,” Hoemeke says. “There’s really not a market demand. But consumers prefer bottles over other packaging, every time.”

Extended-shelf-life (ESL) products, which have a 120-day life, are growing, Hoemeke says. “With the school systems banning soft drinks, there’s greater evidence for ESL and aseptic packaging potential,” he says. “Now there’s a demand for it. It’s basic economics. Everyone talks about the future of aseptic packaging, but now it’s ‘What is the pace?’”

Hoemeke says he thinks aseptic packaging will eventually replace retort can packaging because of its convenience. “Consumers want the resealability that they can get from bottles,” he says.

Federal Mfg. Co. recently rolled out its N-W Series designed especially for non-contact ultra-clean filling. Optional machine features include an aseptic package design.

Federal also offers its “E” series filler bowl as a component of systems that provide extended product shelf life. The bowl is ASME pressure-rated for 50 psi steam or temperatures to 295 degrees. The “E” series spring-loaded filling valve is designed with a bypass to ensure that all valve surfaces and seal rings will be thoroughly cleaned and sanitized using the company’s automated circulating system. The filling valve is completely encapsulated for cleaning and sanitizing. When the filler bowl is properly cleaned and sanitized, a sterile product contact is achieved.

Milwaukee-based Federal has been designing and manufacturing fillers for glass and plastic bottles for the dairy industry for 60 years.

Modern Packaging, Inc., Deer Park, N.Y., designs and manufactures precision packaging systems for the dairy industry. All units are 24-hour production machines that are servo or cam driven, have stainless steel construction and can be either aseptic or positive clean air pressure filling systems. Modern Packaging builds a variety of systems in either straight line or rotary with custom features that best fit dairy processing requirements. All systems are easy to operate, maintain and fulfill all USDA and 3-A dairy standards.

Raleigh, N.C.-based MicroThermics’ equipment and miniature plant trial services bring plant processes into the lab. Using a small amount of product, UHT/aseptic, HTST/pasteurization, hot-fill and continuous cooking are performed quickly and conveniently in MicroThermics’ lab or on site in a plant lab.

Aseptic packaging for milk has a lot to overcome in the United States. “I don’t think any consumer will buy it if it’s not chilled,” Hoemeke says. “Ambient products must be marketed as chilled for now. The market has to change. They’ll have to be in the cold chain for a while.”

Fluid milk works best in aseptic packaging. Drinkable yogurt, one of the industry’s newer innovations, is not a good candidate for 90-day ESL packaging because of its active cultures which require cold temperatures for survival.

Flavored milks, on the other hand, are ideal to bring consumers over to aseptic packaging. One example is Bravo Foods’ Slammers, available in traditional flavors as well as co-branded confectionary varieties such as 3 Musketeers and Milky Way.

“I don’t see white UHT milk being a consumer’s choice yet,” Hoemeke says. “It would take a well-educated consumer. But they’re not there; they’re not ready for it.”

Because refrigeration is not required, soy milk is a perfect choice for aseptic packaging,” Hoemeke says. “I think soy will make great inroads,” he says.

Hoemeke predicts the industry will accept aseptic packaging. “There’s no doubt it will move forward, but it’s never fast enough for the people who make machinery,” he says. “It’s just a matter of time before retort and glass makers switch to aseptic.”  m

Visit the Washington, D.C.-based Aseptic Packaging Council’s Web site at www.aseptic.org and you’ll find a link for branded products in aseptic packaging that are best to be included in an emergency kit:

Milk: Parmalat, Gossner Foods, Horizon Organic, Raging Cow.

Soy/non-dairy: Westsoy, Silk, EAS AdvantEdge, Myoplex, Soy Dream, Rice Dream, Power Dream, Pacific Soy, Pacific Rice, New Moon Chai.

Other beverages: Hi-C, Minute Maid, Juicy Juice, Motts, SoBe Liz Packs.

•Protection: Packages protect contents from light, microorganisms, air and the environment.

•Preservation: Good packages help preserve food and prolong its shelf life during storage, transport, retailing and consumption.

•Communication: Packages carry important product information about ingredients, quantities, nutritional value, use, sell-by dates, etc.

•Convenience: Packages provide convenience for consumers by enabling the food to be transported easily and stored until served.

Source: Tetra Pak