by Jeffrey Steele, Co-Packing Solutions

Co-packers and other food processors are in the forefront when it comes to food safety in the processing plant. They are also leading the way in developing packages that keep unopened and opened foods safer and fresher at home.

Shelf-stable packaging is just one of the advances being used in more and more products today, says John Spink, director of The Packaging for Food And Product Protection (P-FAPP) Initiative at Michigan State University in East Lansing, Mich. “The shelf-stable product offers the benefit of food safety, but also food quality,” Spink says. “It is intended for a longer shelf life and may require less rigorous food-storage requirements, with the quality remaining higher longer.”

According to the United States Department of Agriculture (USDA) Safe Food Handling Fact Sheet, oxygen can expedite the chemical breakdown and microbial spoilage of many foods — deli meats among them. That’s one reason co-packers and other food processors are doing all they can to ensure food remains safe by controlling atmosphere inside the package.

Vacuum Packaging and Modified Atmosphere Packaging (MAP) are two ways they are tapping into science to overcome oxygen’s effects and, in the process, to extend the life of packaged food products.

Vacuum packaging (which removes air from packages and produces a vacuum inside) removes oxygen that microbes can feed off, thereby preventing

bacteria or pathogens from impacting the foods inside, Andy Jaspers, director of research and development at West Liberty Foods, says.

MAP — defined as “the packaging of a perishable product in an atmosphere which has been modified so that its composition is other than that of air” — provides benefits similar to vacuum packaging by replacing some or all of the oxygen in the air inside the package with other gases, carbon dioxide and nitrogen above them.

A co-packer might choose MAP, for example, to help preserve a “fresh-from-the-deli” appearance, Jaspers says. “If you pull a vacuum on a loose-folded pack of shaved meats, for instance, it compresses the product to the point where you can’t pull apart the slices.”

Both approaches help extend shelf life in the store and the home, agrees Elizabeth Andress, project director for the National Center for Home Food Preservation in the Department of Foods and Nutrition at the University of Georgia in Athens, Ga.

However, in the MAP approach, the composition inside the package can change to some degree over the period in which it is stored, Andress says.

“That package will allow some transmission, so there can be some altering of the actual composition over time” in both the store and the home, she adds.

Maryland-based Giant Food recently adopted a MAP process that replaces oxygen with nitrogen, carbon dioxide and carbon monoxide for its ground beef products. But the retailer soon discovered that the new packaging confused some customers because the meat retained its red color inside the package for so long.

The problem: Many customers consider color to be a sign of freshness, and the state-of-the-art packaging kept the meat looking red longer than they thought the meat actually remained fresh. As a result, Giant Food changed to a high-oxygen packaging using 80 percent oxygen and 20 percent carbon dioxide.

“As part of our efforts to continually improve our product and service offerings, we may adopt this packaging for other meat products,” the company’s Web site states.

Resealable packaging

In both of the above approaches to safe packaging, all or most safety and freshness benefits are eliminated as soon as the package is opened within the home. Re-sealable packages were developed in part to address this issue, Andress says.

“These resealable packages provide a benefit to consumers, especially in the area of cheeses and lunch meats,” she says. “You don’t have to take the cheeses and meats out of their original packages and repackage them, so you’re cutting down the contamination or cross-contamination potential. You’re also saving on package costs.”

Keeping products in resealable bags also can help minimize or eliminate the threat of meat juices leaking out and cross-contaminating other foods, Spinks adds.

Resealable packages come in different forms, according to Jaspers. While the zipper-lock back has been the standard for years, new technologies are emerging. Standard tubs that feature snap-on lids to store product after the package is opened, and “peel and seal” packages that let consumers open the package, remove a portion of the product, then reseal and close the package are two examples, he says.

“Once you’ve opened the package, you have exposed the food to the atmosphere,” Jaspers says. “But from a freshness standpoint, and from the perspective of preventing it from picking up the odors and flavors of other foods, you’re resealing it from the rest of the refrigerator.”

Antimicrobial coatings represent one more packaging innovation that can help enhance food safety in the home, Spinks says. These coatings are released when the package is opened, reducing microbial growth. Some packages with these advanced coatings inhibit microbial growth before being opened, he says.

Using packaging to communicate

Spinks notes the differences between recent cases involving contaminated spinach and tainted tomatoes have taught food researchers important lessons.

The ability to trace lot numbers on spinach containers led to successfully tracking contamination sources. No such lot numbers existed on the tomatoes, and that case is still unresolved.

“As co-packers and other manufacturers put product in packages, there is a great opportunity to include lot numbers, which the processor can then track back to recall contaminated source product,” he says.

Such an approach has long been commonplace at West Liberty Foods as an industry standard.

Lot numbers, line numbers and use-by dates, however, represent only part of the communication potential of packaging, Andress says.

Many manufacturers print home safety and usage guidelines on packaging, ranging from recommended cooking temperatures to how soon to consume or discard opened products.

Use-by dates are perceived by consumers as guidance on when they need to open the package, Andress says. But consumers often don’t have a clear understanding of when food needs to be completely consumed or thrown out. Providing the dates by which the food must be consumed or discarded can clarify the matter, she says.

“I do think consumers are recognizing that they are benefiting from packaging innovation,” Andress says. “It seems to me I’ve seen a lot more innovation taking place recently in food packaging than in actual food product.”