As anyone who has opened a package of prepared, processed or case-ready meat and cringed at the smell or sight knows, a little fresh air isn’t always a good thing.

Modified atmosphere packaging (MAP) has been a boon to the industry in many ways, helping to improve shelf-life and appearance of products. That said, residual oxygen and the resulting degradative oxidation in MAP or other types of packaging for fresh and prepared meats can impact the quality of certain meat and poultry products, opening the door to food spoilage by way of aerobic bacteria, yeast or mold.

“We love oxygen because it makes meat brighter, but sometimes, it breaks down into fatty acids and can be your enemy,” points out Jeff Savell, Ph.D., Regents Professor, Meat Science & E. M. “Manny” Rosenthal Chair in Animal Science at Texas A&M Univ.

Some meat and poultry products are particularly vulnerable to the effects of residual oxygen. “Poultry tends to have a bit more of an unsaturated lipid profile than red meat, especially in dark poultry meats where there is more pro-oxidant iron pigments. It doesn’t take much lipid oxidation to pick up an off flavor,” explains Dr. Andrew Milkowski, Ph.D., adjunct professor in the Department of Animal Sciences at the Univ. of Wisconsin in Madison, Wis. Cooked and prepared poultry products tend to have more issues than fresh poultry, he adds.

Solving problems
Poor quality – or poor perceived quality – can cause big problems for a poultry processor. “When a consumer makes a purchase and gets an initial blast of sulfur-like smell when they open the package, it’s not appetizing and can cause them to question the integrity of the product,” notes Jonathan Quinn, business development representative for Multisorb Technologies, Buffalo, NY.

To prevent such quality-related issues with chicken or turkey products, processors have turned to various solutions, from using vacuum-skin packaging systems to slowing down the packaging process to allow for extra oxygen flushing. In addition, many processors utilize sorbents like sachets that contain substances like iron powder or ascorbic acid to react with the oxygen present. Such active packaging solutions, in which the package itself responds to changes in its surrounding environment, have become more common in the past decade, in both the poultry and red-meat sectors.

As with many packaging features, the technology used generally depends on the product and the processor.

“It becomes a cost-benefit decision. Those are different types of things that go through manufacturers’ minds in deciding whether they can effectively use a certain solution,” says Milkowski.

Sorbents can be used in MAP systems and other packaging formats to both absorb moisture and lower oxygen residue, thereby improving quality. Often subtly applied, sorbents are effective with many types of prepared poultry products, including sliced deli meats and ready-to-eat entrees.

Multisorb Technologies offers a variety of “Drop-in, Fit-in and Built-in” sorbents for poultry and other meat products, including self-adhesive oxygen absorbers, oxygen absorbing packets and flat oxygen absorbing cards, along with the company’s own dispensing systems. The oxygen absorbers are customized for the specific meat package and can maintain oxygen levels inside sealed packages of processed meats to less than 0.01 percent.

The ongoing demand for convenience-oriented foods has led to greater use of such absorbers. “Prepared foods is a growing area for us and continues to grow as the consumer seeks out that ease of use,” Quinn says.

Today’s discerning consumer is also driving other innovations related to minimizing oxygen content. “In addition to odor absorbers, we use other oxygen-scavenging technologies that help to retard microbiological growth that exists inside poultry packages,” reports Quinn.

While helping to lower oxygen for optimal freshness and quality, the latest oxygen-scavenging systems appeal to consumers with a less-is-more outlook. “The meat and poultry shopper is looking for a cleaner label, with minimal additives and preservatives while still retaining the color, flavor and texture without an off flavor. That is something we are able to do with odor absorbers and oxygen scavengers,” says Quinn, adding that processors can make a natural or organic labeling claim with products featuring oxygen scavengers, thereby reducing the number of additives.

As the market expands for poultry products that can benefit from oxygen scavengers, Quinn says that sorbent technology is evolving, too. “Poultry is a different animal, literally and figuratively, than any sort of pork or beef product and there are many different opportunities to explore oxygen scavenging in poultry,” he says.

And while Multisorb typically works with prepared and processed meat and poultry companies, Quinn says the company is providing solutions for case-ready products as well, such as its MAPLOX program for fresh meat. “There are different demands and requirements for fresh, but we’re able to retard aerobic microbiological growth with oxygen scavengers,” he says.

Meanwhile, as sachets and other oxygen scavenging systems are used in packages of processed, cured and fresh meats, the possibility of incorporating scavengers into a packaging film still exists. The cost effectiveness of those films would have to be weighed, points out Milkowski.

At Multisorb, Quinn says that evolutions in oxygen scavenging continue. “We are always looking at the chemical and biological reactions that occur and how we can use our sorbent technologies in those areas,” he reports.

For now, he says, keeping oxygen as low as possible to prevent degradation is effective with a multi-pronged approach. “The combination of pairing a moisture regulator with a barrier package is the ultimate, ideal situation,” Quinn declares.