Consumers traditionally prefer a bright red color when purchasing fresh beef products, both ground as well as whole muscle. Retailers and packers often struggle to maintain a bright red color that attracts consumers with processing and packaging methods that offer the longest shelf life and the ability to merchandise fresh product as long as possible.

Processors can limit exposure to oxygen or remove it to increase shelf life, but the lack of oxygen causes a purple color, rather than the bright red which, comes from oxygen exposure.

The purple advantage

Unlike plants, a lack of exposure to oxygen preserves the quality of animal proteins.

“Once you expose any protein to oxygen you just begin oxidation and degradation,” says Dan Siegel, owner of Deli Star, Fayetteville, Illinois, and Ph.D., Meat Science at the Univ. of Illinois. “You can slow that deterioration by keeping oxygen away from it and that’s the idea of the purple color. The problem is that consumers don’t like it as much.”

Packaging expert, Guenter Kuhl from Canton, Massachusetts-based Reiser, agrees and offers other possible reasons why consumers have not yet fully embraced vacuum packaging.

“People don’t necessarily like the look of the vacuum package because it’s not the tray that they’re all used to,” Kuhl says. “What I get from grocery stores is the package doesn’t feel warm. A Styrofoam tray feels warm in your hand. That is one of the feelings that they always describe to me. So, when you have a vacuum package, they have a different sensation when they buy it.”

Historically consumers have always preferred red-colored meat. According to Siegel, the purple hue doesn’t “pop” like the bright red-colored meats typical shoppers are used to. However, maintaining the bright red color in packaged meat presents difficulties. The same chemical reaction that turns the meat bright red – oxidation – also starts the cycle of deterioration and eventually spoilage.

Kuhl adds, “It’s just a really good package that the consumer doesn’t understand. That’s the sad part.”

But consumer knowledge of what fresh meat has traditionally looked like versus what constitutes quality, fresh meat has begun to shift. Retailers such as Rochester, New York-based Wegman’s have made an effort to educate and train consumers to realize that purple beef is as fresh as bright red meat. Scientifically speaking, purple meat holds quality for a longer period of time and gives retailers and packers more time to merchandise and sell the product before spoilage.

Processors have packaging strategies to keep meat bright red in the package longer, thus surviving the sales cycle without turning brown. Rosemary extract, carbon monoxide and vacuum packing with a small amount of nitrite in the film all allow meat to keep its red color. For various reasons though, packers are shying away from these methods and moving toward packaging that eliminates oxygenation of the meat, causing it to show purple in the package. A lack of oxygen and a high-barrier film can keep meat purple for over a hundred days, according to Siegel. This offers packers and retailers a huge advantage in terms of useable inventory andmerchandising.

“Once you stop oxygen, you stop oxidation,” he says.

Kuhl says that in addition to the added shelf life and the food safety advantage that comes with it, vacuum packaging allows the meat to continue to age without exposure to oxygen.

“The beef is actually more tender and juicier than it would be with modified atmosphere packaging (MAP).”

Color chemistry

Myoglobin pigment gives meat its color. According to Siegel, myoglobin pigment goes through a cycle of turning red to brown to purple relative to exposure to oxygen.

Once the animal dies and its blood no longer delivers oxygen to the muscle tissue, the myoglobin pigment becomes deoxygenated and moves into “a reduced state,” Siegel says. At this point in the cycle, the myoglobin pigment will reflect light with a brown color. “But the enzymes naturally inherent in the meat reduce it back to its natural state or shape, which reflects light in a manner that’s purple. Then if oxygen is there again, it grabs on to it and it turns bright red,” he adds. “So, you can envision it to be kind of like a cycle, purple, brown really quick, and then red. You don’t even see the brown. It’ll go red, brown really quick, and then purple.”

As time passes the myoglobin struggles to remain in the reduced state and after prolonged exposure to oxygen it begins to oxidize. Once oxidization sets in the meat turns brown and begins to go bad. Using vacuum packaging slows the deterioration of the meat by keeping oxygen away from it. That lack of oxygen in the package is what gives the meat a purple color. What consumers don’t understand according to both Siegel and Kuhl, is that while the meat appears purple in the package, once it’s opened it blooms bright red.

Preferred packaging

Processors use two common methods to vacuum package beef that presents purple in the package, rollstock and vacuum skin pack (VSP). Rollstock packaging utilizes flexible materials for both the bottom and top pieces of the package, often referred to as a brick pack, while VSP packaging most often uses a tray for the bottom portion of the package.

“I think the all-natural and the bison guys, they settled on that format and that has gained a lot of weight and made a lot of progress with the consumer,” Siegel says in reference to the brick pack. “They view it as being good meat inside even though it doesn’t look as fresh. So, they’re happy with it, I think. If you look at the meat case it’s growing and growing in that category.”

Siegel goes on to say shoppers in Europe prefer VSP packaging. Kuhl says the expense and type of cut, as well as the species, makes a difference when processors decide on which vacuum pack method they choose.

“The VSP is usually on the very high-end cuts because it’s a very expensive package and when you really look at it, you find it more on exotic products like bison and lamb than you do on regular steaks [filet mignons and strips],” Kuhl says. “It’s coming more towards the regular steaks, but VSP is more on those [high-end andexotic].”

Kuhl notes another advantage of the regular rollstock packaging. The background film can, and sometimes is, color coordinated to match the product inside. “Sometimes you have a green background for the grass-fed products. Then you have the gold for the regular products, then you have the black film for the Black Angus products.”

Kuhl and Siegel agree that vacuum packaging beef – whether ground or whole muscle, rollstock or VSP – adds to the safety of the product by providing a significantly longer shelf life. Once consumers understand this, they’ll find it easier to embrace the purple color in the case.

“My wife still wants a bright red steak,” Kuhl says. “She won’t buy the purple steak. I can talk until I’m blue in the face.”

Both believe time and education will eventually bring the consumer to accept the purple meat as a safer and superior product.

“I see more people going toward the purple, the meat case is changing,” Siegel says. “It’s almost become like milk. I’m not going to judge the quality based on the color. If it’s got a fresh date, I know it’s good, and then when you take it out of the package it blooms and it smells good.”