Hoping to prevent gray ground beef, MU researchers see red with LED lights

Consumers want their ground beef to be one color: red.
Consumers want their ground beef to be one color: red. File photo

There’s nothing unusual about fresh hamburger patties being stored in a walk-in cooler, but a few racked in a cooler recently at the University of Missouri were there on a mission.

The patties were laid out in separate compartments. One batch was completely in the dark, another batch was lit with fluorescent bulbs, and a third with LED lights.

They were then monitored to see how fast they lost that cherry-red color consumers prefer when buying fresh meat.

Light and oxygen help turn the color of ground beef into an unappetizing gray or light brown. So it was no surprise that the patties in the dark stayed red the longest.

But those lit with LEDs — whose illumination is produced by light-emitting diodes — fared far better than those under the fluorescent lights, the traditional lighting found in grocery meat cases.

“My gut told me the difference was real,” said Bryon Wiegand, professor of animal science.

The life of fresh red ground beef is short. But can displaying it under energy efficient and cooler-burning LED lights help? Based on the MU research so far, that possibility is being taken seriously.

The MU research advances previous work by Kyle Steele, a graduate student at Kansas State University, who found that LEDs extended the shelf life of ground beef and other meat.

His conclusion was that the cooler operating LEDs kept the internal temperature of the meat lower and slowed the process that turns the meat brown.

The shelf life of ground beef staying red is normally three days, but under LEDs it was extended to four days.

The MU study, besides confirming that LEDs affect shelf life, is examining how LEDs perform in different situations than those tested by Steele. It’s also doing more research to determine whether there’s something else about LEDs other than their cooler temperatures that keeps hamburger red a longer time.

The Missouri Beef Industry Council is plowing money into the MU study, which is entering a second phase in which more hamburger will be tested in meat cases typically used by grocery stores. The trade group calls the research so far “extremely encouraging.”

Discolored hamburger can still be safe to eat, but the appearance makes it tough to sell. It’s either discounted for a quick sale or sent to a rendering plant and turned into a product that can be used in dog food.

The beef industry says $1 billion is lost annually because of discolored or spoiled meat. How much of that is due to ground beef isn’t clear, but experts say it could be in the tens of millions of dollars. That makes extending the shelf life a priority.

“It’s a significant issue to our industry,” said Mark Russell, executive director of the Missouri Beef Industry Council.

The research comes as LEDs continue to make inroads as their price declines. LED technology uses semiconductor chips to convert electricity to light. Proper engineering and coatings can produce a white light comparable to incandescent or fluorescent lights.

Compared with incandescent bulbs, they reduce electricity consumption by 85 percent. Even against fluorescent lights, which have been the main energy-efficient alternative for decades, an LED provides significant savings.

Their potential to do even more has been kicked around. A report by Oklahoma State University in 2012 found that dairy cows at one farm in the state produced more milk after LEDs were installed. Among the theories: The lights are directional and could highlight feeding troughs to encourage feeding.

But a more controlled study to confirm that benefit hasn’t been been done because of a lack of money. LEDs are slowly making inroads at dairy farms in new buildings and major renovations, but for now it’s because of the energy savings and improved lighting that can prevent accidents or other problems.

“While widespread adoption has yet to occur in the dairy industry, there is growing interest from many producers,” said David Darr, vice president of sustainability at the Dairy Farmers of America, a marketing cooperative based in Kansas City.

Grocers are buying more refrigerated meat cases with LEDs, initially for the energy savings and for the better lighting that improves the display of products. But some also are noticing that meat seems to be lasting longer, said Bruce Schneider, LED merchandising specialist for Hussman, a global leader in refrigerated display cases.

“When it comes to fresh meat it’s beyond energy savings,” Schneider said.

Jon McCormick, executive director of the Retail Grocers Association of Greater Kansas City, said area grocers have begun installing meat and other display cases lit with LEDs “across the Kansas City metro.” The cooler light is also helping in other ways such as helping prevent frost on the glass doors of frozen-food display cases.

Wiegand, of the University of Missouri, and his colleague, Carol Lorenzen, have a long interest in meat’s shelf life and have focused on ground beef.

The meat has become more expensive, which makes for a bigger economic loss when it isn’t sold. It’s also more popular because it’s easy to cook.

“We are in the second generation that does not like or does not know how to cook,” Wiegand said.

Most meats can change color, but beef that is ground into hamburger exposes more flesh. Beef actually starts off a bluish purple color, but oxygen binds to the pigment, turning it bright red. Then the pigment stops accepting oxygen, which is when the color starts changing again — to gray.

Special packaging in self-serve cases can curb the change. A mixture of oxygen and carbon dioxide sealed into the package will extend the shelf life to 11 days. But in packages without modified gases, and the meat displayed in those popular full-service meat counters, it’s usually no more than three days.

That LEDs could change the math was clear in the University of Missouri tests. They added a day to bright red hamburger, and even after a week the patties still had some speckles of red. The fluorescent-lit patties started showing discoloring in the third day.

“I was surprised,” Wiegand said.

The meat industry has spent heavily over the last century to find ways to make meat last longer. It wouldn’t be a small thing if another day was added to ground beef.

“It’s a huge deal,” said Betsy Booren, vice president of scientific affairs for the North American Meat Institute.

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