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Why Does Kunoa Beef Look Different Than Other Beef at the Store?

March 14, 2018

From time to time, we get questions about the color of beef. How should it look when you buy it? Why does the color change after I open the package? These are important questions, and the answer begins with a protein in beef called myoglobin.

Myoglobin is responsible for delivering oxygen to the animal’s muscle, and it’s also what gives raw beef its color. Myoglobin is naturally a purplish-brown color, but when it’s exposed to oxygen it changes to a bright red. This process is known as “blooming” and can take up to 30 minutes.

We package all our meat ourselves at our facility in Kapolei using an airtight, vacuum-sealing method that locks almost all oxygen out of the package. In the absence of oxygen, the meat reverts to the purple color. When you get it home and open the package, you’ll notice that the color changes to the bright red we usually associate with raw beef. This is completely normal and expected.

The beef you see in a butcher case, on the other hand, is often bright red because it’s exposed to oxygen. Some plastic packaging is semi-permeable so oxygen from the air is reaching the meat and turning the myoglobin red. Another method of plastic packaging, called “modified atmosphere packaging,” pumps a combination of purified gases found in air (oxygen, carbon dioxide, nitrogen and/or carbon monoxide) into the package to help the meat retain the red color. If the meat isn’t treated with the gases, the oxygen exposure will start to turn the meat brown, even though it’s still safe to eat. 

Even though the color of Kunoa meat in the package may look different than our customers are expected to seeing, we chose the vacuum-sealing method because it extends shelf life and keeps the meat fresh for longer without the use of gases.

Interestingly, the color of meat can also be influenced by other factors, including the animal’s age, species, sex, diet and the amount of exercise it gets. Fat also contributes to color — the more intramuscular fat the lighter the color — so pasture-raised animals like ours that get more exercise than feedlot-raised animals can have a slightly deeper color to the meat.

The next time you bring a package of Kunoa beef home it can be a chemistry lesson for the kids. Watch for the color changing “bloom” after you open the package. To learn more about the color of meat and food safety, the USDA is a great resource.

Find out where to buy Kunoa meat.