NATURAL COLOR CHANGES IN MEAT

Why does my packaged product look brown?

Amazingly, beef can exist naturally in many colors; from purple to red to brown.  There is a protein called myoglobin in meat that is primarily responsible for its color.  When a change in myoglobin occurs, meat color also changes. Myoglobin contains iron and has a binding site that attaches to other biochemical components.  The meat color is determined based on the state of the iron and the nature of the components that attaches to the binding site of myoglobin.  This iron is also an important nutrient in meat.

Most U.S. consumers associate the bright cherry-red color in beef with wholesomeness.  This red color is due to exposure to oxygen in the air which attaches to the myoglobin molecule in the meat.  Yet, the red color is not stable and the oxygen can also be detrimental to beef.  The longer beef is exposed to oxygen, a process called “oxidation” occurs.  True oxidation happens on a molecular level -- we only see or taste the large-scale effects as the oxygen causes free radicals formation that eventually causes beef to slowly deteriorate in flavor and color.

Science shows that meat naturally changes color when it progresses from an aerobic to anaerobic environment; meat goes from bright red to brown to purple in a new vacuum package.  The change from red to brown is due to the natural oxidation of the iron portion of myoglobin.  The change from brown to purple is due to reducing enzymes within the meat.  Lots of age and colder storage temperatures definitely reduces enzyme activity which slows the “color change process” of a steak in vacuum packages.  However, both are crucial elements in creating a great tasting and wholesome steak. 

Keeping your meat away from oxygen for your benefit!

Halperns' Purveyors of Steak and Seafood wants to supply their customers with safe, high quality fresh product and to accomplish this by using a state-of-the-art vacuum packaging system.  This system inherently uses a high oxygen barrier packaging film that protects your meat from oxygen, ensuring that your meat is protected from oxidation, which greatly increases the shelf life and flavor stability of the product.

The incredible nature of beef is that when in an oxygen-free environment, such as the high oxygen barrier film, it starts out bright red after cut fabrication, then turns brown and eventually to purple depending on the oxidation state of iron within the myoglobin molecule inside the meat.  Once you open the vacuum-package (break the seal), this will allow the beef’s purple-red pigment to be exposed to oxygen again and your beef will begin to “bloom” or return to the bright cherry-red color.

Some other packaging systems allow beef to retain its red color because the film allows oxygen to pass through.  This packaging will allow your meat to retain its red color but it will also greatly diminish the shelf life and flavor stability of the product.

How does aging of meat affect tenderness and color?

In addition to breed and diet, age of the meat after animal harvest is a very important contributor to tenderness and great flavor.  As the subprimal cuts age, enzymes create chemical reactions in the muscle tissue resulting in improved flavor and increased tenderness.  As these enzymes complete their task their activity level begins to slow.   As tenderness increases, the color changing phenomenon of beef diminishes, but the wholesomeness and flavor of the product greatly intensifies.  Because of the amount of age we put on our beef, the color transformation from red to brown to purple may take a few days but the eating experience will be outstanding.   

In conclusion, Halperns' Purveyors of Steak and Seafood believe that for our customers, using a high inherent oxygen barrier film that makes meat naturally appear purple-red also gives a higher integrity product with longer shelf life and increases food safety.  Halperns' Purveyors of Steak and Seafood also knows that aging beef products produces a wonderful tasting, tender steak.

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This Halperns’ Fact Sheet was based on publications by Dr. M.C. Hunt, Kansas State University. Dr. Hunt is the industry’s leading expert on color transformations in beef. 

More information on meat color can be found:

http://www.fsis.usda.gov/Fact_Sheets/Color_of_Meat_&_Poultry/index.asp

http://savell-j.tamu.edu/color.html

http://animalrange.montana.edu/courses/meat/meatcol.pdf