The color pink in cooked turkey meat raises a "red flag" to many diners and cooks. Conditioned to be wary of pink in fresh pork, they question the safety of cooked poultry and other meats that have a rosy blush.
Many people who call the U.S. Department of Agriculture's Meat and Poultry Hotline (800-535-4555) report being alarmed when seeing "pink." To them, it means "unsafe" or "under-done."
The color of cooked meat and poultry is not always a sure sign of its degree of doneness. Only a meat thermometer can help you determine whether meat has reached a safe temperature. Turkey, fresh pork, ground beef or veal can remain pink even after cooking to temperatures of 160 degrees F and higher. The meat of smoked turkey is always pink.
To understand some of the causes of "pinking" or "pinkening" in fresh turkey, it's important to know first what gives meat its natural color.
Why is poultry lighter in color than beef?
The protein myoglobin is the major pigment found in the muscles of all vertebrate animals and can exist in various forms, which determine the resulting meat color. The major reason that poultry meat is much lighter in color than beef is that it is dramatically lower in myoglobin. Also, as an animal becomes older, its myoglobin content usually increases. Turkeys today are young -- 14 to 18 weeks old at the time of slaughter.
Why are white and dark meat different colors?
The pink, red or white coloration of meat is primarily caused by myoglobin, which is located in the muscle cells and stores oxygen until the muscle cells need it. To some extent, oxygen use can be related to the bird's general level of activity: Muscles that are exercised frequently and strenuously -- such as the legs -- need more oxygen, and they have a greater storage capacity than muscles needing little oxygen. Turkeys do a lot of standing around, but little if any flying, so their wing and breast muscles are white, their legs, dark.
What causes well-done meat to be pink?
Scientists have found that pinkness occurs when gases inside a gas or electric oven react chemically with hemoglobin in the meat tissues. This is the same process that gives red color to smoked hams and other cured meats.
The presence of high levels of myoglobin can account for poultry having a pink to red color similar to that of an undercooked product.
Other reasons for pinkness in poultry:
Natural presence of nitrites. Nitrites are commonly used to produce a desired pink color in traditionally cured meats such as ham or bologna. So it follows that the natural presence of nitrates and nitrites either in the feed or water supply used in the production of poultry are a factor in nitrite levels in the birds.
One study found that during 40 hours of storage at 40 degrees F, naturally occurring microorganisms converted nitrate to nitrite. It also found that the local water supply had nitrate and thus could serve as a nitrate source during processing.
Young age of meat. Often meat of younger birds shows the most pink because their thinner skins permit oven gases to reach the flesh. The amount of fat in the skin also affects the amount of pink color. Young birds or animals lack the shield of a fat covering.
Grilling. Meat and poultry grilled or smoked outdoors can also look pink, even when well done. You may see a pink-colored rim about a half-inch wide around the outside of the cooked meat. The meat of commercially smoked turkeys is usually pink because it is prepared with natural smoke and liquid smoke flavor.
How to test for doneness
The best way to be sure a turkey -- or any meat -- is done is to use a meat thermometer. If the temperature of the turkey is a minimum of 165 degrees F and is done to family preference, all the meat -- including any that remains pink -- is safe to eat.
If you don't have a meat thermometer, look for visual signs of doneness: When the turkey is pierced with a fork, the juices that run out should be clear, not pink. The meat should be fork tender, and the leg should move easily in the joint.