When it comes to buying and preparing meat and poultry, color often plays a major role in consumer decisions. But color can be deceiving. A blue-tinged chicken, a dark-centered ground beef patty, or a pink turkey breast might cause concern—but they’re not always a sign of spoilage. The U.S. Department of Agriculture (USDA) receives numerous questions about these color differences. This article breaks down the science behind meat and poultry color and clarifies what is safe and what isn’t.
The primary pigment responsible for meat color is myoglobin, a protein found in muscle tissue. In its natural state, myoglobin is purplish-red. When it interacts with oxygen, it turns bright red, forming oxymyoglobin, the color most shoppers associate with freshness. A further reaction with oxygen leads to metmyoglobin, which gives meat a brownish-red hue.
Additional factors include:
Color alone is not a reliable indicator of spoilage. While spoilage may cause darkening or fading, signs like an off-odor, sticky or slimy texture, and tackiness are better indicators. If any of these are present, the meat or poultry should not be used.
Meat color can change in the freezer just as it does in the fridge. Fading or darkening in frozen meat does not compromise safety. However, it can be minimized with proper freezer-grade packaging and by removing excess air before freezing.
White, dry patches on frozen meat and poultry indicate freezer burn. This occurs due to moisture loss and improper packaging. While the meat remains safe to eat, the texture and flavor in those areas are affected. You can trim off freezer-burned portions if desired.
Vacuum-packaged meat, which is not exposed to air, often appears purplish-red due to the presence of myoglobin. When exposed to air, it becomes bright red as oxymyoglobin forms. Over time, continued exposure to oxygen and light causes the formation of metmyoglobin, turning the surface brownish-red—again, not a spoilage issue on its own.
This common concern is related to oxygen exposure. The outer layer of ground beef turns bright red due to air contact, while the interior remains grayish-brown due to lack of oxygen. This is not a sign of spoilage.
Darkening of beef roasts in the refrigerator is typically caused by oxidation of myoglobin. This is a normal chemical change and doesn’t affect safety.
Yes, ground beef can remain pink after cooking, even when it’s fully cooked to a safe temperature. This pink color may result from:
Always use a meat thermometer to ensure the internal temperature reaches 160 °F to destroy harmful bacteria.
Light diffraction on meat surfaces can cause a rainbow-like or iridescent sheen. This phenomenon is harmless and related to the structure of muscle fibers and meat compounds. Proper storage in airtight, light-blocking packaging can reduce this effect.
Cured meats undergo chemical changes involving nitrites and oxygen. Exposure to light and air can oxidize pigments, leading to a gray or green color. These visual changes do not necessarily indicate spoilage but can signal degradation over time.
Raw poultry can range in color from bluish-white to yellow. Factors include:
Younger birds have less subcutaneous fat, which may give skin a bluish tint.
Ground poultry color depends on the muscle parts used:
It can include skin and fat in proportions that mirror the whole bird.
Young chickens (6–8 weeks) may show dark bones and surrounding meat. This is due to immature bone calcification and pigment leaching from the marrow, especially if frozen before cooking. It is harmless if the meat reaches 165 °F.
Safely cooked poultry can be:
Color variation is normal. What matters most is reaching 165 °F internal temperature, checked with a thermometer in the innermost thigh, wing, and thickest part of the breast.
Pink poultry can result from:
Thinner-skinned, younger birds are more susceptible to pink coloration during cooking.
Smoked or grilled poultry often has a pink outer rim, even when thoroughly cooked. This is common in outdoor or commercial smoking and is caused by the penetration of natural or liquid smoke. It is safe as long as the internal temperature exceeds 165 °F.
Understanding the science of meat and poultry coloration helps prevent food waste and unnecessary worry. While color can offer clues about freshness and handling, it is not a definitive indicator of safety. Always rely on smell, texture, and most importantly, a food thermometer to determine doneness and safety. Armed with this knowledge, consumers can make informed choices and safely enjoy meat and poultry products.