Color of Meat and Poultry
I’ve just opened a
package of fresh chicken and the skin looks blue. Is it safe to
My package of ground
beef is dark in the center. Is this old meat?
The turkey was cooked
according to the directions, but the breast meat is pink. Will
it make us sick?
are just a few of the many questions received at the U.S.
Department of Agriculture’s Meat and Poultry Hotline concerning
the color of meat and poultry. Color is important when meat and
poultry are purchased, stored, and cooked. Often an attractive,
bright color is a consideration for the purchase. So, why are
there differences in the color and what do they mean? Listed
below are some questions and answers to help you understand the
affect the color of meat and poultry?
Myoglobin, a protein, is responsible for
the majority of the red color. Myoglobin doesn't circulate
in the blood but is fixed in the tissue cells and is
purplish in color. When it is mixed with oxygen, it becomes
oxymyoglobin and produces a bright red color. The remaining
color comes from the hemoglobin which occurs mainly in the
circulating blood, but a small amount can be found in the
tissues after slaughter.
Color is also influenced by the age of the animal, the
species, sex, diet, and even the exercise it gets. The meat
from older animals will be darker in color because the myoglobin level increases with age. Exercised muscles are
always darker in color, which means the same animal can have
variations of color in its muscles.
In addition, the color of meat and poultry can change as
it is being stored at retail and in the home (see
explanation in question 5). When safely stored in the
refrigerator or freezer, color changes are normal for fresh
meat and poultry.
Does a change in color
Change in color alone does not
mean the product is spoiled. Color changes are normal for
fresh product. With spoilage there can be a change in color
-- often a fading or darkening. In addition to the color
change, the meat or poultry will have an off odor, be sticky
or tacky to the touch, or it may be slimy. If meat has
developed these characteristics, it should not be used.
If the color of meat and
poultry changes while frozen, is it safe?
Color changes, while meat and poultry are frozen, occur
just as they do in the refrigerator. Fading and darkening,
for example, do not affect their safety. These changes are
minimized by using freezer-type wrapping and by expelling as
much air as possible from the package.
What are the white
dried patches on frozen meat and poultry?
The white dried patches indicate freezer burn. When meat
and poultry have been frozen for an extended period of time
or have not been wrapped and sealed properly, this will
occur. The product remains safe to eat, but the areas with
freezer burn will be dried out and tasteless and can be
trimmed away if desired.
THE COLOR OF MEAT
When displayed at
the grocery store, why is some meat bright red and other meat
very dark in color?
Optimum surface color of fresh meat
(i.e., cherry-red for beef; dark cherry-red for lamb;
grayish-pink for pork; and pale pink
for veal) is highly unstable and short-lived. When meat is
fresh and protected from contact with air (such as in vacuum
packages), it has the purple-red color that comes from
myoglobin, one of the two key pigments responsible for the
color of meat. When exposed to
air, myoglobin forms the pigment,
oxymyoglobin, which gives meat a pleasingly cherry-red
color. The use of a plastic wrap that allows oxygen to pass
through it helps ensure that the cut meats will retain this
bright red color. However, exposure to store lighting as
well as the continued contact of myoglobin and oxymyoglobin
with oxygen leads to the formation of metmyoglobin, a
pigment that turns meat brownish-red. This color change
alone does not mean the product is spoiled (see explanation
in question 2).
Why is pre-packaged ground
beef red on the outside and sometimes grayish-brown on the
These color differences do not indicate that the meat is
spoiled or old. As discussed earlier, fresh cut meat is
purplish in color. Oxygen from the air reacts with meat
pigments to form a bright red color which is usually seen on
the surface of ground beef purchased in the supermarket. The
interior of the meat may be grayish-brown due to the lack of
oxygen penetrating below the surface.
A beef roast has darkened
in the refrigerator, is it safe?
Yes, it is safe. The darkening is due to oxidation, the
chemical changes in myoglobin due to the oxygen content.
This is a normal change during refrigerator storage.
Can cooked ground beef
still be pink inside?
Yes, ground beef can be pink inside after it is safely
cooked. The pink color can be due to a reaction between the
oven heat and myoglobin, which causes a red or pink color.
It can also occur when vegetables containing nitrites are
cooked along with the meat. Because doneness and safety
cannot be judged by color, it is very important to use a
meat thermometer when cooking ground beef. To be sure all
harmful bacteria are destroyed, cook all ground beef
products to an internal temperature of 160 ° F throughout.
What causes iridescent
colors on meats?
Meat contains iron, fat,
and other compounds. When light hits a slice of meat, it
splits into colors like a rainbow. There are various
pigments in meat compounds that can give it an iridescent or
greenish cast when exposed to heat and processing. Wrapping
the meat in airtight packages and storing it away from light
will help prevent this situation. Iridescence does not
represent decreased quality or safety of the meat.
grayish or green color on cured meats?
Exposure to light and oxygen causes oxidation to take
place, which causes the breaking down of color pigments
formed during the curing process. Chemicals in the cure and
oxygen, as well as energy from ultraviolet and visible
light, contribute to both the chemical breakdown and
microbial spoilage of the product. Cure, such as nitrite,
chemically changes the color of muscle. Curing solutions are
colored in order to distinguish them from other ingredients
(such as sugar or salt) used in fresh and cured meat
products. For example, cured raw pork is gray, but cured
cooked pork (e.g., ham) is light pink.
THE COLOR OF POULTRY
What is the usual color of raw poultry?
Raw poultry can vary from a
bluish-white to yellow. All of these colors are normal and
are a direct result of breed, exercise, age, and/or diet.
Younger poultry has less fat under the skin, which can cause
the bluish cast, and the yellow skin could be a result of
marigolds in the feed.
What causes the
differences in color of raw ground poultry?
Ground poultry varies in color
according to the part being ground. Darker pink means more
dark meat was used and a lighter pink means more white meat
was included (or skin was included). Ground poultry can
contain only muscle meat and skin with attached fat in
proportion to the whole bird.
What causes dark
bones in cooked poultry?
Darkening of bones and meat
around the bones occurs primarily in young (6-8 weeks)
broiler-fryer chickens. Since the bones have not calcified
or hardened completely, pigment from the bone marrow seeps
through the bones and into the surrounding area. Freezing
can also contribute to this darkening. This is an aesthetic
issue and not a safety one. The meat is safe to eat when all
parts have reached at least 160 °
What color is
safely cooked poultry?
Safely cooked poultry can vary in color from white to
pink to tan. When the temperature of the poultry as measured
in the thigh has reached 180 ° F, there is usually no other
site in the bird lower than the safe temperature of 160 ° F.
Check the temperature in several locations, being sure to
include the wing joint. All the meat—including any that
remains pink—is safe to eat as soon as all parts reach at
least 160 ° F.
Why is some
cooked poultry pink?
Chemical changes occur during cooking. Oven gases in a
heated gas or electric oven react chemically with hemoglobin
in the meat tissues to give it a pink tinge. Often meat of
younger birds shows the most pink because their thinner
skins permit oven gases to reach the flesh. Older animals
have a fat layer under their skin, giving the flesh added
protection from the gases. Older poultry may be pink in
spots where fat is absent from the skin. Also, nitrates and
nitrites, which are often used as preservatives or may occur
naturally in the feed or water supply used, can cause a pink
If fully cooked
smoked poultry is pink, is it safe?
Poultry grilled or smoked outdoors can be pink, even when
all parts have attained temperatures well above 160 ° F. There may be a pink-colored rim
about one-half inch wide around the outside of the cooked
product. Commercially prepared, smoked poultry is usually
pink because it is prepared with natural smoke and liquid
smoke flavor. Federal regulations require all processed
poultry to be cooked to at least 160 ° F instantly, or to an
equivalent level of safety attained by this minimum
USDA Meat and Poultry
Hotline: 1-888-674-6854 (1-888-MPHotline)
Food Safety Inspection
Article Courtesy of the
American Association of Meat Processors