Pigments Found in Meat Main Page
- Color Intensity
- Meat Color and PH
- Color Stability
- Cooked Meat Pigments
- Pinking of Uncurred Cooked Products
- Irridiscence in Processed Meat Products
Pinking of Uncured Cooked Products
Pinking is caused by many factors and should not be confused with the hard to cook phenomena caused by high meat pH. Cooked product can become contaminated with the nitrite.
It takes only small amounts of nitrite to develop cured meat color. Although 50 parts per million are necessary to maintain the pink color in cooked ground beef, pink color can show up with levels as low as 5 parts per million.
A pink color can also be formed in slow cooked meat products that have not been contaminated with nitrite. It is caused by specific conditions that promote interaction of natural meat pigments and nitrogen containing constituents of meat. This color is actually desired in products such as Texas barbecue. Surface pinking, also termed "pink ring" can occur if gas ovens or barbecue grills are used to cook meat products. Incomplete burning of the gas or contaminates in the gas result in the formation of nitrogen dioxide and nitric oxide. Naturally occurring nitrates found in water and vegetables can be converted to nitrites during thermal processing and can cause a pink color to form.This occurrence is rare because nitrates take longer periods of time to be converted to nitrites which in turn yield nitric oxide that forms the color pigment necessary for the pink color. This color is usually seen in slow cooked soups or stews.
Another cause of pink color is the presence of carbon monoxide (CO). Carbon monoxide combines with natural pigments in meat to produce a dark red color in raw and cooked meat. Small amounts of the gas may come from dry ice, or carbon dioxide freezer tunnels used in hamburger production and it will affect color. Carbon monoxide, which has a greater affinity for myoglobin than oxygen, binds almost irreversibly to the raw color pigment. Research has shown that if CO is used in modified atmosphere packages a dark red color develops and it remains after cooking.