You’ve covered your bases— the turkey was in the oven with a digital probe, or separated into white and dark meat, and then cooked to the perfect internal temperature. But when you begin carving your bird, you notice the devastating color that is sure to break the hearts of hunger-mad guests moments before Thanksgiving dinner is served: pink. No need to panic. If you’ve carefully cooked your bird, there are other reasons why you might see that hue.
Several phenomena can cause discoloration in cooked meat. By far the most common, and to some people the most off-putting, is the pink discoloration that frequently occurs in poultry and pork that have been over cooked to temperatures above 80 °C / 175 °F or so. This pink tint makes some people think that the meat is still slightly raw—a common complaint with Thanksgiving and Christmas birds. In pork, the pink hue may even lead diners to suspect that a sneaky cook has injected nitrites into the meat.
In fact, a pigment known as cytochrome is to blame. Cytochrome helps living cells to burn fat. At high temperatures, it loses its ability to bind oxygen and turns pink. Over time, the pigment does regain its ability to bind oxygen, and the pink tinge fades. That is why the leftover meat in the refrigerator rarely seems to have this unseemly blush the next day.
Pink discoloration can also come in other forms, such as spots and speckles. Nearly all of these blotches are the result of the unusual way that various protein fragments and thermally altered pigment molecules bind oxygen. None of them indicate that the meat is still raw or that it will make you ill. Nor do they implicate a sneaky cook.
-Adapted from Modernist Cuisine: The Art and Science of Cooking