Why prawns turn pink

But heat loosens the hold these protein chains have on the carotenoids and releases the astaxanthin, turning the shrimp its lovely shade of pink. This is the same reason lobsters turn red when you cook them. News U. Politics Joe Biden Congress Extremism. Special Projects Highline. HuffPost Personal Video Horoscopes. Get the Shrimp Cakes recipe by Simply Recipes. Get the Shrimp Dip recipe by Simply Recipes. Get the Cioppino recipe by Simply Recipes. Suggest a correction.

Parchment, Wax And Freezer Paper. Thanksgiving Without Turkey? Newsletter Sign Up. This is a large group of colour molecules, the molecule that turns a carrot carotene orange is also part of it.

However, in raw shrimp this astaxanhin is bound to proteins forming a complex called crustacyanin. This causes the two molecules bound together to show as blue! Light cannot be reflected in the right way for it to show the pink colour.

When shrimp are cooked the protein denatures it unfolds and changes shape due to the high temperatures. As a result, the astaxanthin is unbound now and now reflects the light differently, causing the shrimp to be pink! It probably is a combination of time and temperature that will determine whether enough of the protein has denatured for the shrimp to turn pink.

This depends on the exact composition of the shrimp. Also, not all proteins will break down at the exact same time. You seem to be able to watch into the shrimp slightly. During cooking this translucency changes in a white colour, as it does for many other white fish. This change of colour is similar to that of an egg white turning white when boiled or cooked and is caused by the same mechanism: protein denaturation. Proteins are heat sensitive. Proteins tend to be folded up in all sorts of complex configurations helices, curls.

But when they are heated to high enough temperatures they can uncurl and extend. It is not just heat that can cause this transformation from translucent to white. Acids can do the same by denaturing the proteins.

It is a similar process going on but caused by acidity instead of heat. When you cook shrimp it is not just the colour that changes, the shape changes as well. Once the shrimps starts heating up considerably, they will start to curl up.