Frozen prawns - blue dye
I'v been given some prawns from parents where they bought in bulk. The prawns leak a blue dye? Does anyone know if this is normal?
Best Answer
The color should not be a problem for you as long as red coloring in beef packaging doesn't bother you.
That's right, that blue dye is blood. Crustaceans, like the prawn, crab, and lobster, and horseshoe crabs have hemocyanin in their blood to transport oxygen instead of hemoglobin, which we have. Hemocyanin has copper in it to give it its color rather than the iron hemoglobin has.
So to answer your question specifically: Yes, it is normal.
Pictures about "Frozen prawns - blue dye"
Why do prawns turn blue?
When the crustaceans are alive, the astaxanthin is tightly wrapped up and trapped by a special protein called \u201ccrustacyanin\u201d. This is why live crabs and prawns usually look bluish-grey.Can raw prawns be blue?
Prawns can be bought raw or cooked. They can be used in the same way and in the same kind of dishes, though cooked prawns can be eaten cold as they are. When raw, they are blue-grey in colour (and are sometimes called green prawns).Are prawns dyed?
However, no matter what you call them, one fact remains: they only go pink when boiled. The raw prawn contains a complex mixture of pigments, including carotenoids. These give the flesh its natural "blueish", translucent appearance.Why do frozen prawns go black?
Black spot occurs when the shell on the shrimp begins turning black within hours or days after harvesting. This darkening is due to an enzyme process causing oxidation in the shrimp, just like in cut apples. It's not harmful or indicative of spoilage, but it's not attractive.How to Defrost Shrimp and Scallops
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
Images: Steve Johnson, Zaksheuskaya, invisiblepower, Riccardo