system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do most crustaceans / seafood turn from a grayish color to a red / orange color when heat is applied?
gpt
Lobsters and crabs, etc. have a compound called astaxanthin in their shells. This compound is bright red, but it is usually stuck to another compound called crustacyanin that prevents its red color from showing. When the lobster is boiled, the astaxanthin gets separated from the crustacyanin, and it appears bright red since it is no longer stuck to the other chemical.