system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What happens to turn lobster bright red when boiled?
gpt
The dramatic color change during cooking has to do with the way certain biochemicals inside the shellfish react to heat. Lobsters and crabs have a pigment called astaxanthin in their shells. Astaxanthin is a carotenoid pigment: absorbing blue light and appearing red, orange or yellow in color.