Red tuna and freshness

[Peter Aitken]

A lot of people look for nice red tuna, thinking it is a sign a freshness.
Not necessarily! Treatment with carbon monoxide can give a nice red color
that lasts a long time. It's called tailpipe tuna.

http://obsentinel.womacknewspapers.com/articles/2005/12/03/top_stories/tops028102.txt

--
Peter Aitken