While treating "pink slime" with ammonia has been in the news lately, another common practice has been less visible in the past few
years: treating meat, poultry, and fish with carbon monoxide (CO) gas.
CO is not a preservative, but it makes packaged meats look
pink and fresh without the use of dyes--it actually prevents the product from changing color as it gets old.
An estimated 70% of meat,
poultry and fish sold in the US is treated with CO before going on to grocery store shelves. This "atmospheric packaging" is practiced
in the US, Canada, Australia, the UK, and several European countries.
Proponents say that's not a problem and that appearance is not
an indicator of freshness. Well, if that's the case, why do it?
Opponents say that artificially keeping meats from looking their age
is a deceptive practice.
Though this video is from 2007, treating meat with carbon monoxide is a common practice today.
A couple of short videos might help understand why this is still going on.