What is that chemical in my food? It's...
The Center for Science in the Public Interest has a glossary describing the nature and safety of food additives. They now have an app for smartphones, so you can look it up while shopping.
"Chemical Cuisine" Database Now on Sale in iTunes App Store, Android Market
Watch out for this one -
"Octyl acetate, or octyl ethanoate, is an ester that is formed from octanol (octyl alcohol) and acetic acid." (wikipedia)
Oh wait, that is the chemical naturally found in oranges that gives then their " orange" smell. It is also used in orange scented products.
When I was a kid in the 70s there was a magazine ad that showed the ingrediants of an orange by its chemical components.