flamable substances in orange rind?

I have been aware for a long time that it is possible to ignite a volatile exudate of an orange rind in a dramatic puff of flame. What a great way to impress 8th grade students! (You simply peel off a good sized hunk of rind, light a match, place it about 1/4 inch from the outer surface of the peel and bend/fold the peel so that what’s inside the rind squirts out at the flame. Poof! Wizard of Oz!) But I would like to know what that substance is. I haven’t been able to discover it. Do other foods contain volatile substances too? Is there any practical use for the material, aside from its obvious use as a weapon? e.g. the state of Florida declaring war on, say, Missouri. “Stand back, he’s got an orange peel!”

I know the peel contains different alcohols and esters, many of which are flammable. But I’m not sure which exactly it contains.

Well, it’s basically just oil, but it also has other stuff in it that, since IANA biochemist, I’m not equipped to discuss, things like “terpenes”.

Keep away from eyes.

When you make candied orange peel, you have to be careful not to rub your eyes before you wash your hands.

My Grandmother used to save all the orange peel,dry it off and then use it to make a very good fire-lighter for coal fires.

There’s a substance called d-limonene (aka ®-1-isopropenyl-4-methylcyclohexene) that can be extracted from orange peels and that is commonly used as a cleaning solvent and a hand-cleaner-goop solvent because it has a really pleasant orange smell. Limonene is somewhat flammable (flash point of 115 F), and I wonder if this accounts for the flammability of orange peels.

A lot of people seem to assume that d-limonene is harmless because of the smell, but it’s not significantly chemically different from a lot of things that smell bad and that a lot of people would object to working with.

I used to work with paint that contained dipentene, which is a mixture of d- and l-limonene. Dipentene smells bad, and I bet most people wouldn’t want to use hand cleaner containing dipentene, but it’s pretty much the same as d-limonene. Even though d-limonene may not be any better for you than other unsaturated hydrocarbons, it’s a lot more fun to work with because of the smell.