Why does orange pith make my lips tingle?

March 6, 2008 1:57 PM

When I peel an orange or tangerine, I love to eat the pith off of the rind. When I do this, my lips always tingle for a while afterwards. What causes this? I've heard that orange piths have more vitamin C than the fruit itself, so is it the vitamin C causing the tingling?
posted by mahamandarava to food & drink (15 answers total)

I think it's the citric acid that you're feeling. I sometimes feel this too when I eat an orange.
posted by spikeleemajortomdickandharryconnickjrmints at 2:05 PM on March 6, 2008

Most of the oils are in the rind, that may be what's causing the tingling.
posted by wafaa at 2:30 PM on March 6, 2008

Yeah, I'd second the volatile oils (like limonene) that are prominent in citrus rinds.
posted by nanojath at 2:49 PM on March 6, 2008

I can't believe this, but I was thinking the same thing last night. I like to start to peel oranges by sort of half biting the peel to get a finger hold so I can start peeling it. When I do this it tingles and actually feels like it's burning for a little while after where the peel touched my lip. Normally touching the peel does nothing. I think it's from the oil or something in the peel that comes out when I bite it.
posted by sanka at 3:10 PM on March 6, 2008

Sanka I thought I was the only person in the world who did that.
Except it's for a thumb hold - always just the thumb.
posted by Flashman at 4:02 PM on March 6, 2008

I thought it was the pesticide...
posted by onepapertiger at 4:08 PM on March 6, 2008

Orange oil is a skin irritant, due to the limonene content as nanojath pointed out.
posted by oneirodynia at 4:58 PM on March 6, 2008

Nope, Flashman, me makes three. Get weird looks when I do it - I guess folks think I'm gonna eat the whole orange, peel and all.
posted by notsnot at 5:46 PM on March 6, 2008

Not answering the question (sorry), but you guys who like to nibble the rind might like the tiny (cherry tomato size and smaller) oranges they have here in Korea -- you eat 'em whole, rind and all. Your friendly local Korean grocery might have them.
posted by stavrosthewonderchicken at 12:50 AM on March 7, 2008

I'm fairly sure that one of the oils in the zest of oranges is oil of wintergreen (methyl salicylate), better known as one of the components of Deep Heat. Perhaps that's responsible for the tingling?

(We fractionally distilled the oils from the zest of a large pile of oranges during an A-Level chemistry class many years ago, so I can't remember whether any synthesis steps were required unfortunately.)
posted by pharm at 2:20 AM on March 7, 2008

It's possible we synthesised the methyl salicylate from the limonene in the zest of course.
posted by pharm at 2:30 AM on March 7, 2008

stavrosthewonderchicken, I think those are kumquats.
posted by bassjump at 4:42 AM on March 7, 2008

Have you considered that you might be mildly allergic to oranges? Recently I started noticing tingling in my lips and brief numbness when I ate oranges or had freshly squeezed orange juice, and I eventually caved and went to an allergist who diagnosed me with an allergy after a skin prick test. I don't eat the pith, but this certainly seems like a distinct possibility to me in addition to the ones mentioned above. I would imagine that the oils in there would produce a stronger reaction than the orange's flesh.

I love oranges, and being allergic to them sucks.
posted by Jupiter Jones at 7:35 AM on March 7, 2008

Made me think of Spilanthes, which contains limonene but also "spilanthol, which is responsible for the trigeminal and saliva-inducing effect". That effect being a serious tingling sensation.
posted by dragonsi55 at 10:28 AM on March 7, 2008

stavrosthewonderchicken, I think those are kumquats.

Not according to the cross-sectional picture at that Wikipedia page. I dunno. The things I have in mind are really precisely like little teeny oranges.
posted by stavrosthewonderchicken at 12:50 AM on March 18, 2008