Why do Russians eat potatoes without the skin? ARSENIC

[Paul B. Gallagher]

[Resending because I didn't notice that pscotto was diverting my reply 
to his private address.]

pscotto at mtholyoke.edu wrote:

> Wait one darn minute. Solanine is a poison! So there!

Yes. As I said:

>> The solanine and other glycoalkaloids mentioned above are toxic, but 
>> contain no arsenic:
>> <http://en.wikipedia.org/wiki/Solanine>

"Toxic" means "poisonous," though the latter has more punch for the
general reader.

The cited article also says (in the part I quoted), emphasis added:

<http://oregonstate.edu/potatoes/storproc.htm>
> Surface greening is due to chlorophyll formation and is harmless. 
> However, its presence in potatoes is undesirable because of marketing
> restrictions and the fact that ***at times*** an alkaloid called
> solanine increases with the chlorophyll. Solanine and other
> glycoalkaloids cause potatoes to have a bitter, undesirable flavor.

Obviously, the end user can't measure solanine levels directly, so he
will steer clear of potatoes that have a greenish cast, but the experts say:

<http://en.wikipedia.org/wiki/Solanine>
"One study suggests that doses of 2 to 5 mg per kilogram of body weight
can cause toxic symptoms, and doses of 3 to 6 mg per kilogram of body
weight can be fatal."

For a 60-kg adult (132 lb.), 2 mg/kg adds up to 120 mg, and 6 mg adds up
to 360 mg.

Wikipedia goes on:
"Commercial varieties of potatoes are screened for solanine levels, and
most have a solanine content of less than 0.2 mg/g. However, potatoes
that have been exposed to light and started to green can show
concentrations of 1 mg/g or more. In these situations a single unpeeled
potato can result in a dangerous dose."

If the potato has a concentration of 1 mg/g and we need 120 mg for
toxicity (not death, just an upset stomach), then we would need to eat
120 g of peel -- very doable if you don't mind the bitter taste.

Finally, Wikipedia notes:

"Showing green under the skin strongly suggests solanine build-up in
potatoes although each process can occur without the other. A bitter
taste in a potato is another, potentially more reliable indicator of
toxicity. Because of the bitter taste and appearance of such potatoes,
solanine poisoning is rare outside conditions of food shortage."

As a person who frequently eats potato skins, I can confirm that the
bitter taste of greening potatoes is quite unpleasant, and I've always
discarded those. Now I know why. On the other hand, healthy potato skins
(in tubers that have not reacted to sunlight by producing these toxins)
are both safe and tasty.

-- 
War doesn't determine who's right, just who's left.
--
Paul B. Gallagher
pbg translations, inc.
"Russian Translations That Read Like Originals"
http://pbg-translations.com

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