Solanine, the alkaloid in potatoes, is poisonous, but you would have
to eat several pounds of potatoes to be affected.
Thanks for reminding me of that word. I looked it up. The following
is enlightening, sobering, and instructional. We are well advised to
grow our homestead potatoes in a manner certain to keep solanine
levels low, either by hilling or by heavy mulch. And note the higher
solanine level if late-blight occurs.
Solanine
From Wikipedia, the free encyclopedia
Jump to: navigation, search
Solanine
Identifiers
CAS number [20562-02-1]
PubChem 30185
MeSH Solanine
Properties
Molecular formula C45H73NO15
Molar mass 868.059
Except where noted otherwise, data are given for
materials in their standard state
(at 25 °C, 100 kPa)
Infobox disclaimer and references
Solanine is a glycoalkaloid poison found in species of the nightshade
family. It can occur naturally in any part of the plant, including
the leaves, fruit, and tubers. It is very toxic even in small
quantities. Solanine has both fungicidal and pesticidal properties,
and it is one of the plant's natural defenses.
Contents
[hide]
* 1 Solanine poisoning
o 1.1 Symptoms
o 1.2 Correlation with birth defects
* 2 Solanine in potatoes
o 2.1 Avoidance
* 3 Other uses of solanine
* 4 References
* 5 External links
[edit] Solanine poisoning
[edit] Symptoms
Solanine poisoning is primarily displayed by gastrointestinal and
neurological disorders. Symptoms include nausea, diarrhea, vomiting,
stomach cramps, burning of the throat, heart arrhythmia, headache and
dizziness. Hallucinations, loss of sensation, and paralysis, fever,
jaundice, dilated pupils and hypothermia have been reported in more
severe cases.
In large quantities, solanine poisoning can cause death. 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.
Symptoms usually occur 8 to 12 hours after ingestion, but may occur
as rapidly as 30 minutes after eating high-solanine foods.
[edit] Correlation with birth defects
Some studies show a correlation between the consumption of potatoes
suffering from late-blight (which increases solanine and other
glycoalkaloid levels) and the incidence of congenital spina bifida in
humans. However other studies have shown no correlation between
potato consumption and the incidence of birth defects. [1]
[edit] Solanine in potatoes
Solanine occurs naturally in all nightshades, including tomatoes,
capsicum, tobacco and eggplant, as well as plants from other species.
However the most ingested solanine is from the consumption of potatoes.
Potatoes naturally produce solanine and chaconine, a related
glycoalkaloid, as a defense mechanism against insects, disease, and
predators. Potato leaves and stems are naturally high in glycoalkaloids.
When potato tubers are exposed to light, they turn green and increase
glycoalkaloid production. This is a natural defense to help prevent
the uncovered tuber from being eaten. The green colour is from
chlorophyll, and is itself harmless. However, it is an indication
that increased level of solanine and chaconine may be present.
Some diseases, such as potato blight, can dramatically increase the
levels of glycoalkaloids present in potatoes. This is believed to be
a natural reaction of the plant in response to disease and damage.
Commercial varieties of potatoes are screened for solanine levels,
and most have a solanine content of less than 0.2mg/g. However
potatoes that have been exposed to light and started to green can
show concentrations of 1mg/g or more. In these situations a single
unpeeled potato can result in a dangerous dose.
[edit] Avoidance
Solanine and chaconine are present in potato shoots. In potato tubers
30–80% of the solanine develops in and under the skin and thus may be
removed by peeling and removing the eyes. This is advisable if the
tubers show green, but is not a guarantee of safety. Potatoes that
show green under the skin should never be eaten. Potato greening
strongly suggests solanine build-up although each process can occur
without the other. A bitter taste in a potato may be a more reliable
indicator of toxicity.
Deep-frying potatoes at 170° C (306° F) will effectively lower
glycoalkaloid levels, but microwaving is only somewhat effective and
boiling is not.