The New Complete Book of Food
Solanine is made in the green parts of the plant, the leaves, the stem, and any green
spots on the skin. Potatoes exposed to light produce solanine more quickly and in higher
amounts than potatoes stored in the dark, but all potatoes produce some solanine all the
time. Solanine does not dissolve in water, nor is it destroyed by heat; any solanine present in
a raw potato will still be there after you cook it. It is estimated than an adult might have to
eat about three pounds of potatoes or 2.4 pounds of potato skins at one sitting to experience
the first gastrointestinal or neurological signs of solanine poisoning. A child will react to
smaller amounts, 1.5 pounds potatoes, 1.4 pounds potato skins. The U.S. government does
not permit the sale of potatoes containing more than 200 ppm (parts per million) solanine.
The potatoes we buy usually contain only 100 ppm, but the safest course is to discard all
sprouting potatoes or potatoes with green spots on the skin.Diets That May Exclude or Restrict This Food
Low-carbohydrate diet
Low-salt diet (canned potatoes, potato chips, potato sticks, and the like)The Most Nutritious Way to Serve This Food
As fresh as possible, with meat, milk, or grains to complete the potato’s proteins.
With the skin, which is a valuable source of food fiber.Buying This Food
Look for: Firm potatoes with unscarred, unblemished skin. Different varieties of potatoes
have skins of different thickness. This has no effect at all on the nutritional value of the
potato.
Avoid: Potatoes with peeling skin (an immature vegetable that won’t store well); potatoes
with wrinkled or blemished skin (there may be decay inside); potatoes with green spots or
sprouts growing out of the eyes (higher than normal levels of solanine); or moldy potatoes
(potentially hazardous toxins).Storing This Food
Store potatoes in a dark, dry cabinet or root cellar to prevent sprouting and protect them
from mold. The temperature should be cool, but not cold, since temperatures below 50°F
encourage the conversion of the potato’s starches to sugar. If the potatoes are frozen, they
will develop black rings inside.
Use potatoes as quickly as possible. Vitamin C is sensitive to oxygen, so the longer
potatoes are stored, the less vitamin C they will have.