Energy value (calories per serving): Low
Saturated fat: Low Cholesterol: None Carbohydrates: High Fiber: Low
Major vitamin contribution: Vitamin C
Major mineral contribution: Iron, potassium
About the Nutrients in This Food
Cucumbers are mostly (96 percent) water. Their dietary fiber is unique in that it can hold up to 30 times its weight in water compared to the fiber in wheat bran, which holds only four to six times its weight in water. But cucumbers have so much water that there is little room for anything else. Two ounces of fresh cucumber slices has less than one gram dietary fiber—and no significant amounts of vitamins or minerals.
The Most Nutritious Way to Serve This Food
Raw, fresh-sliced, with the unwaxed skin.
Diets That May Restrict or Exclude This Food
Buying This Food
Look for: Firm cucumbers with a green, unwaxed skin. In the natural state, the skin of the cucumber is neither shiny nor deep green, characteristics it
picks up when the cucumber is waxed to keep it from losing moisture during shipping and storage. The wax is edible, but some people prefer not to eat it, which means missing out on fiber. To get your cucumbers without wax, ask for pickling cucumbers, and note the difference in color and texture.
Choose cucumbers with a clean break at the stem end; a torn, uneven stem end means that the cucumber was pulled off the vine before it was ready. Technically, all the cucum- bers we buy are immature; truly ripe cucumbers have very large, hard seeds that make the vegetable unpalatable.
Avoid: Cucumbers with yellowing skin; the vegetable is so old that its chlorophyll pigments have faded and the carotenes underneath are showing through. Puff y, soft cucumbers are also past their prime.
Storing This Food
Store cucumbers in the refrigerator and use them as soon as possible. The cucumber has no starch to convert to sugar as it ages, so it won’t get sweeter off the vine, but it will get softer as the pectins in its cell wall absorb water. You can make a soft cucumber crisp again by slic- ing it and soaking the slices in salted water. By osmotic action, the unsalted, lower-density water in the cucumber’s cells will flow out across the cell walls out into the higher-density salted water and the cucumber will feel snappier.
Preparing This Food
R inse the cucumber under cold, running water. Check to see if the cucumber has been waxed by scraping the skin gently with the tip of your fingernail and then looking for waxy resi- due under the nail. If the skin is waxed, you can peel it off—but not until you are ready to use it, since slicing the cucumber tears its cell walls, releasing an enzyme that oxidizes and destroys vitamin C.
How Other Kinds of Processing Affect This Food
Pickling. Cucumbers are not a good source of iron, but pickles may be. If processed in iron vats, the pickles have picked up iron and will give you about 1 mg per pickle. Pickles made in stainless steel vats have no iron, nor do pickles made at home in glass or earthenware.
Adverse Effects Associated with This Food
Intestinal gas. Some sensitive people find cucumbers “gassy.” Pickling, marinating, and heating, which inactivate enzymes in the cucumber, may reduce this gassiness for certain people—although others find pickles even more upsetting than fresh cucumbers.
False-positive test for occult blood in the stool. The active ingredient in the guaiac slide test for hidden blood in feces is alphaguaiaconic acid, a chemical that turns blue in the presence of blood. Alphaguaiaconic acid also turns blue in the presence of peroxidase, a chemical that occurs naturally in cucumbers. Eating cucumbers in the 72 hours before taking the guaiac test may produce a false-positive result in people who not actually have any blood in their stool.
Monoamine oxidase (MAO) inhibitors. Monoamine oxidase inhibitors are drugs used to treat depression. They inactivate naturally occurring enzymes in your body that metabolize tyramine, a substance found in many fermented or aged foods. Tyramine constricts blood vessels and increases blood pressure. If you eat a food, such as pickles, containing tyramine while you are taking an M AO inhibitor, you cannot effectively eliminate the tyramine from your body. The result may be a hypertensive crisis.