Cooking with Celery

Celery Nutritional Profile
Energy value (calories per serving): Low
Protein: Moderate

Fat: Low
Saturated fat: Low

Cholesterol: None

Carbohydrates: High

Fiber: Moderate

Sodium: High
Major vitamin contribution: Folate
Major mineral contribution: Potassium, phosphorus

About the Nutrients in Celery
Celery has moderate amounts of dietary fiber and small amounts of the B vitamin folate. One-half cup diced raw celery has 1 g dietary fiber and 17 mcg folate (8.5 percent of the RDA for a man, 9 percent of the RDA for a woman).

The Most Nutritious Way to Serve Celery
Fresh, filled with cheese to add protein.

Diets That May Restrict or Exclude Celery
Low-fiber diet

Low-sodium diet

Buying Celery
Look for: Crisp, medium-size pale green celery with fresh leaves. Darker stalks have more vitamin A but are likely to be stringy.

Avoid: Wilted or yellowed stalks. Wilted stalks have lost moisture and are low in vitamins A and C. Yellowed stalks are no longer fresh; their chlorophyll pigments have faded enough to let the yellow carotenes show through.
 

Avoid bruised or rotten celery. Celery cells contain chemicals called furocoumarins (psoralens) that may turn carcinogenic when the cell membranes are damaged and the furocoumarins are exposed to light. Bruised or rotting celery may contain up to a hundred times the psoralens in fresh celery.
 

Storing Celery
Handle celery carefully to avoid damaging the stalks and releasing furocoumarins. Refrigerate celery in plastic bags or in the vegetable crisper to keep them moist and crisp. They will stay fresh for about a week.

Preparing Celery
Rinse celery under cold running water to remove all sand and dirt. Cut off the leaves, blanch them, dry them thoroughly, and rub them through a sieve or food mill. The dry powder can be used to season salt or frozen for later use in soups or stews.
 

What Happens When You Cook Celery
When you cook celery the green flesh will soften as the pectin inside its cells dissolves in water, but the virtually indestructible cellulose and lignin "strings" on the ribs will stay stiff. If you don't like the strings, pull them off before you cook the celery.

Cooking also changes the color of celery. Chlorophyll, the pigment that makes green vegetables green, is very sensitive to acids. When you heat celery, the chlorophyll in its stalks reacts chemically with acids in the celery or in the cooking water to form pheophytin, which is brown. The pheophytin will turn the celery olive-drab or, if the stalks have a lot of yellow carotene, bronze.
 

You can prevent this natural chemical reaction and keep the celery green by cooking it so quickly that there is no time for the chlorophyll to react with the acids, or by cooking it in lots of water (which will dilute the acids), or by cooking it with the lid off the pot so that the volatile acids can float off into the air.
 

Medical Uses and/or Benefits of Celery
Protection against certain cancers. According to the American Cancer Society, fiber-rich foods and vegetables that provide vitamins A and C may lower the risk of cancers of the gastrointestinal and respiratory tracts.
 

Adverse Effects Associated with Celery
Contact dermatitis. Celery contains limonene, an essential oil known to cause contact dermatitis in sensitive individuals. (Limonene is also found in dill, caraway seeds, and the peel of lemon and limes.)
 

Photosensitivity. The furocoumarins (psoralens) released by damaged or moldy celery are photosensitizers as well as potential mutagens and carcinogens. Constant contact with these chemicals can make skin very sensitive to light, a problem most common among food workers who handle large amounts of celery without wearing gloves.
 

Nitrate/nitrite poisoning. Like beets, eggplant, lettuce, radish, spinach, and collard and turnip greens, celery contains nitrates that convert naturally into nitrites in your stomach and then react with the amino acids in proteins to form nitrosamines. Although some nitrosamines are known or suspected carcinogens, this natural chemical conversion presents no known problems for a healthy adult. However, when these nitrate-rich vegetables are cooked and left to stand at room temperature, bacterial enzyme action (and perhaps some enzymes in the plants) convert the nitrates to nitrites at a much faster rate than normal. These higher-nitrite foods may be hazardous for infants; several cases of "spinach poisoning" have been reported among children who ate cooked spinach that had been left standing at room temperature.