Saturday, April 23, 2011
Only young asparagus shoots are commonly eaten; once the buds start to open, the shoots quickly turn woody and become strongly flavoured.
Asparagus is low in calories and is very low in sodium. It is a good source of vitamin B6, calcium, magnesium and zinc, and a very good source of dietary fiber, protein, vitamin A, vitamin C, vitamin E, vitamin K, thiamin, riboflavin, rutin, niacin, folic acid, iron, phosphorus, potassium, copper, manganese and selenium, as well as chromium, a trace mineral that enhances the ability of insulin to transport glucose from the bloodstream into cells. The amino acid asparagine gets its name from asparagus, the asparagus plant being rich in this compound.
The shoots are prepared and served in a number of ways around the world, typically as an appetizer or vegetable side dish. In Asian-style cooking, asparagus is often stir-fried. Cantonese restaurants in the United States often serve asparagus stir-fried with chicken, shrimp, or beef, and also wrapped in bacon. Asparagus may also be quickly grilled over charcoal or hardwood embers. It is also used as an ingredient in some stews and soups.
Asparagus can also be pickled and stored for several years. Some brands may label shoots prepared this way as "marinated".
The bottom portion of asparagus often contains sand and dirt, so thorough cleaning is generally advised in cooking it.
Nutrition studies have shown asparagus is a low-calorie source of folate and potassium. Its stalks are high in antioxidants. "Asparagus provides essential nutrients: six spears contain some 135 micrograms (µg) of folate, almost half the adult RDI (recommended daily intake), 20 milligrams of potassium," notes an article in Reader's Digest. Research suggests folate is key in taming homocysteine, a substance implicated in heart disease. Folate is also critical for pregnant women, since it protects against neural tube defects in babies. Several studies indicate getting plenty of potassium may reduce the loss of calcium from the body.
"Asparagus has long been recognized for its medicinal properties," wrote D. Onstad, author of Whole Foods Companion: A Guide for Adventurous Cooks, Curious Shoppers and Lovers of Natural Foods. "Asparagus contains substances that act as a diuretic, neutralize ammonia that makes us tired, and protect small blood vessels from rupturing. Its fiber content makes it a laxative, too."