Asparagus

by Lee McGuire
May 2001

 

Common Name:        Asparagus
Botanical Name:       Asparagus officinalis
Family Name:           Liliaceae

What member of the lily family is one of the most nutritious vegetables that either you or our fine feathered friend can eat? Why, Asparagus, of course! Each spear is low calorie (for you) and packed with nutrients (for our friends).

History

A little snippet of the history of this member of the lily family is perhaps in order. Asparagus has been with us for a long time. It was originally found edging salt marsh areas in southern Europe in countries circling the Mediterranean Sea. While the ancient Greeks collected asparagus, it was the Romans who figured out how to grow it and preserve the tender spears. They first discovered the best preservation method for these tasty spears by racing chariots from Rome to the snow covered Alps in order to bury the tender spears in the snow. Augustus Caesar expressed enjoyment of the young fresh sprouts in season as well as those preserved in his alpine storage vaults; but, it was Louis the XIV who wanted the tasty spears all year round, so he had the vegetable grown in his green houses.

Asparagus roots have been used in holistic medicine as a remedy for kidney and bladder stones since the Middle Ages. The native people of North America dried the plant and used it as a diuretic.

Europeans prefer all white asparagus, which they obtain by keeping the spears buried beneath the soil. You may perhaps have noticed reading these paragraphs that all the areas mentioned are in temperate climates. If this plant doesn’t get a cool rest or drought period, the result will be fern overgrowth and a lack of production of the delicious spears. Is it then any wonder that in North America some of the major asparagus growing areas are found in the temperate regions such as Michigan, Washington, Northern California and Nova Scotia?

Nutrition

This vegetable contains no fat or cholesterol and is very low in sodium. It is low in calories, only 20 per 5.3 oz. serving, less than four calories per spear. It is an excellent source of vitamins A and C as well as folacin; and, is a significant source of some of the B vitamins such as niacin and Vitamin B6.

Rutin, a phytochemical found in each spear, helps to strengthen capillary walls. However, one of the more impressive constituents of asparagus in this author’s opinion is the high content of Glutathione (GSH), a potent anticarcinogen and antioxidant. According to the Michigan Asparagus Advisory Board, “GSH is used to detoxify carcinogenic electrophiles and protect cells from oxidative damage, thereby preventing damage to DNA and other macromolecules. Thus, GSH acts as an initial and primary defense against chemicals that can cause cell transformation and/or cell death. Asparagus had the highest GSH content of the several foods tested.”

Storage

Like most fresh foods, asparagus is most nutritious when eaten as soon as possible after picking; however, fresh asparagus may be stored in a couple of ways. Put approximately an inch of water in a glass jar and stand the spears upright in the refrigerator and cover with a plastic bag. Alternatively, dampen a paper towel with water and place in the bottom of a plastic storage bag then add the asparagus and seal the bag. If you keep the humidity high and prevent loss of cellular water from the spears, asparagus will last for three or four days before it starts to become more fibrous.

Supply and Preservation

If like many of us, you live in a climate with a short growing season, you can grow your own asparagus if you are ambitious and patient. Crowns do not generally reach full production for about three years. Alternatively, asparagus may be purchased from a supplier - preferably organically grown.

The spears can easily be frozen for future use. Like most green vegetables, asparagus requires blanching. Select spears of approximately equal size, remove the scales with a paring knife and blanch in boiling water. Blanching time for asparagus is approximately two minutes for medium-sized spears and three minutes for larger sized spears. After blanching, immediately immerse in ice-cold water, drain, package and put in the freezer. The author prefers to lay the individual spears out on a cookie sheet covered with wax paper and place them in the freezer for approximately one hour. This allows each spear to freeze individually and prevents the spears sticking together and forming a clump. After an hour or so, bag up the asparagus, remove excess air and place back in the freezer.

Asparagus, like all vegetables, should and can be part of a balanced diet that you feed your beloved bird. The author of this article is a firm believer in rotating all vegetables in a bird’s diet.

Bibliography:
Michigan Asparagus Advisory Board
USDA Nutrient Database
Jersey Asparagus Farms, Inc.
The National Food Safety Database