The New Complete Book of Food
Storing This Food
Store fresh asparagus in the refrigerator. To keep it as crisp as possible, wrap it in a damp
paper towel and then put the whole package into a plastic bag. Keeping asparagus cool helps
it hold onto its vitamins. At 32°F, asparagus will retain all its folic acid for at least two weeks
and nearly 80 percent of its vitamin C for up to five days; at room temperature, it would lose
up to 75 percent of its folic acid in three days and 50 percent of the vitamin C in 24 hours.Preparing This Food
The white part of the fresh green asparagus stalk is woody and tasteless, so you can bend
the stalk and snap it right at the line where the green begins to turn white. If the skin is very
thick, peel it, but save the parings for soup stock.What Happens When You Cook This Food
Chlorophyll, the pigment that makes green vegetables green, is sensitive to acids. When
you heat asparagus, its chlorophyll will react chemically with acids in the asparagus or in
the cooking water to form pheophytin, which is brown. As a result, cooked asparagus is
olive-drab.
You can prevent this chemical reaction by cooking the asparagus so quickly that there
is no time for the chlorophyll to react with acids, or by cooking it in lots of water (which
will dilute the acids), or by leaving the lid off the pot so that the volatile acids can float off
into the air.
Cooking also changes the texture of asparagus: water escapes from its cells and they
collapse. Adding salt to the cooking liquid slows the loss of moisture.How Other Kinds of Processing Affect This Food
Canning. The intense heat of canning makes asparagus soft, robs it of its bright green
color, and reduces the vitamin A, B, and C content by at least half. (White asparagus,
which is bleached to remove the green color, contains about 5 percent of the vitamin A
in fresh asparagus.) With its liquid, canned asparagus, green or white, contains about 90
times the sodium in fresh asparagus (348 mg in 3.5 oz. canned against 4 mg in 3.5 oz. fresh
boiled asparagus).Medical Uses and/or Benefits
Lower risk of some birth defects. As many as two of every 1,000 babies born in the United
States each year may have cleft palate or a neural tube (spinal cord) defect due to their moth-
ers’ not having gotten adequate amounts of folate during pregnancy. The RDA for folate is