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 Corn
Indigenous to the Western Hemisphere, corn is the most abundant grain crop;
worldwide, it is exceeded only by wheat as a cereal grain. Most of the corn
grown in the United States and Canada is field, or dent, corn, which is
allowed to mature on its stalk, dried, and used as animal feed or processed
into flour to make cereals. Flint corn, another field variety, keeps better
than dent corn and is used to make corn-meal. Four corn has soft, starchy
kernels that are easily ground into flour, making it a favorite with Native
peoples to make tortillas and other corn dishes.
Sweet corn, which is harvested while still immature, is the type consumed as
a vegetable. It can be cooked in several different ways: on the cob or with
the soft kernels removed and served fresh, frozen, or canned for future use.
CORN AND NUTRITION
Corn is high in starch and protein, but it lacks two essential amino acids –
lysine and tryptophan; as a result, it is not a suitable protein substitute.
In undeveloped countries, children are sometimes fed a diet made up mostly
of corn, which can lead to two deficiency diseases: kwashiorkor, caused by
inadequate protein, and pellagra, resulting from a deficiency of niacin.
When corn is consumed along with beans and other legumes, however, it
provides a complete protein.
One medium ear of corn contains 83 calories. One cup of kernels provides 13
percent of the Recommended Dietary Allowance (RDA) for folate. It is also a
source or potassium, thiamine, and fiber.
Corn is a good source of lutein, a powerful antioxidant that may help lower
the risk of age-related macular degeneration, a common cause of blindness in
older adults.
Most of the niacin in corn is in the form of niacytin, which is not broken
down in the human digestive tract. Early nutrition researchers were puzzled
by the fact that Mexicans and South Americans did not develop pellagra, even
though their diets were made up mostly of corn. It was discovered that
combining the corn with an alkaline substance releases the niacin in
niacytin; thus, mixing cornmeal with lime water to make tortillas prevented
pellagra. Similarly, Natives in South America ground corn with alkaline
potash to loosen the bran, another practice that released niacin and
prevented pellagra.
While corn may not be a complete food, it is by far our most important farm
crop; not only is it fed to pigs, cattle, and other meat animals, but it is
also used in more than 800 different processed foods. This is why people who
are allergic to corn have difficulty finding corn-free processed foods.
POPCORN
A popular snack food, popcorn is a special variety that grows on a cob
smaller than those of sweet corn. As the kernels are heated rapidly, the
moisture inside them is converted to steam. When the steam pressure builds
to a certain point, it bursts the outer shell and the interior turns into a
fluffy mass of starch and fiber many times larger than the original kernel.
A cup of air-popped plain popcorn has only 30 calories, making it an ideal,
high-fiber snack. Popping the corn in oil and adding a tablespoon of butter,
however, increases the calorie content more than fivefold, to about 155 per
cup.
LATEST STUDIES REVEAL ....
Cooking sweet corn unleashes beneficial nutrients that can substantially
reduce your risk of heart disease and cancer, according to a study in the
Journal of Agricultural and Food Chemistry. The researchers found that the
longer the corn was cooked, the higher the level of antioxidants. In
addition to its antioxidant benefits, cooked sweet corn contains a phenolic
compound called ferulic acid, which may inhibit cancer-causing substances. |
