The New Complete Book of Food
Cooking fresh corn for several minutes in boiling water may destroy at least half of
its vitamin C. At Cornell University, food scientists found that cooking fresh corn in the
microwave oven (two ears/without water if very fresh/4 minutes/600–700 watts) preserves
most of the vitamin C.How Other Kinds of Processing Affect This Food
Canning and freezing. Canned corn and frozen corn both have less vitamin C than fresh-
cooked corn. The vitamin is lost when the corn is heated during canning or blanched before
freezing to destroy the natural enzymes that would otherwise continue to ripen it. Blanch-
ing in a microwave oven rather than in boiling water can preserve the vitamin C in frozen
corn (see above).
Milling. Milling removes the hull and germ from the corn kernel, leaving what is called
hominy. Hominy, which is sometimes soaked in wood ash (lye) to increase its calcium con-
tent, can be dried and used as a cereal (grits) or ground into corn flour. Coarsely ground corn
flour is called cornmeal.
Processed corn cereals. All processed, ready-to-eat corn cereals are much higher in sodium
and sugar than fresh corn.
Added calcium carbonate. Pellagra is a niacin-deficiency disease that occurs most com-
monly among people for whom corn is the staple food in a diet lacking protein foods with
the essential amino acid tryptophan, which can be converted to niacin in the human body.
Pellagra is not an inevitable result of a diet high in corn, however, since the niacin in corn
can be made more useful by soaking the corn in a solution of calcium carbonate (lime) and
water. In Mexico, for example, the corn used to make tortillas is boiled in a dilute solution of
calcium carbonate (from shells or limestone) and water, then washed, drained, and ground.
The alkaline bath appears to release the bound niacin in corn so that it can be absorbed by
the body.Medical Uses and/or Benefits
As a wheat substitute in baking. People who are allergic to wheat or cannot tolerate the glu-
ten in wheat flour or wheat cereals can often use corn flour or hominy instead.
Bath powder. Corn starch, a fine powder refined from the endosperm (inner part) of the corn
kernel, can be used as an inexpensive, unperfumed body or face powder. Because it absorbs
oils, it is also used as an ingredient in dry shampoos.Adverse Effects Associated with This Food
Allergic reaction. According to the Merck Manual, corn is one of the 12 foods most likely
to trigger the classic food allergy symptoms: hives, swelling of the lips and eyes, and upset