Corn
Wednesday, August 20th, 2008
Because corn is a member of the grass family, it is not strictly a vegetable but a grain. However, one type, sweet corn, is prepared and served as a fresh vegetable. The seeds, or kernels, which are the edible part of the plant, form in spikelets on a woody axis called an ear. They are covered with a green husk. Ears of corn vary in size, and the kernels range from white to yellow, orange, red, brown, blue, purple, and black, although sweet corn is always white or butter yellow.
Family Gramineae (Poaceae)
Scientific name Zea mays L.
Common names corn, sweet corn
Moderately good source of fiber, vitamin C, and folate
Variety
Of the many types of corn, sweet corn is the only variety that is eaten fresh as a vegetable. Sweet corn is available in several varieties divided by kernel color. Some sweet corn is pure yellow; some, like Silver Queen, is white; and some, like Butter and Sugar, is bicolored, that is, it has both yellow and white kernels. Popping corn, baby corn, and the white corn known as hominy are different types of eating corn.
Origin & botanical facts
Corn is native to the Americas, probably having originated in Mexico or Guatemala, where historians believe it evolved from a wild grain called teosinte that still grows in the Mexican highlands. The corn plant, which can attain heights of 20 feet, has a hard, jointed stalk. Male flowers develop in the tassel at the top of the stalk, and the female flower is a cluster at the joint of the stalk. Corn is pollinated by the wind. The corn silk hanging from the husk of each ear is the pollen receptor; each thread must receive a grain of pollen for the kernels to develop. Corn grows best during long, hot summers. It requires rich soil and regular fertilizing, particularly with nitrogen. Because the flowers are wind pollinated, plants should be spaced closely together. The ears do not ripen well in cold weather, so the seeds must be planted in plenty of time for the kernels to develop before the first autumn frost. Although each ear of corn produces many kernels, the plant has no natural mechanism for dispersing its seeds. To ensure that it will be tender and succulent for eating, sweet corn is picked before it reaches maturity.
Uses
Sweet corn is a popular vegetable in the United States. The average American eats about 25 pounds of corn every year, most of it frozen or canned, but in summer, corn is preferred fresh on the cob. Because the sugars in the kernels of sweet corn begin to convert to starch as soon as the ear is picked, corn should be eaten as soon after harvest as possible. While still on the cob and after the husks are removed, corn can be boiled, steamed, or microwaved, but the secret to retaining the flavor is to cook it no more than a few minutes. For grilling ears of corn in their husks, the ears should be soaked in water for about 20 minutes and then cooked on a grill rack or in the oven for 10 to 15 minutes. Grilling or roasting husked corn (for 5 to 7 minutes) produces a stronger flavor.
Nutrient composition
Corn provides some fiber, vitamin C, and folate.
Nutrient Content
Energy (kilocalories) 89
Water (%) 70
Dietary fiber (grams) 2
Fat (grams) 1
Carbohydrate (grams) 21
Protein (grams) 3
Minerals (mg)
Calcium 2
Iron 1
Zinc 0
Manganese 0
Potassium 204
Magnesium 26
Phosphorus 84
Vitamins (mg)
Vitamin A 18 RE
Vitamin C 5
Thiamin 0.2
Riboflavin 0.1
Niacin 1
Vitamin B6 0
Folate 38 μg
Vitamin E 0
