Week 32: Corn


Summer’s harvest wouldn’t be complete without golden ears of corn. Whether roasted on the grill or steamed on the stove, each bite of corn is like a hot, buttered burst of sunshine!

Corn is classified as a grain and was domesticated around 9,000 BC in Central America. It takes its name “maize” from the Spanish word “maiz.” Corn grows on stalks 8-12 ft high as “ears” (cobs covered with individual kernels about the size of peas) which are protected by corn silk and husks. Native Americans first planted maize in raised rows and used the stalks to support beans, which supplied nitrogen and nutrients to the soil. Varieties of squash provided ground cover to stop weeds and inhibit evaporation by providing shade over the soil. Today, corn in North America is planted in rows to allow easier cultivation and with a two-crop rotation, often with alfalfa planted every other year.

U.S. farmers grow about 40% of all corn produced worldwide today. An important region of the U.S. is still identified as the “Corn Belt.” This region is typically defined as including Iowa, Illinois, the eastern parts of Nebraska and Kansas as well as North and South Dakota, the southern part of Minnesota, and parts of northern Missouri as well as Ohio and Indiana. Introduced into Africa by the Portuguese in the 16th century, maize has become Africa’s most important staple food crop.

Most of us are familiar with yellow or white corn, but did you know it can also be blue, black, red, pink or purple? Some varieties of corn are bred to produce the “baby corn” used in Asian cuisine. Corn flour lacks the “gluten” of wheat and produces baked goods which do not rise.

Corn is eaten in a variety of ways and is used to make tortillas, polenta, cornbread, hominy, grits, cereals such as corn flakes, popcorn and chips. Corn is also used to produce high fructose corn syrup (a sugar substitute used in processed foods), corn oil, in fermentation and distilleries for making Bourbon Whiskey, for animal feed, biofuels, home heating and plastics.

Ethanol is being used in concentrations of 10% or less as an additive in gasoline for motor fuels to increase the octane rating, lower pollutants, and reduce petroleum use. Home-heating furnaces have been developed which use corn kernels as fuel. They feature a large hopper that feeds the uniformly sized maize kernels (or wood pellets) into the fire.

The resin polylactic acid (PLA), derived from corn starch, is formed into containers and packaging for food and consumer goods. For a few years, natural foods purveyors such as Newman’s Own Organics and Wild Oats have been quietly using some PLA products, but the material got its biggest boost when Wal-Mart, the world’s largest retailer, announced in 2006 that it would sell some produce in PLA containers. Producing PLA uses 65 percent less energy than producing conventional plastics, it generates 68 percent fewer greenhouse gases, and contains no toxins.


Corn is high in antioxidants, but each variety of corn has a different combination of phytonutrients. Yellow corn has carotenoids and blue corn has anthocyanins. Corn is high in protein and is also a good source of fiber and contains vitamins B6, niacin, phosphorus and manganese. Corn supports the growth of healthy bacteria in our large intestines and helps lower the risk of colon cancer.

High Fructose Corn Syrup

Forty percent of all processed, pre-packaged foods sold in U.S. groceries currently contain some processed component of corn, although this component is most often high fructose corn syrup (HFCS). There is significant concern that high fructose corn syrup contributes to obesity, diabetes, liver disease and heart disease. It is also been shown to have contaminants such as mercury. Because it is less expensive to produce than conventional sugar, it is used extensively in food products today. Did you know there is the equivalent of 17 teaspoons in one 20 oz soft drink?

Genetically Engineered Corn

Over 70% of all corn found in U.S. grocery stores has been genetically modified in the form of herbicide-tolerant, or HT corn, or the form of insect-resistant, or Bt corn. (Bt corn gets its name from the transfer of a gene from the soil bacterium, Bacillus thuringiensis, into the corn. A protein toxin produced by this bacterium helps to kill certain insects that might otherwise eat the corn.) While there is no large scale human research on genetically engineered corn and its health impact, there is concern about the introduction of novel proteins into food and their potential for increasing risk of adverse reactions, including food allergies. One way to avoid these potential risks is to select certified organic corn, since GE modifications are not allowed in certified organic food.


Mann, Charles. Cotton (or Anchovies) and Maize.

“The casava transformation in Africa”. The Food and Agriculture Organization of the United Nations (FAO).




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