Teacher Introduction:



Teacher Introduction:

Corn Kernel Dissection

Corn (Zea mays), a distinctive American crop, was developed by the Indians, sweet corn is roasted at 4th of July picnics, and “field” varieties are produced with unparalleled efficiency and dedication by farmers. Currently, about 65% percent of all corn grown in the United States is fed to livestock, poultry and fish. The remaining 35% goes to corn processors who convert it into corn syrups, sweeteners, starches, oils, ethanol and animal feeds. These products, in turn, become the building blocks of thousands of other food and industrial products distributed throughout the world.

The Corn Belt is a group of states where most of the corn in the United States is produced. Together Illinois, Iowa, Nebraska, and Minnesota produce 50% of all the corn grown in the United States. Corn is the major feed grain grown by farmers in the United States, leading all other crops in value and volume of production. Farmers grow corn on every continent of the world except Antarctica.

An ear of corn has an average of 16 rows with 50 kernels per row for a total of 800 kernels. A pound of corn consists of approximately 1300 kernels. An acre (about the size of a football field) of corn, yielding 100 bushels, produces approximately 7,280,000 kernels. Typical average yields in Iowa have topped 180 bushels/acre or about 13 million kernels per acre. Most of the 56 pounds of a bushel of corn is the starch, oil, protein, and fiber, with some natural moisture.

Hybrid varieties of corn have been developed to adapt to specific growing conditions and locations worldwide. Hybrids are the offspring produced by breeding plants of different varieties.

One hundred years ago, starch was basically the only product from corn refining, and the rest of the kernel was used for feed supplements or even burned for heat. Today, there are uses for every part of the kernel – even the water in which it is processed. The corn seed (kernel) is composed of four main parts: the endosperm, the pericarp, the germ, and the tip cap (Diagram 1). The endosperm is most of the dry weight of the kernel. It is also the source of energy for the seed. The pericarp is the hard, outer coat that protects the kernel both before and after planting. The germ is the living part of the corn kernel. The germ contains genetic information, vitamins, and minerals that the kernel needs to grow. The tip cap is where the kernel was attached to the cob.

Corn can be made into fuel, abrasives, solvents, charcoal, animal feed, bedding for animals, insulation, adhesives and more. The kernel is used as oil, bran, starch, glutamates, animal feed and solvents.

A typical grocery store will contain over 4,000 products that list corn ingredients on the label, but many other products also depend on corn, from paper goods and cardboard packaging to all the meat, milk, eggs, poultry and other protein products that come from corn-fed animals.

Nutritional components of yellow dent corn are typically as follows:

Components of Yellow Dent Corn

Starch 61.0 %

Corn Oil 3.8 %

Protein 8.0 %

Fiber 11.2 %

Moisture 16.0 %

(Davis, 2001)

In an average year, nearly four billion bushels of shelled field corn are transported from individual farms by truck, train and barge to industrial corn processing plants. This percentage of “industrial use” versus the amount of corn produced has increased over the decades from 9.9% in 1980 to nearly 34.0% in 2008, due to increased demand for ethanol.

With the new bio-based product initiatives and our need for renewable energy, researchers are looking at corn as a feedstock for other organic chemicals, nutraceuticals, and biodegradable polymers and fibers. This will continue the trend of increasing the percentage of corn grown for industrial processes.

Diagram 1

[pic]

Source:

Educational Standards

Each teacher is responsible for determining the state and/or national standards this activity satisfies with their district. A comprehensive set of national and state science and math standards related to this entire curriculum can be found at the website. The standards can be downloaded as a Microsoft® Word document to make it easier to transfer the standards to this and other documents.

Resources:

1. Davis, Kelly S. Presentation at the Minnesota Nutrition Conference: Minnesota Corn Growers Association. Chippewa Valley Ethanol Company.

files/grains/K.Davis--Dry&WetMillProcessing.pdf. September, 2001.

2. Plymouth Oil Company, LLC., Merrill, Iowa.

3. Iowa Corn Promotion Board and Iowa Corn Growers Association. User/Docs/It%20Begins%20with%20a%20Kernel%20REWRITE.pdf

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download