Maize or corn

Lesson 9 : Millets

Maize or corn

In India, maize is consumed in the form of boiled or roasted as popcorn. In countries like South America, Central America and Africa, it is converted into food products by grinding, alkali processing, boiling, cooking and fermentation.

  1. Nutritive value: Maize contains around 11.0% protein. Maize protein is deficient in amino acids like tryptophan and lysine. Maize is a good source of carotene. It also contains thiamine and folic acid in appreciable amounts (Table).

    Table : Nutritive value of maize

  2. Processing: They are three major processes utilized in the production of maize for human consumption.

  3. Dry milling: Grinding of the whole grain stone or roller mill to produce flour or meal is a simple method used worldwide when the ground products are to be consumed shortly after processing. The large as well as small gifts are used in the production of cornflakes and breakfast cereal. The major advantage of maize dry milling is the lower capital costs as compared to wet milling.

  4. Wet milling: In developed countries like USA, the major milling process for maize is wet milling. The two most important products of wet milling are high fructose corn syrup and ethanol.

  5. Alkali processing: In this, the maize is mixed with water and lime and cooked at 90o C for 50 minutes. The cooked maize is then steeped for 14 hours before being washed with fresh water to remove residual alkali and other waste material from maize. The washed maize is milled to a gritty textured product called “masa”. This is rolled into flat cakes and baked in an oven for 1-2 minutes to produce the traditional tortilla. Masa can also be deep fried to produce tortilla chips or maize chips or it can be dried and finally milled to produce mass flour.

  6. Products of maize
  7. Degerminated flour: This consists mostly of the endosperm and has low content of B vitamins. It is used by brewers as a starch medium for the action of barley malt in the preparation of wort for the production of beer.
    Corn-germ oil: It can be extracted by solvent extraction. Maize oil has become a highly desired vegetable oil owing to its relatively high level of linolenic fatty acid and its excellent flavour.
    Popcorn: The popping of corn is a method of starch cookery. As the kernels of popcorn are heated, the water vapour within them expands, increasing the pressure until it is sufficient to make the kernels explode or ‘pop’. To make popcorn hard corneous endosperm is desirable. 13.5 percent of moisture is recommended for best popping expansion.
    Corn starch: It is made by a process of wet milling in which the hull and germ are removed, the corn ground and mixed with water. The semi-liquid material is separated by passing it over sieves or centrifuging it. The starch settles out while most of the protein remains suspended. The starch is then washed, dried, powdered. Corn starch is widely used because it is inexpensive. Lacks characteristic flavour and cooks to a smooth paste. Corn starch flavoured with vanilla and containing edible colours is sold as custard powder.

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Last modified: Thursday, 8 December 2011, 1:54 PM