Food must be stored to last between harvests and for being transported. Food in storage needs to be protected from being spoiled by microorganisms, being eaten by animals, losing nutritional value or losing its attractiveness.
The usual methods of preserving foods for storage are by drying, canning, freezing, refrigerating, fermentation, pickling, preserving as a sugar concentrate, with chemical additives, smoking, salting, and irradiation.
Drying is the most widely used and perhaps the oldest method. There is, however, competition between all methods of food preservation, and this competition is being settled by the consumer. The result of all this, according to one food expert, is that:
. . . foods best preserved by freezing are generally frozen. Those foods highly acceptable as canned products continue as highly successful consumer goods. The economic struggle for survival between fresh, canned, dried and frozen foods in a free market evidences itself in better foods at lower prices for the consumer.
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Grains are humankinds main food supply and have been so down through the centuries. Grains, being the dry seeds of certain plants, are easy to store and transport, can be grown with relative little labor, and have a high yield for work involved and have high nutritional value.
There are seven grains: millet, rice, wheat, barley, rye, oats and corn. Of these, wheat, rice and corn are the most important since together they provide the basic food for most of the world. The following table shows the world production of these grains for one year (1979). It also lists the world’s major producers of each.
The World’s Main Food Crops (1979)
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Wheat
|
|
Rice
|
|
Corn
|
I441 mmt
|
|
376 mmt
|
|
363 mmt
|
USSR
|
27%
|
China
|
35%
|
U.S.
|
49%
|
U.S.
|
11%
|
India
|
29%
|
China
|
9%
|
China
|
10%
|
Indonesia
|
7%
|
Brazil
|
4%
|
India
|
7%
|
Bangladesh
|
5%
|
Romania
|
3%
|
France
|
5%
|
Thailand
|
4%
|
S. Africa
|
3%
|
Canada
|
5%
|
Japan
|
4%
|
S. Argentina
|
3%
|
Australia
|
4%
|
Burma
|
3%
|
Mexico
|
2.5%
|
Turkey
|
4%
|
Viet Nam
|
2%
|
France
|
2.5%
|
other
|
27%
|
other
|
18%
|
USSR
|
2%
|
|
|
|
|
other
|
22%
|
These three main grain crops provide the basic food for most of the world, whether directly consumed or converted into meat and dairy products. (mmt = million metric tons)
Grains are stored in enormous steel silos as well as in village huts, sacks, piles of grains, piles of sacks, storerooms and warehouses. Our storage methods need to be improved for, according to the World Food and Agricultural Organization, each year up to 20% of the worlds grain, about 250 mmt, is destroyed by pests, rot, and other problems following the harvest.
This information is not as remotely related to the food we eat as it might first appear. Consider all the boxes of cereal, breads, rolls and buns, crackers, cookies, cakes, pies and pancakes you’ve eaten in your life, without grains they’d all disappear. Next consider all the beef, chicken and pork you have eaten they would have to go too since today almost all food animals are fed grains.
Without the animals you would not have the eggs, cheeses and milk either. Beers and liquors would go too because they are produced from grains. The point is that grains are our most important food crop. The quality and amount available will effect the quality of our food and the prices we may pay for many, if not most, of our food.
Grains and other dry foods are easily stored and transported. Other more perishable foods like fruit, vegetables, meat and dairy products need various methods of preservation depending on the individual need of each food.
Grains form the greatest bulk of dry commodities for transportation. Looking at the U.S. system, grains for domestic use are almost entirely moved by truck. Grains for export are moved either by barge, such as those from major corn and soybean production areas along the Mississippi River system, or train, such as those from the major wheat production areas of the South Central Great Plains and the Northern Great Plains.
U.S. domestic perishable foods are primarily transported by truck. In general domestic perishable foods make little use of railways and almost no use of water transportation. Air transportation is used for such items as strawberries where the products are extremely perishable and transit time must be short.
For an idea of the volume we are talking about and a comparison of the domestic movement of food, in 1982 the U.S. moved about 172 mmt of perishables and 187.3 mmt of grains.
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