The term "cereals" is applied to the cultivated grasses--rice, wheat,
corn, rye, oats, and buckwheat. They are widely grown throughout the
temperate zone and are prepared in various forms for use as food.
Cereals contain a high percentage of starch and a low percentage of
water, with varying proportions of mineral matter and fat. In addition
to the four food-stuffs already studied, cereals contain a small amount
of another food-stuff known as protein--a muscle-building material. For
the most part, the cereals contain a large amount of cellulose, which is
broken up during the process of preparation for market and requires long
cooking before being ready for use by the body. The digestibility of the
cereals depends upon the amount of cellulose which they contain and the
thoroughness of the cooking. Cereals are palatable, and they are
valuable, because in cooking they can be blended in various ways with
other substances. They are beneficial also to the body, because their
cellulose acts mechanically on the digestive organs by stimulating them
to action. Cereals are made more attractive by serving with fresh or
cooked fruit.