Foods, their selection and preparation

The protein content varies in both kinds and amounts, averaging about 12 per cent. Oats are highest and rice lowest in protein content. While the cereal proteins belong to the so-called "inefficient group,” they are exceedingly valuable supplements to the efficient proteins in milk, meat, and eggs. Studies show that the proteins in oats rank highest in quality, followed by rice and rye; then wheat and corn. The carbohydrate in the grains is largely in the form of starch. This may be separated and used as such. The characteristic proper- [85] ties of the starches have been considered. The energy value of cereals is contributed in large part by the starch and fat. The amount of fat varies widely among the different grains. Those with the highest fat content, oats and corn, are the ones with the highest energy value. While the fat is stable in the unmilled grain, it is quite unstable in the milled cereal products. For that reason processing methods have been developed which discard the germ, the portion of the grain highest in fat. This increases the stability of the product, but at a sacrifice of nutritive value, since the germ portion is a valuable source of protein, minerals, and vitamins as well as fat. Minerals are abundant in all cereals. The seed must supply enough for the develop¬ ment of the new plant until it is able to ab¬ sorb needed minerals from the soil. The average amount is about two per cent of the weight of the grain. Calcium, phosphorus, and iron are the minerals present in largest amounts. Other common mineral as well as traces of other elements also are present. The kinds and amounts vary with chemical and physical factors in the soil on which the grain is produced. The proximate composition of the grains which are used most for food is given in Table XVIII. Vitamin Content. In addition to these proximate components, the cereals are the valuable food sources of the B vitamins — thiamine, riboflavin, and niacin — and the less well-known factors in this group. They con¬ tain practically no vitamins A, C, or D. When cereals are sprouted, some vitamin C is formed, the amount depending upon the conditions under which sprouting takes place. Also during sprouting the B vitamins are in¬ creased. The Russians, during the long siege of Leningrad, improved both the flavor and the nutritive content of their diet by sprout¬ ing, before use, the cereal which made up most of their limited food supply. Native groups living in the tropics have developed methods of improving the nutritive value of their diets by sprouting or fermenting the basic cereal component. USES OF DIFFERENT CEREALS The form in which the cereals are used varies. In some the whole or partially crushed grain is cooked and eaten as a por¬ ridge or thick mush. Some cereals are ground to a meal or flour for use in breadmaking. In the United States a variety of breakfast foods are made from cereals. Wheat. Wheat is by far the most impor¬ tant of the grains for breadmaking, owing to the presence of two proteins, gliadin and glutenin, which unite when moisture is added to form a substance with elastic properties called '"gluten.” The presence of these gluten¬ forming constituents makes the flour from this grain especially desirable for bread. The different kinds and grades of white flour and Water Protein Fat Carbo¬ hydrate Fiber Minerals Table XVIII • Per cent