FAT IN CEREALS
FAT IN CEREALS.
The fat of cereals helps to contribute to their heat-and energy-producing qualities, and, besides, it is one of the cheaper sources of this food substance. Of the eight grains, or cereals, used as food, oats and corn contain the most fat, or heat-producing material. The oil of corn, because of its lack of flavor, is frequently used in the manufacture of salad oil, cooking oil, and pastry fat.
The fat that occurs in cereals becomes rancid if they are not carefully stored. In the making of white flour, the germ of the wheat is removed, and since most of the fat is taken out with the germ, white flour keeps much better than graham flour, from which the germ is not abstracted in the milling process.
CARBOHYDRATE IN CEREALS.
The food substance found in the greatest proportion in cereals is carbohydrate in the form of starch. Cereals contain many times more starch than any of the other food substances, rice, which is fully three-fourths starch, containing the most, and oats, which are less than one-half starch, the least. Starch is distributed throughout the grain in tiny granules visible only under the microscope, each being surrounded by a covering of material that is almost indigestible.
In the various grains, these tiny granules differ from one another in appearance, but not to any great extent in general structure, nutritive value, or digestibility, provided they are cooked thoroughly. The large amount of carbohydrate, or starch, in cereals explains why they are not hard to digest, for, as is well known, starch is more easily digested than either protein or fat.
This and the fact that some grains contain also a large amount of fat account for the high energy-producing quality of cereals. While it is safe to say that cereals are chiefly valuable for their starch, the tissue-building material in some grains, although in small proportion, is in sufficient quantity to place them with the protein foods.
MINERAL MATTER IN CEREALS.
Cereals contain seven or eight of the minerals required in the diet. Such a variety of minerals is sure to be valuable to the human body, as it is about one-half of the whole number required by the body for its maintenance. Since, as has already been explained, much of the mineral matter lies directly under the coarse outside covering, some of it is lost when this covering is removed.
For this reason, the grains that remain whole and the cereal products that contain the entire grain are much more valuable from the standpoint of minerals than those in which the bran covering is not retained. If a sufficient percentage of minerals is secured in the diet from vegetables, fruits, and milk, it is perhaps unnecessary to include whole cereals; but if the diet is at all limited, it is advisable to select those cereals which retain the original composition of the grain.
WATER IN CEREALS.
Cereals contain very little water in their composition. This absence of water is a distinct advantage, for it makes their nutritive value proportionately high and improves their keeping quality. Just as the strength of a beverage is lowered by the addition of water, so the nutritive value of foods decreases when they contain a large amount of water.
On the other hand, the keeping quality of cereals could scarcely be improved, since the germs that cause foods to spoil grow only in the presence of water. This low proportion of water also permits them to be stored compactly, whereas if water occurred in large amounts it would add materially to their bulk.