Whether the flour makes a better food with the germ incorporated, or without it, is a question to which the milling world has given much time and attention. Some authorities, among whom are Graham and Richardson, are of the opinion that the germ should by all means be removed. They believe that it not only discolors the flour, but has a decided tendency to cause it to become rancid. If the wheat is slightly unsound, the germ present exerts a marked diastasic influence on the flour. Diastase is a peculiar substance generated during the germination of grain for the brewery, and tends to accelerate the formation of sugar during the fermentation of the yeast. Those who favor incorporating the germ in the flour claim that it renders the flour sweeter, and that a more palatable bread results from its use.
*"Raw grain diastase is produced during the production of the embryo in the growing and unripe seed, and probably then acts as translocation diastase for the purpose of preparing nutritive matter for the developing embryo. The portion of such diastase remaining unused in the ripe seed constitutes the diastase of raw or un-germinated grain." Jago says: "Milling experiments on a large scale have been made on the germy semolinas produced during gradual reduction. Semolinas are separations from the second, third, fourth, and fifth breaks. They are similar to middlings, but are coarser, and contain more germ, and less of the flour-forming portions of the wheat. Such semolinas, on being reduced on stones, yield a dark-colored, unsatisfactory flour, which produces a low quality of bread. On rolling and repurifying these semolinas, the resulting flour is of good color, and yields bread of high quality. So far, experiments afford evidence directly in favor of removing the germ. The steady demand for roller-made flour demonstrates that the opinion of the public as consumers is in favor of its removal."
In the microscopical and chemical examination of wheat bran, it is found to contain, like straw, a large amount of cellulose. In addition to this and the aleurone cells which are found on the inner coats, it carries with it some starch when it is separated from the rest of the wheat kernel. Bran is found, in some instances, to be a valuable food for farm stock. It contains a large amount of protein and mineral matter, and the bulk furnished by the cellulose is in some cases an advantage. Wheat is such a popular food for man that the production of by-products is very large. The by-products are those portions of wheat which are undesirable for human food, but make valuable and nutritious food for domestic animals. In the manufacture of flour, about twenty-five to thirty per cent, of the wheat grain is offal, and is available for stock feeding.
When cereals are manufactured from wheat, a much larger per cent, of it is available for human food. Color in this case plays an unimportant part, and the germ is very palatable when properly manipulated and used. "Cereals," says Prof. Atwater, "when properly prepared, are very completely digested and absorbed."
Bunge says, "that the theory that the normal food of the adult is furnished by the proteids and carbohydrates in the proportion met with in cereals, and that this diet would only require the addition of fat, seems to be confirmed by experience. The laborers in some districts in Bavaria, who do the hardest work, are said to live on a diet prepared from flour and lard." While this may prove that, in cases of extreme necessity, people can live on such a diet, it does not prove that in this land of plenty it is a wise thing to thus make the ration.
Fat is an important element of food, but the greater portion of fat has been removed from the wheat by discarding the germ in the manufacture of flour. The amount of fat in the germ is given at from nine to twelve per cent.
Starch makes up the principal part of the bulk of the wheat grain. In different analyses it varies from sixty-three to sixty-seven per cent. This is an important food element, as it may serve as fuel, and yield energy in the form of heat and muscular strength, or it can be transformed into fat.
Dextrine exists in sound wheat in small quantity. The presence of this in either wheat or flour in large quantity would be objectionable. Much sugar indicates unsound wheat. A rather low percentage of soluble extracts is an indication of soundness. The soluble extracts are soluble proteids, sugar, dextrine, potassium, and phosphates.
Gluten is a very important element in the wheat or flour. It is not only important that it be present in sufficient quantity, but its quality must also be considered. Flour containing poor gluten makes fewer loaves of bread to the number of pounds used, and those few are not well risen. Poor gluten will break early, and allow the gases to escape during the process of fermentation. Dough having poor gluten is soft and sticky and easily broken. Flour having good gluten will give a tough, elastic, and well-risen dough. It will absorb and retain much water, thus making a greater number of loaves from the same quantity of flour. Gluten procured by washing such flour is tough and elastic. Good gluten is very necessary to good bread, and, as it is the muscle-forming element of the flour, it is also a very important food element.
The mineral matter of wheat occurs principally in the bran; consequently, like the fat, is mostly lost in the preparation of wheat for human consumption in the form of bread. The wheat is cleaned of straw, large weed seeds, and light particles of chaff and dirt, and in the large mills it is rubbed with brushes and tossed against sharp edges of iron until all the fuzzy ends and loose particles of hair and dirt are removed, and the kernels are bright and free from all foreign substances. The wheat is then passed between rough corrugated rollers, which are just far enough apart to break the kernel open on the crease side and flatten it out. The flakes of wheat are now passed over a fine sieve, and any small floury particles are sifted out, and are called "middlings." The flakes, sometimes called "first break scalp," are now run through another set of rolls, or breaks, and are crushed thinner, and, on passing through another sieve, give up some more fine flour from the starch cells in the center of the kernels. This floury portion or middlings is mixed with that taken out after passing through the first break. Thus the flakes called "break scalp" pass through half a dozen sets of rolls, some flour being sifted out each time, and in the end the flakes have been crushed and rubbed until the floury part of the kernel is all removed, and only the flakes of bran remain. Though the middlings which came out after the first break came from the middle of the kernels, and were more nearly pure starch, while that which came out last was rubbed off the inner surface of the bran, and contained more protein or glutenous compounds, all this is usually mixed together. Strange as it may seem, these middlings, which are already nearly fine flour, are again run between fine rollers, and are sometimes finally ground between burrs. The middlings are separated into two or three portions.
The miller tries to obtain a large percentage of the finer flour which he calls "patent," and a small proportion of bakers' and red dog flour since these bring a less price.
Straight-grade flour comprises the whole of the marketable flour produced from the wheat, without assortment into the grades just mentioned.
The per cent, of moisture in straight-grade flour is almost identical with that of wheat. The per cent. of gluten is proportionately greater than in wheat, the bran and shorts having been removed. The per cent, of ash and phosphoric acid is considerably lower for the same reason. Fat and cellulose are likewise lower in percentage.*
*Jago - Page 306.
Red dog is the lowest grade of flour. It is rich in protein and fat, as it contains much of the wheat germ, and is valuable to stockmen, but has little value in bread-making, because good gluten is lacking.
Wheat can be very completely freed from the germ by the roller process. The germs are sifted out during the process of manufacturing the flour. The germ forms three by-products, known as first, second, and third germ. They are mixed with branny and starchy products of the wheat, the second being the purest. Wheat germ is utilized in the manufacture of breakfast foods. The poorer grades of flour are utilized by stockmen.
The palatability of wheat is well illustrated in our liking for bread, though it is not always so palatable a product as the flour is capable of producing. One reason for its palatability lies in the fact that its gluten is superior to that found in any other grain. It is capable, in skillful hands, of forming a delicate and porous loaf. Cereals manufactured from wheat and other grains are very numerous, and should be used more largely than they are.
The tables show that they possess a high food value. Much truth is put into the mouth of the fabled medicine man of Egypt, when he is made to say: "My soul in this world is dependent upon my body, my body on my stomach, and my stomach on my cook." Nowhere, it seems, has the cook more power over the soul in this way than in the handling of flour and cereal foods. Properly prepared and cooked, they are highly palatable, and very completely digested and assimilated. But if poorly or partially cooked, their high food value is largely lost. Cereals are certainly very excellent food, though fancy names add nothing to their food value, and in some cases their price is very much higher than their food value and their palatability warrant.