BUCKWHEAT (Polygonum fagopyrum L.).

Buckwheat is usually classed with the cereals, but botanically it does not belong to the order of true grasses to which the cereals belong.

Buckwheat is commonly grown in many parts of the United States, and its seed is highly prized for bread and cake making purposes. The buckwheat is ground and the outer black tough hull separated, and the flour is used chiefly for making hot breakfast cakes which are much prized throughout the country. Properly ground buckwheat flour has a more or less dark tint, due to fine particles of the outer envelope which escape the bolting process. Acreage and Yield of Buckwheat.—This crop is not grown in many states. New York, Pennsylvania, and Michigan produce the largest quantities. The statistical data for buckwheat grown in the United States in 1906 are as follows:

Composition of Buckwheat Flour. The composition of finely bolted buckwheat flour is as follows:

The above is the composition of a white flour more finely ground and bolted than is advisable for palatable purposes. In the grinding of the above flour the germ which contains a greater part of ether extract is eliminated and also a large quantity of the bodies rich in protein. The composition of a less highly refined flour and one which is more palatable and more nutritious is given in the following data:

Milling Process.-In the preparation of the so-called highest grade of buckwheat flour, that is, that which is most carefully ground and thoroughly bolted, the process employed is as follows: During the process of milling the buckwheat grains pass to a receiving separator which removes all the coarse particles, stones, straws, etc., by means of a series of sieves. At the same time

any dust which they contain is blown out by a current of air. The sifted grains pass next to the scouring machines, in which they are thoroughly scoured, cleaned, and polished. From these machines the grains pass to a separator containing magnets, by means of which any pieces of metal, in the form of nails, screws, pieces of wire, etc., are removed.

The grains next pass through a steam dryer for removing the greater portion of the water employed for the scouring. As soon as they are dry they are again treated to a blast of air, which removes any dirt, dust, or light particles which may have been detached during the process of drying. The grains next pass to the shelling rolls, where the greater part of the outer hulls is removed. This process is accomplished by means of an apparatus which is called a sieve scalper. After the separation of the outer hulls the residue of the material passes to a drying chamber, where the moisture is reduced to about 10 percent, thus insuring the keeping qualities of the flour. After drying the grains are ready for the rolls. After entering the roils the process is practically the same as that which is employed in milling wheat, consisting of a series of breaks and reductions, with the attendant bolting and grading, and this process is prolonged until the flour is practically removed from the feed or middlings. The sifting cloths used in the bolting of buckwheat flour are somewhat coarser than those for wheat, and this allows some of the dark particles of the inner hulls to pass into the flour, which gives it a dark color on baking. It is quite possible to make a buckwheat flour as white as that from wheat, but in this country the public taste requires a darker product, so that the white flour does not readily sell. The requisite degree of darkness is secured by using bolting cloths which will allow a part of the inner hulls (middlings) to pass into the flour. Two grades of flour are generally produced —a whiter one in which finer cloths are used, and a darker flour made by using coarser bolting cloths, allowing larger quantities of middlings to pass through. The outer hulls which are first removed are used for fuel, although from their composition it is seen that they contain a large quantity of carbohydrates and might be very profitably used in connection with some highly nitrogenous food, such as cottonseed meal or flaxseed meal for feeding cattle. The middlings are used principally as cattle food, and especially by dairymen.

The above process, while it makes a white and fine-looking flour, is not to be compared with the meal made in the old-fashioned way of grinding between stones and separating the principal part of the outer hull by bolting. This oldfashioned flour is more nutritious, that is, it contains more fat and protein, has a greater fuel value, or in other words has a greater number of calories and makes a much more palatable cake than the fine modern flour.

Buckwheat Cakes.-Buckwheat cakes are prepared from batter made by mixing buckwheat flour into a paste of the proper consistency, seeding it with yeast, and allowing it to remain in a moderately warm place until fermenta

tion takes place. The proteins of buckwheat have some agglutinating power, and thus, when treated as above, make a cake capable of a considerable degree of aeration. Baking powders are often used as a substitute for yeast and permit of preparation in a few minutes instead of waiting for the fermentation above mentioned. The product made in this way cannot be considered so palatable or nutritious as the old-fashioned product. The batter is baked on a smooth hot iron or soapstone, polished and kept bright in order to prevent the sticking of the cake. The proper polishing of the iron is a better means of preventing sticking than greasing. The batter is poured over the smooth iron and is of a consistency to flatten out without help and to form a film over the baking iron, which produces a cake about onefourth of an inch in thickness. The cake is to be turned as soon as the side in contact with the iron is brown. It is evident that in this baking process there can be no very profound change in the starch granules, but this does not appear to materially interfere with the digestibility of the product. Buckwheat cakes are eaten hot, usually with butter and sirup. Maple sirup, sorghum sirup, or cane sirup in a pure state are highly prized for use with buckwheat cakes. These sirups are both condimental and nutritious. Mixed sirups made of glucose, melted brown sugar, or molasses, or mixtures of all these bodies are more commonly furnished to the consumer than the pure sirup mentioned above. Honey is also used very extensively as a condimental flavor for cakes of this kind.

Adulterations.-There is probably no bread or cake making material which is subjected to more extensive adulteration than buckwheat flour. Much of what is sold as buckwheat flour may be regarded as imitations of that substance. Mixtures of rye flour, Indian corn flour, wheat flour, and other ground cereals are used as a substitute for buckwheat. There can be no objection from the hygienic point of view to such substitutes but the use of these mixtures under the name of buckwheat can be regarded in no other light than as an unpardonable fraud.

Detection of Adulterations.-There is rarely any mineral adulteration practiced with buckwheat flour and if so it is easily detected by incineration. Any content of ash, unless baking powder has been used, above 2 percent may be regarded with suspicion as indicating an admixture of some mineral substance. The cereal flours used for adulteration are readily detected by the microscope in the hands of an experienced observer. The field of the microscope has only to be compared with the microscopic appearance of genuine buckwheat starch in order to detect the added substance.

Buckwheat Starch.-The microscopic appearance of buckwheat starch is shown in the accompanying figure. The granules of buckwheat starch are very characteristic. They consist of chains or groups of more or less angular granules with a well defined nucleus, and without rings or with

very faint rings. The contour of buckwheat starch is more angular than that of any other common cereal with exception of maize and rice, and it is this and the relative size which enable the observer to distinguish it from other starches. The size of the granules is quite uniform, varying usually only from 10 to 15 microns* in diameter. In so far as the angular appearance is concerned the granules of buckwheat starch have a general resemblance to that of maize and rice and oats, but a comparison under the microscope

FIG. 23.-BUCKWHEAT STARCH. X 200.-(Courtesy of Bureau of Chemistry.)

of the three starches reveals lines of distinction which with a little practice would prevent the observer from drawing a false conclusion.

Next to wheat the most important cereal used as a human food in the United States is Indian corn. According to the magnitude of the crop, Indian corn is the leading cereal of the country. Statistical data on the production of Indian corn in the United States during 1906 are given in the following table:

Acreage,..

Yield per acre,.

Production,.

Value per bushel,.

Total value,....

96,737,581

30.3 bushels

-2,927,416,091

39.9 cents .1,166,626,479 dollars

*A micron is one thousandth of a millimeter.

Indian corn is universally employed as food throughout all parts of the country, but more especially in the South, where the daily dietary is rarely complete without one or more meals in which Indian corn is served in some form or other. Although it is grown much more extensively in the North than in the South, it is not so generally used as human food. Indian corn grows in all kinds of soil and produces, under favorable conditions, large yields in all parts of the country. It is the most important agricultural crop of many states, namely, Indiana, Illinois, Iowa, Missouri, and Kansas. It is planted in the late winter and spring in different parts of the country. The planting season varies from January in Florida to June in Maine and Minnesota and the earlier varieties will mature in 120 days.

Maize is a crop which requires an abundance of rainfall and a high temperature during the growing season. Maize is planted in rows about three and one-half feet apart and in hills of about the same distance apart, or it may be drilled between the rows so that one stalk grows a distance of about from nine inches to a foot from its fellows. It requires constant cultivation during the early period of its growth and a careful preparation of the seed bed. Good farmers give from four to seven cultivations to the growing crop. The field must be kept free of weeds and in good tilth to secure the best results.

Many hundreds of analyses of the maize kernel have been made, but a combination of them all in the following data may be regarded as typical of the Indian corn grown in this country.

The consideration of the above data shows that Indian corn is a ration in which the protein is rather low. In other words, the ratio of protein to the carbohydrates and fat is rather large. It is a food product which is particularly well suited to furnish heat and energy and support a high degree of muscular exertion. For this reason it is a food product which is particularly well adapted to men engaged in hard manual labor.

Sturtevant

Varieties.-There are many distinct varieties of Indian corn. has published a description of several hundred. These varieties are classified under various subspecies. The polymorphic species, Zea mays, according to Sturtevant, can be divided into a number of groups which, on account of their well defined and persistent characters, may be considered as presenting specific claims and may properly receive specific nomenclature. The grouping adopted is founded upon the internal structure of the kernel for cultivated varieties, and the presence of a husk to the kernel in the assumed aboriginal form.