AMOUNT OF SUGAR LOST IN FERMENTATION.

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Amount of Sugar Lost in Fermentation. The total quantity of sugar and other carbohydrates lost in fermentation amounts to about 2 percent of the weight of flour used. Sometimes it is much greater and sometimes less than this. The nutritive value of the product is diminished in proportion to the extent of the loss of sugar. The carbon dioxid produced during fermentation has no food value, and the alcohol is largely lost in the form of vapor during the process of baking. About half the loss is due to carbon dioxid and half to alcohol. The alcohol, although lost mostly during the baking, serves a useful purpose,-in the expansion of the vapor it aids the carbon dioxid in making the bread more porous. The hydrolysis which takes place in baking converts some of the starch to dextrinoid or saccharoid

conditions. It is evident that from 6 to 8 percent of total starch present in the flour is changed during the fermentation and baking into more or less soluble forms.

Texture and Size of Loaves Made from Different Kinds of Flour.The variations in bread and size of loaves made from different kinds of flour when the conditions of fermentation and baking are the same depends upon the texture and quantity of the gluten material in the flour. The difference in the appearance and size of loaves is shown by a photograph of the crosssections of three loaves of bread in Fig. 36.

It is seen that the loaves made from graham flour and entire wheat flour are somewhat coarser in structure and are less in size than those made from the same quantity of standard patent flour.

MACARONI.

The preparation of wheat flour of a high glutenous character and molded into various forms, usually tubes, cylindroids, or fine shreds, is known in the trade under various names such as noodles, spaghetti, and macaroni. An examination of a number of these bodies shows them to have the following average composition:

These bodies, it is seen, do not have a composition very different from that of a first-class bread except in their content of moisture and protein. They are made from various kinds of wheat, especially hard wheat which forms a tenacious gluten product well suited to molding into the different forms which these bodies have. Their nutritive value is practically the same as that of good wheat bread of the same moisture content.

Domestic Macaroni.-The introduction of varieties of wheat with the properties suitable for making macaroni has been thoroughly exploited by the Department of Agriculture. The macaroni wheat grown as a subvariety is known botanically as Triticum durum. The durum wheats are not regarded as of equal value to the ordinary wheats for general milling purposes and command a lower price. The French name is Blé dur and the German name is Hartweizen. The wheat of this subspecies grows rather tall, having broad, smooth leaves of a whitish green color and a very hard cuticle. The heads are comparatively slight in most varieties, compactly formed, and occasionally very short. All the durum wheat is bearded and the beards are exceptionally long. The kernels are hard and glassy, often partly translucent. They are generally yellowish white in color, occasionally inclined to red, and the grains are generally rather large. In other aspects this wheat resembles barley and for this reason in Germany it is often called Gerstenweizen. The general appearance of these wheats both in the field and in the individual heads is shown in the accompanying figures.

Macaroni wheats are well adapted to semi-arid regions; in fact it may be said that they are the product of such an environment rather than adapted

FIG. 38.-DROUGHT-RESISTANT MACARONI WHEATS (HEADS AND GRAINS).

1, Kubanka; 2, Nicaragua; 3. Velvet Don; 4. Black Don; 5, Wild Goose.-(Bulletin No.3, Bureau of Plant Industry, U. S. Dept. of Agriculture.)

MANUFACTURE OF MACARONI.

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to it. For this reason they are wheats which are able to resist continued dry weather and high temperature. These wheats do not grow well in acid soils but flourish best in an alkaline soil of fine texture and well supplied with humus and the necessary plant foods. The largest quantity of macaroni wheat is grown in east and south Russia. These wheats have given very good results in the semi-arid regions of the United States. The appearance of the wheat as it grows in the field is shown in the accompanying plate.

The domestic macaroni is now made in many factories in the United States and there is a continually increasing demand for the domestic article. The hardiest varieties of wheat are used in the manufacture of this article in the United States, especially the hard Kansas winter wheat.

Composition of Domestic Macaroni.-In the table below is given the mean composition of twenty samples of macaroni of domestic origin, made from domestic wheat. In the second column is given the mean composition of five samples of imported macaroni.

Preparation of Flour for Macaroni.—The term Semolina or Semola (Italian) or Semoule (French) is usually applied to the flour used in the manufacture. of macaroni. In the United States the flour which is used is obtained by selecting the hardest wheat and preparing the flour in the usual manner. In France and Italy the preparation of semolina is accomplished in separate mills. The devices for grinding are essentially the same as those for producing the best grade flour, the main difference being that the wheat is moistened slightly before grinding and the flour is less fine than ordinary baking flour.

Evidently very slight changes in the method of milling would enable the ordinary mill to produce a fine grade of macaroni flour either from the macaroni wheat or from any very hard glutinous wheat grown in the United States.

Manufacture of Macaroni.-As practiced in the best districts of Italy, macaroni is manufactured according to the following method:*

The durum wheat is ground into semola and sieved to remove the starchy part of the grains and leave the clear, light amber, or glutinous part. Three or four grades of quality are made, and these depend on the size of the sieve meshes.

The semola is put into a special iron mixer, shaped like an old-fashioned artillery mortar, except that it is square instead of cylindrical, and furnished in the bottom with special screw-shaped fans with which to stir the paste *Fairchild, U. S. Dept. Agr., Bureau of Plant Industry, Bulletin 25.