WHEAT 



WHEAT 



661 



As will be noted, the grain contains 10 to 11 per 

 cent of water. As a matter of fact, as grain is 

 usually handled and shipped, the percentage of 

 water would average much higher. It is well 

 known that wheat transported from a dry climate 

 to one more humid will absorb five to twenty-five 

 per cent of additional weight in moisture. This is 

 particularly true when shipments are made by 

 water. As wheat is handled in milling it is custom- 

 ary to add to it a considerable amount of water 

 before being processed, as in its normal condition 

 it is too dry. It will be seen that the grain has 

 large absorptive powers ; and the same facts have 

 been observed in the different manufactures pro- 

 duced from it. 



Of the mineral elements in wheat, fully one-half 

 is phosphoric acid, while the greater part of the 

 remainder, consisting of one-third of the whole, is 

 potash. 



The wheat grain is characterized by a small 

 embryo or germ, while the percentage of endo- 

 sperm constitutes a very large proportion of the 

 entire contents, the ratio being as one to thirteen. 

 The embryo, while having a high nutritive value, 

 is not a desired element in the manufacture of 

 flour, although it is utilized to a considerable 

 extent in the production of certain cereal foods 

 and always constitutes a most valuable by-product. 



The endosperm is composed largely of pure starch 

 cells which form the chief constituent of wheat- 

 flour as usually made. However, it contains proteids, 

 which by their presence add largely to the value 

 of flour as usually prepared in the form of baker's 

 bread. These proteids have been classified as fol- 

 lows : (1) globulin, (2) albumin, (3) proteose, (4) 

 gliadin and (5) glutenin. For all practical purposes 

 only the last two named are considered in the manu- 

 facture of flour. These two proteids combined com- 

 pose what is known as gluten. It is the gluten 

 contained in the starchy parts of the wheat grain 

 which distinguishes it from flour made from cer- 

 tain other cereals, notably corn. Corn flour or meal 

 is heavy and sodden when baked into bread as com- 

 pared with flour made from wheat or rye. The dif- 

 ference is due to the presence of gluten. In the 

 process of bread-making the flour is made into a 

 dough by the use of water and the addition of leav- 

 ening. When fermfentation seta in, or, to use the 

 common phrase, the bread begins to rise, carbonic 

 acid gas is formed; this is imprisoned in the dough, 

 which expands with the internal pressure and thus 

 forms an open, porous loaf. The dough owes this 

 elastic quality to the presence of the gluten. 

 Gluten can be obtained from flour by washing the 

 dough with water until all the starchy parts have 

 been removed. The lump of gluten thus obtained 

 will prove to be of a light, yellow color, tenacious 

 and elastic. When dried, it will be semi-transparent, 

 and closely resembles glue. The quantity of gluten 

 in flour is important, but more depends on the 

 quality. As it is not easy to determine the quality 

 except by actual bread-making tests, millers usually 

 select the wheats preferred on the basis of the per- 

 centage of total gluten contained. 



In the manufacture of flour, the percentage of 



the grain recovered in the form of flour varies 

 around 70 per cent. The lowest limit of the grades 

 secured will depend on the markets open to the 

 miller. The amount of merchantable flour recovered 

 is also governed somewhat by the processes of mil- 

 ling. There remain always the by-products, known 

 in commerce under the various names of bran, 

 shorts, or middlings. 



If a grain of wheat be cut into transverse sec- 

 tions, the various parts of which it is composed will 

 be clearly seen. The embryo, which is rejected in 

 milling, will be shown lying along the side opposite 

 that on which is the furrow. Covering the starchy 

 parts of the grain are several layers of fiber or 

 husk, also rejected in the milling process. These 

 layers are technically known as the aleurone, 

 nucellus, testa and pericarp, although these blend 

 more or less into each other according to the con- 

 dition of maturity of the grain. 



The wheat plant. — The wheat plant is strictly of 

 artificial character and habits. This is well-illus- 

 trated by the nature of its growth. It is probable 

 that if cultivation should cease for even a few 

 years the plant would perish from the face of the 

 earth. Under normal conditions wheat completes 

 its round of growth within the limits of each recur- 

 ring s"eason. Seeded in the spring it will mature a 

 crop in twelve to twenty weeks, according to 

 season and variety. Its nature has been so adjusted, 

 however, that what are called fall or winter varie- 

 ties are cultivated, to a large extent, throughout 

 much of the producing area of the world. These 

 varieties are sufficiently hardy to withstand the 

 winter season, and when planted in the fall will 

 mature the following year, one to two months 

 earlier than those seeded in the spring. There 

 is relatively no variation in the different types and 

 varieties so far as manner of life and growth are 

 concerned. 



In germinating, the seed or grain of wheat 

 throws out a whorl of three temporary roots. With 

 the development of the stalk, which immediately 

 takes place, additional whorls are thrown out at 

 each node. The permanent set of roots will be 

 found near the surface branching outward and 

 downward. 



If the wheat has been planted deep the stalk may 

 exhaust itself in reaching the surface, and, in the 

 case of alternate freezing and thawing, the slender 

 thread conijecting the tiny plant at the surface 

 with the parent seed may be separated too soon 

 ■and the vitality of the plant be endangered. The 

 roots of the growing plant may penetrate to a depth 

 of four feet or more, a fact which is somewhat con- 

 trary to the common opinion. 



While the stems of the wheat are hollow, it is 

 not unusual for them to be more or less filled with 

 pith. 



In winter varieties the stalks of the plant do 

 not rise above the crown of leaves, which are first 

 produced, until the advent of spring. The mat of 

 blades which covers the ground serves the useful 

 purpose of protecting the plant throughout the 

 dormant period of the winter season. 



During the early growth the nodes are close 



