EXERCISE 43 



THE PROPERTIES OF WHEAT WHICH AFFECT ITS VALUE AND USE 



Statement. The physical properties of wheat indicate its milling properties, its value as seed, 

 and its freedom from disease. The properties of first interest to the miller are quality and yield of 

 flour, which is indicated by the color, texture, hardness, and gluten content. These properties are also 

 of first interest to the farmer, for in general the value of wheat for milling purposes determines its value 

 for seed. 



Object. To study those physical properties of wheat which are factors in determining its food and 

 seed value. 



Materials. One-half pint sample of each type of wheat obtainable. 



Directions. From the various samples of wheat select kernels showing variations of color, from 

 whitish to deep red. Select kernels with a bright luster and glossy in appearance ; also kernels that 



are dull and bleached. Find kernels that are 

 light colored, translucent, and hard. Such 

 kernels are described as clear amber in color. 

 Compare different varieties of wheat as to 

 color ; as to hardness ; as to texture. 



In general the darker wheats have a high 

 gluten content, and are very hard and flinty in 

 texture. These are desirable characteristics in 

 the milling of wheat. The light-yellowish, 

 translucent kernels are also hard and flinty 

 and even more desirable in these respects than 

 the darker wheats. Durum wheat is an ex- 

 ample of the clear amber-colored kernels. 



The color, hardness, and texture of a wheat 

 are indications of the gluten content. The 

 dark-colored and amber-colored wheats have 



Fig. 52. A comparison of the size of the loaf of bread made from 

 the same quantity of soft and hard wheat 



The slice at the left was cut from a loaf made of soft winter wheat ; the 

 one at the right from a loaf made from the same quantity of hard wheat 



a flinty texture, contain a high percentage of gluten, and have high milling qualities. 

 The gluten content of hard and soft wheats may be compared as follows : 



Place twenty-five grams of flour from each in a cup and add water sufficient to make a dough of the 

 proper consistency for bread-making purposes. Work each to a uniform dough, cover, and allow to 

 stand one hour. Wash out the starch with running water, using a cheesecloth screen to prevent the 

 loss of bits of gluten during washing. When the gluten is apparently free from starch, work out as 

 much water as possible without the gluten's becoming too sticky to handle, and dry at a moderate 

 temperature, as in a warming oven, but -do not burn. Weigh it as dry, crude gluten. Record the re- 

 sults in the blank form. 



Repeat the exercise with other types of flour and compare the results. 



Questions. For what purpose is flour that is high in gluten used ? For what purpose is flour that 

 is low in gluten used? Name the principal hard- wheat regions of the United States; the principal 

 soft- wheat regions. 



References. Waters, H. J. Essentials of Agriculture, pp. 158-163. Ginn and Company. Hunt, T. F. 

 The Cereals in America, pp. 59-60. Orange Judd Company. Dondlinger, P. T. The Book of Wheat, pp. 10, 

 48-49. Orange Judd Company. Lyon and Montgomery. Examining and Grading Grains, pp. 9-14. Ginn 

 and Company. 



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