WHEAT 39 



41. Composition. — In round number.s, the entire wheat 

 grain lias the following average cooiposition: — 



Per Cent 



Water 10..5 



Gluten and other mtrogenous constituents (protein) . . 12.0 



Fats, etc a little more than 2.0 



Crude fiber a little less than 2.0 



Ash a httle less than 2.0 



Starch and other nitrogen-free extract . . more than 71. .5 



Total lOOO 



The higher the percentage of protein in normally ma- 

 tured wheat grains tlie higher, as a rule, are the quality and 

 breadmaking A'alue of the wheat. The protein is often as 

 much as 2 per cent either above or below the average 

 just given, and still greater extremes in composition some- 

 times occur. An}' climatic or other condition that prevents 

 the complete maturitj' of the wheat into pltimp grains 

 tends to reduce the proportion of starch, which is the ma- 

 terial last to be added to the grain; this reduction in the 

 percentage of starch nattn'alh' raises the percentage of ni- 

 trogen. It has been found at the Tennessee Experiment 

 Station (Bui., Vol. XVI, Xo. i) that wheat grown in the 

 South contains a high percentage of protein. Hard grains, 

 which present a horny appearance, are usually richer in 

 protein than those which have a less flintj' appearance. 



Gluten, the principal nitrogenous constituent in wheat, 

 is not only prized for its high nutritive value, but also 

 because to its presence is due the " rising power " possessed 

 by wheat flour as compared wdth flour or meal from Indian 

 corn. Gluten is the sticky residue left in the mouth when 

 one chews ungTound wheat grains. The favorable action 

 of this sticky gluten in making flour bread to rise, or to 



