COMPOSITION OF CEREALS 27 



Proportion of Each Part and Composition in Corn* 



Per , Chemical composition < 



cent Pro- Carbohy- 



of tein Oil Ash drates 



whole per per per per 



kernel cent cent cent cent 



Seed-coat, including tip cap. 7.3 4.0 1.1 1.0 93 



Aleurone layer 11.2 22.0 5.0 1.4 71 



Endosperm 70.3 9.0 0.3 0.3 91 



Germ 11.2 20.0 35.0 10.0 35 



Whole corn 100.0 11.3 4.0 1.5 82.8 



The seed-coat is high in carbohydrates, but this is mostly in the 

 iorm of fiber. The aleurone layer is rich in protein. The endosperm 

 is rich in starch, while the germ contains most of the ash and oil of 

 the kernel and is also rich in protein. 



While the above composition of parts applies in a way to all 

 cereals, yet there is much variation. For example, wheat, oats, and 

 barley have a smaller germ than corn, usually only 4 to 5 per cent 

 instead of 11* per cent; also they have less seed-coat and more 

 endosperm. 



Composition of Cereals. While the above table shows the gen- 

 eral composition of a cereal grain it can not be said that there is a 

 constant or definite composition, as no two ears of corn or samples 

 of wheat will analyze alike. The following table gives a general sum- 

 mary of analysis of the cereals, as compiled in United States Bureau 

 of Chemistry, Bulletin 120, but even this can not be relied on as 

 a final comparison, since other general averages will vary from this. 



Composition of Cereals (Water Free) Pounds Per 100 Pounds 



Pro- Crude Carbohy- 



Grain tein Fat fiber dratea 



Oats 13.7 4.3 12.2 66.3 



Wheat 14.2 2.3 2.8 78.7 



Rye 13.4 1.8 2.3 80.2 



Barley 13.3 1.8 5.6 76.0 



Corn 10.0 4.4 2.2 81.9 



Any particular sample may vary widely from the above. For 

 example, different samples of wheat may vary from 9 to 16 per cent 

 protein, and corn may vary from 3 per cent to 7 per cent in fat, and 

 so on, but in general we consider oats and wheat to be richer in 



* Illinois Bulletin 87. 



