The Plant. 91 



contains one part of water. This makes possible a direct con- 

 version to lower sugars, and upon inversion by enzymes or acids, 

 one part of this sugar yields two parts of dextrose. 



Tri-saccharides are represented in plants by raffinose. This 

 sugar occurs in cotton seed and the germs of wheat, barley and 

 other seeds. It sometimes occurs in sugar beets, especially as a 

 result of disease or injury, and in quantity sufficient to interfere 

 with the refining of the beet sugar. Raffinose inverts to equal 

 parts of dextrose, levulose and galactose. 



Poly-saccharides are the most abundant of the carbohydrates. 

 Starch, which is one of the simpler members of this group of com- 

 pounds, is an unknown multiple of a chemical group containing 

 six parts of carbon and the equivalent of five parts of water. It 

 may be considered as a multiple of the compound dextrose, in 

 which each part of dextrose has lost one part of water. Diastase 

 of sprouting seeds and the enzyme ptyalin, which occurs in saliva, 

 convert starch to a mixture of simpler, gummy carbohydrates, 

 known as dextrines and then to maltose. 



Hot, dilute acids invert starch completely to dextrose and by 

 this means, in addition to the action of diastase, the chemist de- 

 termines the amount of starch in plants. This process is also, 

 as has been stated, the basis for the commercial production of 

 corn syrup or glucose syrup. The large amounts of starch in 

 cereal grains, as barley and corn, and in some root crops, as the 

 potato, give them value for the production of alcohol and alco- 

 holic liquors. Alcohol is not formed directly from starch, but 

 is a product of the fermentation of the sugars to which starch 

 may be converted by malt extract. * 



The amounts of starch found in some plants and plant products 

 are as follows, expressed in per cent of the air dried material : 



Percent 



Wheat flour 66.55 



Corn meal 7 1 . 00 



Corn plant (ears glazed) 15.40 



Corn stover .95 



Oat meal . . 56 . 23 



Per cent 



Rice grain 79.4 



Barley grain 62.0 



Potato tnber 75.5 



Bean grain 42 . 7 



Pea grain 40.5 



