CONCENTRATED FOODS 283 



are carried off by the current, are separated by sedimentation. 

 The letter, when dried and ground up, is sold as gluten meal- 

 The germs are collected and treated in a similar manner and 

 sold as maize- germ meal, or, pressed into the form of a cake, 

 as maize-germ cake. 



Sometimes the gluten, germs, and husks are mixed, dried, 

 and ground up together, and the product is called "gluten 

 feed." The composition of the last-mentioned substance is 

 very variable. It depends chiefly upon the proportion of 

 husks that are included. Bran, rice sludge, and other foreign 

 materials are occasionally mixed with it in different proportions. 

 These products are sold under various fancy names. Wheat 

 gluten is often used up in a similar manner. 



In the manfacture of starch from potatoes, the cells of the 

 tubers are ruptured by machinery, and the starch is washed 

 out with water as far as possible. As it is only possible to 

 remove about half the total starch in this way, the residual 

 sludge when dried is fairly rich in carbohydrates. It is 

 practically destitute of nitrogenous matter and fat. The 

 nutritive value of potato sludge is, therefore, much inferior to 

 the gluten products obtained from wheat, rice, and maize. The 

 latter contain large percentages of protein and carbohydrates, 

 and also a certain amount of fat. 



Molasses and Sugar Feeds. Ordinary household sugar is 

 prepared from sugar cane and sugar beet. In both cases the 

 material is reduced to pulp, and the sugar extracted in aqueous 

 solution. This solution is concentrated by evaporation in 

 vacuum pans and the sugar is crystallised out. A consider- 

 able amount of sugar, however, remains in an uncrystallisable 

 condition and forms the black viscous liquid called molasses 

 or treacle. The uncrystallisable sugar has the same nutritive 

 value as that which crystallises, and it forms about 60 per cent, 

 of the total residue, treacle. 



Cane sugar molasses is used as food for human beings; 

 that obtained from beet is more impure, has a strong bitter 

 taste, and is not fit for this purpose. It is, however, used in 

 large and increasing quantities for cattle feeding. Apart from 

 water, the impurities consist mainly of amides and potash salts. 



