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THE MANUFACTURE OF GLUTEN FEED. 

 By T. B. WAGNER. 



Among the concentrated feeding stuffs found on the American market we may 

 concede to gluten feed the first place, not only because of the high percentage of 

 nutritive materials in gluten feed, but because of its palatability and its remarkable 

 degree of digestibility. Within the last few months various statements have appeared 

 in chemical journals, as well as in bulletins issued by 'agricultural experiment stations, 

 with reference to the chemical analysis of this product. Considering the importance 

 of gluten feed as an animal food, anything published on the subject will be read with 

 interest, not only by officials connected w:th agricultural experiment stations, but by 

 dealers and buyers, and, last but not least, by the manufacturers themselves. In 

 view of this general interest, it may not be amiss to state the details of its manufacture. 

 Broadly speaking, gluten feed is the ground kernel of Indian corn, from which the 

 germ and most of the starch have been removed. The following steps lead up to its 

 production: 



The com bought by us is of the No. 2 and No. 3 grades. To remove impurities, 

 stones, dirt, dust, etc., the grain is passed through cleaning and separating machinery 

 and the purified corn is then delivered to the steeping tanks, wherein it is soaked in 

 warm water, slightly acidulated with sulphur dioxid. This treatment brings about a 

 softening of the grain and facilitates the subsequent separation of the germ, which 

 is effected after it has passed through a preliminary grinding whereby the corn is 

 broken up and the germ set free. The balance of the material is now ground fine 

 in Buhr mills, the coarser part, namely, the bran, being separated by running the 

 mass over silk sieves, while the starch liquor is concentrated and sent over slightly 

 inclined planes, the "starch tables," upon which, by a process of settlement and 

 washing, the starch fills up in a solid layer. The lighter ingredients, gluten, fiber, 

 etc., are carried off in the current of water over the end of the starch tables. We 

 have thus obtained, first, the* germ from which the well-known corn oil and corn-oil 

 cake are obtained; second, the starch which furnishes the raw material for the corn 

 starch of commerce and the manufacture of corn sirup and corn sugar; third, the bran, 

 being the hulls of the kernel; and, fourth, the gluten. The third and fourth, after 

 repeated washings, are united, when still in a wet state, deprived of the largest part of 

 the water by filter pressing, and delivered to the driers, where the water is reduced 

 to approximately 10 per cent. The feed is now passed through grinding mills and 

 reduced to a considerable degree of fineness. 



The gluten feed thus obtained varies in composition in proportion to the efficiency 

 factor prevailing in the individual works. For instance, in a well equipped and well 

 regulated factory the amount of protein usually runs at 26 per cent (on a commercial 

 basis), whereas in factories conducted less efficiently the amount of protein may 

 not exceed 18 per cent. The amount of starch in the feed will vary correspondingly. 

 I have made the statement before that gluten feed represents the corn minus germ 

 and starch. You will ask, and very properly so, What becomes of the mineral con- 

 stitutents of the corn and the soluble organic matter, which are extremely valuable 

 as, for instance, the organic phosphorus compounds? By far the largest amount of 

 these constituents is leached out in the steeping of the corn. Were it desired only to 

 recover the phosphorus salts, there would not be much difficulty involved in isolating 

 them, but the steep water contains a large amount of other ingredients which greatly 

 add to the food value of the gluten feed, such as albuminoids, sugar and other car- 

 bohydrates, potassium salts, etc., which, however, are hygroscopic and frustrate all 

 efforts to recover them in dry form. Dr. Arno Behr devised ways and means of recover- 

 ing these substances, which are fully described in United States patent No. 491.'_ ) :-U. 

 issued February 7. 1893. Briefly explained, Behr recovers these constituents of the 



