11)09.] PUBLIC DOCUMENT — No. 31. 139 



THE ACIDITY, SULFITE CONTENT AND COLOR 



OF GLUTEN FEED. 



BY P. V. GOLDSMITH, B.SC. 



1. Process of Manufacture. 



Gluten feed is the name applied to the finely ground endo- 

 sperm (body of the corn) after the removal of the starch and 

 corn germ. The corn is first soaked in quite dilute sulphurous 

 acid, which softens the grain sufficiently to allow the sej^aration 

 of the various partsj the dilute acid also serves to check exces- 

 sive fermentation. After soaking for the requisite length of 

 time the corn is coarsely ground and passed through a series 

 of separators, shakers and presses, which process results in a 

 reasonably distinct separation of germ, starch, gluten and hulls. 

 The gluten, together with that portion of the starch which can- 

 not be separated by mechanical means, and the hulls are mixed 

 with the evaporated steep water from the steeping vats, and the 

 mixture dried and ground is the gluten feed of commerce. This 

 so-called steep water, in which the corn was at first soaked, con- 

 tains much of the more readily soluble material of the corn, and 

 when mixed with the feed after evaporation imparts to it a dark 

 color. 



Most of the feeds offered for sale at the present time possess 

 a sharp acid taste and a bright yellow color. The claim has been 

 made that they contain an excess of injurious dyes as well 

 as excessive amounts of sulphurous acid. The object of this 

 investigation has been to determine : — 



The nature of the acidity. 



The amount of sulphurous acid present. 



The presence and source of the added color. 



