4 SULPHUR BLEACHING OF COMMEECIAL OATS AND BARLEY. 



The views of the Board of Food and Drug Inspection of the United 

 States Department of Agriculture "- with respect to the use of sulphur 

 dioxid in foods are as follows: 



No objection will be made to foods which contain the ordinary quantities of sul- 

 phur dioxid if the fact that such foods have been so prepared is plainly stated upon 

 the label of each package. An abnormal quantity of sulphur dioxid placed in food 

 for the purpose of marketing an excessive moisture content will be regarded as 

 fraudulent adulteration under the food and drugs act of June 30, 1906, and will be 

 proceeded against accordingly. 



In some States the laws and in other States the grade rules under 

 which the grain-inspection departments work prohibit the grading of 

 bleached or chemically treated oats and barle}', but owing to the diffi- 

 culty of distinguishing, except in extreme or exceptional cases, between 

 the bleached and unbleached grain without submitting it to a chemical 

 test, these prohibitions are not always carried out. When such grain 

 is refused a grade it is designated as "purified" by the inspectors and 

 sold by sample instead of by grade. 



Selling bleached oats by sample has alwaj^s been more or less 

 unsatisfactory^ and has led to many disputes between buyer and seller. 

 In marketing this class of grain, when it is not designated as "purified" 

 it is customary to make up standard samples to which trade names 

 are often given. These samples are sent to prospective buyers inva- 

 riably in cloth sacks of open fiber which allow the sulphurous-acid 

 odor to be dissipated. Upon delivery of the grain on the basis of 

 these samples, the odor of sulphurous acid is readily detected and the 

 buyer is dissatisfied because he believes the car of grain delivered is 

 not like the original sample. 



METHOD OF SULPHUR BLEACHING. 



There are several types of grain bleachers in use, the most common 

 of which is the "tower" or "chimney" bleacher, so called because of 

 the style of its construction. The different forms of this type vary 

 principally in the manner of distributing the grain at the top and in 

 the way in which it passes through the bleacher. These tower bleach- 

 ers are constructed of brick, masonr}^ or wood covered with galvan- 

 ized iron; and for convenience in handling the grain through them the 

 towers are built close to the elevator, the top of the tower usually 

 corresponding with the upper working floor of the elevator, which 

 may be at a height of 25 to 60 feet above the ground. On the interior 

 of the bleaching tower, which is about 3 or 4 feet square, are alter- 

 nating series of deflecting shelves set at an angle of about 45" to the 

 horizontal plane. The purpose of these shelves is to retard the move- 

 ment of the grain and to distribute it evenly through the tower after 

 it falls from the spout at the top, as shown in figure 1. 



a Food Inspection Decision No. 89, U. S. Department of Agriculture, Mar. 5, 1908. 

 [Cir. 74] 



