THE BLEACHING OF FLOUR 477 



In his previous Report, Dr. Monier-Williams made sweeping 

 assertions regarding the injurious effect of bleaching on flour. 

 He now produces experimental evidence to show that when 

 flour is exposed to the atmosphere, stored in calico bags under 

 conditions very similar to those which prevail in the retail trade, 

 it absorbs a minute proportion of nitrite from the air. The 

 quantit}* so absorbed was an amount equivalent to i*2 parts of 

 sodium nitrite per million, whereas commercially bleached flour 

 of the type manufactured in London did not contain more than 

 i "6 parts. The difference is so small that it is difficult to avoid 

 the conclusion that the same ultimate result is attained whether 

 the flour be bleached rapidly by artificial means or slowly by the 

 gradual absorption of nitrogen peroxide from the atmosphere. 

 This contention is dismissed in the Report because a sample of 

 pure carrotene did not absorb nitrite from the air. The power 

 flour, starch and similar materials have of absorbing all sorts of 

 things from the surrounding atmosphere is entirely ignored. 



Not only does ordinary bleached flour absorb no further 

 nitrogen peroxide on exposure but highly bleached flour loses 

 most of its nitrite on prolonged storage and it is admitted that 

 " under ordinary conditions of storage " there is " an approximate 

 figure towards which the nitrite content of all samples, whether 

 highly bleached or unbleached, will eventually converge." 



Hitherto the Local Government Board experts have been 

 silent as to the effect of bleaching on the baking qualities of 

 flour, though this is in reality the crux of the whole position. 

 No baker would use a flour if it had any effect on the quality of 

 his bread : the public are greater adepts at noticing such niceties 

 than is generally supposed. The services of Mr. Kirkland, of 

 the Borough Polytechnic, have now been called in to make 

 bread from flour subjected to different degrees of bleaching far 

 in excess of the commercial quantities. He reports that, with 

 the exception of the loaf from a flour containing 75 parts of 

 sodium nitrite per million, all the loaves were of excellent quality 

 and had no taste or smell ! 



Comment should be unnecessary. Dr. Monier-Williams 

 himself shows that his earlier conclusions were entirely 

 illogical and it is difficult to understand the attitude he took 

 up in his former report. 



The whole question has been the subject of an important 

 legal case during 191 2 in connexion with a prosecution for flour 



