48 THE PROTEIN ELEMENT IN NUTRITION 



nitrite in a dilution of 1 part in 5,000 to 200,000 has a distinct 

 inhibiting action on gastric digestion. Harden also showed a 

 distinct, though small, inhibition in the peptic digestion of samples 

 of bleached flour as compared with unbleached. 



Another method by which the millers are able to make use of 

 inferior wheats in the production of the finest white flours is by 

 the addition of " improvers." These were found to consist 

 essentially of phosphoric acid, or acid phosphates of calcium, 

 magnesium, potassium, phosphorus trichloride, and penta- 

 chloride, oxides and sulphides of phosphorus, acids such as 

 iodic, hydrofluoric, formic, acetic, propionic, etc., alcohol, 

 aldehyde, and ketones. The claim for these is that more bread 

 can be obtained per sack of flour by their use, which simply means 

 that more water can be supplied to the consumer at the price of 

 bread. The protein content of flour is an important matter from 

 the standpoint of nutrition, especially where bread enters largely 

 into the diet. Flour from weak wheats, which are generally 

 poor in gluten, contain less protein than flour from strong wheats, 

 which are rich in gluten. But by the use of " improvers " flour 

 from weak wheat is made to simulate flour from a stronger 

 wheat, although much inferior to it in protein. 



The indiscriminate addition of such substances as strong hydro- 

 fluoric acid, phosphorus pentachloride, oxides and sulphides of 

 phosphorus, etc., to flour is most dangerous. It does not appear 

 desirable that such an indispensable foodstuff as flour, the purity 

 and wholesomeness of which are of first importance to the com- 

 munity, should be manipulated and treated with foreign sub- 

 stances whose utility from the point of view of the consumer is 

 more than questionable.* 



The general conclusion to be drawn from the result of these 

 investigations is that millers, in the desire to produce fine flour 

 of dazzling whiteness at as great a profit to themselves as 

 possible, have considerably impoverished the flour in its protein 

 content, fat, and mineral constituents ; that, in order to be able 

 to make use of inferior wheats, or increase the commercial value 

 of the flour, they have introduced a method of bleaching with 

 nitrogen peroxide gas, and a system of improving the " strength " 

 of low-grade flours by the addition of foreign chemical substances. 

 Neither the effects of the bleaching processes nor the addition of 

 " improvers " in any way increases the dietetic value of the 

 * Lancet, Local Government Reports, vol. i., 1911. 



