Quality in Wheaten Flour. 



41 



colour standard. It is largely a question of optics. Refraction 

 and reflection of light most materially affect the judgment of the 

 observer in looking at a loaf of bread. A flour which is white or 

 even very white but weak may make puddings of good colour, 

 but loaves of poor dingy appearance. However, if an improved 

 aeration be effected, either by successful treatment of the flour by 

 the miller or baker or even by the admixture of some stronger 

 darker flour, the resulting bread is made to appear much whiter. 

 The causes which affect colour in flour do not seem to have been 

 definitely determined. Modern developments of flour milling have 

 eliminated dirt and dark fungoid contamination and in increasing 

 degree are still diminishing the amount and intensity of friction in 

 milling, whereby discoloration due to the pulverising of the husk 

 is diminished. It is desirable to obtain a more thorough acquain- 

 tance with the colouring matter of wheat and flour to know with 

 more precision what it is, how it is distributed by Nature in wheat, 

 and what happens to it in milling. 



Scientific and milling circles have been much exercised as to 

 whether artificial bleaching of flour is due to nitrating or oxidising 

 or to both. Chemists should consider the point why the addition 

 of alkali turns some flours yellow, and why the addition of acid 

 or acid salts has sometimes a whitening effect. 



Cerealists and chemists might jointly consider whether it is a 

 fact that climate materially affects the colour of wheat ; for 

 instance, whether a red-skinned wheat grown in California does 

 in fact become white-skinned after a few seasons there, and, if so, 

 what. change has been effected in the nature and distribution in 

 the berry of the colouring matter. 



Strength (Size and Shape of Loaf). — In most cases a large loaf 

 is an indication of the high gas-yielding capacity of the flour from 

 which it is made, and is ordinarily also an indication of high 

 diastatic power. A 2-lb. loaf measuring 3,000 c.c. is better 

 aerated than one measuring 2,200 c.c, and is therefore more likely 

 to be digested easily. A flour from which large shapely loaves 

 can be made probably contains more nitrogenous matter than a 

 weak flour, and is therefore more highly esteemed from the 

 dietetic point of view. The effect of these considerations in the 

 commercial world is to cause a demand for strong flours and 

 wheats, and as ordinarily there is a larger supply of weak wheats 

 than of strong, the latter realise a higher price than the former. 

 It has therefore become important to ascertain the ultimate cause 

 of strength from the chemist's point of view, also to ascertain 

 whether the potential strength of any flour or wheat has been 

 developed or utilised to maximum advantage. It has recently 

 ' been stated or suggested that the quantity of gas given off in 

 fermentation is either the direct cause of strength or is to be 



