234 ENVIRONMENT AND BAKING QUALITIES. 



The characters of the wheat grain which may be affected by 

 change of environment are the following : — 



1. Colour. While the general colour, red or white, of any 

 wheat remains the same no matter under what conditions it is 

 grown, nevertheless the depth or tone of colour in red or white 

 wheats is not constant. In India, white wheats, when well grown 

 under dry farming conditions, are frequently much darker in tint 

 than the same wheat grown carelessly under a superabundant 

 supply of canal irrigation. Similar differences are to be seen in 

 red wheat. 



2. Size and weight of grain. The size and absolute weight of 

 the grain vary very considerably both in different localities in the 

 same year and also in the same locality in different seasons. 



3. Composition. Much of the work on the effect of environ- 

 ment on the characters of the wheat grain has been concerned with 

 the effect of change of environment on the nitrogen content of the 

 grain — ^the nitrogen content being taken not only as a measure of 

 the percentage of gluten, but also as a rough indication of the strength 

 of a wheat. There are, however, exceptions to the general rule 

 that the higher the nitrogen the greater the strength so that, in 

 the present state of knowledge, the only safe method of estimating 

 strength is by milling and baking tests. Quality as well as quantity 

 of gluten is important in this respect. For a flour to be really 

 strong there must be sufficient gluten of the right quahty present. 

 So far, while no accurate relation has hitherto been found between 

 chemical composition and the bread-making Viilue of wheat, never- 

 theless the trend of recent investigations on this subject affords 

 hope that the strength of wheat may be explained from a chemical 

 standpoint. Thus AVood^ has found in the case of Fife and other 

 strong wheats that the water soluble phosphates in these flours is 

 high — overO'l per cent, and the chlorides and sulphates very low. 

 They also contain more magnesia than lime. Weak wheats, on the 

 other hand, yield flours with a low proportion of soluble phosphates, 



' See Jago — The Technology of Bread-making, London, 1911, p. ;}23. 



