WHEAT. 241 



gas at the end of this time, and the loaves will go into the 

 oven distended with gas under pressure from the elasticity of 

 the gluten which forms the walls of the bubbles. The heat 

 of the oven will cause each gas bubble to expand and a large 

 loaf will be the result. If the ferment (enzyme) of the flour is 

 of low vitality it will not be able to keep the yeast supplied 

 with all the sugar it needs, the volume of gas formed in the 

 latter stages of the fermentation of the dough will be small, 

 and the dough will go into the oven without any pressure of 

 gas inside it, little expansion will take place, as the tempera- 

 ture rises and a small loaf will be produced."^ Wood shows 

 how the activity of the enzymes can be readily determined. 



After some excellent research work the same writer says : 

 " After making a great number of analyses, it was found that 

 the amount of soluble phosphate in wheat was a very good 

 index of the shape and texture of the loaf it would make. The 

 toughness and elasticity of the gluten, no doubt, depend on 

 the concentration of the soluble phosphate in the wheat grain, 

 the more the soluble phosphate the tougher and more elastic 

 the gluten, and a tough and elastic gluten holds the loaf in 

 shape as it expands in the oven, and prevents the small 

 bubbles of gas running together into large holes and spoiling 

 the texture." He then outlines a simple method by which 

 the amount of soluble phosphate might be satisfactorily indi- 

 cated from the smallest sample. 



In a recent publication,' Dr. Saunders makes the following 

 interesting statements : " Baking strength is not inherited 

 as a Mendelian unit character ... as a matter of fact, 

 baking strength is extremely complex, varying from season to 

 season, and being sometimes radically transformed by a 

 year's storage of the flour. . . . The highest baking 

 strength was attained when the wheat was stored about three 

 or four years. . . . Bleaching whitens the flour in a 

 manner somewhat similar to natural ageing, but bleaching 

 does not improve the baking qualities of the flour at all, or 

 certainly not to any clearly demonstrable degree. The material 

 improvement of flour by storage continues whether the flour 

 has been bleached or not." 



Factors Affecting the Chemical and Physical Compo- 

 sition OF Wheat. — The epidermis, epicarp, endocarp, testa, 

 aleurone layer and embryo are the first formed and the endo- 

 sperm last of all. That is, the framework first develops, then 

 the plastids form starch, and at maturity desiccation takes 



