5.2 



A STUDY OF WHEAT. 



come brittle, and the nucleus is destroyed ; the rings are not 

 affected, but the edge becomes broken and ragged. Bean flour 

 will seldom be subjected to an intense dry heat. -In all kinds 

 of baking, and in the treatment of the flour wherever heat is 

 used, there is more or less moisture accompanying it. Where 

 there is an extreme moist heat there is a great change pro- 

 duced in the starch, but not enough to destroy its identity. 

 A microscopist can detect the presence of bean starch when 

 mixed with wheat, even after it has been baked into bread. 

 Figure 10 gives us the appearance of bean starch after it has 



Fig. 12. Cells of Bean loaded with Starch and Glutin. Magni- 

 fied 4J5 Diameters. Drawn with the Camera Lucida. 



been baked. The moisture of the dough has caused the grains 

 to expand slightly, while the heat has rendered them brittle 

 and ragged. The nucleus and rings are slightly affected. At 

 b some of the cellular structure appears. 



In figure n we have some of the starch grains after they 

 have been boiled in a pudding. They show very little resem- 

 blance to the original grain, yet it is sufficient when you see 

 a large quantity of the grains to identify them. They have 

 swollen to an enormous size, have lost their rings, though they 

 retain their nucleus as well as their general shape. At b can 



