202 Kansas Academy of Science. 



ents existing in the flour, chiefly the gliadin and the glutenin, when 

 the flour is stirred with water. 



Gliadin is a gluey, adhesive substance which binds the glutenin 

 and other constituents of the flour together in the dough and pro- 

 duces the well-known condition so essential to the production of 

 good bread, in which the carbon dioxide produced by yeast is held 

 in small bubbles that give the loaf its lightness. If the gluten is 

 too weak the partitions between the globules are broken, and glob- 

 ules coalesce, with the production of coarse-grained bread. A weak 

 gluten will yield under the weight of the loaf, and, instead of rising 

 in a well-rounded form, will flatten out and run over the edge of 

 the pan, if possible. The production of a good loaf depends on the 

 physical properties of the gluten. It is well known that small per- 

 centages of substances may cause very great differences in the phys- 

 ical properties of mixtures. It is, therefore, quite reasonable to 

 expect that the physical properties of gluten may be profoundly 

 aft'ected by small quantities of associated substances. This would 

 be a purely physical phenomenon. It is, however, also possible 

 that small quantities of substances may influence the character of 

 the loaf in an entirely different manner, by favoring or inhibiting, 

 as the case may be, the growth of the yeast. 



It is well known that graham flour lacks the power to yield as 

 round and light a loaf as does white flour produced from the same 

 wheat. This fact suggested experiments to ascertain the effect of 

 substances in the bran and shorts the action of which is excluded 

 from white flour. These effects were tested in different ways, 

 which will be detailed later, using bran, extracted bran, extract 

 from bran, extract from wheat scourings, etc. 



Recent research has shown that the protein substances consist in 

 large part of nuclei derived from a considerable number of amino 

 acids. It is highly probable that, in the growth of the yeast in the 

 flour, hydrolysis of the proteins takes place with the liberation of 

 some of these amino acids, and it is possible that they play an im- 

 portant part in the development of the yeast, or affect the physical 

 properties of the gluten. A part of our study in this connection 

 then, has been to ascertain what effect, if any, the addition of small 

 amounts of amino acids has on the character of the loaf producer!. 

 As but few of the amino acids represented in proteins are to be 

 purchased in the market, our experiments in this line are not com- 

 pleted as yet. It is planned to import as complete a list of these 

 substances as can be obtained for continuation of this investiga- 

 tion. 



