THE CONSUMPTION OF WHEAT 291 



duction of carbon dioxide and alcohol; (2) the production of 

 soluble carbohydrates, as dextrin, from insoluble forms, as 

 starch"; (3) the production of lactic and other acids; (4) the 

 formation of other volatile carbon compounds; (5) a change 

 in the solubility of the proteid compounds; (6) the formation 

 of amine and ammonium compounds from soluble proteids and 

 (7) the partial oxidation of the fat. In addition to these 

 changes there are undoubtedly many others which take place. 

 Inasmuch as many of the compounds formed during the 

 fermentation process are either gases or are volatile at the 

 temperature of baking, appreciable losses of dry matter must 

 necessarily take place in bread making. These losses are 

 usually considered as amounting to about 2 per cent of the 

 flour used. In exceptional cases, as in prolonged fermentation, 

 under favorable conditions, the losses may amount to 8 per 

 cent or more." It is claimed that the losses need not exceed 

 2 per cent and that they may be reduced to 1.1 per cent. 

 Liebig calculated that in Germany the yeast plant consumed 

 as much food daily as would supply 400,000 persons with 

 bread. 



On account of this consumption of nutritive elements by 

 yeasts, and on account of the uncertainty of their working, 

 chemical substitutes were sought 50 years ago in the United 

 States and Germany. The substitutes for yeast are easily adul- 

 terated, they must be prepared with great care in order that 

 they may not be inefficient or harmful, and even when suc^ 

 cessful the bread is usually rather tasteless. As a consequence, 

 they have not met with success. Another loss occurs when 

 the bread is baked. The carbon dioxide is largely retained in 

 the dough, but the alcohol passes off. In 1858 it was esti- 

 mated that 300,000 gallons of spirits were lost annually in 

 London from baking bread, a loss of over a million dollars. 

 Over $95,000 were spent in an effort to devise means to save 

 these fumes. It was given up, not on account of failure to 

 secure the alcohol, but because the bread baked in the process 

 was dry, unpalatable and unsalable. 



In baking, the starch is rendered soluble by the heat, the 

 fermenting growth is killed, and the gluten is solidified, so that 

 the cavities formed by the carbonic gas retain their figure, 

 > U. S. Dept. Agr., Off. Exp. Sta., Bui, 67, p. 11. 



