64 



DE. EUTTAN ON THE 



The influence of the baking powder salts on the proteolytic action of pepsin was tested 

 by taking two grammes of the crumb of each bread with its natural moisture. To this, in 

 a "70 c.c. beaker, was added 5 c.c. of the glycerine extract, and 45 c.c. of 0.25 % solution of 

 hydrochloric acid. The relative digestion was determined by weighing the undigested 

 residue dried at 100° C, after two hours digestion at 40° 0. The residues a, b and c, are 

 results from breads made with different flour by different persons, using the same yeast 

 and baking powder. 



The breads were found to contain 40 % of water, so the calculations are made for 

 1.2 gramme of dried bread. 



Table 2. — Peptic Digestion. 



Here two grammes of each bread were taken, after drying it to constant weight at 100° 

 C, and reducing to fine powder. Other conditions were the same as Table 1. 



Note. — An experiment to test the relative action of pepsin on yeast bread and on bread 

 prepared with alum baking powder was tried in 1879 by Dr. J. W. Knight. ' He found 

 that 1.2 gramme of dried bread gaA'e 0.4 gramme residue in the yeast bread and 0.66 

 residue in the case of the bread made from the baking powder, shewing that the pure 

 bread was one-third more soluble in gastric juice than the other. 



This single experiment is the only one I can find recorded, where the test of artificial 

 digestion was appealed to to decide the question of the wholesomeness of alumed bread. 

 The result obtained in this solitary experiment is similar to the aA^erage of the six 

 experiments given in the two preceding tables. 



SEraES II. — The DigestibilUi/ of Breads made ivilh Alum and ullier Baking Poivders coiiijmred 

 tvith Ihai of Breads made with Yeast or of Plain Unleavened Bread. Pancrealic (Tri/ptic) 

 Digestion. 



Here, as in Series I, two grammes of bread were taken in each case, either dry or 

 with natural moisture. To this 2 c.c. of the extract of pancreas aboA^e mentioned was 

 added, and the whole made up to 50 c.c. with a 1 % solution of sodium carbonate. The 

 full action of the pancreatin was compared by weighing the dried residues, while the 

 amylolytic action was determined by comparing the quantity of dextrine formed. 



' Analyst, vol. v ; also pamphlet on "Alum, its effects on the system when introduced in baking powder," 1880. 



