334 Canadian Record of Science. 



Chemical Notes on "Wheat and Flour. 



By J. T. Donaxd, M.A. 



(Read before the Natural History Society, Montreal, January 31, 1887.) 



The quantity of flour used in the preparation of the 

 staple bread is so much in excess of that used for all other 

 purposes, that any examination of flour as a commercial 

 article must necessarily be made from the point of view of 

 its bread-making qualities. 



In the baker's estimation, strength and color are the 

 most important qualities of flour. In the matter of color 

 alone, the whiter a flour the better. Strength is a term 

 employed not always in precisely the same sense, but by it 

 is generally meant the " capacity of a flour for producing 

 a well risen loaf." For bakery use it is, I believe, impos- 

 sible to obtain a flour that is too strong, and the flour most 

 in demand for bread making is that known as " strong 

 bakers'." The baker's demand for "strong" flour begets 

 the miller's search for a "hard" wheat, for experience has 

 shown that it is only from a "hard" wheat that a " strong " 

 flour can be obtained ; soft wheat yielding a flour deficient 

 in strength. 



The hardness and softness of wheat and strength of flour 

 are physical characters, but they correspond to important 

 differences in the chemical composition of the grain and 

 flour. A "hard" wheat and a "strong" flour are always 

 richer in nitrogen than a soft wheat and a weak flour, and 

 of this greater amount of nitrogen in the "hard" wheat 

 and "strong" flour a larger percentage is insoluble albu- 

 minoids or gluten than is the case in the soft wheat and 

 weak flour. * The average nitrogen yielded by analysis of 

 a series of soft Canadian wheat was 1.74 p. a, whilst a series 

 of hard Manitoba wheat averaged 2.32 p.c. nitrogen. A 

 sample of hard wheat from Portage la Prairie yielded 

 moist gluten 36 .43 p.c. ; a soft wheat from Gretna gave, by 

 similar treatment, only a shade under 25 p.c. or 24.96 p.c. 



* U.S. Dept. Agriculture, Bureau of Chemistry Bulletin, No. 4, 

 page 30. 



