6o 



Chemical Work on Canadian Wheat. 



2. That there is a well-marked relationship between the 

 "baking strength"* of a flour and its percentages of protein, 

 gliadin, and dry gluten. The data from both series of flours 

 clearly indicate this relationship, though it was not always pos- 

 sible to establish a definite ratio between the chemical and baking 

 results, f 



3. That, while the protein content is undoubtedly the best 

 single measure of strength when judging normally ripened wheats 

 of the same variety, the character of the gluten must be especially 

 taken into consideration when discriminating between wheats of 

 different varieties. In flours of high bread-making values the 

 gluten is resilient, elastic, firm, and cohesive ; in poor flours it 

 may be flabby, non-resilient, soft, or sticky. 



4. That the view held by many chemists that the gliadin ratio 

 or " number " is of importance as an index of strength received 

 no confirmation from the analysis of Canadian flours. The 

 generally accepted statement that from 55 to 65 per cent, of the 

 protein should exist in the form of gliadin is undoubtedly incor- 

 rect; the larger number of the strongest flours examined pos- 

 sessed a gliadin number below fifty. The gliadin number, though 

 holding with the other nitrogenous data in parts of the series, is 

 on the whole erratic, and apparently of very little value for 

 diagnostic purposes. The percentage of gliadin is, according to 

 our evidence, decidedly more valuable. ft 



5. That we failed to obtain any evidence confirmatory of the 

 view held by Mr. Wood : that the amount of nitrogen and ash 

 free extract controlled the volume of loaf. If the size of the 

 loaf is determined by the volume of gas evolved in the bread- 

 making process, then this volume is dependent on the enzymic 

 action (which may affect the protein as well as the carbohydrates) 

 rather than on the amount of sugar present in the flour. § We 

 have not observed any relationship between the percentages of 

 sugar, as actually determined, and the volume of loaf. 



6. That, while certain of our data seemed to indicate an agree- 

 ment between the ratio to total nitrogen of soluble salts and shape 

 of loaf — as held by Professor Wood — they did not permit of any 

 direct correlation. § § 



* In determining the " baking*strength " of a flour, values have been assigned to 

 water added, water retained, volume, shape and texture of loaf and form of crust 

 (Bulletin No. 57, -Exp. Farm Series, p. 18). 



t Bulletin No. 57, pp. 41, 45, 50. Report of the Chemist, Exp. Farm Series, 

 1908-09, p. 146. 



ft Quality in Wheat, Bulletin 57, pp. 41, 42. Report of the Chemist, Exp. Farm, 

 1908-09, p. 146. 



§ Quality in Wheat, Bulletin 57, pp. 43, 47, 48. 



§§ The Grades of Wheat, Bulletin 60, p. 19. Report of the Che mist, Exp. Farms, 

 1908-09, p. 147. 



