Section III., 1905 [17] Trans. R. S. C. 



II. — On the Determination of the Constituents of Gluten. 

 By Thomas Macfarlane. 



(Read May 25, 1905.) 



Much analytical work has been done, and many papers written on 

 the subject of 'wheat gluten. So much has this been the case that to 

 give its complete history would require very considerable labour. For- 

 tunately this is not at present necessary, because two comparatively 

 recent treatises may be cited as bringing the subject up to date. Those 

 are " The Chemistry of Gluten," by George G. ISTasmith (Transactions 

 of the Canadian Institute, March, 1904), and "Ueber die Proteinstoffd 

 des Weizenklobers," by 'J. Konig and P. Eintelen (Zeitschrift fiir 

 Untersuchung der Nahrungs und Genussmittel, 1904, Band 8, pp. 401, 

 721.) 



The investigation described in the last mentioned paper has for 

 its object to trace the connections which exist between the gluten con- 

 tents of a flour and its fitness for breadmaking. The results of Konig 

 and Eintelen's efforts in this direction are not, however, satisfactory 

 to themselves, as is evident from the concluding sentences of their paper, 

 which run as follows : — " From this it will be seen that the important 

 " and much discussed question of the relations of its gluten to the 

 "fitness of a flour for baking (Backfahigkeit) is far from being solved, 

 " and that, in all likelihood, there are still other methods than those 

 " described i in this paper, which will have to be adopted in order fully 

 " to explain the causes upon which the baking capabilities of flour 

 " depend." 



Here it becomes necessary to refer briefly to the processes followed 

 by Konig and Eintelen, in order that it may be possible to point out 

 wherein they differ 'from the methods of examination which I have 

 adopted. The dough-l)all was prepared from the flour in the usual 

 manner, and kneaded under a stream of distilled water (which had 

 been previously saturated vnih. gypsum) until the water dropped clear 

 from the gluten, all the starch having been removed. The quantity of 

 water was not measured. The nitrogen in the resulting gluten was 

 ascertained by the Kjeldahl process, designated simply as gluten nitrogen 

 and calculated to its percentage in the nitrogen of the original , flour. 

 To ascertain the amount of alcohol-soluble proteid in the gluten, or 

 rather of its nitrogen, the product from kneading the dough was not 

 used, but a determination made direct from the flour itself by treating 

 it with 70 per cent alcohol, and estimating the nitrogen in the result- 

 ing solution. It is evident that the nitrogen extracted in this way 

 must also have included that which is dissolved out by the water used 



Sec. III., 1905. 2. 



