2;>6 The Clumistnj of the Sfniu/fh of Wheat Flour 



made up to the 50 c.c. mark with distilled water and the flask was placed 

 in an incubator kept at 37° C. When the protein was completely in 

 solution, the liquid was filtered quickly into a small flask, which was 

 then stoppered and kept in the incubator. From time to time, the optical 

 rotation of the alkaline solution was determined in a Ir/- polar! metric 

 tube, using a Schmidt and Haensch instrument and sodium light. This 

 procedure was continued for about 300 hours, when the value had 

 become practically constant. Graphs were then con.structed .showing 

 the progress of the racemisation, the ordinates representing specific 

 rotation values and the abscissae the number of hours during which the 

 reaction had been allowed to proceed. 



In carrying out the determinations in the above manner, some delay 

 always occurred in eft'ccting complete solution of the gliadine in the 

 alkali. The difliculty was satisfactorily overcome in the following way. 

 The 1 grm. sample of dry protein in the 50 c.c. flask was first dissolved 

 in 10 c.c. of 70 per cent, alcohol. The 25 c.c. of .standard soda were then 

 slowly run in, the flask being gently shaken during the process. The 

 volume was then made up to 50 c.c. with distilled water and the flask 

 was placed in the incubator. A clear solution was obtained in a few 

 minutes by this method. 



The racemisation data of the glutenine samples were obtained in a 

 somewhat similar manner. 1 grm. samples of the dry protein were 

 weighed into 50 c.c. flasks containing a little distilled water. The 25 c.c. 

 of standard soda were then run in slowly and the flask was gently 

 shaken. A jelly like mass was first obtained, which quickly liquefied 

 when the flask was put in the incubator. The volume was then made 

 up to the 50 c.c. mark with distilled water and the polarimetric readings 

 were taken as described above. 



Investigation of the gliadine samples. 

 1. Specific rotations in 70 per cent, alcohol. 



2 per cent, solutions of the gliadine preparations in 70 per cent, 

 alcohol were examined by means of the polarimeter with the following 

 results: 



Gliadine from Manitoba flour [ajy^ = — 93-60°. 

 ,, EngUsh „ [a]/, = - 93-78°. 



Osborne (6) gives the value of — 92-28° for the specific rotation of gliadine 

 in 80 per cent, alcohol. 



