148 



flour, and greatest amount in the shorts, that is, the endosperm has least, 

 and the embryo most. This accounts for the discoloration of flour con- 

 taining the embryo. The enzyme must be increased in amount or in- 

 tensity during the process of germination, and up to six days germination, 

 the extracts become darker, and the action on phenols also gives the 

 same degi'ees of difference. The enzyme is more resistive to heat than 

 those already noted. Bertrand and Bourquelot* say the oxydase extracted 

 from Russula foetens Pers. is so resistive to heat that it has to be boiled 

 some time before being destroyed. 



Boutrouxt has separated an oxydase from dougli by soaking dough 

 witli twice its weight of water for half an hour, extracting by means 

 of a press, then clearing by filtering through a Chamberlain filter. The 

 extract was at first clear, tlien a precipitate formed, after which it turned 

 brown, becoming black in the course of some weeks. His oxydase, how- 

 ever, lost its activity at 100 degrees C. 



That the oxydase extracted by Boutroux is identical with the present 

 one extracted from the various flours and grain is very probable. The 

 difference in its resistance to heat may be due to a different kind of 

 wheat, or to influences of environment. 



Whether it be necessary to have a diastase present, as is claimed by 

 Raciborslcif, it is impossible to determine, for the methods of separating 

 the oxydases Avill also cause the separation of diastase and other fer- 

 ments, and tliere is no known method of separating the majority of 

 enzymes from one another. 



*Green,J. H. The Soluble Ferments and Fermentation, 1901. 

 t Boutroux, L. LePain et la Panifieation, 1897. 

 tRaciborski. Ber. der deut. bot. Ges. XVI. 119,1898. 



