220 



OKUMURA ; CHEMISTRY OF SAKE BREWING. 



extract with 30 % alcohol as above described. 1 took lO cc. of 

 this neutral solution for each experiment and warmed it in a 

 large water bath to various degrees whereupon some starch paste 

 was added. After digestion at 40°C. for 30 minutes Fehling' s 

 solution v,\as applied. 



At 60° for lom. active. 



,, 60^ ,, 30m. active. 



65" ,, lom. active. 



,, 65-' ,, 30m. active. 



70" ,, 25m. killed. 



We observe here that this enzyme still remains active 

 above 65^C., when the solution is neutral. 



Acetate of phenlhydrazin produces in the enzyme solution 

 after several days a small amount of amorphous sediment which 

 increased upon the addition of a littte alcohol. This sediment 

 was filtered and yielded jMilloii s reaction. 



In another experiment I mixed a concentrated solution of the 

 enzyme with a few drops of ammonical silver solution ; after 24 

 hours standing in darkness a brown colouration was observed. 



Behaviour to Guaiacum Tincture. 



Schuiibeiii observed the interesting fact that diastase of malt 

 yields a strong blue coloration when it comes in contact with 

 tincture of guaiacum and peroxide of hydrogen. This coloration is 

 due to the oxidation of guaiaconic acid caused by the action of 

 enzyme and peroxide of hydrogen. However, the latter is not 

 always necessary, as there exist enzymes which bring on this 

 blue coloration also with the aid of common oxygen. E. Schdne 

 has found that guaiacum tincture, if perfectly fresh, also yields 

 this reaction wirh common diastase of malt, which I have 

 compared with the enzyme of the koj'i fungus in this regard. 



I dissolved the freshly precipitated kqfi enzyme in a mode- 

 rate quantity of water and then added to 10 cc. this solution, one 

 drop of guaiacum tincture, and a few drops of diluted peroxide of 

 hydrogen, but only a slightly bluish coloration was obtained, 

 while the control experiment with malt diastase yielded at once a 

 very strong reaction, indicating a considerable difference also 

 on this point between these two diastatic enzymes. 



