Oct. 18, 1915 
Enzyms of Apples 
113 
duced into one arm of the apparatus, 0.01 gm. of the material to be oxi¬ 
dized placed in the other arm, the proper amount of distilled water added 
in each arm, and the apparatus placed in the constant-temperature box 
and allowed to stand for 30 minutes to come to a uniform temperature. 
The apparatus was then closed, the shaking started, and the manometer 
readings taken at 15-minute intervals. The final readings, with the 
kind of material and nature of oxidizable reagent used in each case are 
given in Table VI. 
Table VI .—Oxidase activity of various apple preparations toward different oxidizable 
reagents 
Variety and material. 
Oxidizable reagent. 
Time of 
maximum 
action. 
Diminished 
pressure. 
Rome Beauty: 
Acetone-dried powder. 
Pyrogallol. 
Min . 
45 
60 
Cm. 
O. IO 
Do.r. 
Pyrocatechol. 
. 60 
Do.. 
Guaiacol. 
0 
Do. 
Tyrosin. 
O 
Yellow Newtown Pippin: 
Acetone-dried powder. 
Pyrogallol. 
45 
60 
•35 
i- 75 
• 15 
0 
Do. 
Pyrocatechol. 
Do. 
Guaiacol. 
60 
Do. 
Tyrosin. 
King David: 
Acetone-dried powder. 
Pyrogallol. 
60 
. 20 
Do. 
Pyrocatechol. 
60 
45 
• 15 
0 
Do. 
Guaiacol. 
60 
Do. 
Tyrosin. 
Arkansas Black: 
Acetone-dried powder. 
Pyrogallol. 
0 
Do..*. 
Pyrocatechol...... 
45 
• 55 
0 
Do. 
Guaiacol. 
Do.*. 
Tyrosin. 
0 
Juice from pulp with quartz sand. 
Pyrogallol. 
30 
30 
i -45 
3 - SO 
0 
Do. . . t.. *..*. 
Pyrocatechol. 
Juice from pulp with quartz sand(boiled). 
Do. 
Pyrogallol. 
Pyrocatechol. 
0 
These results clearly show that apple pulp and apple juice contain an 
active oxidase, or oxidases, which accelerate the absorption of atmos¬ 
pheric oxygen by pyrocatechol and pyrogallol, and to a slight extent by 
guaiacol. The activity toward pyrocatechol is much greater than toward 
the other reagents, indicating the probability that the tannin of apples, 
which is so readily oxidized on exposure to air under the influence of the 
oxidases present, is of the pyrocatechol type. 
PROTEASES 
Protein-splitting enzyms in the flesh of the apple were tested for as fol¬ 
lows: A saturated solution of egg albumin was prepared and 5 c. c. of 
it were placed in each of three test tubes. In one of these, 5 c. c. of apple 
juice, prepared by grinding the pulp with quartz sand, were added; to 
the second, 5 c. c. of the same juice, which had been boiled for 10 minutes, 
