Enzyms of Apples 



113 



duced into one arm of the apparatus, 0.0 1 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 



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. 



Protein-splitting enzyms in the flesh of the apple were tested for as fol- 

 lows: A saturated solution of ^gg 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, 



