no 
Journal of A gricuUural Research voi .v, No. 3 
Table III .—Results of tests for invertase in the flesh of apples 
Variety and material. 
Reducing sugars. 
Before action. 
After action. 
Yellow Newtown Pippin: 
Decanted juice. 
Gm. 
0. 0113 
. 0212 
. OII3 
None. 
. 0098 
. 0202 
.0103 
None. 
Gm. 
0.0113 
. O217 
.OIO3 
None. 
.0103 
. 0207 
.0113 
None. 
Decanted juice (boiled). 
Decanted juice (neutralized). 
Control (water only).. 
Rome Beauty: 
Decanted juice. 
Decanted }uice (boiled). 
Decanted juice (neutralized). 
Control. 
These results being so contrary to what was expected, it was thought 
best to use material prepared for examination in several other ways in 
testing for invertase. Accordingly, a water extract was made of some 
acetone-dried powder from Rome Beauty apples, another sample of the 
same apples was ground with quartz sand and its juice expressed, and 
finally a sample of the Gore’s concentrated apple juice was diluted to 
about the same concentration as normal apple juice. Each of these 
materials was then incubated with sugar solution in the usual way, using 
unboiled and boiled samples of both the acid and neutralized juice in each 
extract. The reducing sugars found in the digested mixture from the 
unboiled or “active” extract and from an equal aliquot of boiled extract 
are given in Table IV. 
Table IV .—Tests for invertase in various preparations from the flesh of apples 
Material. 
Reducing sugars found after 
action. 
Active extract. 
Boiled extract. 
Water extract of acetone-dried pulp. 
Gm. 
0. 0207 
.0396 
.0376 
. OI92 
. OI92 
Gm. 
0. 0207 
.0396 
Lost. 
. 0187 
. 0192 
Juice concentrated by Gore’s process. 
Juice concentrated by Gore’s process (neutralized). 
Juice from pulp ground with quartz sand. 
Juice from pulp ground with quartz sand (neutralized).... 
The results shown in Tables III and IV indicate the absence of any 
invertase in apple flesh and confirm the observations of Warcollier (12), 
referred to above. It appears, therefore, that changes during ripening 
which result in the inversion of sucrose, if they actually occur, must be due 
to some other cause than the presence of invertase in the apple tissues. 
The fact that some investigators have not been able to find evidence of 
this inversion of sucrose during ripening casts some doubt upon its actual 
