160 REporT OF THE CHEMIST OF THE 
These results show that the added malic acid underwent fermen- 
tation to a marked extent. The disappearance of added malic 
acid was complete at 55° F., while at. the higher temperatures 
it was not complete. 
(2) Effect of temperature upon destructive fermentation of 
malic acid.—The effect of temperature upon the disappearance 
of malic acid can be studied in connection with the data presented 
in the preceding and following tables: 
TaBLE XVII.—RELATION OF TEMPERATURE TO THE DESTRUCTIVE 
FERMENTATION OF Matic AcIp. 
PERCENTAGE OF Maric Acip In APPLE JUICE AND VINEGAR KEPT aT 
AGE. ; 
55° F. 60°F. | 65° F. 70° F. 75° F. 80° F. 
| | 
Months. Exp. 31.:}| Exp. 32. | Exp. 33. Exp. 34. | Exp. 35. Exp. 36. 
Hreshss Gis. 0.54 0.54 0.54 0.54 0.54 0.54 
ace thee nicotene 0.43 0.02 0.03 0.01 0.01 0.01 
eens ARG eee 0.34 0.01 0.01 0.01 0.01 0.01 
Gane ncete wes 0.32 0.01 | 0.01 0.01 0.01 0.01 
OA emery ccs. « 0.30 0.01 | 0.01 0.01 0.01 0.01 
Zh eet Rime ees 3 | 0.00 0.00 | 0.00 0.00 0.00 0.00 
! 
The general tendency appears to be a less rapid loss of malic 
acid at lower temperatures. At 70° F. and above, the loss was 
uniform. 
(3) Effect of sterilizing apple juice upon decrease of malic 
acid.—In experiments 25, 26 and 27 the apple juice was sterilized. 
Parallel experiments with normal material were carried on at 
the same time. The tabulated results are given below. The 
general tendency, as shown by these results, is a less rapid and 
complete destruction of malic acid in sterilized material. In 60 
months, malic acid had disappeared entirely in those experi- 
ments where there had been no sterilization, but was still present 
in marked amounts in the sterilized samples. Sterilization must 
have destroyed the organisms responsible for the destruction of 
malic acid and apparently after this the conditions were not 
favorable for their growth. 
