Jan. 5,1924 
Physiological Studies on Apples in Storage 
While the oil coating thus secured would probably never be sufficient 
to result in bad flavor in the fruit, due to its inducing anerobic respirar- 
tion, it undoubtedly differs in degree only from the effect produced by 
the heavier oil coating secured by wiping the fruit with a well oiled 
cloth, the method followed in the “oiled coating” here discussed. In 
the storage tests of holding fruit in oiled papers in connection with this 
work, small-sized wrappers were used, and there was apparently little, 
if any, oil transferred to the fruit. Under these circumstances no varia¬ 
tion in rate of ripening in storage could be detected between fruit not 
wrapped and fruit wrapped in oiled paper. The wraps used, however, also 
failed to control the development of storage scald, although containing 
a very appreciable quantity of oil. The results obtained with this paper, 
together with the general appearance of fruit on which storage scald 
has been controlled by oiled wraps, strongly suggests that some oil 
must be transferred from the wrapper to the fruit if scald control is to 
be effective. In that case, the ripening of the fruit would be somewhat 
retarded by the use of oiled wraps. 
SUMMARY 
Changes in apples as they approach the condition of ripeness on the 
tree have been studied. These changes include (1) increase in size, 
(2) increase in the area and intensity of the red color and the change 
in the green or ground color from leaf green to yellow green, (3) a pro¬ 
gressive softening of the fruit, and (4) a decrease in the apparent acidity 
in the fruit. Fruit softened very rapidly while still on the trees at 
Arlington, Va., during the warm, dry autumn of 1922. 
Changes in the fruit following picking are primarily a continuation 
of pre-picking changes. Softening, acidity change, sugar change, etc., 
continue after picking much as while the fruit is still on the tree. The: 
rate of these changes varies with the temperature at which the fruit is ; 
held. 
Rate of softening of apples while in 32 0 F. storage as compared wither 
storage at 70 0 F. varies with varieties. Ben Davis softened as much in . 
2% months at 32 0 F. as in 12 days at 70° F., Winesap and Rome Beauty 
as much in 3 to 4 months at 32 0 F. as in 12 days at 70° F., York Imperial 
as much in about 5 months at 32 0 F. as in 12 days at 70° F., while Deli¬ 
cious and Rhode Island Greening were softer at the end of 12 days at * 
70° F. than they were at the end of their storage period, about 6 months,' 
when placed in 32 0 storage immediately after picking. 
All varieties used showed a constant decrease in acidity during the 
time the apples were held in 32 0 storage. Rate of decrease was very/ 
nearly the same in all varieties, regardless of acid content. Thus Deli¬ 
cious, with an initial acid content of about 3 cubic centimeters N/10 
acid per 10 grams of wet tissue, lost acid until after 6 months only 2 cubic 
centimeter N/10 acid was present, a loss of from 30 to 40 per cent. Rhode 
Island Greening, with an acid content equivalent to 9 cubic Centimeters 
N/10 acid at the beginning of the season, also lost only about 1 cubic 
centimeter N/10 acid, or about 12 per cent. Range of varieties tested, 
in order of decreasing acid content, is Rhode Island Greening, Ben 
Davis, York Imperial, Winesap, Rome Beauty, and Delicious. Per¬ 
centage loss of acid during 6 months in storage is in the reverse order, 
those varieties showing lowest total acidity showing highest percentage 
loss. 
