20 
Journal of Agricultural Research 
Vol. XXVII, No. I 
acidity decreased relatively less rapidly during exposure to warm tem¬ 
peratures than did softening of the fruit. It would seem from these data 
that fruit ripened rapidly at high temperatures would be higher in acidity 
for the same degree of softness than would the same fruit ripened more 
slowly at lower temperatures. Thus it appears that while apples will 
lose acidity when held at temperatures of around 70° F., this loss is less 
rapid in proportion to the other ripening processes than it is at 32 0 F. 
It is also apparent from the data on which Figures 12 and 13 are based 
that acidity loss is relatively rapid in fruit remaining on the trees. 
Figures 6, 7, and 8 show that first-pick delayed-storage fruit was softer 
throughout the year than was second and third pidk immediate-storage 
fruit. Figure 12 shows, however, that the early-pick delayed-storage 
fruit was distinctly more acid than the late-picked fruit. Rapid loss in 
acidity in fruit on the tree is undoubtedly due in part to the increase in 
size of the fruit. 
EFFECT OF TYPE OF PACKAGE OR OF ROOM VENTILATION UPON ACIDITY OF 
THE FRUIT 
Magness and Burroughs reported no consistent variation in acidity 
due to ventilation of the storage rooms, or to type of package in which 
the fruit was stored. Tests have been repeated on the effect of package 
on acidity of the fruit and are reported in Table II. 
From the above data it is apparent that wide fluctuations exist in the 
acidity of individual apples or groups of apples, and that large numbers 
must be used if a figure representing the correct average is to be ob¬ 
tained. Individual figures in the above tables are based upon analysis 
of from 10 to 20 apples. The irregular variation in the data obtained 
indicates that this is not a sufficient number to represent accurately the 
condition of the various lots of fruit. It is apparent, however, that there 
is no distinctive variation in acidity due to type of package. Temper¬ 
ature, which regulates the rate of softening and general respiratory 
activity, appears also to regulate mainly the rate of acidity loss. 
CHANGES IN COLOR OF FRUIT IN STORAGE 
As discussed earlier, there appears to be no change in the red color of 
apples after they are removed from direct sunlight. The chlorophyll 
green tends to disappear in storage, however, leaving a yellow ground 
color. Careful observation indicates that this change in color occurs 
only very slowly in 32 0 F. temperature and rather rapidly at higher tem¬ 
peratures. It apparently is rather closely associated with the softening 
process in fruit exposed to normal storage conditions. Wide variation 
occurs, however, in the ground color of individual apples in storage which 
apparently can not be associated with the softness of the fruit. 
CHANGES IN SUGARS, PECTINS, MOISTURE CONTENT, ETC., DURING STORAGE 
Analysis to determine the chemical changes in the fruit here studied 
while in storage, other than change in acidity, have not been made. 
The work of Bigelow, Gore, and Howard ( 2 ), of Magness and Burroughs, 8 
and of numerous other workers has shown that there is a sharp increase 
* Magness, J. R. f and Burroughs, A. M. op. cit 
