RIPENING, STORAGE, AND HANDLING OF APPLES 49 



The rate of ripening following picking is determined almost en- 

 tirely by the temperature at which the fruit is held. 



The exact rates of softening of a large number of varieties of 

 apples when held at temperatures ranging from 30° to 85° F. have 

 been determined. 



There is a wide variation in the softening rates of different varie- 

 ties of apples when held at 32° F. Winesap, Arkansas {Mammoth 

 Black Twig), Yellow Newtown, York Imperial, and Arkansas Black 

 were hard when picked, and softened slowly. Rome Beauty, Stay- 

 man Winesap, Ben Davis, and King David grown in Virginia were 

 softer when picked and reached prime eating condition earlier. 

 Grimes Golden and Mcintosh reached a full soft condition still 

 earlier. 



Apples grown in New York State were harder when picked than 

 the same varieties in Virginia. The former softened slightly faster 

 in storage at 32° F. 



Apples in Washington State were in about the same condition 

 of hardness when picked as Virginia apples. They softened some- 

 what slower when held at 32° F. than the same varieties from 

 Virginia. 



The softening of different varieties at 40° F. was in about the 

 same order as at 32°. All varieties softened with great rapidity at 

 70°. Even varieties such as Winesap and York Imperial, though 

 hard when picked, were in prime eating condition within a few days. 



Most varieties when held at higher temperatures have an initial 

 short period after picking when little softening occurs. Following 

 this initial period softening proceeds rapidly. 



At 70° F. softening proceeds approximately twice as fast as at 

 50°. At 50° it is almost double the rate at 40°, while at the latter 

 temperature softening proceeds fully twice as rapidly as at 32°. 

 About 25 per cent longer time was required for fruit to ripen at 

 30° than was required at 32°. 



Holding apples at low temperatures for a period and then remov- 

 ing them to higher temperatures does not result in more rapid 

 softening than the holding of similar fruit continuously at the 

 higher temperature. 



Late picking has not resulted in the fruit softening faster than 

 earlier picked apples while held continuously in storage at 32° F. 

 At temperatures of 40°, 50°, and 70° F., respectively, late-picked 

 apples softened somewhat more rapidly than did early-picked fruit 

 from the same tree. 



Fruit held at temperatures of 50° F. or above from time of picking 

 until full eating ripe was usually somewhat more yellow than fruit 

 held until equally soft at 30° or 32°. At 36° and 40° the degree 

 of yellowing was intermediate. 



Apples held at the different storage temperatures were analyzed 

 at the time they reached full soft condition, to determine the effect 

 of the storage temperature upon the sugar and acid content. 



There was a slight increase in the total quantity of sugar in all 

 varieties between the time of picking and when the fruit was full 

 soft. 



