within a treatment than he did between treatments. In comparing fruit cooled 
by these relatively rapid methods with fruit that was cooled from 67° to 32° F, 
in 20 days, he found the fruit that took 20 days to cool was slightly softer 
than the more rapidly cooled fruit. Sainsbury (52) found tunnel cooling greatly 
reduced the time required to cool apples over the room cooling method. Phillips 
(38) described a forced-air circulation unit which cooled apples from 68° to 
40° in 75.1 hours compared to 240 hours required where cooling relied only upon 
convection air currents in the storage room. Vacuum cooling of apples has been 
found unsatisfactory as a cooling method for apples because of desiccation or 
Wilting NOt inne wEEUntwiEheresultimen darkened or Jsunken-areas! (75) 8, /13') 027). 
See also (15, 19, 50, 64). 
Phillips (41) found the cooling time could be reduced from 87 to 24 
hours by maintaining a 10-degree differential between the storage room air and 
the mean fruit temperature throughout the cooling period. 
Air Movement and Humidity 
In studies on the effect of air movement and humidity on the cooling 
rate and moisture losses in apples, Dewey (7) found Golden Delicious took about 
Ewicewasmloneute cool in still ain as an moving alrty Invair-at¥l sto 223C- 
(33.8-35.6° F.), Golden Delicious took approximately 5 hours to cool from 25° C. 
@5e2so> maton? Ce i Cbeoeet= aingstillevatn and .2) 1/4 hours and 2 3/4 hours in 
air moving at a rate of 7/70 and 385 f.p.m., respectively. He reported cooling 
was equally good in air of 70 or 90 percent relative humidity and found moisture 
losses to be too small to be considered significant. Greater water loss from 
apples in a storage with a blower in operation than in a storage without a 
blower operation has been reported by Christopher, et al. (4). Zahradnik (66) 
found no differences in firmness between apples from a storage with continuous 
blower operation and those from a storage in which the blowers were programed 
to operate only when the thermostat called for refrigeration. Comin, et al. 
(6) previously reported water loss from apples to be no greater with forced-air 
draft than with gravity flow, provided the relative humidity was maintained be- 
tween 85 and 90 percent. 
With increased ventilation in either regular or CA storage Hall, et al. 
(22) reported a reduction in scald on Granny Smith apples. (See sections on 
scald and volatiles.) 
The efficiency of the air distribution systems of cold storages also 
plays a role in cooling fruit. A survey of fruit storages in Canada (16, 17, 
18) revealed that more air distribution systems suffered reduced efficiency 
from poor air returns than from any other single factor. Placement of storage 
containers directly on the storage room floor has been shown to be undesirable 
as well, because the transmission of ground heat through the floor caused the 
bottom layer of fruit to have a higher equilibrium temperature than layers above 
dt ae rop(aeeualsou 250 2G.) 49). 935.0 D2 o) 
Containers and Stacking Patterns 2/ 
The rate at which apples cool is affected by the nature of the storage 
containers, packing materials and stacking pattern. Fisher (10) found apples 
2/ See also section on Shipping Containers. 
12 
