106 
Joumal of Agricultural Research 
Vol. XXIX, No. 3 
However, there is some indication 
that frozen apples stored undisturbed 
for an extended period in the original 
position after thawing will suffer 
somewhat deeper and more serious 
bruises when moved than unfrozen 
fruit similarly stored. Freezing, even 
if unaccompanied by visual injury, 
tends to soften the fruit, making it less 
resistant to injury after an extended 
storage period. But the severity of 
injury is not nearly so great as in 
fruit bruised while hard frozen. 
Table V.— Comparison of the effect of 
bruising unfrozen and partially frozen 
Rome Beauty apples as shown by the 
depth of the injured portion when 
thawed 
Treatment 
Bruise 
depth 
Ratio 
of 
depth 
of 
frozen 
to un¬ 
frozen 
bruises 
30 POUNDS PRESSURE APPLIED 
FOR BRUISING 
Unfrozen.. 
Mm. 
6 0 
Bruised hard frozen 
14. 2 
2.4 
Thawed 1 hour at 68° F 
13 4 
2 2 
Thawed 3 hours at 68° F 
8.0 
1.3 
Thawed 5 hours at 68° F 
7.8 
1.3 
Thawed 7 hours at 68° F 
7. 7 
1 3 
Thawed 24 hours at 68° F 
7.0 
1.2 
Thawed 7 hours at 40° F 
10.9 
1.8 
Thawed 24 hours at 40° F 
7.5 
1.3 
Thawed 48 hours at 40° F 
6.6 
1.1 
50 POUNDS PRESSURE APPLIED FOR BRUISING 
Unfrozen.. 
9. 5 
Bruised hard frozen 
17.5 
1. 8 
Thawed 1 hour at 68° F 
17.4 
1.8 
Thawed 3 hours at 68° F 
12.3 
1.3 
Thawed 5 hours at 68° F . 
12.9 
1.4 
Thawed 7 hours at 68° F 
12.0 
1.3 
Thawed 24 hours at 68° F 
10.3 
1.1 
Thawed 7 hours at 40° F. 
14. 6 
1.5 
Thawed 24 hours at 40° F__ 
11.0 
1.2 
Thawed 48 hours at 40° F _ 
10.7 
1.1 
Effect of freezing on depth of 
BRUISES ALREADY PRESENT. -Yellow 
Newtown apples were used in experi¬ 
ments to obtain data upon the effect 
of freezing apples which were already 
bruised. The fruit was subjected to 
temperature and handling conditions 
similar to those followed in the other 
bruising experiments, but before being 
frozen it was stored for certain periods 
after bruising (Table YI). 
Table VI. — Effect of freezing upon depth 
of bruises previously made with 30 
pounds pressure on Yellow Newtown 
apples 
Treatment after 
bruising 
Storage 
! tem¬ 
pera¬ 
ture 
after 
bruis¬ 
ing 
Length 
of 
storage 
period 
Bruise 
depth 
Frozen... 
°F. 
70 
Days 
1 
Mm. 
6.7 
Unfrozen.... 
70 
1 
6.0 
Frozen___ 
70 
3 
6.6 
Unfrozen..._ 
70 
3 
6.6 
Frozen.... 
70 
6 
6.1 
Unfrozen... 
70 
6 
6.1 
Frozen. 
40 
14 
6.0 
Unfrozen.. 
40 
14 
6.0 
There is no indication that bruises 
made before the fruit was frozen be¬ 
come more serious in depth when the 
fruits are subsequently frozen, nor that 
they change in appearance. Tests with 
other varieties gave similar results. 
Effect of different thawing 
TEMPERATURES ON DEPTH OF BRUISES 
on hard frozen fruit. —To deter¬ 
mine what effect the temperature at 
which fruit is held while thawing has 
on the injury from bruises, a number 
of Esopus Spitzenburg apples were 
frozen hard, and bruised as already 
described. The fruit was then thawed 
at various temperatures from 32° to 
70° F. 
No significant differences appear in 
the depth of bruises made on hard- 
frozen fruit when it is subjected to 
various thawing temperatures (Table 
VII). 
DETERMINATION of the internal tem¬ 
perature AT WHICH VISUAL INJURY 
TAKES PLACE IN FROZEN APPLES 
Certain peculiarities in the reaction 
of apples to supposedly fatal temper¬ 
atures have been noted in reading 
the temperature bv means of the 
thermocouples. Apples quite similar 
in weight and appearance show marked 
variations in the rate of cooling and of 
freezing, and exhibit the most diverse 
phenomena in visual injury. Experi¬ 
ments were made to test the hypotheses, 
repeatedly noted, that ice formation 
is not in itself necessarily injurious to 
the fruit but that apparently a certain 
EXPLANATORY LEGEND FOR PLATE 5 
A. —Cross section of Yellow Newtown apple, bruised while unfrozen by the application of 35 pounds of 
pressure to areas on its surface. 
B. —Cross section of Yellow Newtown apple, bruised while hard frozen by the application of 35 pounds 
of pressure to areas on its surface, showing the severity made on hard-frozen tissue. 
