30 
Journal of Agricultural Research 
Vol. XXVII, No. r 
Table IX .—Composition of intercellular atmosphere of apples held at 8o° F. ( 26.5 0 C.) 
Respi¬ 
ration 
experi¬ 
ment 
No. 
(Table 
VIII). 
Description of fruit. 
C 0 2 . 
02. 
Per cent 
Naby 
difference. 
*>3 
Winesap, untreated. 
Per cent. 
9.2 
Per cent. 
14. 2 
76. 6 
2 
Winesap, oil coated. 
14. O 
I* 7 
84-3 
4 
Rome Beauty, untreated. 
5 - 5 
l6. 2 
78-3 
5 
i 
Rome Beauty, oil coated. 
18.8 
2.9 
78.3 
Analyses for oxygen in the fruit held at 8o° F., where the respiratory 
ratio was much superior to unity, showed about the same quantity 
present as in similar fruit held at 64.5° F., where the anerobic respiration 
apparently was just starting, and apparently represents about the con¬ 
centration present when oxygen is the limiting factor in fruit respiration. 
The total quantity of oxygen entering the oil-coated fruit at 64.5° F. 
was approximately the same as the total amount entering at 8o° F. It 
appears, therefore, that in fruit coated as heavily as the fruit here tested 
about 6o° marked the highest temperature at which the oxygen supply 
entering the fruit was sufficient to prevent anerobic respiration. When 
held at temperatures above 6o° anerobic respiration was very pronounced. 
DISCUSSION OF EFFECT OF COATING SURFACE OF FRUIT UPON THE RIPEN¬ 
ING PROCESSES 
From the data presented above it is apparent that coating the surface 
of the fruit with such substances as oil or paraffin tends to retard respira¬ 
tion, regardless of the temperature at which the fruit is held, and thus 
to retard the ripening processes. The degree of this retardation will 
vary with the thickness of the coating. Apples heavily coated with 
either oil or paraffin are retarded in ripening much more than apples 
lightly coated. 
So long as the substances used in coating the fruit are entirely tasteless 
and odorless, the flavor appears to be normal until anerobic respiration 
sets in. Anerobic respiration may occur in fruit held at 3 2 0 F., if the coat¬ 
ing is very heavy. The higher the temperature at which the fruit is held 
the less the coating that will be required to induce anerobic respiration. 
At 64.5° fruit lightly coated appeared to show just the beginning of 
anerobic respiration, while the respiration of similarly treated fruit when 
held at 8o° F. was largely anerobic. In fact it seems highly probable 
that anerobic respiration will occur in certain fruits at very high 
temperatures without any coating of the surface. Taylor and Overholser 
(26) reported that very high temperatures inhibited the ripening of 
Bartlett pears, with associated loss of quality. It seems probable that 
anerobic respiration occurred.. Gerber’s high respiratory ratio on apples 
held at very high temperatures (30° and 33 0 C.) may have been due to 
oxygen depletion in the tissues. 
There is a wide variation in the amount of oxygen in the tissues of 
different varieties of apples under similar conditions. Magness and 
