2 4 
Journal of Agricultural Research voi. xxvn, no. r 
EFFECT OF COATING UPON THE COLOR CHANGES OF THE FRUIT 
Much more marked than the influence of coating the surface on the rate 
of softening of apples was its influence upon color. Coated fruit showed 
very little change in the intensity of its green color during the time it 
was in storage. At the end of the storage season such fruit was very 
nearly the same shade of green as at the time of placing in storage. 
EFFECT OF COATING UPON THE ACIDITY OF THE FRUIT 
Determinations for acidity were made upon coated fruit and upon 
control fruit throughout the storage season, and there was no consistent 
variation in acidity due to coating the fruit. Certain varieties showed 
somewhat higher acidity in coated fruit at the end of the season and 
others showed less acidity. Because of the wide variation in acidity in 
individual apples it would be necessary to use large samples to determine 
accurately whether coating does influence the rate of acidity loss, and 
fruit was not available in sufficient quantities to determine this more 
accurately. 
EFFECT OF COATING UPON THE FLAVOR OF THE FRUIT 
The flavor of apples that had been coated either with oil or with 
paraffin varied greatly with the quantity of the coating material present. 
Unless very heavy coatings had been used, the fruit was of good quality 
when removed from storage at 32 ° F. If heavy coating had been used, 
however, the fruit was stale, flat, and of distinctly unpleasant flavor when 
removed from 32 0 F. storage. 
After holding for 10 days at a temperature of 6o° to 70° F.,much of 
the fruit that was of good quality when removed from a 32 0 F. room de¬ 
veloped undesirable flavors, becoming stale and fermented in taste. Cer¬ 
tain varieties, particularly Rome Beauty, became entirely inedible. Some 
of the very lightly coated fruits maintained a good flavor throughout 
the period of the tests. These were the fruits that showed a minimum 
retardation of softening and of color change, and obviously carried very 
little of the coating material. 
The tests so far carried out demonstrate clearly that the ripening 
processes of apples may be retarded by coating the fruit with substances 
that reduce the permeability of the epidermis. This retardation is at 
the expense of flavor, however, unless the coatings be very light. Coat¬ 
ings so light as not to injure the flavor of the fruit will cause only 
a very slight retardation of the softening process, with a somewhat 
greater effect upon the color of the fruit. 
RESPIRATION OF COATED AND NORMAL APPLES AT DIFFERENT TEM¬ 
PERATURES 
In order to determine the causes of the retardation of ripening in 
coated fruit, as well as the cause of the development of bad flavor that 
may accompany this retardation, the respiration of certain lots of fruit 
was measured. It is important that both oxygen absorption and 
C 0 2 output be determined, to arrive at a real measure of what is going 
on in the fruit. In the absence of oxygen, fruit will still give off C 0 2 
by anerobic respiration, as has been shown by Hill (17) and others. 
Consequently, the measurement of the oxygen absorption is essential 
to a knowledge of the source of the C 0 2 given off by the fruit. 
