Nov. 12, 19x7 
Jonathan-Spot and Scald of Apples 
299 
The results of the two experiments and of other similar experiments 
indicate that apples at a fluctuating temperature develop but little, if any, 
more scald than similar apples at an average but constant temperature. 
EFFECT OF AERATION AND HUMIDITY ON APPEE-SCAED 
There has been a great diversity of opinion as to the importance of 
ventilation in the development of scald. Powell and Fulton (17) found 
that paper wrappers did not reduce the amount of scald on apples, but 
that paraffin wrappers did. They further found that an atmosphere of 
moist oxygen favored the development of scald, while an atmosphere of 
nitrogen prevented it, at least during short periods of storage. Greene (11) 
reported that wrapping fruit retarded the ripening processes and delayed 
the appearance of scald. 
Fulton (9) reported that extra wrappings on 
suited in a decrease in the oxygen of the pack¬ 
age and an increase in the carbon dioxid and 
caused the fruit to soften prematurely and take 
on a bad flavor. He found that these conditions 
were still more emphasized by storage in tightly 
stoppered glass bottles. 
Hill (12) found that storing apples and peaches 
in either nitrogen or hydrogen resulted in a bleach¬ 
ing or browning of the skin and in the development 
of disagreeable flavors. Peaches stored in carbon 
dioxid developed similar conditions, but a more 
nauseating flavor. The peaches in hydrogen and 
those in nitrogen became soft, but those in car¬ 
bon dioxid did not. He thought that the firmness 
of the fruit in the latter case was due to the fact 
that the gas decreased the hydrolysis of pectose. 
Thatcher (21) stored apples in various gases. 
He found that in an atmosphere of air or of 
oxygen the apples became visibly overripe within 
four weeks, that in hydrogen or in nitrogen they did not soften so rapidly, 
but soon became discolored and unhealthy in appearance, while in carbon 
dioxid they retained their color, flavor, and firmness for more than 
six months. He also found that berries softened much sooner in the 
air than in carbon dioxid. He concluded that the enzyms that par¬ 
ticipate in the changes of the carbohydrates during the ripening proc¬ 
esses are oxidases and inhibited by carbon dioxid, an end product of 
oxidation. 
The writers (2) have reported experiments indicating the importance 
of aeration and humidity in the prevention of apple-scald. 
The experimental studies mentioned in the last reference (2) were 
continued in a much more extensive series of experiments carried out 
cartons of berries re- 
too 
r 
\ €0 
\ 40 
20 
u 
U 
O $ /O 20 
TEMP&MTURC C£NTtGMO£ 
Fig. 16. —Graphs showing the 
effect of aeration and humid¬ 
ity on apple-scald. The 
solid graphs show the 
amount of scald developed 
in moist chambers at the 
end of $ and n weeks and 
the dotted graph the amount 
in an open container. The 
apples were Grimes from 
cold storage. The experi¬ 
ment was started on Novem¬ 
ber 6, 1915. 
