178 
Journal of Agricultural Research 
Vol. XXIV, No. i 
Tabi,^ IX .—Effect of gas absorbents upon the development of internal browning 
Condition of fruit after ii weeks at o“ C. 
Treatment.* 
Nor¬ 
mal. 
Trace, 
Slight. 
Mod¬ 
erate. 
Severe. 
Per 
Per 
Per 
Per 
Per 
cent. 
cent. 
cent. 
cent. 
cent. 
Ordinary commercial wrappers. 
0 
5 
0 
60 
35 
Wrappers impregnated with cocoa butter. 
65 
35 
0 
0 
0 
Wrappers dusted with animal charcoal. 
45 
50 
5 
0 
0 
Wrappers dusted with silica powder. 
0 
5 
5 
45 
45 
Wrappers impregnated with olive oil. 
55 
45 
0 
0 
0 
Wrappers impregnated with paraffin. 
25 
65 
10 
0 
0 
Wrappers impregnated with lard-tallow mixture... 
30 
60 
10 
0 
0 
Wrappers impregnated with vaseline. 
Commercial wrappers, with 225 cc. concentrated 
potassium hydroxid in bottom of container. 
Commercial wrappers, with 225 gr. soda lime in 
65 
35 
0 
0 
0 
80 
20 
0 
0 
0 
bottom of container. 
0 
5 
5 
50 
40 
* Apples sealed in cans with arrangement for slow renewal of air. 
The data in Table IX show a very striking relation between the pre¬ 
vention of the browning and gas absorbents. In these tests 95 per 
cent of the treated fruit was marketable, as compared to only 5 per 
cent of that of the controls. The figures also indicate a definite rela¬ 
tion between the capacity of the various absorbents for taking up esters 
and the prevention of the disease. Paraffin, which according to Gilde- 
meister and Hoffman (ji) has an absorbing power of approximately 
one-half that of the other substances, showed the least prevention of 
browning. The poor showing made by the tallow-lard mixture was 
possibly due to the fact that it became rancid before the experiment 
was little more than started. 
All the tests with gas absorbents, as well as those with air circulation, 
seem to indicate that internal browning is caused by the accumulation 
of certain materials in the nature of essential oils or other volatile sub¬ 
stances. 
A very perplexing question which then arises is that of the appear¬ 
ance of scald on the surface while internal browning develops in the flesh 
of the fruit. In an attempt to answer this question, the writer placed 
fruit under optimum conditions for the development of both diseases. 
That is, apples were placed in stagnant air at a temperature which 
favors the development of the disease. The results of these tests were 
very interesting. In every case it was found that the scald and brown¬ 
ing developed almost simultaneously. The scald rapidly developed 
into what is termed “deep scald,“ while the browning diffused outward 
at a similar rate from the points of initial appearance about the vascular 
bundles. In many specimens where the diseases were retarded more on 
one side of the fruit than on the other, a very interesting comparison of 
their spread could be made. The generally observed appearance of 
scald on the surface without the internal browning and the reverse con¬ 
dition would then seem to indicate that these two regions of the fruit 
are most susceptible to the essential oils, or that these substances ac¬ 
cumulate more pronouncedly in these than in any other region of the 
apple. The disease seemingly appears first in that region which is most 
