18 BULLETIN 1166, U. S. DEPARTMENT OF AGRICULTURE. 
While there is an appreciable quantity of hydrocyanic acid in the 
seeds, so long as the liberating enzyme is eliminated in the process 
of manufacture, as evidently occurred in this sample, there should 
be no danger from feeding reasonable quantities of dried pomace 
such as this. Auld (8) has shown that the liberation of hydro- 
cyanic acid from similar glucosides is retarded in normal digestion, 
even in the presence of the glucosidoclastic enzyme. On the other 
hand, fermented, moldy, or yeast-containing feeds generally contain 
enough of the enzyme to supply any deficiency, so that the safest 
course is to see that precautions are taken by the manufacturer of the 
dried pomace to eliminate not only the enzyme but the cyanophoric 
glucoside. This could be accomplished either by removal of most of 
the seeds or by first " digesting " the moist press cake in a warm 
place for several hours, then thoroughly cooking the pomace during 
or, preferably, before drying. 
The possibility of turning to good account the substance that may 
make the presence of the seeds in a feed dangerous is worthy of 
some consideration. For example, it has been shown that apple 
seeds contain from 0.62 to 1.38 per cent of amygdalin, which, in the 
kernels of bitter almonds, is the source of the volatile oil of that 
name. Bitter almonds are reported to contain from 1 to 3 per cent 
of amygdalin, and other seed kernels, recommended as a source of 
the volatile oil, contain from 1.5 to 3 per cent (123 y 12^). After 
decomposition of the amygdalin and removal of the volatile oil from 
apple seeds the thoroughly heated and dried residues might prove to 
have some value as a feed. 
It has been suggested that material containing such large quantities 
of pectin substances as dried apple pomace might cause injury if 
fed in excess, owing to the formation of methyl alcohol from the 
pectin. 27 Fellenberg (65) reported that he obtained methyl alcohol 
from the digestion of foods containing pectin, and Tutin (133) has 
shown that not only methyl alcohol but acetone is liberated from 
pectin by the action of the enzyme pectase and also of cold dilute 
alkali on pectin. Here again, however, heating the material thor- 
oughly in a moist condition would serve to destroy the liberating 
enzyme if it were present in the pomace. Considering the large quan- 
tity of pectin consumed daily by animals and by man, injury from 
this source appears very remote. 
DRIED APPLE-PECTIN PULP. 
Several apple residues intermediate in composition between 
straight apple pomace and apple-pectin pulp are obtained by sub- 
jecting the straight pomace to a second or third pressing, with or 
without the addition of water and soaking between pressings 
(p. 8). To avoid confusion, "apple-pectin pulp," synonymous 
with " extracted apple pomace," is here applied only to the product 
which remains after treating the original dried apple material, 
whether chops, waste, or dried pomace, with cold water to remove 
sugars and other soluble substances, and subsequently extracting the 
27 A portion of dried pomace (sample 37254), subjected to destructive distillation in a 
copper retort, yielded 1.5 per cent methyl alcohol and over 2 per cent acetic acid. This 
work was done by W. F. Sterling, in the leather and paper laboratory of the Bureau of 
Chemistry. 
