The evening times., 1899-08-01
TEE CURING OF TOBACCO
A Chemical Enquiry by the Depart
ment Of Agriculture.
An Effort to Secure a Cigar Leaf
That in Aroma and Other Proper
That Produced in Cuba-COncin-
sions Already Reached by Experts.

si0ns Already Reached by Experts.
The Department Of Agriculture is con,
Quoting an enquiry into! the matter of cur
| ing tobacco This enquiry has been prompt
| ed mainly by reason of the fact that Ameri-
can planters are making strenuous efforts
| to produce cigar, leaf. which will fav-
orably compare with that grown in Cuba.
| This effort is being made in Florida, anG
| 1t is said that already reasonable meas
ure of success has been attained The ex-
periments on the part of the Department
are being conducted by Prof. Oscar Loaw, OF
the Division of Vegetable Physiology ana
Pathology. o. ff
At present considerable attention is be-
| ing given to the various methods of ''pe-
| tuning" This is an operation first prac-
| ticed in Cuba, and consists of spraying
| liquid on the tobacco leaves during and af
| ter the sweating process. The filters only
and not the wrappers are petuned, thus
| giving them darker color, and improved
| ilaVor, and the appearance and character
of strong tobacco. The composition of the
petuning liquid used in Cuba is kept ge
cret and it is said that practically every
| Cuban planter claims to have a process
known only to himself.
1t is generally believed that the princi-
pal method employed in preparing the pc
tuning fluid is by pouring organic liquids,
yielding ammonium carbonate, over crush
| ed tobacco stems and letting this mixture
| digest. 1t is said that this liquid is very
| liable to purify. and that consequently a
! most luXuriant growth Of bacteria Is pro-
| duced within few days in the warm eli
| mate of Cuba. 1t is also said that on the
| cttrfon of How fnh var IN
are found. The ammonium carbonate con-
| tanned in the petuning fluid increases the
| alkaline reaction in the fermenting leaf,
| and gives energy to the oXidiZing process,
| which brings on the dark color so much
| esteemed in the filler leaves. 1t has been
| suggested that the ammonium carbonate
| would dissolve some resinous matter from
| the stems and lead to an Improvement in
| the aroma of the filler leaves, for there is
! a theory that the aroma depends to great
| extent upon the resinous contents of the
| tobacco plant.
Petuning is practiced in some parts of
| the United States, but it is claimed that a
majority of American tobacco manufactu-
| rers contend that the effect OF the treat
| ment is overrated.
BY some advanced American growers a
hot solution of ammonium carbonate is
| left to act upon the stems of tobacco. This
extract is prepared daily for use, and it is
! maintained that American tobacco thus
| treated does not show any bacterial flora
on its surface. The petuning liquid often
| has a different composition. The tobacco
stems are sometimes soaked in water con-
tanning rum, molasses, or sour wine. The
molasses is supposed to disguise the bitter
| taste derived from the stems.
| Closely connected with the petunfng pro-
cess is the so-calied conditioning" OF to-
| Earcn This consists in SnraylnR the leaves
with per cent solution of glycerine. The
operation is carried on mainly with plug
and cigarette tobaccos, and is intended 10
keep them moist and pliable.
1t has long been recognized by tobacco
experts that the main features OF the pro-
cesses going on in the sweating, or the So
| called fermentation, is in oxidation. This
| is accompanied by certain decompos!tlons
liberating ammonia, and is the source OF
the striking DEVELOPMENT of heat in the
| fermenting piles.
| Some experts declare that it is only the
common oxygen of the air that attacks GER
tain compounds in the cells. Other ex-
perts attribute all the oxidations and the
development of heat to the action of GER
tain bacteria, which are specific for diff
ferent kinds of tobacco and which impart
10 each of them specific aroma. The COM
mon oxygen theory was held by Nessler
and Schosing, and the bacterial theory by
Schuland. Schuand prepared pure cul-
lures of microbes found upon different
kinds of tobacco and by transferring those
obtained from Havana tobacco TO German
tobacco be expected to develop the Havana
aroma in the German leaf. The expert
ment was not success. Davalos describ-
ed mold fungi and microbes occurring up
on Havana tobacco but did not prove their
| Importance in the fermentation process.
Vernhout described only one kind of bac-
terium which he found on fermenting to-
bacco leaves. This developed at 122 de-
grees Farenheit upon agar plates, and was
thermophile kind of the group of bacil-
lus subtilis. This bacterium has been
proved to develop also in decoctions of to-
bacco and to be capable OF decomposing
proteids with development of ammonia
| koning describes several kinds of bacteria
upon fermenting tobacco. Besides the
widely known bacteria mycodes and sub
this, he described five new aerobic kinds.
The Department of Agriculture will or
der a direct microscopic investigation of
the leaves of fermenting tobacco. The sum-
mary of the conclusions thus far reached
by the scientists of the department fol-
lows:
THE so-called tobacco fermentation is
not caused by bacteria.
The amount of water present in nor
mally fermenting tobacco leaves is INSULT
from the interior of the cells to the surface
of the leaves. 1t barely suffices for imbibI-
tion of the organic matter.
There exists no bacterial coating on the
fermenting tobacco leaves under norman
conditions, but some spores may occur
I'm the so-cailed petuning of tobacco ALI
immense number of bacteria may be trans
ferred to the leaves. These bacteria, how
ever, are not essential for the fermenta-
ton, but on the contrary, may prove nox,
ious as soon as small surplus of water
1 enables them TO further develop.
"Suchsland's theory that the aroma Of
tobacco is caused by specific bacteria is in
correct.
The principal changes that take place
during the curing and fermenting of to-
bacco are due to the action of soluble fer
ments or enzyms.
Several kinds of enzyms act in the cur
ing process, (a) an amylolytic; (b), pro-
teolytic and (c). two oXidizing enzyms,
while in the fermenting process the main
changes are due to oxidiZing enzyms alone
and consists in the oxidation of nicotine and
other compounds.
The presence of the amylolytic and the
proteelytic enZyms is inferred from the
standardization of the starch and the de-
composition of proteids, but the enzyms
themselves have not yet been isolated from
the Tobacco leaf
I'm green tobacco two oxidizing enzyms
may exist an oxidase and peroxidase The
former succumbs much more readily to nox-
ious influences than the latter and in all
probability eXerts a more powerful action
'The development of color and aroma rs
due principally to the action of the oXidiz-