The evening times., 1899-05-24
fHE CHEMISTRY OF
CIGAR LEAF TOBACCO
Dr.. Loew's Report to the De-
partment of Agriculture.
Flavor and Aroma Not Due Entirely
to Nicotine.
Interesting Analysis of the Products
of Different SectiOns-The
Curing Process.

The Department of Agriculture, in fol-
lowing out its line OF tobacco investiga-
tions, has issued report on the curing
and fermentation of cigar leaf tobacco.
1t is the policy Of the department to ex-
tend and supplement the investigations
made by the division Of soils into the to-
bacco districts Of the United States. The
work includes the mapping of soil areas.
studies In fermentation. improvements in
breeding and selection, enquiry into the
conditions Of growth and manipulation in
foreign countries, and the question Of sup
plying tobacco to foreign markets.
1t is said that, in examining and classi-
flying the soils Of the principal tobacco dis
tricts in this country. certain facts develop
ed in regard to the commercial value Of
the crop from certain soils, which could
not be clearly understood or explained
without a further investigation of the
methods of curing. fermenting, and hand
ling OF the tobacco, and possibly Of breed
ing new varieties AS soon as it was de-
termined by Secretary Wilson that the
work could be undertaken, Prof. Whitney
Chief OF the Division OF Soils, and in
charge Of tobacco Investigations, requested
the chief OF the Division of Vegetable
Physiology and Pathology to detail an ex-
pert to examine into the curing and fer
mentation OF tobacco. In accordance with
this request, Dr. Oscar Loew was detailed
to carry on the enquiry and went to Quin-
cy, Fla. where he spent some time during
the fermentation season.
1t is reported that DR.. Loew discovered
the real cause OF the fermentation of to-
bacco. and it is said at the department
that this discovery cannot fail to prove of
great scientific interest and economic val
ue and that 1t will unquestionably modify
the methods OF curing and fermenting
when the investigation shall have been
carried further and the conditions and
principles Of the process are better un-
derstood.
In the introduction to his report DR..
Loew says:
The production OF tobacco adapted to
the different market demands has become
a prominent factor in national economy.
OF particular Importance is the production
OF superior cigar leaf tobacco The filler
leaf of cigar must above all things have
a good favor, good aroma, and good burn.
In the wrapper leaf however. still other
qualities come in. such as elasticity. pill
ability. size. shape. color. size Of the veins.
the fineness and peculiar grain of the Ha-
vana type, and the smooth sickness Of the
Sumatra.
Little is known OF the chemical proper
ties OF the leaf. especially OF those which
contribute to the favor and aroma. II is
probable that the actual amount Of nicotine
is relatively unimportant. and it Is GER
tain that the excellence OF the leaf and Its
adaptation to market demands is not de-
pendent, except in a very general way.
upon the amount of nicotine. 1t has long
been known that certain of the potassium
salts, especially potassium chlorid, canno;
be used at all for the production of high
types of cigar tobacco as they give the leaf
poor burn. II Is furthermore an old ex-
perienee of tobacco growers that excessive
nitrogenous manuring tends to produce
large leaf of Inferior quality. containing
an increased amount OF nicotine. II the
prime object of tobacco culture were the
production of nicotine. as the prime OBJ
ject in raising sugar beets is the produc-
ton Of sugar. then the rational procedure
would be to furnish an excess OF nitro
genous manures. but nicotine alone does
not make a good cigar tobacco any more
than alcohol alone would make good
wine The substances producing the favor
and aroma, therefore. although probably
present in minute quantities. are much
more important than the actual percentage
of nicotine found in the cured leaf.
whitney has shown that tobacco suit
ed to our domestic cigars is grown only
upon certain soils and under certain cli-
matte conditions.
There are two periods in the curing
process The first period. in which the
cells of the leaves are still alive and in
duce processes of metaboltsm anc the sec
ond period in which the cells have died
and the chemical changes have. therefore,
no connection with the living protoplasm.
In the former period, which may last only
a few days the starch contents Is dis
solved and the sugar formed Is partly con-
sur-d by an increased respiration and
partly transported to the rib:, where
starch may be formed again. In the lat
ter period the enzyms are alone active.
"The so-eailed fermentation process de-
velops in the tobacco leaves the charac-
teristic qualities of the commercial arti-
Gle. 1t is natural to suppose that the
same agency which finishes the curing
process after the death Of the GELS remains
active during the so-cailed fermentation
process after the death Of the cells remains
irlme ediately after the curing when ootn are
done by the grower. but where the cured
tobacco is bought up by manufacturers sew
cral months may pass hefore II is SUD-
jeoted to the sweating process. This ope-
ration begins when the toh: eco is in the
rroper order or case" being brought
into this condition naturally o. damp
day, or by an exceedingly cautious moist
ening. a,c;eing ally vis;Dl, water on the
leaves. TIE amount Of vate, applied must
Just suffice to bring on moderate imbibi-
tion.
THE sweating Of the Florida leaf in
bulk requires from six to eight weeks, the
original crude and rank smell Of the cured
tobacco being gradually changed to the
proper aroma of the finished tobacco. and
the glossy appearance and the texture be-
ing well brought out. Light-colored wrap
pe RS require a slower and coole- :eImenta-'
tion than the dark oolored leaved used
as dark wrappers or filters.
Small quantities of starch are some
tines found in fermentcd toi acco when
tie curing process has not been carried out
n: opt rly in all Larts OF the lea or in parts
o. leaves broken or injured by fungi, but
this occurrence of stall Percentage of
s:ar cb interferes with the favor just as
little as does the closely related cellulose.
The well-preparcd tobacco wrappers from
Floi ida examined by 'hs vIiter. did not
show a trace Of starch.
LAS to the disappearance OF the last
remnant of sugar during the sweating;
some authors assume oxidation to carbon
dioxide and water. and others dssume
partial transformation to ,acetic acid
When it is taken into consideration that
an alkaline medium can soon change glu-
cose into organic acids, especially in the
presence Of air, more simple explanation
would be at hand than the assumption Of
q perfect combustion Of the glucose. There
are organic acids present in the original
tobacco leaf, such as citric, malic. and
oxalic acids, in the form of neutral salts.
A part of these acids may be changed and
in the fermentation process,
while other acids may be formed by the
the glucose undergoes. The n:co-