Year: 1887

page_text: Date of Application, 14th Apr., 1887
Complete Left, 13th Jan., 1888
Complete Accepted, 17th Feb., 1888
I, AUGUST SCHUHMANN, of Düttlenheim near Strassburg, Elsass in the German
Empire, Manufacturer, do hereby declare the nature of this invention to be as
follows:
As-is well known, the dextrine of commerce has an unpleasant very penetrating
odour and flavour, which prevents its use for technical
many
purposes.
I have observed that this objectionable smell and taste is not inseparable from the
dextrine but is rather the consequence of the irrational method at present used for
preparing it.
At present dextrine is prepared in the dry way by sprinkling starch flour with acid,
mixing it thoroughly, and drying it, after which the dry compound is roasted under
stirring at a temperature of from 100 to 150° Cent.
A bad smelling dextrine is thus obtained which cannot be freed from the acid and
the cellulose contained therein, and which is therefore a very imperfect product.
According to my invention I obviate these disadvantages by preparing the dextrine
as follows:
Starch flour is mixed with fresh water to a thick milk, to which is added one per
cent. by weight of a fixed acid. This mass is well stirred and left for 24 hours,
after which the acid water is decanted and the precipitated starch is washed with
fresh water until lithmus paper is no longer colored red thereby.
The starch thus treated is then mixed with fresh water to a milk of 15° Beaumé
and there is added to it one half per cent. by weight of a saturated solution of
sulphurous acid, and the compound is boiled in a digester at a pressure of from 3 to 4
atmospheres, samples being taken at intervals. As soon as these shew traces of glucose,
the treatment is stopped and after the small quantity of sulphuric acid formed during
the process has been fixed, the mass is placed in a filter of animal charcoal, from which
it issues as a perfectly clear liquid devoid of smell and taste. This becomes milky
when cold and exposed to the air, and can be evaporated to any desired consistency or
to dryness

page_text: The dry mass thus obtained is of a brilliant white colour and has all the properties
of commercial dextrine, but is perfectly free from smell and flavour, as also from acid
and cellulose.
The above described process for preparing the dextrine is not more expensive than
that now used and it, has the further advantage that much larger quantities can be
treated at one time.
With certain kinds of very pure starch flour the preliminary treatment with cold
acidulated water is advantageous but not indespensable; if it be omitted, the starch is
best converted into paste before adding the acid. In order to obtain a product having
increased solubility in cold water, the product resulting from the above described
treatment, after binding the acid, may be replaced in the digester and again boiled at
a temperature of about 150° Cent. The heating may also be effected in an oil bath or
by superheated steam instead of in a digester.

page_text: An Improved Manufacture of Dextrine or Soluble Starch Free from
Smell and Taste.
1, AUGUST SCHUHMANN, of Düttlenheim, near Strassburg, Elsass, in the German
Empire, Manufacturer, do hereby declare the nature of this invention and in what
manner the same is to be performed to be particularly described and ascertained in
and by the following statement:-
As is well known, the dextrine of commerce has an unpleasant, very penetrating
odour and flavour, which prevents its use for many technical purposes.
I have observed that this objectionable smell and taste is not inseparable from the
dextrine but is rather the consequence of the irrational method at present used for
preparing it.
At present dextrine is prepared in the dry way by sprinkling starch flour with acid,
mixing it thoroughly and drying it, after which the dry compound is roasted under
stirring at a temperature of from 100 to 150° Centigrade.
A bad smelling dextrine is thus obtained which cannot be freed from the acid and
the cellulose contained therein and which is therefore a very imperfect product.
According to my invention I obviate these disadvantages by preparing the dextrine
as follows:
Starch flour is mixed with fresh water to a thick milk to which is added one per
cent by weight of a fixed acid. This mass is well stirred and left for 24 hours after
which the acid water is decanted and the precipitated starch is washed with fresh
water until litmus paper is no longer colored red thereby.
The starch thus treated is then mixed with fresh water to a milk of 15° Beaumé and
there is added to it one half per cent. by weight of a saturated solution of sulphurous
acid, and the compound is boiled in a digester at a pressure of from 3 to 4 atmospheres,
samples being taken at intervals. As soon as these shew traces of glucose the treat-
ment is stopped and after the small quantity of sulphuric acid formed during the
process has been fixed, the mass is placed in a filter of animal charcoal from which it
issues as a perfectly clear liquid devoid of smell and taste. This becomes milky when
cold and exposed to the air, and can be evaporated to any desired consistency or to
dryness.
The dry mass thus obtained is of a brilliant white colour and has all the properties
of commercial dextrine, but is perfectly free from smell and flavour as also from acid
and cellulose.
The above described process for preparing the dextrine is not more expensive than
that now used and it has the further advantage that much larger quantities can be
treated at one time. With certain kinds of very pure starch flour the preliminary
treatment with cold acidulated water is advantageous but not indispensable; if it be
omitted the starch is best converted into paste before adding the acid.
In order to obtain a product having increased solubility in cold water the product
resulting from the above described treatment, after binding the acid may be replaced in

page_text: the digester and again boiled at a temperature of about 150° Cent. The heating
may
also be effected in an oil bath or by superheated steam instead of in a digester.
Having now particularly described and ascertained the nature of this inven
tion and in what manner the same is to be performed, I declare that what
I claim is :-
:-
1. An improved manufacture of dextrine free from acid and cellulose as also from
taste and smell, wherein starch flour which may or may not have been previously
treated with acidulated water is placed in the form of starch milk together with
sulphurous acid, in a digester and is boiled therein under a pressure of about 4 atmo-
spheres the boiling being discontinued as soon as traces of glucose show themselves
substantially as herein described.
2. Subjecting the product obtained as set forth in the preceding claim to additional
heating to a higher degree in a digester either in an oil bath or by means of super-
heated steam in order to render the same more soluble in cold water, substantially as
herein described.
3. The use of dextrine obtained as set forth in the preceding claims, for various
technical purposes.
2000
ABEL & IMRAY,
Agents for the Applicant.