Solutions of Sweet Carbamides in Oils, Fats, Waxes, Resins, and Process of Making the same.
Year: 1894

page_text: Date of Application, 14th Aug., 1894-Accepted, 15th Sept., 1894
COMPLETE SPECIFICATION.
Solutions of Sweet Carbamides in Oils, Fats, Waxes, Resins, and
Process of Making the same.
I, ADOLPH SOMMER, of Cambridge, in the County of Middlesex, State of
Massachusetts, United States of America, 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 :-
Heretofore it has been impossible to impart an agreeable sweet taste, which
would be permanent and not be open to some serious objection, to the natural
ingestible carbon compounds which are saponifiable and either liquid or liquefiable
at or below 150 degrees centigrade, to wit:-The oils, fats, waxes, resins and
acids occurring therein. Now I have found that this object can be accomplished
and that these compounds can be sweetened, without destroying their transparency
and other physical properties (except their taste), by the use of certain sweet
carbamides such as paraphenetol carbamide and its sweet homologues as for instance
paraanisol carbamide. Paraphenetol carbamide, being the most common and
cheapest of these sweet carbamides, I employ almost exclusively in actual
practice.
I have however observed that in the cold state the neutral compounds of the
above mentioned class are almost incapable of dissolving these sweet carbamides,
and that only when heated therewith do they take up a perceptible amount of these
substances. The solubility of the paraphenetol carbamide in the above mentioned
compounds I find to be greatest between 140 and 160 degrees centigrade. Higher
temperatures should be avoided, because they darken the mixture and decompose
the carbamide, liberating sometimes ammonia.
If too large a proportion of one of these carbamides has been dissolved by the
aid of heat, a portion crystallizes out on cooling. But many of the above mentioned
carbon compounds are capable of retaining sufficient of the carbamide, after
solution has once taken place, to impart to them a decidedly sweet taste, even after
they have stood in the cold and any undissolved carbamide has been filtered off.
The amount thus retained in solution after cooling varies greatly, ranging from
scarcely one tenth of one per cent. to over one per cent. of the weight of the
compound acting as solvent.'
In practice I proceed as follows: I take from two to eight parts (seldom more)
of paraphenetol carbamide or of its sweet homologues or of a mixture of such
carbamides to every thousand parts of oil, fat, wax, resin or acid occurring therein,
triturate the carbamide till it is reduced to an impalpable powder, then incorporate
with it the compound to be sweetened in the liquid state, and digest the mixture
in a steam bath or oil bath between 100 and 150 degrees centigrade. When the
carbamide has dissolved, the solution is removed from the bath and allowed to stand
in a cool place for a day or longer. If, after standing undisturbed, some of the
carbamide has crystallized out and the solution is to be transparent at the
ordinary temperature, it is filtered through paper or some other medium suitable
for the purpose.
Instead of triturating the carbamide and subjecting the mixture to a high
temperature, it is sometimes preferable to dissolve the carbamide in a volatile
solvent, such as alcohol, to add this solution to the liquid or liquefied compound
and to expel the alcohol or other volatile solvent by gently heating the mixture.
However, some of the above mentioned carbon compounds, especially those oils,
fats and waxes which contain no free acids, are capable of holding but a very small
percentage of paraphenetol carbamide or its sweet homologues in solution, so that

page_text: it often happens that upon standing the largest portion of the carbamide which
had been dissolved by heating separates out and the oil, fat or wax is left almost
tasteless.
Now I have found that this separation can to a great extent be avoided and the
solubility of the carbamides in oils, fats and waxes be increased by the addition of
acids which themselves are soluble in oils, fats or waxes.
Many of the acids which are available for this purpose (as for instance oleic
acid) occur either free or in combination in the natural oils; fats waxes and resins,
but others which do not occur therein may also be used, as for instance lactic acid.
These acids I find to dissolve the paraphenetol carbamide and its sweet homologues
much more readily than their glycerides or ethers, and to be able to hold the same
in solution when added to or present in the neutral oils, fats or waxes. However,
unless it is desirable to impart a sour taste to the product, (which I generally do
by means of concentrated lactic or glacial acetic acid), I prefer to acidify the oil
fat or wax, if it does not naturally contain a sufficient amount of free acid, by
saponifying a small portion of it by means of an alkali such as caustic soda, then
decomposing the soap by agitating the mixture with a dilute acid, as for instance
dilute sulphuric acid, and finally washing the oil, fat or wax with water and filtering
it, if necessary, through salt.
In order to prepare the solution the carbamidė is either first combined with or
dissolved in the acid, and this combination or solution added to the oil, wax or fat,
or the acid is first added to or produced in the oil, fat or wax, and the carbamide
dissolved in the mixture. In either case the solution is hastened by digesting the
mixture in a water bath. If however the oil, fat or wax already contains a
sufficient amount of free acid, a further addition need not be made, unless a sour
taste is to be imparted.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is :
1. The solution of paraphenetol carbamide or its sweet homologues in those
natural ingestible carbon compounds which are saponifiable and either liquid or
liquefiable at or below 150 degrees centigrade.
2. The method of forming a solution of paraphenetol carbamide or its sweet
homologues in oils, fats and waxes, which consists in dissolving the said carbamides
in the oil, fat or wax by means of an acid soluble in the said oil, fat or wax.
3. The method of dissolving paraphenetol carbamide or its sweet homologues in
oils, fats or waxes, which consists in combining the carbamide with an acid soluble
in the oil, fat or wax, and then adding this combination in the oil, fat or wax.
4. The method of dissolving paraphenetol carbamide or its sweet homologues in
oils, fats or waxes, which consists in first acidifying the oil, fat or wax by either
adding an acid which is soluble therein or by saponifying a portion of it and
decomposing the soap and then digesting the carbamide with the acidified oil, fat
or wax.
5. The solution in oils, fats or waxes of paraphenetol carbamide or any of its
sweet homologues and an acid soluble in the oil, fat or wax.
Dated this 14th day of August 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.