An Improved Preserving Agent and Method of Producing the same.
Year: 1893

page_text: ate of Application, 18th Sept., 1893-Accepted, 21st Oct., 1893
COMPLETE SPECIFICATION.
An Improved Preserving Agent and Method of Producing the same.
I, MARTIN EKENBERG, Chemical Engineer, of No. 3 Aguegatan, Stockholm in
the Kingdom of Sweden,.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 :-
This invention relates to a preserving agent consisting of aldehydic acid
(ethylidenlactic acid) and acetic acid, which may be most advantageously produced
in the following manner.
The whey, obtained in the ordinary operation of making cheese and containing
lactalbumine is mixed with 5 to 10% pure fine whiting, boiled and cooled down to
about 40°-45° centigrade and then inoculated with purely cultured bacteria of
lactic and acetic acids. The mixture is then poured into clean glass flasks holding
about 70 litres each and is kept in these at a temperature of 40°-45° centigrade for
8 to 10 days. During the fermentation the mixture is stirred once every other day.
The necks of the glass flasks are in the meantime closed with cotton wool in order
to prevent extraneous bacteria from getting into the said flasks.
After complete fermentation the mixture has tannin added thereto and is then
boiled, when albuminate and phosphate is precipitated in the form of a floculent
precipitate, which carries the bacteria along with it. The precipitate is filtered off
and the solution is diluted with just as much sulphuric acid or oxalic acid as is
required for precipitating the lime so as to avoid an excess of the precipitating
agent.
When this latter precipitate has been filtered off, the acid solution constituting
the preserving agent is obtained. This contains from 4 to 6% in all of aldehydic
and acetic acids.
If a stronger preserving agent is required the whey is, previous to the fermenta-
tion, mixed with some kind of sugar as sugar of milk, cane-sugar or the like whereby
the percentage of acid can be increased to from 10-12%. The product of this
process contains in general from 2 to 5 parts of aldehydic acid and two parts of
acetic acid. It is advantageously used when preserving fruit, vegetables and the
like in lieu of common vinegar. It is owing to the fact that it contains lactic acid
it is in many respects preferable, as it thereby facilitates the digestive process,
while on the other hand other antiseptic matters render it more difficult.
Another preserving agent with the same properties as that above described
although lacking its aroma, and being more expensive, is obtained by mixing a
common solution of acetic acid with a solution of aldehydic acid, which is produced
for instance by dissolving lactate of zinc or lactate of lime in water and then
precipitating the zinc or the lime in the usual manner.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A preserving agent consisting of a mixture of watery solutions of aldehydic
acid and acetic acid.
2. The method of producing the preserving agent referred to in the first claim
consisting in mixing common whey, with or without sugar, with whiting, boiling
the mixture and cooling the same and then inoculating it with purely cultured
bacteria of lactic or acetic acids, and after the fermentation adding thereto tannin
ID 0.

page_text: and boiling the whole, filtering off the precipitate, diluting with sulphuric or oxalic
acid and again filtering off the precipitate obtained, substantially as described.
Dated this 18th day of September 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.