A Process of Treating Potatoes.
Year: 1898

page_text: Date of Application, 8th Sept., 1898-Accepted, 7th Jan., 1899
COMPLETE SPECIFICATION.
A Process of Treating Potatoes.
I, JOHN GOTTIHILF NEUMANN, of No. 120, South Delaware Street, in the City
of Indianapolis, in the County of Marion, in the State of Indiana, in the
United States of America, Commission Merchant, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be par-
ticularly described and ascertained in and by the following statement:-
-
My invention has for its object the preparation of potatoes to make a product
for the market that among other thing has two prominent characteristics, viz.
ease of preservation and quickness in the preparation of the article for the table.
The article is exempt from decomposition in any weather or climate, and is
prepared for the table within about three minutes. The article possessing these
characteristics still contains all the original elements of nutrition with the advan-
tage also of presenting such nutritious portions freed from all impurities. The
article is desiccated and an important advantage resulting from this treatment
of potatoes is the reduction in weight, which means a great saving in freight and
ultimate cost.
Another very important advantage of my invention is in the effect of such
treatment upon what are called " watery" potatoes that are, as prepared by most
people, unfit for food and therefore a loss. Such potatoes when treated by my
process make as valuable a food product as potatoes in the best condition. The
step in my process that contributes largely to this effect is the extraction of
some of the moisture from the potatoes before cooking by pressure or otherwise,
whereby mealiness of the product, which is evidence of a good potato, is obtained.
The most important steps of my process consist in chemically disintegrating
the vegetable tissues of the tubers, quickly cooking the product, reducing the
latter when cooled to small particles and then desiccating the same.
One means of disintegrating the vegetable tissues is by subjecting the potato
to the action of sulphur dioxide or its compounds, which also effects other changes
hereafter mentioned. I also preferably extract the moisture by compression
previous to cooking, and subject the compressed material to a hot water bath.
There are other important features in my invention in addition to the foregoing,
all of which will more fully appear from the following description and claims:
While a valuable product can be made by the process set forth in the broad
statement of my invention above, I shall here describe the details of the process
which I have found preferable and which makes the best product.
In detail the raw potatoes are pared and sliced preferably into four pieces.
They are then washed in cold water. The starch that settles from this cutting and
washing of the potatoes may be gathered as a by-product, but this forms no part
of my invention.
The potatoes are then placed in cold water which contains a small quantity of
sulphur dioxide in the form of sulphite or bisulphite of lime or any other suitable
forin. A practicable proportion is ten grains of the chemical to a callon of

page_text: water. The potatoes are soaked in this solution one to six hours. The chief
purpose of subjecting the potatoes in this manner to the action of sulphur dioxides
or its compounds is to effect a disintegration of the vegetable tissues that form so
considerable a part of the potato, such as cellulose. This also neutralizes the
salts, separates all slimy and fatty matters, and dissolves the albumenoids. The
sulphurous gas further penetrates the potato, and, until entirely spent, it helps
to effect a speedier solution of the starch in the final product. A similar effect
may also be brought about more or less completely by fermentation, which step
in the process, however, is preferable after cooking, but the method above set
forth is the better.
After soaking the potatoes are repeatedly washed in fresh water whereby the
impurities and non-nutritious elements are removed. Then some of the moisture
is extracted from the potatoes. This is preferably done by slightly pressing the
same between cloth, the cloth taking up the surplus moisture. It may, however,
be done by partly evaporating the moisture in a centrifugal extractor, or by any
other means so that on the average the potatoes lose about 20 per cent. of their
moisture and retain only as much water as is necessary in the cooking, but not
sufficient to transform the starch granules not in direct contact with the boiling
water into paste.
I preferably then plunge the potatoes into hot water or subject them to a steam
bath for the purpose of instantly producing a pasty starch coating around the
outside which keeps the water or steam in which the potatoes are then boiled,
from penetrating the same. It is preferable this coat shall be produced quickly
and for that purpose boiling water is preferred, although a scalding temperature
will suffice. The potatoes are then cooked either by steaming or boiling. I
preferably cook the potatoes by boiling them with a small quantity of soda or
other alkaline substances in an open vessel with repeated changes of water. The
purpose of putting soda or other alkaline substances in the water is to remove
any atoms of sulphurous gas that may still remain suspended in the potato.
The soda or other alkaline substances by their neutralizing power counteract or
prevent the formation of sulphuric acid. The repeated change of the water is
for the same purpose, and for further purifying the article.
I stop the boiling promptly when the potatoes are fairly cooked for the purpose
of preserving largely the individuality of the small particles of starch and to
prevent the product from being converted into a pasty mass.
The product of the foregoing steps of my process is then cooled and, when
cold is mashed. Mashing the potatoes when cold is an important feature in my
process as it keeps the potatoes not only mealier, but of brighter color than if
they were mashed hot. If the potatoes were mashed hot, the steam developed
during the mashing would penetrate the starch granules and cause them to lose
their individuality, and the product when dried would be sticky and have the
greyish tint of fully dissolved and afterwards dried starch.
It is preferable, but not necessary, after cold mashing to subject the product
to an hour's fermentation. By this I mean to let the product stand for about
an hour during which slight fermentation is taking place. This fermentation
may be hastened by a slight addition of vinous or lactic ferment. It acts on the
cooked potato somewhat as the sulphur dioxide does on the raw ones, at least it
facilitates the dissolution of the ultimate product.
After this the product is reduced to small pieces or particles, say into ver-
micular or granular form. The product is then desiccated which is the last step
in the process. This is preferably done by baking in a closed vessel or oven and
then desiccating the product in an open container. Any means of desiccation
will be tolerably satisfactory.
The product resulting from the foregoing described process is of bright yellow
color. This distinguishes it from the product that would result from a process
where the granules of starch were thoroughly dissolved, for in such case the
product would have a steel grey color or tint. The latter product would also not be

page_text: mealy and would be sticky if moist, very hard if dry, and more or less non-soluble
when moistened, and in these particulars it is quite the opposite of my product.
I might also add that if potatoes were treated without cooking the same,
they would, when dissolved, be dark colored, of a biting taste and either paste-
like or lumpy according to the more or less accomplished assimilation of the
starchy and fibrous matters, and would never be mealy. The product of my
process when dissolved in hot water to prepare it for the table not only has the
appearance, the sweetness, the flavor and consistency of a freshly cooked mealy
potato, but is superior because of the elimination of the impurities, and the fact
that it can be easily preserved and quickly prepared.
Having now particularly described and ascertained the nature of my inven-
tion, and in what manner the same is to be performed, I declare that what
I claim is:-
1. The process of preparing and preserving potatoes which consists in chemi-
cally disintegrating the vegetable tissues of the tubers, forming a pasty coat on
the exterior, and cooking the product, then cooling the same, reducing it to
particles or small pieces, and finally desiccating it, substantially as set forth.
2. The process of preparing and preserving potatoes which consists in disin-
tegrating the vegetable tissues of the tubers in the manner specified, forming a
thin pasty coat on the exterior, and cooking the product, next cooling the same,
reducing it to particles or small pieces and desiccating the latter, substantially
as set forth.
3. The improved process of preparing and preserving potatoes, consisting in
disintegrating the vegetable tissues of the tubers by treatment with a suitable
compound of sulphur dioxide, producing a thin pasty coat on the exterior, and
cooking the product, allowing the same to cool, then reducing it to a vermicular
or equivalent form, and desiccating it by baking, substantially as set forth.
4. The improved process of preparing potatoes which consists in disintegrating
the vegetable tissues by soaking in a solution of sulphur dioxide, subjecting the
product to a steam bath to form a pasty coat thereon, cooking in an alkaline
bath, mashing the product when cool, and desiccating it by baking, substantially
as set forth.
Dated this 27th day of August 1900